Download 15 Years of Research, 11(1) - National Rehabilitation Information

reSearch
A collection of research reviews on
rehabilitation topics from NARIC and other
information resources.
Volume 11, Issue 1, 2016
W
Revisting Piriformis Syndrome:
15 Years of Research
e began our reSearch publication in April
of 2006 and have covered a variety of
topics over the past ten years. In this issue of reSearch we are revisiting one of the earliest
topics, searching our database REHABDATA and a
few new databases to provide updated information
on Piriformis Syndrome (PS).
According to the National Institute of Neurological Disorders and Stroke’s Information Page
on PS and WebMD: Piriformis syndrome is a
rare neuromuscular disorder that occurs when the
piriformis muscle compresses or irritates the sciatic nerve. The piriformis muscle is a flat, narrow
band-like muscle located in the buttocks near the
top of the hip joint and is important to lower body
movement as the muscle stabilizes the hip joints and
lifts and rotates the thigh away from the body. The
sciatic nerve is the longest nerve in the body passing alongside and through the piriformis muscle,
going down the back of the leg, and then branching
off into smaller nerves ending that end in the feet.
The piriformis muscle enables individuals to walk,
shift weight from one foot to the other (side to side),
and maintain balance. This muscle is also used in
sports that involve lifting and rotating the thighs
as well as in almost every motion of the hips and
legs (i.e., running, jogging, etc.) (http://www.ninds.
nih.gov/disorders/piriformis_syndrome/piriformis_
syndrome.htm & http://www.webmd.com/painmanagement/guide/piriformis-syndrome-causessymptoms-treatments).
In the case of PS, the piriformis muscle impinges (compresses) on the sciatic nerve either as
a result of an issue with the muscle itself or due
to injury. It can be difficult to diagnosis PS as the
symptoms often mimic sciatica – a disorder that
extends from the hip down the back of the thigh
and surrounding areas resulting pain, inflamma-
tion, tenderness, tingling, and numbness. The
causes of sciatica can range from a herniated disc,
bone spur on the spine, or narrowing of the spine
(spinal stenosis) which compresses part of the
nerve (http://www.mayoclinic.org/diseases-conditions/sciatica/basics/definition/con-20026478).
How is PS diagnosed?
According to WebMD there is no definitive
test for PS and physicians often rely on the patient
to provide information on symptoms and medical
history (i.e., trauma to the area, repetitive/vigorous
activity, or prolonged sitting) and a physical examination. Because symptoms may be similar to
other conditions your physician/specialist may order radiological tests such as magnetic resonance
imaging (MRI) to rule out other causes of sciatic
nerve compression (i.e., herniated disc, bone spur,
or spinal stenosis) (http://www.webmd.com/painmanagement/guide/piriformis-syndrome-causessymptoms-treatments).
Continued on page 2 ...
Table of Contents
NIDILRR Funded Projects ......................... page 3
NARIC Citations ......................................... page 6
CIRRIE Citation........................................... page 8
Cochrane Citation ....................................... page 8
PEDro Citations ........................................... page 9
PubMed Citations ........................................ page 10
Quick Looks ................................................ page 29
Search Terms ............................................... page 31
Page 2
... Continued from previous page
How is PS treated?
Your physician, specialist, and/or physical
therapist may prescribe a course of treatment that
may include anti-inflammatory medications; exercises and stretches to help reduce sciatic nerve
compression; cessation of running, bicycling, or
similar activities and avoidance of certain activities/positions that trigger pain; and massage and/or
osteopathic manipulative treatment as well as acupuncture to help alleviate pain and increase range
of motion. Additional medications may include
muscle relaxants, corticosteroid injections, and injections of the botulinum toxin (botox). Finally, in
some cases surgery may be recommended (http://
www.ninds.nih.gov/disorders/piriformis_syndrome/piriformis_syndrome.htm & http://www.
webmd.com/pain-management/guide/piriformissyndrome-causes-symptoms-treatments).
This edition of reSearch provides a “snapshot”
of over 10 years of research on piriformis syndrome. This “snapshot” presents a general overview of piriformis syndrome and various treatment methodologies. The combined search terms
for this edition of reSearch included: piriformis
syndrome, sciatica, piriformis muscle, sciatic
nerve, and neuromuscular conditions. A listing of
over 150 additional descriptor terms between the
NARIC, CIRRIE, Cochrane, PEDro, and PubMed
databases can be found at the end of this document.
A search of the REHABDATA database resulted in 5 documents published between 2002 and
2012. The CIRRIE and Cochrane database searches results in 1 document from 2010 and 2011, respectively. A search of PEDro, a database specializing in physiotherapy evidence-based research,
resulted in 4 documents published between 2006
and 2015. Finally, a search of the PubMed database resulted in 56 documents between 2006 and
2015. Sixty-one new citations on piriformis syndrome between all the aforementioned databases
are included in this research brief.
References:
Piriformis Syndrome (n.d.). National Institute
on Neurological Disorders and Stroke. NINDS
Piriformis Syndrome Information Page. Retrieved
from http://www.ninds.nih.gov/disorders/
piriformis_syndrome/piriformis_syndrome.htm.
Piriformis Syndrome (n.d.). WebMD Online.
Pain Management Health Center. Retrieved from
http://www.webmd.com/pain-management/guide/
piriformis-syndrome-causes-symptoms-treatments.
Sciatica (n.d.). MayoClinic Online. In Diseases
and Conditions. Retrieved from http://www.
mayoclinic.org/diseases-conditions/sciatica/basics/
definition/con-20026478.
Page 3
NIDILRR Funded Projects Related to
Piriformis Syndrome
In addition to document searches, we searched our
NIDILRR Program Database to locate grantees/
projects related to Piriformis Syndrome. While no
specific projects address this condition, we identified several on directly-related topics (i.e., exercise,
fitness, mobility, muscular issues and trauma).
The search resulted in 13 currently funded and 13
projects that are no longer active. Project information and their publications are offered as additional
resources for our patrons.
Advanced Rehabilitation Research Training
Center on Neuro-Musculoskeletal Rehabilitation
Project Number: 90AR5011 (formerly
H133P110014)
Phone: 973/324-3550
Email: [email protected].
http://kesslerfoundation.org/researchcenter/postdoctoralfellowshipprogram.php.
Development of a Pediatric Intelligently Controlled Assistive Rehabilitation Elliptical (PediICARE) Training System to Promote Walking
and Fitness in Children with Physical Limitations
Project Number: 90IF0060 (formerly
H133G130274)
Phone: 402/413-4505
Email: [email protected].
http://www.madonna.org/researcher/movement/
research.
Dose-Response Effects of Transformative Exercise in Improving Health and Function in Adults
with Spinal Cord Injury and Multiple Sclerosis
Project Number: 90DP0059 (formerly
H133A130044)
Phone: 205/975-9010
Email: [email protected].
Dynamic Supported Mobility for Infants and
Toddlers with Cerebral Palsy
Project Number: 90IF0076 (formerly
H133G140166)
Phone: 215/590-2495
Email: [email protected].
Interactive Exercise Technologies and Exercise
Physiology for People with Disabilities
Project Number: 90RE5009 (formerly
H133E120005)
Phone: 205/975-9010
Email: [email protected].
http://www.rectech.org.
Machines Assisting Recovery from Stroke and
Spinal Cord Injury for Reintegration into Society (MARS3)
Project Number: 90RE5010 (formerly
H133E120010)
Phone: 312/238-1277
Email: [email protected].
http://www.mars-rerc.org.
Project WOWii: Developing and Testing a WebBased Intervention to Promote Exercise Among
Those with Spinal Cord Injury
Project Number: 90IF0091
Phone: 214/648-1054
Email: [email protected].
Rehabilitation Engineering Research Center on
Technologies to Support Successful Aging with
Disability (RERC TechSAge)
Project Number: 90RE5016 (formerly
H133E130037)
Phone: 404/894-1413
Email: [email protected].
http://techsage.gatech.edu.
Rehabilitation Research and Training Center on
Developmental Disabilities and Health
Project Number: 90RT5020 (formerly
H133B130007)
Phone: 312/413-1647 (V), 800/996-8845 (V),
312/413-0453 (TTY)
http://www.rrtcdd.org.
http://healthmattersprogram.org.
Rehabilitation Research and Training Center
on Secondary Conditions in Spinal Cord Injury
Project Number: 90RT5002 (formerly
H133B090002)
Page 4
Phone: 202/877-1694
Email: [email protected].
http://sci-health.org.
http://www.youtube.com/user/HealthyTomorrow.
https://www.facebook.com/rrtcsci.
RRTC on Developing Optimal Strategies in
Exercise and Survival Skills to Increase Health
and Function
Project Number: 90RT5027 (formerly
H133B140012)
Phone: 312/238-4864
Email: [email protected].
http://www.ric.org/research/centers/dosesses.
University of Washington Rehabilitation
Research and Training Center on Promoting
Healthy Aging for Individuals with Long-Term
Physical Disabilities
Project Number: 90RT5023 (formerly
H133B130018)
Phone: 866/928-2114
Email: [email protected].
http://agerrtc.washington.edu.
https://www.facebook.com/pages/Healthy-AgingRRTC/308875452523165.
https://twitter.com/AgingRRTC.
Weight Management and Wellness for People
with Psychiatric Disabilities
Project Number: 90IF0100
Phone: 312/355-1696 (V), 312/422-0706 (TTY)
Email: [email protected].
http://www.cmhsrp.uic.edu/health/weight-wellbeing.asp.
These projects have completed their research activities and are now closed.
Development of an Intelligently Controlled Assistive Rehabilitation Elliptical (ICARE) Training System to Promote Walking and Fitness in
Persons with Physical Limitations
Project Number: H133G070209
Phone: 402/483-9669
Email: [email protected].
http://www.madonna.org/research_institute/movement_neurosciences/about_us/index.html.
The Effectiveness of an Off-Axis Elliptical Training Program on Improving Gait Function in
Children with Cerebral Palsy
Project Number: H133F130031
Phone: 404/413-1246.
Email: [email protected].
ENhancing ACTivity and Participation for
Persons with Arthritis (ENACT)
Project Number: 90RT5009 (formerly
H133B100003)
Phone: 617/353-2735
Email: [email protected].
http://www.bu.edu/enact.
https://twitter.com/BU_ENACT.
Evaluating the Effects of Activity-Based Therapy for Individuals with Chronic Spinal Cord
Injury
Project Number: H133G080031
Phone: 404/350-7595
Email: [email protected].
Health Activity Rehabilitation Research Training Center (HARRTC)
Project Number: H133P050005
Phone: 573/884-1499
Email: [email protected].
http://harrtc.missouri.edu.
Multitherapy Approach to Tendon
Rehabilitation
Project Number: H133G20178
Phone: 913/588-6799
Email: [email protected].
Musculoskeletal Disorders in Children and
Adults, Including Arthritis
Project Number: G008300042
Muscle Strength, Physical Work Capacity, and
Functional Performance in Individuals with
Down Syndrome
Project Number: H133G040323
Phone: 217/333-2131
Email: [email protected].
Page 5
NEW DOOR: Nutrition, Exercise, Weight
Management & Disability Obesity Options and
Resources
Project Number: 90IF0001 (formerly
H133G120093)
Phone: 510/225-6349
Email: [email protected].
http://wid.org/access-to-health-care/health-accessand-long-term-services/new-door.
Rehabilitation Engineering Research Center
for Successful Aging with Disability: Optimizing Participation Through Technology (OPTTRERC)
Project Number: 90RE5002 (formerly
H133E080024)
Phone: 323/442-2903
Email: [email protected].
http://www.isi.edu/research/rerc.
https://www.facebook.com/aging.rerc?v=wall.
https://twitter.com/agingrerc.
http://www.youtube.com/user/agingrerc1.
Rehabilitation Research and Training Center in
Neuromuscular Diseases (RRTC-NMD)
Project Number: 90RT5001 (formerly
H133B090001)
Phone: 916/734-4280
Email: [email protected].
http://www.ucdmc.ucdavis.edu/pmr/research/index.html.
Sensorimotor Training and Assessment in Adults
with Hemiplegic Cerebral Palsy: The ULTrA
Program
Project Number: H133G050151
Phone: 734/763-6755
Email: [email protected].
http://www.motorcontrol.umich.edu/ultra.
Video Gaming Technology to Promote Health
and Fitness Among Adolescents with Disabilities
Project Number: H133G100278
Phone: 409/772-9498
Email: [email protected].
Why do I see different grant numbers?
In 2014, President Obama signed the Workforce
Innovation and Opportunity Act (WIOA) into
law. As part of WIOA, the institute changed its
name from the National Institute on Disability and
Rehabilitation Research (NIDRR) to the National
Institute on Disability, Independent Living, and Rehabilitation Research (NIDILRR) and moved from
the Department of Education to the Administration
for Community Living (ACL) at the Department of
Health and Human Services. Approximately 250
active grants received new ACL grant numbers
and all new grants funded under NIDILRR have
only an ACL grant number. For more information
about NIDILRR/ACL grant numbers please visit:
http://naric.com/?q=en/content/about-nidilrraclgrant-numbers-0.
Page 6
Documents from NARIC’s
REHABDATA search listed
are listed below:
2012 – NEW!
Grinberg, Y., Gustafson, K.J., Joseph, S., & Triolo,
R.J. (2012). Human distal sciatic nerve fascicular anatomy: Implications for ankle control using
nerve-cuff electrodes. Journal of Rehabilitation
Research and Development (JRRD) (formerly the
Bulletin of Prosthetics Research), 49(2), 309-322.
NARIC Accession Number: J63551
ABSTRACT: Study examined the fascicular anatomy of the human lower sciatic nerve and evaluated
the potential of selective activation of ankle musculature with a multicontact nerve-cuff electrode.
Eight human sciatic nerves were examined in four
formalin-fixed female cadavers. Three complete
sciatic nerves and branches were dissected from the
piriformis to each muscle entry point to characterize the branching patterns and diameters. Fascicle
maps were created from serial sections of each distal
terminus below the knee through the anastomosis
of the tibial and common fibular nerves above the
knee. Similar branching patterns and fascicle maps
were observed across specimens. Fascicles innervating primary plantar flexors, dorsiflexors, invertors,
and evertors were distinctly separate and functionally organized in the proximal tibial, common fibular, and distal sciatic nerves; however, fascicles
from individual muscles were not apparent at these
levels. The fascicular organization is conducive to
selective stimulation for isolated and/or balanced
dorsiflexion, plantar flexion, eversion, and inversion
through a single multicontact nerve-cuff electrode.
These neuroanatomical data are being used to design
nerve-cuff electrodes for selective control of ankle
movement and improve current lower-limb neural
prostheses.
2006 – NEW!
Chang, K-F, Chang, S-W, Li, C-M, Shieh, S-F, &
Wu, W-T. (2006). Measurement of motor nerve
conduction velocity of the sciatic nerve in patients
with piriformis syndrome: A magnetic stimulation study. Archives of Physical Medicine and Rehabilitation, 87(10), 1371-1375.
NARIC Accession Number: J51440
ABSTRACT: The motor nerve conduction velocity
(MNCV) was measured at the gluteal segment of
the sciatic nerve by magnetic stimulation in patients
with piriformis syndrome and healthy control subjects, and compared with the conventional electrodiagnostic methods. The mean value for MNCV of the
sciatic nerve at the gluteal segment from L5 nerve
root to gluteal fold in patients with piriformis syndrome was significantly slower than the mean value
of the same segments in controls. The MNCV of the
sciatic nerve in S1 component showed no significant difference between the patients and controls. A
negative relationship was found between the disease
duration and the MNCV values of sciatic nerves in
patients with piriformis syndrome.
Hurdle, M-F., Locketz, A.J., Smith, J., & Wisniewski, S.J. (2006). Ultrasound-guided piriformis injection: Technique description and verification.
Archives of Physical Medicine and Rehabilitation,
87(12), 1664-1667.
NARIC Accession Number: J51766
ABSTRACT: Article describes a technique for performing ultrasound-guided piriformis injections.
Piriformis injections are commonly used in the evaluation and treatment of patients with buttock pain
syndromes. The piriformis is traditionally injected
using electromyographic, fluoroscopic, computed
tomographic, or magnetic resonance imaging guidance. Ultrasound offers several advantages over traditional imaging approaches, including acceptability, compact size, lack of ionizing radiation exposure,
and direct visualization of neurovascular structures.
2004
Bond, M.J., Broadhurst, N.A., & Simmons, N.
(2004). Piriformis syndrome: Correlation of
muscle morphology with symptoms and signs.
Archives of Physical Medicine and Rehabilitation,
85(12), 2036-2039.
NARIC Accession Number: J48380
ABSTRACT: Presents study conducted to determine
whether patients with low back or buttock pain had
any piriformis muscle abnormalities and to correlate
the diagnostic findings with two symptoms and two
clinical signs commonly associated with patients
Page 7
who have buttock pain. The piriformis muscle was
injected with bupivacaine after pain was assessed
on a visual analog scale using the resisted abduction
test. The symptoms examined were pain going up
inclines or stairs and pain referred to the posterior
thigh. The signs were pain on resisted abduction of
the adducted flexed hip and pain produced by needling the muscle. Odds ratios and 95 percent confidence intervals were calculated comparing each of
the signs and symptoms with normal morphology.
The highest odds ratios were found for pain on walking up inclines (10.8), referred pain (5.3) and pain
on needling the piriformis muscle (6.0).
2002
Dombi, G.W., Fishman, L.M., Michaelsen, C., Ringel, S., Rosner, B., Rozbruch, J., & Weber, C. (2002).
Piriformis syndrome: Diagnosis, treatment, and
outcome: A 10-year study. Archives of Physical
Medicine and Rehabilitation, 83(3), 295-301.
NARIC Accession Number: J43761
ABSTRACT: Study was conducted to validate an
operational definition of piriformis syndrome based
on prolongation of the H-reflex with hip flexion, adduction, and internal rotation (FAIR) and to assess
surgical and nonsurgical treatments. Researchers develop working diagnostic criteria, validate evidence
of the syndrome, and assess treatment of cases diagnosed by each criterion. Authors conclude that
the FAIR test correlates well with a working definition of piriformis syndrome and is a better predictor of successful physical therapy and surgery than
the working definition. The FAIR test, used in conjunction with injections and physical therapy and/or
surgery, appears to be effective for diagnosing and
treating piriformis syndrome.
Full-text copies of these documents may be available through NARIC’s document delivery service.
To order any of the documents listed above, note the
accession number and call an information specialist at 800/346-2742.
There is a charge of 5 cents for copying and shipping with a $5 minimum on all orders.
Page 8
Document from the Center
for International
Rehabilitation Research
Information and Exchange
(CIRRIE-3) search at cirrie.
buffalo.edu is listed below:
2010 – NEW!
Hopayian, K., Riera, R., Sambandan, S., & Song,
F. (2010). The clinical features of the piriformis
syndrome: A systematic review. European Spine
Journal, 19(12), 2095-109.
Available in full-text at: http://www.ncbi.nlm.nih.
gov/pmc/articles/PMC2997212.
ABSTRACT: Piriformis syndrome, sciatica caused
by compression of the sciatic nerve by the piriformis
muscle, has been described for over 70 years; yet, it
remains controversial. The literature consists mainly
of case series and narrative reviews. The objectives
of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical
features in patients reported to have PS; second, to
identify future research questions. A systematic review was conducted of any study type that reported
extractable data relevant to diagnosis. The search
included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline.
Screening, data extraction and analysis were all performed independently by two reviewers. A total of
55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The
most common features found were: buttock pain,
external tenderness over the greater sciatic notch,
aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start
with comparing the frequencies of these features in
sciatica patients with and without disc herniation or
spinal stenosis.
Document from the Cochrane
Database of Systematic Reviews search
at www.thecochranelibrary.org is listed
below:
2011 – NEW!
Boulias, C., Furlan, A.D., Gordon, A., Ismail, F.,
Sheean, G., & Waseem, Z. (2011). Botulinum toxin
injections for low-back pain and sciatica. Cochrane Database of Systematic Reviews, 2011, Issue
1. Art. No.: CD008257. DOI: 10.1002/14651858.
CD008257.pub2.
ID: CD008257
Available in full-text at: http://onlinelibrary.wiley.
com/doi/10.1002/14651858.CD008257.pub2/epdf.
ABSTRACT: Background: Adequate relief from
low-back pain (LBP) is not always possible. Emerging evidence suggests a role for botulinum neurotoxin
(BoNT) injections in treating pain disorders. Proponents of BoNT suggest its properties can decrease
muscle spasms, ischemia and inflammatory markers,
thereby reducing pain. Objectives: To determine the
effects of botulinum toxin injections in adults with
LBP. Search methods: We searched CENTRAL (The
Cochrane Library 2009, issue 3) and MEDLINE,
EMBASE, and CINAHL to August 2009; screened
references from included studies; consulted with
content experts and Allergan. We included published
and unpublished randomized controlled trials without
language restrictions. Selection criteria: We included
randomized trials that evaluated BoNT serotypes
versus other treatments in patients with non-specific
LBP of any duration. Data collection and analysis:
Two review authors selected the studies, assessed the
risk of bias using the Cochrane Back Review Group
criteria, and extracted the data using standardized
forms. We performed a qualitative analysis due to
lack of data. Main results: We excluded evidence
from nineteen studies due to non-randomization,
incomplete or unpublished data. We included three
randomized trials (N =123 patients). Only one study
included patients with chronic non-specific LBP; the
other two examined unique subpopulations. Only one
of the three trials had a low risk of bias and demonstrated that BoNT injections reduced pain at three and
eight weeks and improved function at eight weeks
better than saline injections. The second trial showed
Page 9
that BoNT injections were better than injections of
corticosteroid plus lidocaine or placebo in patients
with sciatica attributed to piriformis syndrome. The
third trial concluded that BoNT injections were better than traditional acupuncture in patients with third
lumbar transverse process syndrome. Both studies
with high risk of bias had several key limitations.
Heterogeneity of the studies prevented meta-analysis.
There is low quality evidence that BoNT injections
improved pain, function, or both better than saline
injections and very low quality evidence that they
were better than acupuncture or steroid injections.
Authors’ conclusions: We identified three studies that
investigated the merits of BoNT for LBP, but only
one had a low risk of bias and evaluated patients with
non-specific LBP (N = 31). Further research is very
likely to have an important impact on the estimate of
effect and our confidence in it. Future trials should
standardize patient populations, treatment protocols
and comparison groups, enlist more participants and
include long-term outcomes, cost-benefit analysis and
clinical relevance of findings.
Documents from the Physiotherapy Evidence
Database search at
w w w. p e d r o . o r g . a u
are listed below:
2011 – NEW!
Byeon, G.J., & Kim, K.H. (2011). Piriformis
syndrome in knee osteoarthritis patients after
wearing rocker bottom shoes. The Korean Journal of Pain, 24(2), 93-99.
No abstract is available.
2009 – NEW!
Chen, R.N., & Chen, Y.B. (2009). Clinical
observation on therapeutic effect and instant
analgestic effect of inhibitory-needling at Ashi
point as major point for treatment of piriformis
syndrome. [Chinese - simplified characters].
Zhongguo Zhen Jiu [Chinese Acupuncture & Moxibustion], 29(7), 550-55.
No abstract is available.
2007 – NEW!
Bottrell, O., Campbell, H., Cramp, F., Ellyatt, P.,
Smith, C., & Wilde, B. (2007). Non-surgical management of piriformis syndrome: A systematic
review. Physical Therapy Reviews, 12(1), 66-72.
Available in full-text at: http://www.crd.york.ac.uk/
crdweb/ShowRecord.asp?AccessionNumber=1200
7009218&UserID=0.
ABSTRACT: The aim of this review was to identify and evaluate the evidence for the non-surgical
management of Piriformis Syndrome. A systematic
review of electronic databases was carried out up
to February 2006. This was supplemented by hand
searching journals and snow-bailing from reference lists. Strict inclusion/exclusion criteria were
applied. Five independent observers reviewed the
methodological quality of the core studies using
the published Physiotherapy Evidence Database
(PEDro) critique tool. Differences were resolved
by consensus. Two studies met the inclusion/
exclusion criteria. PEDro scores were 6/10 and
10/10. Both studies demonstrated positive effects
Page 10
for Botulinum toxin type A (Botox) injections
compared to a placebo or control treatment. One
study identified this positive effect in addition to
a physiotherapy protocol. Evidence implies that
Botox is a potentially successful treatment for
Piriformis Syndrome; however, a paucity of highquality clinical trials limits evidence of its overall
efficacy. Further clinical trials of the effectiveness
of non-surgical measures in the management of this
syndrome are indicated.
2002 – NEW!
Anderson, C., Fishman, L.M., & Rosner, B. (2002).
Botox and physical therapy in the treatment of
piriformis syndrome. American Journal of Physical Medicine & Rehabilitation, 81(12), 936-942.
ABSTRACT: OBJECTIVE: This study evaluates the efficacy of Botulinum toxin A injections
used in conjunction with physical therapy for the
treatment of piriformis syndrome. DESIGN: This
a double-blind, placebo controlled clinical trial
using electrophysiologic criteria for patient selection and a visual analog scale to assess treatment
efficacy in relieving pain. RESULTS: As measured
on the visual analog scale, patients injected with
Botulinum toxin A experienced more relief from
pain than patients receiving lidocaine with steroid
(p < 0.05) and more relief than patients receiving
placebo (p = 0.001). CONCLUSIONS: Injection
with Botulinum toxin A is an effective adjunct
to physical therapy in the treatment of piriformis
syndrome. H-reflex prolongation by flexion, adduction, and internal rotation (FAIR test) beyond 1.86
msec (3 SD) of the mean is a clinical indication of
piriformis syndrome.
Documents from the National
Library of Medicine PubMed
search at www.pubmed.com are
listed below:
2015 – NEW!
Abascal, F., Canga, A., Cerezal, L., Hernando, M.F.,
& Pérez-Carro, L. (2015). Deep gluteal syndrome:
Anatomy, imaging, and management of sciatic
nerve entrapments in the subgluteal space. Skeletal Radiology, 44(7), 919-34.
PMID: 25739706
ABSTRACT: Deep gluteal syndrome (DGS) is an
underdiagnosed entity characterized by pain and/
or dysesthesias in the buttock area, hip or posterior
thigh and/or radicular pain due to a non-discogenic
sciatic nerve entrapment in the subgluteal space.
Multiple pathologies have been incorporated in this
all-included “piriformis syndrome,” a term that has
nothing to do with the presence of fibrous bands, obturator internus/gemellus syndrome, quadratus femoris/ischiofemoral pathology, hamstring conditions,
gluteal disorders and orthopedic causes. The concept
of fibrous bands playing a role in causing symptoms
related to sciatic nerve mobility and entrapment represents a radical change in the current diagnosis of
and therapeutic approach to DGS. The development
of periarticular hip endoscopy has led to an understanding of the pathophysiological mechanisms underlying piriformis syndrome, which has supported
its further classification. A broad spectrum of known
pathologies may be located nonspecifically in the
subgluteal space and can therefore also trigger DGS.
These can be classified as traumatic, iatrogenic, inflammatory/infectious, vascular, gynecologic and
tumors/pseudo-tumors. Because of the ever-increasing use of advanced magnetic resonance neurography (MRN) techniques and the excellent outcomes
of the new endoscopic treatment, radiologists must
be aware of the anatomy and pathologic conditions
of this space. MR imaging is the diagnostic procedure of choice for assessing DGS and may substantially influence the management of these patients.
The infiltration test not only has a high diagnostic
but also a therapeutic value. This article describes
the subgluteal space anatomy, reviews known and
new etiologies of DGS, and assesses the role of the
Page 11
radiologist in the diagnosis, treatment and postoperative evaluation of sciatic nerve entrapments, with
emphasis on MR imaging and endoscopic correlation.
Akgün, U., Canbek, U., İmerci, A., Oztekin, H.H., &
Zeren, B. (2015). Bilateral piriformis syndrome
in two elite soccer players: Report of two cases.
Orthopaedics & Traumatology, Surgery & Research
(OTSR), 101(8), 987-90.
PMID: 26522381
ABSTRACT: Piriformis syndrome, a relatively rare
condition, is described as entrapment of a sciatic
nerve at the level of the piriformis muscle. There
have been a few reports of bilateral piriformis syndrome in literature. In this study, we present bilateral piriformis syndrome in two professional soccer
players from different teams who are symptom free
at last follow-up after surgery. In both patients, resting EMG records were read normal, however EMG
recording during the activity revealed prolonged Hreflexes. Both patients had no relief from conservative treatment and rehabilitation, therefore surgical
treatment was performed. Preoperative mean visual
analogue scale (VAS) value was 7, and decreased to
3 at the sixth month follow-up visit and at the longer term follow-up, mean 85 months (74-96) it was
valued at 1. Both soccer players returned to their
active sports lives in the sixth postoperative month.
According to Benson’s functional evaluation scale,
in long-term follow-up, there have been excellent
results and both patients resumed their professional
carrier for many years (mean 7 years).
Akgun, K., Erbilir, T., Erden, M.G., Misirlioglu,
T.O., & Palamar, D. (2015). Piriformis syndrome:
Comparison of the effectiveness of local anesthetic and corticosteroid injections: A double-blinded, randomized controlled study. Pain Physician,
18(2), 163-71.
PMID: 25794202
Available in full-text at: http://www.painphysicianjournal.com/current/pdf?article=MjI2OA%3D%3D
&journal=87.
ABSTRACT: BACKGROUND: Piriformis syndrome (PS), which is characterized by pain radiating
to the gluteal region and posterior leg, is accepted as
one of the causes of sciatalgia. Although the impor-
tance of local piriformis muscle injections whenever
PS is clinically suspected has been shown in many
studies, there are not enough studies considering the
clinical efficacy of these injections. OBJECTIVE:
To investigate the differences between local anesthetic (LA) and LA + corticosteroid (CS) injections
in the treatment of PS. STUDY DESIGN: A prospective, double-blinded, randomized controlled
trial. SETTING: Physical medicine and rehabilitation department of a university hospital. METHODS: Fifty-seven patients having unilateral hip and/
or leg pain with positive FAIR test and tenderness
and/or trigger point at the piriformis muscle were
evaluated. Out of 50 patients randomly assigned to
2 groups, 47 patients whose pain resolved at least
50 percent from the baseline after the injection were
diagnosed as having PS. The first group (n = 22) received 5 mL of lidocaine 2 percent while the second
group (n = 25) received 4 mL of lidocaine 2 percent
+ 1 mL of betametazone under the guidance of ultrasound. OUTCOME ASSESSMENT: Numeric Rating Scale (NRS) and Likert Analogue Scale (LAS).
RESULTS: No statistically significant difference (P
> 0.05) was detected between the groups in NRS
score values at resting (P = 0.814), night (P = 0.830),
and in motion (P = 0.145), and LAS values with long
duration of sitting (P = 0.547), standing (P = 0.898),
and lying (P = 0.326) with evaluations at baseline,
first week, and first and third months after the injection. A statistically highly significant (P < 0.005)
reduction of pain was evaluated through NRS scores
at resting (P = 0.001), in motion (P = 0.001), and at
night (P = 0.001) and LAS values with long duration
of sitting (P = 0.001), standing (P = 0.001), and lying
(P = 0.001) in both of the groups. LIMITATIONS:
Presumed limitations of this study include having a
relatively small sample. CONCLUSION: LA injections for the PS were found to be clinically effective. However, addition of CS to LA did not give an
additional benefit. This gives us the idea that PS is
mostly muscular in origin and responds well to both
LA and LA+CS injections.
Page 12
Al-Al-Shaikh, M., Aubry, S., Kastler, B., Michel, F.,
Parratte, B., & Vidal, C. (2015). An MRI evaluation of changes in piriformis muscle morphology induced by botulinum toxin injections in the
treatment of piriformis syndrome. Diagnostic
and Interventional Imaging, 96(1), 37-43.
PMID: 24703886
Available in full-text at: http://tinyurl.com/h9964rt.
ABSTRACT: PURPOSE: Botulinum toxin (BT) injection is a new treatment for piriformis syndrome
(PS). The main purpose of our study was to use MRI
to evaluate changes in piriformis muscle morphology after treatment with BT injections. PATIENTS
AND METHODS: Twenty patients presenting with
PS who had undergone an MRI were included retrospectively: 12 patients treated with BT injections
and eight untreated patients. The following parameters were assessed and compared to a normal contralateral muscle: maximum thickness, volume, and
Goutallier’s classification grade of fatty infiltration
of the piriformis and internal obturator muscles.
Pain was assessed through a visual analogue scale
(VAS). RESULTS: The untreated patients had
no significant difference in the volume (P=1.0) or
thickness of the piriformis muscle (P=0.61). The
treated patients showed a significant reduction in the
thickness (-4.2mm; P<0.001) and volume (-74.4mm
(3); P<0.001) and an increase in the fatty infiltration
(P<0.001) of the piriformis muscle treated by BT
injection. Muscular atrophy was correlated with the
number of BT injections and with the time until an
MRI was performed. There was also significant pain
relief after BT treatment. CONCLUSION: BT leads
to atrophy and fatty degeneration of the piriformis
muscle that can be quantified by MRI and these factors explain why BT injections are effective in the
treatment of PS.
Albayrak, A., Atici, Y., Balioglu, M.B., Ermis, M.N.,
Kargin, D., & Ozcafer, R. (2015). Piriformis syndrome: Treatment of a rare cause of posterior
hip pain with fluoroscopic-guided injection. Hip
International, 25(2), 172-5.
PMID: 25837782
ABSTRACT: INTRODUCTION: Piriformis syndrome involves the irritation of the piriformis muscle due to various reasons that are primarily related
to anatomical variation or sciatic nerve compression
due to contraction caused by overuse. In this study,
we aimed to define an injection method that is easy
to apply, safe, simple and repeatable. MATERIALS
AND METHODS: We administered percutaneous
lidocaine and depomedrol injections into the hips of
28 patients (14 men and 14 women) under fluoroscopic control. Bipolar injections of the piriformis
muscle were performed at the medial pole, the intersection of the sciatic notch and the sacroiliac joint,
and at the lateral pole of the femoral insertion region. Each injection was 5 cc, and the contrast agent
was observed after the dyeing process. RESULTS:
Clinical examinations were performed before and
6 weeks after the injections. The average of Harris
Hip Score increased from a pre-injection score of
44.5 to a post-injection score of 68.5, and the Visual Analog Scale scores decreased from 8.3 to 4.2
(p<0.05). COMMENTS: Our findings lead to the
conclusion that fluoroscopy-guided percutaneous
local anaesthetic and corticosteroid injection is a
simple and effective piriformis syndrome treatment
that can feasibly be effectively performed by orthopaedic surgeons.
Beaulieu, C.F., Fredericson, M., Kraus, E., Ratliff,
J., & Tenforde, A.S. (2015). Piriformis Syndrome
with Variant Sciatic Nerve Anatomy: A Case Report. PM & R: The Journal of Injury, Function, and
Rehabilitation, pii: S1934-1482(15)00994-6. doi:
10.1016/j.pmrj.2015.09.005. [Epub ahead of print]
PMID: 26377629
ABSTRACT: A 68-year-old male long distance
runner presented with low back and left buttock
pain, which eventually progressed to severe and debilitating pain, intermittently radiating to the posterior thigh and foot. A comprehensive workup ruled
out possible spine or hip causes of his symptoms. A
pelvic magnetic resonance imaging neurogram with
complex oblique planes through the piriformis demonstrated variant anatomy of the left sciatic nerve
consistent with the clinical diagnosis of piriformis
syndrome. The patient ultimately underwent neurolysis with release of the sciatic nerve and partial
resection of the piriformis muscle. After surgery
the patient reported significant pain reduction and
resumed running three months later. Piriformis syndrome is uncommon but should be considered in the
differential diagnosis for buttock pain. Advanced
imaging was essential to guide management.
Page 13
Bhattad, S.B., Gupta, A., Sharma, D., Singh, S.,
Sinha, A., & Suri, D. (2015). Piriformis Syndrome
in a Young Child: An Unusual Clinical Entity.
Indian Journal of Pediatrics, 2015 Aug 21. [Epub
ahead of print].
PMID: 26289660
No abstract is available.
Byrd, J.W. (2015). Disorders of the Peritrochanteric and Deep Gluteal Space: New Frontiers for
Arthroscopy. Sports Medicine and Arthroscopy
Review, 23(4), 221-31.
PMID: 26524558
ABSTRACT: Arthroscopic techniques for the hip
joint have evolved into endoscopic methods for
extra-articular disorders. These endoscopic strategies provide a less invasive alternative to open
procedures for traditionally recognized forms of
pathology. Endoscopy has defined new disorders
amenable to surgical correction and has redefined
some of these existing disorders. The peritrochanteric and deep gluteal regions represent two of the
most currently active areas of exploration. Peritrochanteric problems include trochanteric bursitis,
full-thickness and partial-thickness tears of the abductors including the gluteus medius and minimus,
and external coxa saltans (snapping iliotibial band).
Deep gluteal disorders include piriformis syndrome,
and other variations of deep gluteal syndrome, and
ischiofemoral impingement. Each of these evolving
areas is highlighted in this chapter.
Cass, S.P. (2015). Piriformis syndrome: A
cause of nondiscogenic sciatica. Current Sports
Medicine Reports, 14(1), 41-4. doi: 10.1249/
JSR.0000000000000110.
PMID: 25574881
ABSTRACT: Piriformis syndrome is a nondiscogenic cause of sciatica from compression of the sciatic nerve through or around the piriformis muscle.
Patients typically have sciatica, buttocks pain, and
worse pain with sitting. They usually have normal neurological examination results and negative
straight leg raising test results. Flexion, adduction,
and internal rotation of the hip, Freiberg sign, Pace
sign, and direct palpation of the piriformis cause pain
and may reproduce symptoms. Imaging and neuro-
diagnostic studies are typically normal and are used
to rule out other etiologies for sciatica. Conservative
treatment, including medication and physiotherapy,
is usually helpful for the majority of patients. For recalcitrant cases, corticosteroid and botulinum toxin
injections may be attempted. Ultrasound and other
imaging modalities likely improve accuracy of injections. Piriformis tenotomy and decompression of
the sciatic nerve can be done for those who do not
respond.
Drampalos, E., Lomax, A., Paul, A., Sadiq, M., &
Thompson, T. (2015). Intrapiriformis lipoma:
An unusual cause of piriformis syndrome. European Spine Journal, 24 Suppl 4, S551-4.
PMID: 25424688
ABSTRACT: INTRODUCTION: We report on a
patient with an unusual cause of non-discogenic sciatica. MATERIAL AND METHODS: A 48-year-old
woman presented with a 10-day history of gradually worsening left buttock pain radiating to the ipsilateral posterior thigh and calf. She had a similar
episode of less intense pain 8 months before which
lasted about 2 months. She denied any history of antecedent trauma or back pain. MRI scan revealed a
well-defined, fat-containing lesion of the left piriformis muscle similar to a lipoma displacing the sciatic
nerve but not invading it. The sciatica was relieved
after excision of the lesion. The patient remained
asymptomatic after the operation. CONCLUSION:
The present case suggested that an intrapiriformis
lipoma can cause secondary piriformis syndrome
and medical practitioners should be aware of this
condition and consider lipomas and other occupying
lesions of the pelvic muscles as a differential diagnosis in patients presenting with radicular pain.
Guler, T., Gunduz, O.H., Misirlioglu, T.O., Ozer, T.,
& Yıldırım, P. (2015). A case of drop foot due to
piriformis syndrome. Acta Neurologica Belgica,
115(4), 847-9.
PMID: 25676003
Page 14
No abstract is available.
Jeong, H.S., Joe, E.G., Kang, H.S., Lee, E.G., Lee,
G.Y., & Lee, J.W. (2015). Long-term assessment
of clinical outcomes of ultrasound-guided steroid
injections in patients with piriformis syndrome.
Ultrasonography, 34(3), 206-10.
PMID: 25672769
Available in full-text at: http://www.ncbi.nlm.nih.
gov/pmc/articles/PMC4484286/pdf/usg-14039.pdf.
ABSTRACT: PURPOSE: The purpose of this
study was to evaluate the long-term efficacy of ultrasound (US)-guided steroid injections in patients
with piriformis syndrome. METHODS: Between
January 2010 and October 2012, 63 patients (23
men and 40 women; average age, 63.2 years; range,
24 to 90 years) were diagnosed with piriformis syndrome based on clinical history, electromyography,
and flexion-adduction-internal rotation test results.
They were divided into two groups. The first group
(37 subjects) received a US-guided steroid injection
around the piriformis muscle. The second group (26
subjects) received both piriformis muscle and spinal
epidural injections. The therapeutic effect was categorized as improvement, partial improvement, or
failure depending on the degree of symptom alleviation one month after injection, based on a review of
each patient’s medical records. RESULTS: In the first
group, 15 patients (40.5 percent) showed improvement, seven (18.9 percent) showed partial improvement, and 15 (40.5 percent) failed to respond to the
initial treatment. In the second group, eight patients
(30.8 percent) showed improvement, 11 (42.3 percent) showed partial improvement, and seven (26.9
percent) failed to respond to the initial treatment. A
second piriformis injection was performed in four
cases, after which two patients showed improvement within three years, but the other two showed
no therapeutic effect. CONCLUSION: US-guided
steroid injection may be an effective treatment option for patients with piriformis syndrome.
2014 – NEW!
Arooj, S., & Azeemuddin, M. (2014). Piriformis
syndrome: A rare cause of extraspinal sciatica.
Journal of the Pakistan Medical Association, 64(8),
949-51.
PMID: 25252525
Available in full-text at: http://jpma.org.pk/PdfDownload/6894.pdf.
ABSTRACT: Piriformis syndrome is a rare entity
resulting in severe unilateral isolated buttock pain
shooting in nature, non discogenic in origin. MR
imaging of pelvis plays an important role in such
patients to see the normal anatomy of piriformis
muscle and its relationship with sciatic nerve. A
35-year-old woman presented with one year history
of radiating leg pain with normal MR lumbosacral
spine. MRI pelvis showed an abnormal orientation
of left sciatic nerve through cleaved fibers of the
piriformis muscle. The patient’s symptoms were relieved by surgical decompression. The purpose of
this case report is to show the role and importance
of MR imaging for tracing sciatic nerve and its relationship to the Piriformis muscle. MR imaging
of pelvis for sciatic nerve plays an important role
in symptomatic patients with isolated buttock pain
having normal MRI lumbosacral spine.
Asensio-Samper, J.M., De Andrés, J., Eichenberger,
U., Fabregat, G., Martínez-Sanjuan, V., Roselló,
M., & Villaneuva-Pérez, V.L. (2014). Computertomographic verification of ultrasound-guided
piriformis muscle injection: A feasibility study.
Pain Physician, 17(6), 507-13.
PMID: 25415775
Available in full-text: http://www.painphysicianjournal.com/current/pdf?article=MjE5MA%3D%3D
&journal=85.
ABSTRACT: BACKGROUND: Approximately 6
to 8 percent of lumbar pain cases, whether associated with radicular pain or not, may be attributed to
the presence of piriformis muscle syndrome. Available treatments, among others, include pharmacotherapy, physical therapy, and injections of different
substances into the muscle. Various methods have
been used to confirm correct needle placement during these procedures, including electromyography
(EMG), fluoroscopy, computed tomography (CT),
Page 15
or magnetic resonance imaging (MRI). Ultrasonography (US) has now become a widely used technique and therefore may be an attractive alternative
for needle guidance when injecting this muscle. OBJECTIVE: The objective of this study was to assess
the reliability of US in piriformis injection of patients with piriformis syndrome. STUDY DESIGN:
Feasibility study; 10 patients with piriformis muscle
syndrome were injected with botulinum toxin A using a US-guided procedure. Then patients were administered 2 mL iodinated contrast and were then
transferred to the CT scanner, where they underwent pelvic and hip imaging to assess intramuscular distribution of the iodinated contrast. SETTING:
Multidisciplinary Pain Management Department
in Spain. RESULTS: Of all 10 study patients (8
women, 2 men), 9 had intramuscular or intrafascial
contrast distribution. Distribution did not go deeper
than the piriformis muscle in any of the patients.
The absence of contrast (intravascular injection)
was not observed in any case. LIMITATIONS: The
main limitation of our study is the use of ionizing radiation as confirmation technique. CONCLUSION:
Ultrasound-guided puncture may be a reliable and
simple procedure for injection of the piriformis
muscle, as long as good education and training are
provided to the operator. US has a number of advantages over traditional approaches, including accessibility and especially no ionizing radiation exposure
for both health care providers and patients.
Aytekin, A., Develi, S., Ekinci, S., & Parlak, A.
(2014). Piriformis syndrome: A case with nondiscogenic sciatalgia. Turkish Neurosurgery, 24(1),
117-9.
PMID: 24535806
Available in full-text at: http://www.turkishneurosurgery.org.tr/pdf/pdf_JTN_1267.pdf.
ABSTRACT: Piriformis syndrome is a clinical picture of non-discogenic sciatica caused by compression of the sciatic nerve by the piriformis muscle.
It has variable etiologies and the patho-physiology
is not fully understood. The major etiology was
known to be the spasm, edema and inflammation of
the piriformis muscle and sciatic nerve compression
of the muscle later on. Patients can be diagnosed immediately with a comprehensive clinical examination and early diagnosis makes the treatment much
easier. Diagnosis of the piriformis syndrome, a very
rare cause of low back pain, first requires that this
syndrome is remembered, and then a differential diagnosis should be performed. A case of piriformis
syndrome diagnosed in a patient who presented with
low back pain is reported in this study.
Baxter, B., Gulledge, B.M., Harrysson, O.L.,
Levine, D., Marcellin-Little, D.J., Osborne, J.A., &
Tillman, L. (2014). Comparison of two stretching
methods and optimization of stretching protocol
for the piriformis muscle. Medical Engineering &
Physics, 36(2), 212-8.
PMID: 24262799
ABSTRACT: Piriformis syndrome is an uncommon diagnosis for a non-discogenic form of sciatica whose treatment has traditionally focused on
stretching the piriformis muscle (PiM). Conventional stretches include hip flexion, adduction, and external rotation. Using three-dimensional modeling, we
quantified the amount of (PiM) elongation resulting
from two conventional stretches and we investigated
by use of a computational model alternate stretching protocols that would optimize PiM stretching.
Seven subjects underwent three CT scans: one supine, one with hip flexion, adduction then external
rotation (ADD stretch), and one with hip flexion, external rotation then adduction (ExR stretch). Threedimensional bone models were constructed from the
CT scans. PiM elongation during these stretches,
femoral neck inclination, femoral head anteversion,
and trochanteric anteversion were measured. A computer program was developed to map PiM length
over a range of hip joint positions and was validated
against the measured scans. ExR and ADD stretches
elongated the PiM similarly by approximately 12
percent. Femoral head and greater trochanter anteversion influenced PiM elongation. Placing the hip
joints in 115° of hip flexion, 40° of external rotation
and 25° of adduction or 120° of hip flexion, 50°
of external rotation and 30° of adduction increased
PiM elongation by 30-40 percent compared to conventional stretches (15.1 and 15.3 percent increases
in PiM muscle length, respectively). ExR and ADD
stretches elongate the PiM similarly and therefore
may have similar clinical effectiveness. The optimized stretches led to larger increases in PiM length
and may be more easily performed by some patients
due to increased hip flexion.
Page 16
Dauty, M., Dubois, C., Fouasson-Chaillou, A., &
Menu, P. (2014). Piriformis syndrome diagnosis:
On two professional cyclists. Annals of Physical
and Rehabilitation Medicine, 57(4), 268-74.
PMID:
24731941
Available in full-text at: http://tinyurl.com/zuw7unp.
No abstract is available.
Denk, C.C., Gundogmus, B., Ozisik, P.A., Taskiran,
O.O., & Toru, M. (2014). CT-guided piriformis
muscle injection for the treatment of piriformis
syndrome. Turkish Neurosurgery, 24(4), 471-7.
PMID: 25050669
Available in full-text at: http://www.turkishneurosurgery.org.tr/pdf/pdf_JTN_1356.pdf.
ABSTRACT: AIM: Piriformis syndrome is a rare
neuromuscular disorder that occurs when the piriformis muscle compresses or irritates the sciatic nerve.
The treatment of piriformis syndrome includes injections into the piriformis muscle around the sciatic
nerve. These invasive approaches have been used
with various techniques to increase the safety of
the procedure. Computed tomography (CT)-guided
injection of the piriformis muscle and the clinical
outcome of the patients are discussed. MATERIAL
AND METHODS: The authors presented 10 consecutive patients that underwent CT-guided piriformis
injection between March and December 2007. Three
patients had a history of a severe fall on the buttocks, one had gluteal abscess formation following
deep intramuscular injection, and another one had
a habit of prolonged sitting on the carpet. Etiology
was not identified in the other patients. Main complaints of the patients were pain and numbness in the
legs. Hypesthesia was the major neurological finding. Magnetic resonance imaging (MRI) and electromyography (EMG) were performed in all patients.
RESULTS: Nine patients had full and sustained recovery of their symptoms after piriformis injection.
Only the patient who had gluteal abscess formation
following deep intramuscular injection showed moderate improvement. Another patient was operated on
in the 6th month after piriformis injection due to an
extruded disc herniation. CONCLUSION: CT-guided piriformis injection is a safe and effective method
in the treatment of piriformis syndrome.
Fowler, I.M., Mendez, R.J., Moran, T.J., Tucker,
A.A., & Weimerskirch, B.P. (2014). A randomized
comparison of the efficacy of two techniques for
piriformis muscle injection: Ultrasound-guided
versus nerve stimulator with fluoroscopic guidance. Regional Anesthesia and Pain Medicine,
39(2), 126-32.
PMID: 24509422
ABSTRACT: BACKGROUND: Piriformis muscle
injections are most often performed using fluoroscopic guidance; however, ultrasound (US) guidance has recently been described extensively in the
literature. No direct comparisons between the two
techniques have been performed. Our objective
was to compare the efficacy and efficiency of fluoroscopic- and US-guided techniques. METHODS:
A randomized, comparative trial was carried out to
compare the two techniques. Twenty-eight patients
with a diagnosis of piriformis syndrome, based on
history and physical examination, who had failed
conservative treatment were enrolled in the study.
Patients were randomized to receive the injection
either via US or fluoroscopy. Injections consisted
of 10 mL of 1 percent lidocaine with 80 mg of triamcinalone. The primary outcome measure was
numeric pain score, and secondary outcome measures included functional status as measured by the
Multidimensional Pain Inventory, patient satisfaction as measured by the Patient Global Impression
of Change scale, and procedure timing characteristics. Outcome data were measured preprocedure,
immediately postprocedure, and 1 to 2 weeks and
3 months postprocedure. RESULTS: We found no
statistically significant differences in numeric pain
scores, patient satisfaction, procedure timing characteristics, or most functional outcomes when comparing the two techniques. Statistically significant
differences between the two techniques were found
with respect to the outcome measures of household
chores and outdoor work. CONCLUSIONS: Ultrasound-guided piriformis injections provide similar outcomes to fluoroscopically guided injections
without differences in imaging, needling, or overall
procedural times.
Page 17
Khasru, M.R., Rasker, J.J., & Siddiq, M.A. (2014).
Piriformis syndrome in fibromyalgia: Clinical
diagnosis and successful treatment. Case Reports
in Rheumatology, doi: 10.1155/2014/893836. Epub
2014 Sep 22.
PMID: 25328750
Available in full-text at: http://www.ncbi.nlm.nih.
gov/pmc/articles/PMC4190119/pdf/CRIRH2014893836.pdf.
ABSTRACT: Piriformis syndrome is an underdiagnosed extraspinal association of sciatica.
Patients usually complain of deep seated gluteal
pain. In severe cases the clinical features of piriformis syndrome are primarily due to spasm of the
piriformis muscle and irritation of the underlying
sciatic nerve but this mysterious clinical scenario is
also described in lumbar spinal canal stenosis, leg
length discrepancy, piriformis myofascial pain syndrome, following vaginal delivery, and anomalous
piriformis muscle or sciatic nerve. In this paper, we
describe piriformis and fibromyalgia syndrome in a
30-year-old young lady, an often missed diagnosis.
We also focus on management of the piriformis syndrome.
Koebke, J., Konstantinidis, G.A., Natsis, K., Paraskevas, G., Piagkou, M., & Totlis, T. (2014). Anatomical variations between the sciatic nerve and
the piriformis muscle: A contribution to surgical
anatomy in piriformis syndrome. Surgical and
Radiologic Anatomy, 36(3), 273-80.
PMID: 23900507
PURPOSE: To detect the variable relationship between sciatic nerve and piriformis muscle and make
surgeons aware of certain anatomical features of
each variation that may be useful for the surgical
treatment of the piriformis syndrome. METHODS:
The gluteal region of 147 Caucasian cadavers (294
limbs) was dissected. The anatomical relationship
between the sciatic nerve and the piriformis muscle
was recorded and classified according to the Beaton and Anson classification. The literature was reviewed to summarize the incidence of each variation. RESULTS: The sciatic nerve and piriformis
muscle relationship followed the typical anatomical
pattern in 275 limbs (93.6 percent). In 12 limbs (4.1
percent) the common peroneal nerve passed through
and the tibial nerve below a double piriformis.
In one limb (0.3 percent) the common peroneal nerve
coursed superior and the tibial nerve below the piriformis. In one limb (0.3 percent) both nerves penetrated the piriformis. In one limb (0.3 percent) both
nerves passed above the piriformis. Four limbs (1.4
percent) presented non-classified anatomical variations. When a double piriformis muscle was present,
two different arrangements of the two heads were
observed. CONCLUSIONS: Anatomical variations
of the sciatic nerve around the piriformis muscle
were present in 6.4 percent of the limbs examined.
When dissection of the entire piriformis is necessary
for adequate sciatic nerve decompression, the surgeon should explore for the possible existence of a
second tendon, which may be found either inferior
or deep to the first one. Some rare, unclassified variations of the sciatic nerve should be expected during
surgical intervention of the region.
Yin, G.L., Wang, F. (2014). Warm acupuncture
combined with muscle strength technique for 46
cases of piriformis syndrome. [Article in Chinese].
Chinese Acupuncture & Moxibustion, 34(4), 407-8.
PMID: 24946654
No abstract is available.
2013 – NEW!
Benrath, J., Blunk, J.A., Nowotny, M., & Scharf, J.
(2013). MRI verification of ultrasound-guided
infiltrations of local anesthetics into the piriformis muscle. Pain Medicine, 14(10), 1593-9.
PMID: 23758696
Available in full-text at: http://painmedicine.oxfordjournals.org/content/painmedicine/14/10/1593.
full.pdf.
ABSTRACT: OBJECTIVE: Patients presenting
with buttock pain syndromes are common. Up to
eight percent of these conditions may be attributed
to piriformis syndrome. Included in several therapeutic and diagnostic approaches, injections directly
into the piriformis muscle may be performed. Because the muscle lies very close to neurovascular
structures, electromyographic, fluoroscopic, computed tomographic, and magnetic resonance imaging (MRI) guidance have been employed. In few
studies, an ultrasound-guided technique was used
to inject a local anesthetic into the piriformis muscle without impairing adjacent neuronal structures.
Page 18
DESIGN: Feasibility study in healthy human subjects. Confirmation of ultrasound-guided injections
by MRI. SUBJECTS: In 10 male human subjects,
ultrasound-guided injections of 3 mL of a local anesthetic into the piriformis muscle were performed.
METHODS: Directly after the injection, the subjects
were placed in an MRI scanner, and the placement
of the liquid depot was confirmed by MRI imaging.
Somatosensory deficits were evaluated after the injection. RESULTS: The MRI showed that 9 of 10 of
the injections were correctly placed within the piriformis muscle. The distance of the depot to the sciatic nerve decreased over time due to dispersion, but
the nerve itself was not reached in the MRI. Only
one subject experienced slight, short-term sensorimotor deficits. CONCLUSIONS: MRI confirmed the
correct placement of the local anesthetic within the
muscle. The dispersion of the fluid 30 minutes after the injection could be visualized. Moreover, only
one subject experienced slight motor deficits without anatomical correlate. This ultrasound-guided
method will be further employed in ongoing clinical
studies.
the position and orientation of the probe in the magnetic field. The tracked ultrasound probe was used to
find the posterior superior iliac spine. Subsequently,
three points were captured to register the ultrasound
image with the CT or magnetic resonance image
scan. Moreover, after the registration was obtained,
the navigation system visualized the tracked needle
relative to the CT scan in real-time using two orthogonal multi-planar reconstructions centered at
the tracked needle tip. Conversely, a recent study
revealed that fluoroscopically guided injections had
30 percent accuracy compared to ultrasound guided
injections, which tripled the accuracy percentage.
This novel technique exhibited an accurate needle
guidance injection precision of 98 percent while advancing to the piriformis muscle and avoiding the
sciatic nerve. The mean (± SD) procedure time was
19.08 (± 4.9) minutes. This technique allows for
electromagnetic instrument tip tracking with realtime 3-D guidance to the selected target. As with
any new technique, a learning curve is expected;
however, this technique could offer an alternative,
minimizing radiation exposure.
Candler, S.A., Clendenen, S.R., Duench, S., Ghazi,
S.M., Glynn, L., Osborne, M.D., & Palmer, S.C.
(2013). Needle placement for piriformis injection
using 3-D imaging. Pain Physician, 16(3), E30110.
PMID: 23703429
Available in full-text at: http://www.painphysicianjournal.com/current/pdf?article=MTkyNQ%3D%3
D&journal=75.
ABSTRACT: Piriformis syndrome is a pain syndrome originating in the buttock and is attributed to
6 to 8 percent of patients referred for the treatment
of back and leg pain. The treatment for piriformis
syndrome using fluoroscopy, computed tomography
(CT), electromyography (EMG), and ultrasound
(US) has become standard practice. The treatment of
Piriformis Syndrome has evolved to include fluoroscopy and EMG with CT guidance. We present a case
study of five successful piriformis injections using
3-D computer-assisted electromagnet needle tracking coupled with ultrasound. A 6-degree of freedom
electromagnetic position tracker was attached to the
ultrasound probe that allowed the system to detect
Chen, C.K., & Nizar, A.J. (2013). Prevalence of
piriformis syndrome in chronic low back pain
patients. A clinical diagnosis with modified FAIR
test. Pain Practice, 13(4), 276-81.
PMID: 22863240
ABSTRACT: PURPOSE: Piriformis syndrome is
a collection of symptoms and signs of pain from
piriformis muscle and is characterized by pain in
buttock with variable involvement of sciatic nerve.
This syndrome is often overlooked in clinical practice because its presentation has similarities with
other spine pathologies. A major problem with the
clinical diagnosis of piriformis syndrome is the lack
of consistent objective findings and an absence of
single test that is specific for piriformis syndrome.
Therefore, a precise and reliable clinical method of
diagnosing piriformis syndrome should be developed by clinicians. METHODS: This is a prospective observational study involving 93 consecutive
patients who attended the pain management unit for
chronic low back pain. The diagnosis of piriformis
syndrome was made using the modified flexion ad-
Page 19
duction internal rotation (FAIR) test, which is a combination of Lasègue sign and FAIR test. Prevalence
of piriformis syndrome based on this technique was
compared with the previous data using other techniques. Chi square (χ2) analysis was performed to
detect the relationship between piriformis syndrome
and the potential risk factors. RESULTS: On the
basics of our diagnostic criteria, the prevalence of
piriformis syndrome was 17.2 percent among low
back pain patients. All the patients diagnosed with
piriformis syndrome responded well with piriformis
muscle injections. No significant associations were
detected between piriformis syndrome and spine
disorders. CONCLUSIONS: Piriformis syndrome is
a painful condition that is often overlooked in the
differential diagnosis of chronic buttock or low back
pain. The modified FAIR test together with piriformis muscle injection is potentially a reliable method
for the clinical diagnosis of piriformis syndrome.
Chen, S., Fan, Y., Li, H.T., Liu, J.M., Qi, F.J., Tian,
J.G., & Tian, W.H. (2013). Observation on therapeutic effect of round-sharp needle of new nineneedle and elongated needle for piriformis syndrome with triple puncture method. [Article in
Chinese]. Chinese Acupuncture & Moxibustion,
33(5), 422-5.
PMID: 23885616
ABSTRACT: OBJECTIVE: To compare the efficacy differences between round-sharp needle of
new nine-needle and elongated needle for piriformis syndrome, and explore its action mechanism.
METHODS: Eighty cases were randomly divided
into a round-sharp needle of new nine-needle group
(round-sharp needle group) and an elongated needle
treatment group (elongated needle group), 40 cases
in each group. The round-sharp needle group was
treated with round-sharp needle (0.60 mm x 125
mm) at three points in piriformis with triple puncture method, while the elongated needle group was
treated with elongated needle of ordinary specifications (0.32 mm x 125 mm) at three points in piriformis with triple puncture method. Besides, the two
groups were also treated with routine acupuncture
at Weizhong (BL 40) and Yanglingquan (GB 34), 3
times every week, 2 weeks as one course of treatment. After one course of treatment, the clinical
effect was evaluated and the pain threshold values
were measured before and after treatment in the two
groups. RESULTS: The total effective rate in the
round-sharp needle group was 92.5 percent (37/40),
which was superior to 77.5 percent (31/40) in the
elongated needle group (P < 0.05). Compared before
treatment, the pain threshold values after treatment
in two groups were improved significantly (both P <
0.01). The increment of pain threshold value in the
round-sharp needle group was higher than that in the
elongated needle group (P < 0.01). CONCLUSION:
Round-sharp needle of new nine-needle is effective
in treatment of piriformis syndrome and is better
than ordinary elongated needle, which is related to
that it can effectively increase pain threshold value
of the local tissue.
Delabie, A., Foulon, P., Havet, E., Le Gars, D., Page,
C., & Peltier, J. (2013). Relationships between
piriformis muscle and sciatic nerve: Radioanatomical study with 104 buttocks. [Article in
French]. Morphologie, 97(316), 12-8.
PMID: 23414787
ABSTRACT: OBJECTIVE: The relationships between the piriformis muscle and the sciatic nerve
are close and may be changing. In some cases, these
relationships are the cause of a piriformis syndrome,
an under-diagnosed etiology of non discal sciatica.
The aim of the study was to explore, by the MRI,
the sciatic nerve and the piriformis muscle. MATERIELS AND METHODS: One hundred and four
buttocks were explored by MRI for 52 randomly
selected patients. RESULTS: In 59.6 percent of cases, no variation of the piriformis muscle and sciatic
nerve were found. In 26 percent of cases, the sciatic
nerve was divided into the pelvis. In 9.6 percent of
cases, it was divided into the pelvis, the piriformis
muscle was bifid and the common peroneal nerve
ran between both heads. The piriformis muscle was
bifid in 10.6 percent of cases, hypertrophic in 13.5
percent of cases and atrophic in 2.9 percent of cases.
Page 20
Jankovic, D., Peng, P., & van Zundert, A. (2013).
Brief review: Piriformis syndrome: etiology, diagnosis, and management. Canadian Journal of
Anaesthesia, 60(10), 1003-12.
PMID: 23893704
Available in full-text at: http://tinyurl.com/jf8vhfs.
ABSTRACT: PURPOSE: In this narrative review,
we aim to provide the pathophysiology and diagnostic criteria of the piriformis syndrome (PS), an
underdiagnosed cause of buttock and leg pain that
can be difficult to treat. Based on existing evidence,
frequencies of clinical features are estimated in patients reported to have PS. In view of the increasing popularity of ultrasound for intervention, the
ultrasound-guided technique in the treatment of PS
is described in detail. SOURCE: A literature search
of the MEDLINE® database was performed from
January 1980 to December 2012 using the search
terms e.g., “ piriformis injection”, “ ultrasound guided piriformis injection”, “ botulinum toxin”, “pain
management”, and different structures relevant in
this review. There was no restriction on language.
PRINCIPAL FINDINGS: A review of the medical
literature pertaining to PS revealed that the existence
of this entity remains controversial. There is no definitive proof of its existence despite reported series
with large numbers of patients. CONCLUSION:
Piriformis syndrome continues to be a controversial
diagnosis for sciatic pain. Electrophysiological testing and nerve blocks play important roles when the
diagnosis is uncertain. Injection of local anesthetics, steroids, and botulinum toxin into the piriformis
muscle can serve both diagnostic and therapeutic
purposes. An ultrasound-guided injection technique
offers improved accuracy in locating the piriformis
muscle. Optimizing the therapeutic approach requires an interdisciplinary evaluation of treatment.
Koda, M., Murakami, K., Murakami, M., Nakajima,
A., Nakajima, H., Rokkaku, T., Toda, T., Watanabe,
H., & Yamada, T. (2013). Sciatica caused by pyomyositis of the piriformis muscle in a pediatric
patient. Orthopedics, 36(2), e257-9.
PMID: 23383745
Available in full-text at: http://tinyurl.com/hsyr9jx.
ABSTRACT: Because the sciatic nerve leaves the
pelvis through the greater sciatic notch underneath
the piriformis muscle, any pathology of the piriformis muscle could result in entrapment of the sciatic
nerve; this is widely known as piriformis muscle
syndrome. Pyomyositis of the piriformis muscle
may be a cause of piriformis muscle syndrome. Piriformis muscle syndrome caused by pyomyositis of
the piriformis muscle in pediatric patients is rare.
This article describes a case of sciatica caused by
pyomyositis of the piriformis muscle in a pediatric
patient. A 6-year-old boy presented with right buttock and thigh pain following a mild fever and sore
throat. The pain worsened, and he became unable
to walk. On admission, his temperature was 38.4°C.
He reported severe right-sided buttock and lateral
thigh pain. Positive Freiberg sign was observed.
Laboratory examination revealed elevated white
blood cell count and C-reactive protein level. T2weighted magnetic resonance images of the pelvis
revealed high-intensity changes of the piriformis
muscle and iliosacral joint. Thus, piriformis syndrome caused by pyomyositis of the piriformis muscle was diagnosed. Oral antibiotics (10 mg/kg per
day of cefdinir) were administered. Pain gradually
decreased, and the patient was able to walk. Final
follow-up examination at 6 months after symptom
onset revealed no sciatic pain. Follow-up magnetic
resonance imaging revealed normalized intensities
of the piriformis muscle. The endopelvic fascia provides a route for infection from the pelvis to the piriformis. The pyomyositis of the piriformis muscle in
the current case may have occurred secondary to the
pyoarthritis of the sacroiliac joint. Endopelvic infections involving the piriformis muscle may mimic
hip diseases in pediatric patients.
Mutlu, H., Ozyurek, S., Sivrioglu, A.K., & Sonmez, G. (2013). Piriformis syndrome occurring
after pregnancy. BMJ Case Reports, 2013. pii:
bcr2013008946. doi: 10.1136/bcr-2013-008946.
PMID: 23536625
Available in full-text at: http://www.ncbi.nlm.nih.
gov/pmc/articles/PMC3618849/pdf/bcr-2013008946.pdf.
No abstract is available.
Page 21
2012 – NEW!
Bakkum, B.W., & Chapman, C. (2012). Chiropractic management of a US Army veteran with low
back pain and piriformis syndrome complicated
by an anatomical anomaly of the piriformis muscle: A case study. Journal of Chiropractic Medicine, 11(1), 24-9.
PMID: 22942838
Available in full-text at: http://www.ncbi.nlm.nih.
gov/pmc/articles/PMC3315859/pdf/main.pdf.
ABSTRACT: OBJECTIVE: The purpose of this
article is to present the case of a patient with an
anatomical anomaly of the piriformis muscle who
had a piriformis syndrome and was managed with
chiropractic care. CASE REPORT: A 32-year-old
male patient presented to a chiropractic clinic with
a chief complaint of low back pain that radiated into
his right buttock, right posterior thigh, and right posterior calf. The complaint began 5 years prior as a
result of injuries during Airborne School in the US
Army resulting in a 60 percent disability rating from
the Veterans Administration. Magnetic resonance
imaging demonstrated a mildly decreased intradiscal T2 signal with shallow central subligamentous
disk displacement and low-grade facet arthropathy at
L5/S1, a hypolordotic lumbar curvature, and accessory superior bundles of the right piriformis muscle
without morphologic magnetic resonance imaging
evidence of piriformis syndrome. INTERVENTION
AND OUTCOME: Chiropractic treatment included
lumbar and sacral spinal manipulation with soft tissue massage to associated musculature and home
exercise recommendations. Variations from routine
care included proprioceptive neuromuscular facilitation stretches, electric muscle stimulation, acupressure point stimulation, Sacro Occipital Technique
pelvic blocking, CranioSacral therapy, and an ergonomic evaluation. CONCLUSION: A patient with
a piriformis anomaly with symptoms of low back
pain and piriformis syndrome responded positively
to conservative chiropractic care, although the underlying cause of the piriformis syndrome remained.
Bubb, K., Cassidy, L., Loukas, M., Shoja, M.M.,
Tubbs, R.S., & Walters, A. (2012). Piriformis syndrome: Implications of anatomical variations, diagnostic techniques, and treatment options. Surgical and Radiologic Anatomy (SRA), 34(6), 479-86.
PMID: 22327640
ABSTRACT: Details of piriformis syndrome, including the proper diagnosis and most effective form
of treatment, continue to be controversial. While
the cause, diagnosis, and treatment of piriformis
syndrome remain elusive, many studies have been
conducted to investigate newly developed diagnostic techniques as well as various treatment options
for piriformis-induced sciatica. Despite the quantity
of literature, few studies have demonstrated statistically significant results that support one form of
treatment over another. Thus, despite the evidence
supporting the newer treatment methodologies for
piriformis syndrome, research should continue.
It is important not only to evaluate treatment outcomes based on associated pain relief, but also to
investigate the functional and anatomical return that
patients experience from these studied treatments
in order to fully explore the most effective form of
therapy for piriformis syndrome.
Calabria, E., Crusco, S., Masala, S., Meschini, A.,
Simonetti, G., & Taglieri, A. (2012). Piriformis
syndrome: Long-term follow-up in patients
treated with percutaneous injection of anesthetic
and corticosteroid under CT guidance. Cardiovascular and Interventional Radiology, 35(2), 37582.
PMID: 21607823
ABSTRACT: PURPOSE: This study was designed
to evaluate the efficacy of CT-guided injection of anesthetic and corticosteroid for the treatment of pain
in patients with piriformis syndrome unresponsive
to conservative treatment. METHODS: We enrolled
23 patients with piriformis syndrome, proposing a
percutaneous intramuscular injection of methylprednisone-lidocaine. Among them, 13 patients accepted
and 10 refused to undergo the procedure; the second
group was used as a control group. Clinical evaluation was performed with four maneuvers (Lasègue
sign, FAIR test, Beatty and Freiberg maneuver) and
a VAS questionnaire before the injection, after 5-7
days, and after 2 months. A telephonic follow-up
was conducted to 3, 6, and 12 months. RESULTS:
Procedural success was achieved in all patients who
were treated without any complications. After 2
months, among 13 treated subjects, 2 of 13 patients
showed positivity to FAIR test (hip flexion, adduction, and internal rotation), 2 of 13 were positive to
Lasègue sign, and the Beatty maneuver was positive
Page 22
in 1 patient. Patients who underwent conservative
treatment were positive respectively in 7 of 10 (p
= 0.01), 6 of 10 (p = 0.03), and 6 of 10 (p = 0.01).
The VAS score showed a difference between patients treated with percutaneous approach and those
managed with conservative therapy at the baseline
evaluation (p = 0.04), after 2 months (p = 0.02), and
12 months (p = 0.002). We observed a significant
reduction in pain for patients treated percutaneously, who were evaluated with the VAS scale at 5-7
days, 2 months, 3, 6, and 12 months (p < 0.001).
CONCLUSIONS: Our findings suggested potential
benefit from the percutaneous injection of anesthetics and corticosteroids under CT guidance for the
treatment of piriformis syndrome.
Grossman, G.E., Justice, P.E., Katirji, B., & Preston,
D.C. (2012). Piriformis syndrome surgery causing severe sciatic nerve injury. Journal of Clinical
Neuromuscular Disease, 14(1), 45-7.
PMID: 22922582
ABSTRACT: Piriformis syndrome is a controversial entrapment neuropathy in which the sciatic
nerve is thought to be compressed by the piriformis
muscle. Two patients developed severe left sciatic
neuropathy after piriformis muscle release. One had
a total sciatic nerve lesion, whereas the second had a
predominantly high common peroneal nerve lesion.
Follow-up studies showed reinnervation of the hamstrings only. We conclude that piriformis muscle
surgery may be hazardous and result in devastating
sciatic nerve injury.
Kitagawa, Y., Takai, S., Tamai, K., & Yokoyama, M.
(2012). Chronic expanding hematoma extending over multiple gluteal muscles associated with
piriformis syndrome. Journal of Nippon Medical
School, 79(6), 478-83.
PMID: 23291848
Available in full-text at: https://www.jstage.jst.
go.jp/article/jnms/79/6/79_478/_pdf.
ABSTRACT: We report on a patient with an unusual, slowly enlarging hematoma of the left buttock.
A 62-year-old man presented with a 6-year history
of an enlarging mass of the left buttock. He had first
noted the mass 6 years earlier and had had sciatica
of the left lower limb for the last 2 months. He denied any history of antecedent trauma. The lesion
extended over 3 gluteal muscles (the gluteus medius, gluteus minimus, and piriformis). On microscopic examination, the lesion showed typical signs
of chronic expanding hematoma. The sciatica was
relieved after surgical removal of the lesion. The lesion had not recurred at the last follow-up 4 years
after the operation. The present case suggested that
chronic expanding hematoma can extend into multiple muscles due, perhaps, to long-term growth and
the anatomical and functional conditions of the affected muscles. Our case also suggests that chronic
expanding hematoma can be a cause of piriformis
syndrome.
Miller, T.A., Ross, D.C., & White, K.P. (2012). The
diagnosis and management of piriformis syndrome: Myths and facts. The Canadian Journal
of Neurological Sciences, 39(5), 577-83.
PMID: 22931697
ABSTRACT: Piriformis syndrome (PS) is an uncommon, controversial neuromuscular disorder that
is presumed to be a compression neuropathy of the
sciatic nerve at the level of the piriformis muscle
(PM). The diagnosis is hampered by a lack of agreed
upon clinical criteria and a lack of definitive investigations such as imaging or electrodiagnostic testing.
Treatment has focused on stretching, physical therapies, local injections, including botulinum toxin, and
surgical management. This article explores the various sources of controversy surrounding piriformis
syndrome including diagnosis, investigation and
management. We conclude with a proposal for diagnostic criteria which include signs and symptoms,
imaging, and response to therapeutic injections.
2011 – NEW!
Burger, E.L., Cooley, R., Estes, S., Gonzalez, P.,
Lindley, E.M., Patel, V.V., & Robinson, E.S. (2011).
Piriformis syndrome versus radiculopathy following lumbar artificial disc replacement. Spine,
36(4), E282-7.
PMID: 21270711
ABSTRACT: STUDY DESIGN: Case series. OBJECTIVE: To describe the presentation, diagnostic
challenges, and treatment of five patients with piriformis syndrome after lumbar artificial disc replacement. SUMMARY OF BACKGROUND DATA:
Page 23
Until recently, spinal fusion was considered the standard for surgical treatment of severe lumbar degenerative disc disease. However, artificial disc replacement now offers an alternative solution. Piriformis
syndrome results from entrapment of the sciatic
nerve at the greater sciatic notch, with symptoms of
pain and numbness radiating from the buttock to the
foot, mimicking radiculopathy. METHODS: In this
case series, we report five patients who developed
piriformis at our institution after artificial disc replacement. RESULTS: Five patients, aged 35 to 46
years, developed some or all of the following symptoms in the affected leg after artificial disc replacement: posterior leg and buttock pain, calf weakness,
and toe and ball of foot numbness and tingling. The
onset of symptoms ranged from 6 days to 8 months
postoperative, and became debilitating over time.
Each patient was diagnosed with piriformis syndrome through physical examination. Three of the
patients received a piriformis injection and reported
50 percent to 100 percent pain relief lasting 1 to 3
weeks. The patients subsequently underwent physical therapy that provided relief of their piriformis
syndrome-related pain and enabled them to resume
their normal activities. CONCLUSION: Piriformis
syndrome has not previously been described in the
literature as a sequela of lumbar artificial disc replacement. Our case series indicates that this complication may be underdiagnosed. Careful consideration after artificial disc replacement is required if
the patient presents with buttock, leg or foot pain,
and/or numbness. It is important for physicians to
recognize the symptoms of piriformis syndrome and
to differentiate piriformis syndrome from nerve root
compression and irritation or referred pain from spinal structures. Although controversial, the proper diagnosis of piriformis syndrome may have prevented
some of these patients from undergoing unnecessary
surgical procedures.
2010 – NEW!
Assoum, H.A., Jawish, R.M., & Khamis, C.F.
(2010). Anatomical, clinical, and electrical observations in piriformis syndrome. Journal
of Orthopaedic Surgery and Research, 5, 3. doi:
10.1186/1749-799X-5-3.
PMID: 20180984
Available in full-text at: http://www.ncbi.nlm.
nih.gov/pmc/articles/PMC2828977/pdf/1749799X-5-3.pdf.
ABSTRACT: BACKGROUND: We provided clinical and electrical descriptions of the piriformis syndrome, contributing to better understanding of the
pathogenesis and further diagnostic criteria. METHODS: Between 3550 patients complaining of sciatica, we concluded 26 cases of piriformis syndrome,
15 females, 11 males, mean age 35.37 year-old. We
operated 9 patients, 2 to 19 years after the onset of
symptoms, 5 had piriformis steroids injection. A
dorsolumbar MRI were performed in all cases and
a pelvic MRI in 7 patients. The electro-diagnostic
test was performed in 13 cases, between them the
H reflex of the peroneal nerve was tested 7 times.
RESULTS: After a follow-up 1 to 11 years, for the
17 non operated patients, 3 patients responded to
conservative treatment. 6 of the operated had an excellent result, 2 residual minor pain and one failed.
3 new anatomical observations were described with
atypical compression of the sciatic nerve by the piriformis muscle. CONCLUSION: While the H reflex
test of the tibial nerve did not give common satisfaction in the literature for diagnosis, the H reflex
of the peroneal nerve should be given more importance, because it demonstrated in our study more
specific sign, with six clinical criteria it contributed
to improve the method of diagnosis. The cause of
this particular syndrome does not only depend on
the relation sciatic nerve-piriformis muscle, but the
environmental conditions should be considered with
the series of the anatomical anomalies to explain the
real cause of this pain.
Beltran, J., Beltran, L.S., Bencardino, J., &
Ghazikhanian, V. (2010). Entrapment neuropathies III: Lower limb. Seminars in Musculoskeletal Radiology, 14(5), 501-11.
PMID: 21072728
ABSTRACT: Clinicians frequently encounter compressive neuropathies of the lower extremity.
The clinical history and physical examination, along
with electrodiagnostic testing and imaging studies,
lead to the correct diagnosis. The imaging characteristics of the compression neuropathies can include acute and chronic changes in the nerves and
the muscles they innervate. We provide a detailed
Page 24
review of compression neuropathies of the lower
extremity with an emphasis on magnetic resonance
(MR) imaging characteristics. We discuss the clinical presentation, etiology, anatomical location, and
MR imaging appearance of these neuropathies, including the piriformis syndrome, iliacus syndrome,
saphenous neuropathy, obturator neuropathy, lateral
femoral cutaneous neuropathy (meralgia paresthetica), proximal tibial neuropathy, common peroneal
neuropathy, deep peroneal neuropathy, superficial
peroneal neuropathy, tarsal tunnel syndrome, Baxter’s neuropathy, jogger’s foot, sural neuropathy,
and Morton’s neuroma.
Dye, J.A., Farrokhi, S., Kochevar, R.J., Powers,
C.M., Tonley, J.C., & Yun, S.M. (2010). Treatment of an individual with piriformis syndrome
focusing on hip muscle strengthening and movement reeducation: A case report. The Journal of
Orthopaedic and Sports Physical Therapy, 40(2),
103-11.
PMID: 20118521
Available in full-text at: http://www.jospt.org/doi/
pdf/10.2519/jospt.2010.3108.
ABSTRACT: STUDY DESIGN: Case report. OBJECTIVE: To describe an alternative treatment approach for piriformis syndrome using a hip muscle
strengthening program with movement reeducation.
BACKGROUND: Interventions for piriformis syndrome typically consist of stretching and/or soft
tissue massage to the piriformis muscle. The premise underlying this approach is that a shortening
or “spasm” of the piriformis is responsible for the
compression placed upon the sciatic nerve. CASE
DESCRIPTION: The patient was a 30-year-old
male with right buttock and posterior thigh pain for
2 years. Clinical findings upon examination included reproduction of symptoms with palpation and
stretching of the piriformis. Movement analysis during a single-limb step-down revealed excessive hip
adduction and internal rotation, which reproduced
his symptoms. Strength assessment revealed weakness of the right hip abductor and external rotator
muscles. The patient’s treatment was limited to hipstrengthening exercises and movement reeducation
to correct the excessive hip adduction and internal
rotation during functional tasks. OUTCOMES: Following the intervention, the patient reported 0/10
pain with all activities. The initial Lower Extremity Functional Scale questionnaire score of 65/80
improved to 80/80. Lower extremity kinematics for
peak hip adduction and internal rotation improved
from 15.9 degrees and 12.8 degrees to 5.8 degrees
and 5.9 degrees, respectively, during a step-down
task. DISCUSSION: This case highlights an alternative view of the pathomechanics of piriformis
syndrome (overstretching as opposed to overshortening) and illustrates the need for functional movement analysis as part of the examination of these
patients. LEVEL OF EVIDENCE: Therapy, level 4.
Han, Y.J., Jeon, S.Y., Moon, H.S., & Sung, C.H.
(2010). Post-radiation piriformis syndrome in a
cervical cancer patient: A case report. The Korean Journal of Pain, 23(1), 88-91.
PMID: 20552082
Available in full-text at: http://www.ncbi.nlm.nih.
gov/pmc/articles/PMC2884211/pdf/kjp-23-88.pdf.
ABSTRACT: The piriformis syndrome is a condition allegedly attributable to compression of the sciatic nerve by the piriformis muscle. Recently, magnetic resonance neurography and electrophysiologic
study have helped to diagnose piriformis syndrome.
High dose radiotherapy could induce acute and delayed muscle damage. We had experienced piriformis syndrome with fatty atrophy of piriformis muscle after radiotherapy for recurrent cervical cancer.
Kallitsis, E.A., Kanakis, D.N., Lazaris, A.C., Papadopoulos, E.C., Paraskevakou, H.A., & Patsouris,
E.S. (2010). Piriformis syndrome: An attempt to
understand its pathology. Clinical Neuropathology, 29(2), 65-70.
PMID: 20175954
ABSTRACT: OBJECTIVE: Gross anatomy of the
hip rotators and histology of the sciatic nerves in
adult cadavers were studied, aiming to the identification of possible pathologic changes related to the
piriformis syndrome (PS). MATERIAL: 50 cadavers were dissected; in 17 cases with macroscopical
findings the sciatic nerves were harvested (34 sciatic nerves; 17 cadavers). History of low back or leg
pain was not available. METHOD: Site anatomy
and additional findings at the harvesting sites were
recorded, such as anatomical variations, adhesions,
hematomas etc. All nerves were additionally microscopically analyzed. In cases with findings at the dis-
Page 25
section, the contralateral unaffected nerves served as
controls. All the dissected nerves were conserved in
10 percent formalin solution, embedded in paraffin,
stained with Hematoxylin and Eosin (H&E) and immunolabeled with antibodies against Neurofilament
(NF). RESULTS: Both the H&E staining as well as
the performed immunohistochemistry showed, to a
variable degree, significant alterations in the structure of the affected nerves compared to the controls.
CONCLUSIONS: These findings both in the local
anatomy and sciatic nerve correspond to lesions that
are expected in PS. Nevertheless, since this was a
cadaveric study, unassociated to a certain pain patient’s history, results should be considered and interpreted as an indication of a sciatic nerve injury in
PS.
2009 – NEW!
Akbas, M., Dere, K., & Luleci, N. (2009). A rare
cause of a piriformis syndrome. Journal of Back
and Musculoskeletal Rehabilitation, 22(1), 55-8.
PMID: 20023365
Available in full-text at: http://tinyurl.com/z6a786e.
ABSTRACT: BACKGROUND AND OBJECTIVE: A less common but important cause of buttock and leg pain known as “Piriformis Syndrome”.
Piriformis syndrome is all intrinsic pathology of the
piriformis itself, such as myofascial pain, anatomical
variations, hypertrophy, and myositis ossificans or it
is caused by trauma to the pelvis or buttock. In this
case report we are going to present a rare cause of
piriformis syndrome. CASE REPORT: Our first case
was a 32 year old woman. She was referred to our
pain clinic for leg pain that radiates from buttock to
backside of the knee for five years. She did not have
any problems in her history or laboratory findings.
But in her lower extremity ortho roentgenogram, her
leg was 2 cm short at the effected side. Second case
was a 23 year old woman who had pain radiating
from gluteal region to backside of the knee. In her
history she had a car accident two years ago. In this
accident, she had a fracture of collum femoris, and
her leg was 1 cm short at the effected side. CONCLUSION: We conclude that “short leg” is one of
the rare causes of piriformis syndrome and can be
seen alone or with the other causes. The injection
on piriformis muscle could be more effective for the
patients who have PS after the “short leg” treated.
Al-Tannir, M., Daher, Y., El-Rajab, M., Khatib, H.,
Naja, Z., Tayara, K., & Ziade, F. (2009). The effectiveness of clonidine-bupivacaine repeated
nerve stimulator-guided injection in piriformis
syndrome. The Clinical Journal of Pain, 25(3),
199-205.
PMID: 19333169
ABSTRACT: OBJECTIVES: Piriformis syndrome
(PS) is often refractory to conventional therapies.
Guided injection techniques generally necessitate
a computed tomography or fluoroscopic guidance
that may not be available in most pain management
centers in addition to its relative high cost. The aim
of this clinical trial is to investigate whether clonidine-bupivacaine nerve-stimulator guided injections
are effective in achieving long-lasting pain relief in
PS compared with bupivacaine guided injection.
METHODS: A pilot study conducted on 18 patients
(15 females, 3 males) diagnosed with PS showed
the adequacy of nerve stimulator guided technique
assessed via confirmatory visualized tomography
scan demonstrating a worthy coverage of the piriformis muscle in about 84 percent of the cases. This
randomized double-blind trial included 80 patients
with PS who received a nerve stimulator-guided
piriformis injection (group C received 9 mL bupivacaine 0.5 percent and 1 mL clonidine 150 mcg/
mL; group B received 9 mL bupivacaine 0.5 percent
and 1 mL saline). Pain characteristics and analgesics
consumption were the primary end points assessed
for 6 months. RESULTS: Group C showed significantly lower pain scores and analgesics consumption than group B (P<0.0001). Pain at 6 months was
significantly greater in group B (78 percent) than in
group C (8 percent) (P<0.01). For every 18 months
of PS pain, the outcomes demonstrated that a patient
needed 1 additional injection to the initial injection.
DISCUSSION: Repeated clonidine-guided piriformis injection relieved PS symptoms and reduce
analgesic consumption for a 6-month period. It is a
cost-effective useful treatment for PS refractory to
traditional therapeutic approaches.
Page 26
Cole, J.L., Foye, P.M., & Kirschner, J.S. (2009).
Piriformis syndrome, diagnosis and treatment.
Muscle Nerve, 40(1), 10-8.
PMID: 19466717
ABSTRACT: Piriformis syndrome (PS) is an uncommon cause of sciatica that involves buttock pain
referred to the leg. Diagnosis is often difficult, and
it is one of exclusion due to few validated and standardized diagnostic tests. Treatment for PS has historically focused on stretching and physical therapy
modalities with refractory patients also receiving
anesthetic and corticosteroid injections into the piriformis muscle origin, belly, muscle sheath, or sciatic
nerve sheath. Recently, the use of botulinum toxin
(BTX) to treat PS has gained popularity. Its use is
aimed at relieving sciatic nerve compression and
inherent muscle pain from a tight piriformis. BTX
is being used increasingly for myofascial pain syndromes, and some studies have demonstrated superior efficacy to corticosteroid injection. The success
of BTX in treating PS supports the prevailing pathoanatomic etiology of the condition and suggests a
promising future for BTX in the treatment of other
myofascial pain syndromes.
Chen, R.N., & Chen, Y.B. (2009). Clinical observation on therapeutic effect and instant analgestic effect of inhibitory-needling at Ashi point
as major point for treatment of piriformis syndrome. [Article in Chinese]. Chinese Acupuncture
& Moxibustion, 29(7), 550-2.
PMID: 19835123
ABSTRACT: OBJECTIVE: To observe therapeutic effect and analgesic eJfect of needling at Ashi
point for treatment of piriformis syndrome. METHODS: Eighty cases were randomly divided into
an inhibitory-needling method group (INM) and a
routine-needling method group (RNM), forty cases
in each group. The acupuncture at Ashi point as
major point with inhibitory-needling munipulation
was applied in the INM group, the acupuncture at
Huantiao (GB 30) ,Zhibian (BL 54) ,Yanglingquan
(GB 34) with routine-needling method in the RNM
group. The therapeutic effect, the instant analgesic
effect and score of Visual Analogue Scale (VAS)
were observed. RESULTS: After treatment, the effective rate of 92.5 percent in the INM group was
better than that of 82.5 percent in the RNM group (P
< 0.05); the instant analgesic effect rate of 75.0 percent in the INM group was better than that of 52.5
percent in the RNM group (P < 0.01); the score of
VAS in both groups had decreased with a significant
difference between two groups (P < 0.05). CONCLUSION: The treatment of inserting the needle at
Ashi point as major point with inhibitory-needling
method has excellent effectiveness and good instant
analgesic effect, with fewer point(s) selection and
rapid effect.
Ganju, A., & Halpin, R.J. (2009). Piriformis syndrome: A real pain in the buttock? Neurosurgery,
65(4 Suppl), A197-202.
PMID: 19927068
ABSTRACT: OBJECTIVE: Herein, we provide
an unbiased review of piriformis syndrome (PS), a
highly controversial syndrome for which no consensus exists regarding diagnostic criteria or pathophysiology. METHODS: A review of the literature in the
English language. RESULTS: A nonpartisan review
of the medical literature pertaining to PS revealed
that the existence of this entity remains controversial. There is no definitive proof of its existence
despite reported series with large numbers of patients. CONCLUSION: PS remains a controversial
diagnosis for sciatic pain. The debate regarding the
clinical significance of PS remains active. Nonetheless, there may be a subset of patients in whom the
piriformis muscle is a source of pain. The syndrome
should be considered in the differential diagnosis of
patients with unilateral lower extremity pain.
Zou, Z. (2009). Fifty-two cases of the piriformis
syndrome treated by centro-square needling.
Journal of Traditional Chinese Medicine, 29(1), 112.
PMID: 19514181
Full-text is available at: http://www.journaltcm.
com/modules/Journal/contents/stories/091/4.pdf.
No abstract is available.
Page 27
2008 – NEW!
Alonso, J., de Dios, B.J, Redondo, M.V., Reus, M.,
& Vázquez, V. (2008). Piriformis syndrome: A
simple technique for US-guided infiltration of the
perisciatic nerve. Preliminary results. European
Radiology, 18(3), 616-20.
PMID: 17972081
ABSTRACT: The piriformis syndrome is an uncommon cause of sciatica, buttock or thigh pain.
Because of the deep location of the muscle and sciatic nerve, infiltration has traditionally been guided
by electromyography, fluoroscopy, computed tomography or magnetic resonance imaging. The aim
of the present study is to describe a simple technique for ultrasound (US)-guided perisciatic infiltration of corticosteroids and anaesthetic using the
inferior gluteal artery as a landmark. This technique
was used satisfactorily in ten patients. Although the
series in the study is limited, the procedure for USguided infiltration of the perisciatic nerve is a quick,
simple, economical and effective technique and can
be considered an alternative in the percutaneous
treatment of the piriformis syndrome.
Boyajian-O’Neill, L.A., Coleman, M.K., McClain,
R.L., & Thomas, P.P. (2008). Diagnosis and management of piriformis syndrome: An osteopathic
approach. Journal of the American Osteopathic
Association, 108(11), 657-64.
PMID: 19011229
Available in full-text at: http://jaoa.org/article.
aspx?articleid=2093614.
ABSTRACT: Piriformis syndrome is a neuromuscular condition characterized by hip and buttock
pain. This syndrome is often overlooked in clinical
settings because its presentation may be similar to
that of lumbar radiculopathy, primary sacral dysfunction, or innominate dysfunction. The ability to
recognize piriformis syndrome requires an understanding of the structure and function of the piriformis muscle and its relationship to the sciatic nerve.
The authors review the anatomic and clinical features of this condition, summarizing the osteopathic
medical approach to diagnosis and management. A
holistic approach to diagnosis requires a thorough
neurologic history and physical assessment of the
patient based on the pathologic characteristics of
piriformis syndrome. The authors note that several
nonpharmacologic therapies, including osteopathic
manipulative treatment, can be used alone or in conjunction with pharmacotherapeutic options in the
management of piriformis syndrome.
Filler, A.G. (2008). Piriformis and related entrapment syndromes: Diagnosis & management.
Neurosurgery Clinics of North America, 19(4), 60922.
PMID: 19010285
ABSTRACT: Highly reliable evidence for piriformis syndrome and other pelvic sciatic syndromes
arises from three major categories of data: magnetic resonance neurography diagnostic imaging,
open magnetic resonance-guided injection studies,
and patient treatment outcome studies. This article
reviews the evidence in each category. This is part
of a Point-Counterpoint discussion with Dr. Robert
Tiel’s presentation of “Myth and Fallacy”.
Gruen, G.S., Kobbe, P., & Zelle, B.A. (2008). Case
report: Recurrent piriformis syndrome after
surgical release. Clinical Orthopaedics and Related Research, 466(7), 1745-8.
PMID: 18264837
Available in full-text at: http://www.ncbi.nlm.nih.
gov/pmc/articles/PMC2505267/pdf/11999_2008_
Article_151.pdf.
ABSTRACT: Piriformis syndrome is an uncommon condition characterized by sciatic nerve entrapment at the greater sciatic notch. Nonoperative
treatment such as physical therapy, nonsteroidal
antiinflammatory drugs, and local injections often
results in relief of symptoms. For patients who do
not benefit from nonoperative therapy, surgical exploration and decompression of the sciatic nerve has
been effective. However, the success of surgery may
be diminished by scar formation or hematoma in the
anatomically restricted sciatic notch. We report two
patients with piriformis syndrome who responded
primarily to surgical decompression and had recurrent symptoms resulting from scar tissue formation
in the sciatic notch. On revision surgery, polytetrafluoroethylene pledgets were placed around the sciatic nerve to avoid compression and entrapment by
scar tissue. Both patients had satisfactory outcomes
at three year follow-up.
Page 28
Tiel, R.L. (2008). Piriformis and related entrapment syndromes: Myth & fallacy. Neurosurgery
Clinics of North America, 19(4), 623-7.
PMID: 19010286
This article explores the myths surrounding piriformis syndrome. It looks at the syndrome’s history
ranging from early hypothesis to acceptance; then
from disfavor to resurrection as a diagnosis for patients with leg pain devoid of objective neurologic
deficits, without disc herniations. It includes a critical review of the clinical literature and treatment
strategies. It calls for a renaming of the syndrome to
“nonlocalizing sciatica” and restriction of surgical
resection of the piriformis to cases where all other
treatment has failed. This is part of a Point-Counterpoint discussion with Dr. Aaron Filler’s presentation
of “Diagnosis and Management”.
2007 – NEW!
Anderhuber, F., Braun, E.M., & Windisch, G.
(2007). Piriformis muscle: Clinical anatomy and
consideration of the piriformis syndrome. Surgical and Radiologic Anatomy (SRA), 29(1), 37-45.
PMID: 17216293
ABSTRACT: Patients with lumbosacral and buttock pain provide tacit support for recognizing the
piriformis muscle as a contributing factor to the pain
(piriformis syndrome). One hundred and twelve
cadaveric specimens were observed to elucidate
the anatomical variations of the piriformis muscle
referred to the diagnostic and treatment of the piriformis syndrome. The distance between the musculotendinous junction and the insertion was measured
and the piriformis categorized into three types: Type
A (71, 63.39 percent): long upper and short lower
muscle belly; Type B (40, 35.71 percent): short upper and long lower muscle belly; Type C (1, 0.9 percent): fusion of both muscle bellies at the same level. The diameter of the piriformis tendon at the level
of the musculotendinous junction ranged from 3 to
9 mm (mean: 6.3 mm). The piriformis showed the
following possible fusions with adjacent tendons. In
type one (60, 53.57 percent) a rounded tendon of the
piriformis reached the upper border of the greater
trochanter. In type two (33, 29.46 percent) it first
joined into the gemellus superior tendon and at last
both fused with the obturator internus tendon and inserted into the medial surface of the greater trochan-
ter. A fusion of the piriformis, obturator internus
and gluteus medius tendon with the same insertion
area as above was observed in type three (15, 13.39
percent) and finally in type four (4, 3.57 percent)
the tendon fused with the gluteus medius to reach
the upper surface of the greater trochanter. Based on
this survey anatomical causes for the piriformis syndrome are rare and a more precise workup is necessary to rule out more common diagnosis.
Ho, J., Kang, H.Y., Kim, K.I., Lee, S.H., Oh, J.M.,
Shin, W.G., & Yoon, S.J. (2007). Low-dose botulinum toxin type A for the treatment of refractory
piriformis syndrome. Pharmacotherapy, 27(5),
657-65.
PMID: 17461700
ABSTRACT: STUDY OBJECTIVES: To evaluate
the efficacy of a single, low-dose injection of botulinum toxin type A in relieving pain in Korean patients with piriformis syndrome resistant to conventional therapy, and to assess the drug’s influence on
these patients’ quality of life. DESIGN: Prospective,
single-site, open-label trial. SETTING: Rehabilitation medicine clinic in Seoul, Korea. PATIENTS:
Twenty-nine patients with a confirmed diagnosis of
chronic piriformis syndrome and 82 age- and sexmatched healthy subjects were enrolled from April
1, 2003-February 28, 2004. Intervention. In 20 of
the patients, botulinum toxin type A 150 U was injected using computed tomographic guidance into
the affected unilateral piriformis muscle. The other
nine patients served as active controls and received
an injection of dexamethasone 5 mg and 1 percent
lidocaine. The healthy subjects did not receive any
injection. MEASUREMENTS AND MAIN RESULTS: The patients’ pain at baseline and at 4, 8,
and 12 weeks after treatment was rated by using a
numeric rating scale. Health-related quality of life
was assessed by using the validated Korean version
of the Medical Outcomes Study 36-Item Short Form
Health Survey (SF-36) at baseline and at 4 weeks of
treatment. Healthy subjects also completed the SF36 at baseline. Pain intensity scores were significantly lower at 4, 8, and 12 weeks after treatment than at
baseline (p<0.0001). Baseline scores from the SF36 subscales, including those for physical functioning (p<0.0001), role physical (p<0.0001), bodily
pain (p<0.0001), general health (p<0.0001), vitality (p<0.0001), and social functioning (p<0.002),
Page 29
were significantly lower in the patients than in the
healthy subjects. Four weeks after treatment, physical functioning (p=0.003), role physical (p=0.021),
bodily pain (p=0.016), general health (p=0.013),
vitality (p=0.031) and social functioning (p=0.035)
improved significantly from baseline in the patients.
However, at 4 weeks, patients in the active control
group were withdrawn from the study because their
pain did not improve, and continuation without further medical care was considered unethical. CONCLUSION: A low dose of botulinum toxin type A
relieved pain and improved quality of life in patients
with refractory piriformis syndrome.
2006
Descarreaux, M., Fortin, J., Mayrand, N., & Normand, M.C. (2006). Diagnosis and management
of posttraumatic piriformis syndrome: A case
study. Journal of Manipulative and Physiological
Therapeutics, 29(6), 486-91.
PMID: 16904496
ABSTRACT: OBJECTIVE: The aim of this study
is to describe the clinical management of a young
male patient with sciatica symptoms that developed
after an avulsion of the ischial tuberosity. This is a
rare injury, but complications may occur. CLINICAL FEATURE: A 19-year-old patient developed
sciatica 6 months after a football injury. The patient
described his symptoms as a shooting pain from
the buttock to the lateral part of the foot, along the
back of his thigh and calf, sometimes accompanied
by paresthesia. Physical examination showed restricted hip range of motion and a positive Bonnet’s
test. X-ray analysis revealed a bony overgrowth of
the right ischial tuberosity. INTERVENTION AND
OUTCOME: A treatment plan was designed to decrease the pain level, increase sacroiliac and lumbar
joint mobility, and augment muscular extensibility.
The patient received 20 treatments over a period of
approximately 3 months. Complete recovery was
observed 5 months later. CONCLUSION: Although
many differential diagnoses were contemplated, it
is most likely that changes in muscular tension and
gait pattern, resulting from the ischial tuberosity
avulsion, contributed to overuse of the piriformis
muscle leading to a piriformis syndrome.
Quick Looks
Online Resources Related to
Piriformis Syndrome
Piriformis syndrome (PS) is a rare neuromuscular
disorder that occurs when the piriformis muscle
compresses or irritates the sciatic nerve causing
pain, tingling, and numbness in the buttocks and
along the path of the sciatic nerve descending into
the lowering thigh and into the leg. Unfortunately,
there are little to no support/organizational resources
for individuals experiencing this syndrome. However, there are various informational websites that
provide an overview of PS, detail the condition, and
offer suggestions for treatment and/or exercises.
As always, we provide these resources as a service
to our patrons but strongly recommend consulting
with a medical professional before attempting any
self-treatment or exercises on your own.
5 Things to Know About the Piriformis Stretch
from Healthline.com
http://www.healthline.com/health/fitness-exercise/
piriformis-stretch#2.
Find an Orthopaedist Through the American
Academy/Association of Orthopaedic Surgeons
http://www7.aaos.org/member/directory/search.
aspx?directory=public.
Google Video Search Results for Exercises for
Piriformis Syndrome
http://tinyurl.com/j2dlvkb.
How Can I Banish That Pain in My Butt?
in Runner’s World at RunnersWorld.com
http://www.runnersworld.com/injury-preventionrecovery/how-can-i-banish-that-pain-in-my-butt.
Continued on next page ...
Page 30
Information about Diagnosis and Treatment of
Piriformis Syndrome from Orthopedics.about.
com
http://orthopedics.about.com/cs/sprainsstrains/a/
piriformis.htm.
Piriformis Syndrome Information Sheet
from TherapeuticAssociates.com
Includes diagrams for exercises to help PS and to
strengthen the piriformis muscle
http://www.therapeuticassociates.com/wp-content/
uploads/GFLF_Rehab_Piriformis.pdf.
Move Forward by the American Physical
Therapy Association
Find a Physical Therapist: http://aptaapps.apta.org/
findapt/index.aspx.
http://www.moveforwardpt.com/Default.aspx.
Piriformis Syndrome from Physiopedia.com
Includes videos, diagrams for stretches and
maneuvers
http://www.physio-pedia.com/Piriformis_Syndrome.
National Center for Complementary and
Integrative Health (NCCIH)
Toll Free: 888/644-6226 (V), 866/464-3615 (TTY)
Pain Information Page: http://nccih.nih.gov/health/
pain.
http://ccih.nih.gov.
Piriformis Syndrome: A Royal Pain in the Butt
on MultiBriefs.com (Video Included)
http://exclusive.multibriefs.com/content/piriformissyndrome-a-royal-pain-in-the-butt/sports-fitness.
Continued from previous page ...
National Center on Health, Physical Activity, and
Disability (NCHPAD)
An information center concerned with physical activity and disability.
Toll Free: 800/900-8086 (V/TTY)
NCPAD Program Database:
http://www.nchpad.org/Directories/Programs.
NCPAD Parks Database:
http://www.nchpad.org/Directories/Parks.
NCPAD Personal Trainers Database:
http://www.nchpad.org/Directories/19/Personal~
Trainers.
NCPAD Factsheets on Exercise and Fitness:
http://www.nchpad.org/Articles.
http://www.nchpad.org.
Physical Medicine and Rehabilitation for
Piriformis Syndrome from Medscape.com
http://emedicine.medscape.com/article/308798overview.
Piriformis Syndrome: How to Detect It and
Strengthening and Stretching Programs to Help
You Heal on RunnersConnect.net
http://runnersconnect.net/running-injury-prevention/piriformis-syndrome-running.
Piriformis Syndrome Information at
SportsInjuryClinic.net
http://www.sportsinjuryclinic.net/sport-injuries/hipgroin-pain/piriformis-syndrome.
Piriformis Syndrome from WebMD Pain
Management Health Center
http://www.webmd.com/pain-management/guide/
piriformis-syndrome-causes-symptoms-treatments.
Stretches and Exercise for Sciatic Pain from
Piriformis Syndrome from Spine-Health.com
Includes video and diagrams for stretches and maneuvers
http://www.spine-health.com/wellness/exercise/
stretches-and-exercise-sciatic-pain-piriformis-syndrome.
What is Piriformis Syndrome? on
Spine-Health.com
http://www.spine-health.com/conditions/sciatica/
what-piriformis-syndrome.
Page 31
Search Terms for the Revisiting Piriformis Syndrome

Acupuncture/Methods/Needles/Points
Therapy

Analgesics

Anti-Inflammatory Agents

Arthritis

Arthroscopy

Athletic Injuries

Back Pain/Complication/Diagnosis/Lower

Biomechanical Phenomena

Botulinum Toxins/Administration
Therapeutic/Type

Buttocks

Case-Control Studies

Chiropractic

Chronic Disease

Clinical Management

Decompression/Surgical

Diagnosis

Diagnostic Imaging

Double-Blind Method

Drug Combinations/Therapy

Electric Stimulation Therapy (EST)

Electromyography/Physiology

Evaluation Techniques

Exercise/Methods/Therapy

Feasibility Studies

Fluoroscopy

Functional Evaluation

Hip Joint

Impingement

Injections/Epidural/Intramuscular/Methods

Injury

Intervertebral Disk Displacement

Ischium

Leg Pathology

Limbs

Longitudinal Studies

Magnetic Resonance Imaging (MRI)

Manipulation/Osteopathic Methods

Measurements

Movement/Physiology

Muscle/Piriformis/Spasms/Stretching

Muscular Diseases/Impairments

Myography

Nerve Block

Nerve Compression Syndromes

Neural Conduction

Neuromuscular Agents/Diseases

Neuroradiography

Osteopathic Medicine

Outcomes
Pain/Management/Measurement/Therapy


Peripheral Nerves

Physical Examination

Physical Therapy/Modalities

Piriformis Syndrome

Postoperative Complications

Prevalence

Prospective Studies

Radiography/Methods

Randomized Controlled Trials

Rehabilitation

Resistance Training/Methods

Retrospective Studies

Sacrococcygeal Region

Sacroiliac Joint

Sciatic Nerve/Neuropathy

Sciatica/Diagnosis/Surgery/Therapy

Spinal Nerve Roots

Sports-Related

Surgical Procedures

Systematic Review

Tendons/Anatomy

Tomography/Methods/X-Ray Computed

Treatment

Ultrasonography/Methods
About reSearch:
reSearch is an information product from the National Rehabilitation Information
Center (NARIC). Each issue is based on real-world queries received by our information
specialists from researchers, educators, and rehabilitation professionals around the world.
We search several sources both in-house and online, to fill these requests including:

REHABDATA and the NIDILRR Program database

Education Resources Information Center
 National Clearinghouse of Rehabilitation Training Materials
 Campbell and Cochrane Collaborations
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