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PAIN MEDICINE
Volume 10 • Number 1 • 2009
PRELIMINARY RESEARCH
Pulsed Radiofrequency Lesioning of the Suprascapular Nerve for
Chronic Shoulder Pain: A Preliminary Report
Po-Chou Liliang, MD,* Kang Lu, MD, PhD,* Cheng-Loong Liang, MD,* Yu-Duan Tsai, MD,*
Ching-Hua Hsieh, MD,† and Han-Jung Chen, MD, PhD*
*Department of Neurosurgery, E-Da Hospital, I-Shou University and †Department of Trauma and Emergency Surgery,
Chang Gung Memorial Hospital in Kaohsiung, Kaohsiung, Taiwan
Objective. Chronic shoulder pain is difficult to treat, and the efficacy of most interventions is limited.
This study was conducted to evaluate pulsed mode radiofrequency (PRF) lesioning of the suprascapular nerve for treating chronic shoulder pain.
Interventions. Thirteen procedures using PRF lesioning of suprascapular nerve were performed
under fluoroscopic guide in 11 patients (13 shoulder joints) with chronic shoulder pain for at least
3 months.
Outcome Measures. The patients were evaluated for pain, shoulder disability function, and medication requirements prior to and after treatment.
Results. At 1-month follow-up assessment, 10 (76.9%) shoulder joints had significant pain relief
(visual analog scale ⱖ 50% reduction), and at 6-month follow-up assessment, nine (69.2%) still had
significant pain relief. The mean VAS score of 11 patients before PRF was 7.5 ⫾ 1.0, and the scores
at 1-month and 6-month follow-up were 2.8 ⫾ 2.6 and 2.5 ⫾ 2.8, respectively. A significant pain
reduction (P < 0.001) was observed. The mean Shoulder Pain and Disability Index scores at
6-month follow-up also showed a significant decrease compared with pre-PRF (P < 0.001). Medication requirements were evaluated 1 month and 6 months after the PRF. Nine (81.8%) patients had
their medication requirement decreased.
Conclusions. Pulsed mode radiofrequency lesioning to suprascapular nerve is a potential treatment
option for patients suffering chronic shoulder pain. It provides long-lasting pain relief and decreases
pain medication requirements.
Key Words. Radiofrequency; Suprascapular Nerve Block; Shoulder Pain
Introduction
C
hronic shoulder pain is common in the community that may cause an important functional disability. There are many conservative
treatments in managing for this problem, includ-
Reprint requests to: Po-Chou Liliang, MD, No. 1, E-Da
Road, Jiau-Shu Tsuen, Yan-Chau Shiang, Kaohsiung
County, 824, Taiwan. Tel: 886-7-6150011; Fax: 886-76150982; E-mail: [email protected].
© American Academy of Pain Medicine 1526-2375/09/$15.00/70 70–75
ing physiotherapy, nonsteroidal anti-inflammatory
drugs (NSAIDs) and intra-articular corticosteroid
injections; however, evidence of their efficacy is
limited [1].
Suprascapular nerve block using local anesthetics and steroids has been successful in treating
chronic shoulder pain from degenerative disorders
and inflammatory diseases [2–4]. The results
support the hypothesis that the suprascapular
nerve is an important mediator of shoulder pain.
doi:10.1111/j.1526-4637.2008.00543.x
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ABSTRACT
71
Pulsed Radiofrequency Lesioning
Diagnostic Suprascapular Nerve Blocks
We performed suprascapular blocks in 19 patients
(using 0.5% Bupivacaine). Thirteen patients
(69%) had positive results (50% or more pain
relief following diagnostic blocks). Of these 13
patients, two did not receive PRF lesioning procedures. One did not have a similar shoulder pain
after the suprascapular block, and another was
reluctant to receive PRF after diagnostic block.
After positive results of diagnostic suprascapular
nerve blocks, the patients were scheduled for PRF
lesioning of the suprascapular nerve.
However, the effects of suprascapular nerve block
using corticosteroids are limited in duration [2–4].
Thus, the long-term efficacy of corticosteroids is
limited.
Pulsed mode radiofrequency (PRF) lesioning is
a nonneurolytic lesioning method for pain relief
and can relieve pain without evidence of neural
damage. Some preliminary reports support its
long-term efficacy in pain relief [5–7].
Shoulder pain is rarely treated by PRF lesioning
[8–10]. This study reports the use of PRF lesioning to treat 11 (13 shoulder joints) patients with
intractable shoulder pain who had previously
failed to respond to conventional therapy.
Right coracoid process
Methods
This study was approved by the institutional
review board (E-Da Hospital). Informed consent
was obtained from all patients. This study
included 11 patients (13 joints) received PRF
lesioning for chronic shoulder pain from June to
October 2006. The patients were referred by
medical practitioners, neurosurgeons, orthopedists, and physiotherapists for treatment. They
had exhausted conservative therapies, including
oral analgesics, intra-articular corticosteroid injections, and physical therapy. All patients were 18
years old and above and had experienced shoulder
pain for at least 3 months.
Right suprascapular
notch
Right scapular spine
Figure 2 Anteroposterior view of radiograph showing the
correct placement of a radiofrequency needle to block the
suprascapular nerve.
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Figure 1 Path of suprascapular nerve in relation to scapula
and radiofrequency needle.
PRF Lesioning Procedures
In order to perform the surgical procedure under
strict sterile conditions, the PRF lesioning procedure was performed in the operating room. Each
patient was placed in a prone position, and the skin
overlying the operation area was prepared and
draped.
A standard RF lesion generator (Neurotherm
JK 25T) was used for the whole procedure. The
suprascapular notch was identified under C-arm
fluoroscopy at an angle slightly oblique to the
treated side and angled cephalo-caudal [8]. After
sterile preparation and administration of local
anesthesia, a 22-gauge 10 mm active tip RF needle
10 cm in length was inserted and advanced toward
the suprascapular notch (Figures 1 and 2). Proper
localization of nerve was achieved by sensory and
motor stimulation. Sensory stimulation was per-
72
Liliang et al.
Outcome and Follow-Up
Patients were observed in the outpatient department for a minimum follow-up period of 6 months
after discharge. Patients were encouraged to enter
a rehabilitation program after discharge. The
patients were evaluated for pain relief, functional
disability, medication requirements and pre- and
postprocedure complications. The response to
PRF was independently assessed by a nurse who
was not involved in the performance of the procedure. Changes in pain were recorded by using a
visual analog scale (VAS) ranging from 0 (no paint)
to 10 (extremely severe pain). Improvements of
VAS ⱖ50% were considered substantial pain
relief. Pre- and postoperative pain and disability
relating to the shoulder were measured by the
Shoulder Pain and Disability Index (SPADI) [11].
Pain medication requirements were recorded on a
scale from 0 to 4 (0 = no medication, 1 = over-thecounter medications, 2 = nonnarcotic prescription
medications, 3 = narcotic medications, 4 = rou-
tinely narcotic medications). Scale decreased by at
least 1 point was considered to have a decreased
medication requirement. Pre and post PRF, VAS
and SPADI scores were compared using Paired
samples t-test. The results were considered significant if P values were less than 0.05. The data were
analyzed using the spss 12.0 software package.
Results
Tables 1 and 2 present the details of clinical characteristics, managements, outcomes, and complications for all subjects. Eleven patients (five male,
six female) with 13 painful shoulders (eight right,
five left) were treated by PRF lesioning. Two
patients (patients 3 and 11) had bilateral chronic
shoulder pain. The mean age was 43.7 ⫾ (SD)
14.2, ranging from 24 to 67 years. The mean pain
duration was 41.6 ⫾ 43.2 months, ranging from 3
to 120 months.
Of the 11 patients who underwent PRF lesioning, two had pain recurrence before the end of
the 6-month follow-up and required a repeat RF
procedure. This occurred after the 1-month
follow-up in patient 10 and after the 4-month
follow-up in patient 2. At 1-month follow-up
assessment, 10 (76.9%) shoulder joints had significant pain relief. One patient (patient 9) reported
no significant improvement. One patient (patient
3) experienced substantial pain reduction (VAS
8→4) in her left shoulder but no improvement in
right shoulder. One patient (patient 10) had substantial pain relief (VAS 7→2) for only 4 weeks and
underwent a repeat PRF procedure 6 weeks later.
Patient 2 had significant pain relief for 4 months
and underwent a subsequent PRF procedure after
pain recurrence. Subsequent PRF procedure
Table 1 Clinical characteristics, treatment, and complications for patients with chronic shoulder pain for whom a
pulsed radiofrequency lesioning was performed
Patient
No.
Age/Gender/Side
Pain Duration
(Months)
Shoulder
Pathology
Treatment
before PRF
Treatment
after PRF
Complication
1
2
3
4
5
6
7
8
9
10
11
32/F/L
36/M/R
57/F/B
31/M/R
24/M/R
39/F/R
67/M/R
40/F/L
66/F/R
48/F/L
41/F/B
54
120
48
3
3
90
3
3
96
14
24
RCL
AC
AC
RCL
RCL
RCL
RCL
RCL
AC
AC
RCL
OA
OA, IAS, PT
OA
OA
OA
OA
OA
OA
OA
OA, PT
OA, PT
—
OA, PT
OA
—
PT
OA
—
—
OA
OA, PT
—
—
Wound pain
—
—
—
—
—
—
—
—
—
AC = adhesive capsulitis; B = bilateral; F = female; IAS = intra-articular steroid; L = left; M = male; M = month; OA = oral analgesics; PT = physical therapy;
R = right; RCL = rotator cuff lesion.
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formed, (50 hertz; 1 ms pulsed width; up to 0.5
volt) and the patient reported paresthesia in the
shoulder joint. Upon motor stimulation (2 hertz;
1 ms pulsed width; up to 1 volt), muscle contractions in the suprascapular and infrascapular
muscles were observed. Two PRF cycles of 180
seconds were performed after localization. The
RF current was delivered at a width of 20 ms and
at 45 V. The tip temperature worked at 38°C initially, and then the temperature increased slowly
to 42°C within 30 seconds. The patients were
observed for 30 minutes after the PRF lesioning
procedure. If there no significant complications
(including pain, bleeding and pneumothorax) were
observed, the patient was discharged.
73
Pulsed Radiofrequency Lesioning
Table 2 Outcomes measurements for patients with chronic shoulder pain for whom a pulsed radiofrequency lesioning
was performed
VAS Score
Medication Scale
SPADI-Pain Subscale
SPADI-Disability
Subscale
Patient No. Preoperative after 1 m after 6 m preoperative after 1 m after 6 m Preoperative After 6 m Preoperative After 6 m
1
2
3
4
5
6
7
8
9
10
11
(L)
(R)
(L)
(R)
1
2
4
8
0
2
2
2
1
7
6
2
0
2
3
4
8
0
1
1
0
0
6
7
1
0
1
4
2
0
2
2
0
2
2
64
80
72
14
40
68
43
75
40
8
63
23
2
1
2
1
1
3
2
2
0
0
1
0
0
2
2
0
0
0
0
0
0
2
3
0
40
52
66
42
46
62
60
46
0
12
10
4
0
48
68
10
20
20
45
38
23
50
43
31
0
5
9
14
0
43
45
5
L = left; m = month; R = right; SPADI = Shoulder Pain and Disability Index; VAS = visual analog scale.
reproduced good pain relief in these patients. At
6-month follow-up assessment, nine (69.2%)
shoulder joints still had significant pain relief.
Table 3 presents the VAS scores and SPADI
score before and after PRF of the 11 patients. The
mean VAS score of 11 patients before PRF was
7.5 ⫾ 1.0, and the score at 1-month and 6-month
follow-up were 2.8 ⫾ 2.6 and 2.5 ⫾ 2.8, respectively. A significant pain reduction (P < 0.001) was
observed at 1-month and 6-month follow-up.
There was no significant difference in VAS score
between 1 month and 6 months (P = 0.26). The
mean SPADI scores at 6-month follow-up also
showed a significant decrease compared with prePRF (P < 0.001).
The medication requirements were evaluated 1
month and 6 months after the procedure. Nine
(81.8%) patients had their medication requirement decreased.
Complications
No significant complications were observed except
one puncture wound pain (patient 2) which presented temporally for 1 week.
Discussion
This study of 11 cases of intractable chronic shoulder pain showed a clear benefit from the use
PRF lesioning of the suprascapular nerve. Nine
(69.2%) joints had significant pain relief lasting for
6 months. Even when the pain recurred, the procedure was easily repeated. This report is important for clinicians as chronic shoulder pain is not
only debilitating but also difficult to manage [1,2].
Medical treatment including simple analgesia,
NSAIDs, intra-articular steroid injection, and
surgery all have certain limitations [1].
The suprascapular nerve is a motor sensory
peripheral nerve arising from the upper trunk of
the brachial plexus (C5 and C6) and branching to
supraspinatus and infraspinatus muscles. This
suprascapular nerve sends sensory fibres to about
70% of the shoulder joint, including the superior
and posterosuperior regions of the shoulder joint
and capsule [12] as well as the acromioclavicular
joint. Afferent nociceptive input from the shoulder
joint is blocked through suprascapular nerve
blockage using local anesthetics and steroids.
Some studies have provided evidence that supras-
Table 3 Visual analog scale (VAS) and Shoulder Pain and Disability Index (SPADI) scores before and after pulsed
lesioning radiofrequency (PRF)
Measurements
Pre-PRF
After 1 m
After 6 m
P value
VAS score
SPADI-pain subscale
SPADI-disability subscale
7.5 ⫾ 1.0
57.3 ⫾ 13.0
38.9 ⫾ 15.9
2.8 ⫾ 2.6*
—
—
2.5 ⫾ 2.8*
24.9 ⫾ 26.2
21.4 ⫾ 6.4
P < 0.001
P < 0.001
P < 0.001
Data: mean ⫾ SD.
* Compared with Pre-PRF data.
m = month.
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8
9
8
8
8
7
8
6
7
9
7
7
6
74
In summary, PRF lesioning to suprascapular
nerve offers a treatment option with good outcomes for patients suffering from chronic shoulder
pain. When performed by experienced physicians,
PRF lesioning for suprascapular nerve is safe and
effective. The treatment offers lasting pain relief
and can augment a functional rehabilitation
program. Although this study produced successful
results, caution is advised in drawing conclusions
from this single study. Controlled, randomized
investigations with a larger sample size are necessary to further clarify the role of PRF in the treatment of chronic shoulder pain.
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capular nerve blockage is safe, effective, and promising for patients with acute and chronic shoulder
pain [2–4,12]. However, the shortcoming of
suprascapular nerve blockage is its short-lasting
pain relief. Although pain relief can be prolonged
by steroids, long-lasting pain reduction exceeding
12 weeks has not been reported [2–4].
Classic RF lesioning in which a constant high
temperature (60–80°C) is applied to target tissue
reduces chronic pain by nerve ablation. It can
provide long-lasting pain relief; however, irreversible damage to neural tissue could occur. Unlike
classic RF lesioning, PRF lesioning achieves pain
relief by delivering strong electric fields [13] (may
be capable of disrupting neuronal membranes and
function) and heat bursts with tip temperatures no
more than 42°C. Therefore, the risk of neural
damage and neuritis is minimized [14].
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and long-lasting analgesic technique. Exactly how
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the symptoms remains unclear. Many experimental works have attempted to elucidate the exact
analgesic mechanism of PRF lesioning. Recent
studies have examined electrical fields on upregulation of immediate early gene (IEG) and c-Fos
[16,17]. Application of PRF lesioning to the rat
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suprascapular nerve for the treatment of chronic
shoulder pain. Shah [8] and Gurbet [9] reported
that each PRF procedure provided at least 12
weeks of pain relief and improved shoulder function. Rohof had not provided detailed outcome
measurement [10]. Gurbet [9] only reported a
small series without long-term follow-up data. In
the current study, 69.2% joints had substantial
pain reduction for 6 months. Nine (81.8%)
patients had decreased medication requirements.
Only one patient suffered from puncture wound
pain, which was considered a minor complication
and presented temporally for 1 week. The present
study does suggest that at least partially relief of
chronic shoulder pain may be accomplished by
PRF. All patients were selected consecutively.
Long-term follow-up records were available for
pain and disability.
Liliang et al.
Pulsed Radiofrequency Lesioning
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