Download Role of osteotomy in knee ligament deficiency

Role of Osteotomy in ACL and PCL
Deficient Patients
Satyam Patel
Feb. 2007
mod. from Cole Beavis Nov. 2002
Outline
• Natural history of ACL and PCL deficient patients
• Principles of osteotomy in management of knee
instability and malalignment
• Management of combined knee instability and
malalignment
• Not discussed / deferred to future talk : role of
osteotomies in management of collateral ligament
related instability about the knee.
Natural History of ACL/PCL Deficient Knee
• Literature somewhat difficult to interpret
– Variety of factors influence natural history
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Meniscal tears
Chondral damage from original injury
Heterogeneous population (grades I-III)
Types of conservative treatments
– Outcome measures often difficult to measure
• “return to sport”
• “return to previous function”
Natural History of ACL Deficient Knee
• Generally agreed upon principles
– Gait altered
• “quadriceps avoidance”
– Repeated episodes of subluxation
• Meniscal and chondral damage
– Degenerative changes present in most patients
within 6-10 years of injury
• Worst in subset of patients with meniscal injury
• Medial compartment > lateral compartment
Natural History of ACL Deficient Knee
• Dejour - from Fu Knee Surgery
“…osteophyte and superficial destruction of cartilage
are likely to develop within 10 years in knees with
ACL rupture. Significant arthrosis develops after
longer periods (20-30 years). An additional meniscal
lesion or meniscectomy constitutes a turning point in
the evolution of arthrosis. The meniscal factor is not
the main factor; it is a contributory factor in the
evolution of arthrosis in the ACL deficient knee.”
Natural History of PCL Deficient Knee
• Commonly reported in the literature that the
natural history of isolated PCL deficiency is
benign
• Controversial
• Cadaveric and clinical studies have shown high
incidence of patellofemoral joint and medial
compartment arthrosis
Natural History of PCL Deficient Knee
• Miller, Bergfeld, Fowler, Harner, Noyes (ICL 99)
“…degenerative change is probably inevitable,
and that current surgical techniques cannot forestall
it. PCL injuries may not be as benign as we previously
thought, especially with advanced (grade 3) injuries.”
Principles of Tibial Osteotomy
Principles of Tibial Osteotomy
• Coventry
– established high tibial osteotomy as a treatment for
unicompartmental OA
• Goal of osteotomy
– to transfer joint forces from the arthritic compartment
to the more normal compartment
Principles of Tibial Osteotomy
• Mechanical axis
• line drawn from the center of hip rotation through the center
of the knee to the center of the ankle mortise
• a normal axis is a straight line
• Anatomic axis (tibiofemoral angle)
• obtained by the intersection of the lines drawn along the
shaft of the femur and tibia
• normally 5-7 degrees of valgus
Principles of Tibial Osteotomy
• Anatomic
– Comparison of femoral
and tibial shafts
– 5 - 7º valgus
• Mechanical
– Line of ground reaction
force transmission
– 0 - 1º varus
Principles of Tibial Osteotomy
• Mechanical Axis
– Location determines
percentage of load
carried in each
compartment
– In the normal knee 60%
of weight bearing is
through the medial
compartment
Principles of Tibial Osteotomy
• Type of osteotomy
– Medial compartment OA with varus deformity
• valgus-producing osteotomy
– Lateral compartment OA with valgus deformity
• varus-producing osteotomy
– Alteration in tibial slope for ligamentous deficiency
• Extension type for ACL deficient
• Flexion type for PCL deficient
Principles of Tibial Osteotomy
• Type of osteotomy
Extension
Valgus
Principles of Valgus Tibial Osteotomy
• Indications for valgus osteotomy
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pain unresponsive to conservative measures
isolated medial compartment OA
age < 60
no more than 10-15 of varus on WB film
pre-op ROM > 90
<15 of flexion contracture
Principles of Valgus Tibial Osteotomy
• Contraindications:
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narrowing of the lateral compartment
lateral tibial subluxation > 1cm
flexion contracture > 15 degrees
ROM < 90 degrees
> 20 degrees of correction needed
large varus thrust
inflammatory arthritis
tricompartmental arthritis
severe patellofemoral disease
Principles of Valgus Tibial Osteotomy
• Aim for mechanical axis to pass through medial 1/3
of lateral compartment
• Determine amount of correction
– Multiple recommendations for post-op valgus anatomic
alignment
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Fu
Vainionppa
Insall
Keene
5 - 13º
> 7º
10º
7 - 13º
– Most common reason for failure of osteotomy is
undercorrection
Principles of Tibial Osteotomy
• Technique
– Preop plan with long leg
weight bearing xrays
– Calculate size of wedge
using bone width and
trigonometry
– Traditionally, 1mm for 1º
correction
• Only valid for a 56mm
diameter metaphysis
Principles of Tibial Osteotomy
• Level of Tibial Osteotomy
– Above the tubercle (most common)
• High healing rates
• Limited degree of correction
– Below the tubercle
• Greater range of correction
• More bone proximally for fixation
• Lower healing rates
Valgus Closing Wedge
Valgus Closing Wedge
• Lateral wedge resection
• Hinge on medial cortex
• Can resect more bone
anteriorly to decrease
tibial slope (extension
type osteotomy)
– ACL deficiency
Valgus Closing Wedge
• Benefits
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Can compress across osteotomy
Quadriceps pull compresses osteotomy
No bone graft harvest site
No risk of bone graft shifting
Inherently more stable
• Drawbacks
– Shortens quads mechanism and leg
– Infrapatellar scarring
– Can unmask MCL laxity
Valgus Opening Wedge
Valgus Opening Wedge
• Medially based wedge
• Multiple variations in techniques
• Can incorporate anterior opening wedge
– Increases tibial slope (PCL deficiency)
Valgus Opening Wedge
• Advantages
– Useful with medial bone loss or MCL laxity
– Tensions MCL
• Drawbacks
– Limited compression
– Bone graft donor site morbidity
Fixation of Osteotomies
• Cast
• Staples
• Plate
– Compression, buttress
• External fixator
Osteotomies and ACL / PCL
Deficient Knees
Osteotomy and ACL Deficient Knees
• Valgus osteotomy
described in treatment of
unicompartmental
arthrosis associated with
ACL deficiency
– Shift mechanical axis
laterally and decrease
force through diseased
medial compartment
Osteotomy and ACL Deficient Knees
• Osteotomy has been
used in treatment of
instability
– Extension type to
decrease tibial slope and
anterior tibial translation
Osteotomy and ACL Deficient Knees
• Osteotomy has been
used in treatment of
instability
– Extension type to
decrease tibial slope and
anterior tibial translation
Osteotomy and ACL Deficient Knees
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Approach
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Patients with arthritic, ACL deficient knee and
failing conservative treatment
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3 groups of patients
1. Primary symptom is instability
2. Primary symptom is pain
3. Both pain and instability
Osteotomy and ACL Deficient Knees
• Primarily instability
Pain + Malalignment - 
ACL Reconstruction
Pain - Malalignment + 
Pain - Malalignment - 
Pain + Malalignment + 
Osteotomy and Reconstruction
ACL Reconstruction
Osteotomy and Reconstruction
Osteotomy and ACL Deficient Knees
• Primarily pain
Instability +
Instability Instability Instability +
Malalignment Malalignment +
Malalignment Malalignment +
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ACL Reconstruction
Osteotomy
?Arthroscopic debridement
Osteotomy and Reconstruction
Osteotomy and ACL Deficient Knees
• Technique
– Preoperative planning aiming for 8-10° of valgus
– Initial arthroscopy
• Assess articular surfaces
• Address meniscal pathology
– High tibial osteotomy
• Lateral closing wedge for most
• Medial opening wedge for MCL laxity
• Ensure fixation does not cross region of future tunnels
Osteotomy and ACL Deficient Knees
• Technique con’t
– ACL reconstruction follows osteotomy
• Staged or as part of same procedure
• Bone patellar tendon bone, hamstring and allograft
have all been reported
– Increased risk of patella baja with BTB
Osteotomy and ACL Deficient Knees
• Technique contd
– Postop combined procedure
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CPM immediately postop
Hinge brace locked in extension x 4 weeks; touch WB
Brace unlocked and WB progressed from 4-8 weeks
At 8 weeks postop brace discontinued and aggressive ACL
rehab program x 3-6 months
– Staged
• ACL follows 6 months after osteotomy
• Osteotomy hardware removed at time of ACL
Osteotomy and ACL Deficient Knees
• Outcomes
– Return to pre-injury level is rare
• Few reports of patients returning jumping, pivoting sports
– Those with severe pain should expect improvement
• 80-92% patient satisfaction
– Maximal benefit obtained in patients wishing to
return to light athletic activities
• 30-78% return to sports
Osteotomy and PCL Deficient Knees
• Few reports in literature
– Similar indications as for ACL with symptomatic
varus malalignment and unicompartmental disease
• PCL deficiency  medial and patellofemoral arthrosis
– Must select patients carefully
– Also described as treatment of posterolateral
instability with varus thrust in absence of arthrosis
• Correct mechanical axis prior to ligament reconstruction
Osteotomy and PCL Deficient Knees
• Increasing tibial slope has
been shown to decrease
tibial translation (sag)
– Anterior opening wedge
osteotomy
– Anteromedial opening
wedge to address tibial
slope and varus
malalignment
Osteotomy and PCL Deficient Knees
• Increasing slope by 50%
resulted in shift of resting
position of knee between
3-5mm (reduced posterior
sag)
• Few reports and no long
term results for this
technique
– Additional studies required
Biomechanical studies
• Am J Sports Med. 2004 Mar;32(2):376-82.
• Ten cadaveric knees were studied using a robotic testing system using
three loading conditions:
– (1) 200 N axial compression
– (2) 134 N A-P tibial load
– (3) combined 200 N axial and 134 N A-P loads
• Tibial slope was increased from 8.8 +/- 1.8 deg. to 13.2 +/- 2.1
degrees,
– anterior shift of tibia relative to femur (3.6 +/- 1.4 mm).
– Under axial compression, the osteotomy caused a significant anterior tibial
translation up to 1.9 +/- 2.5 mm (90 degrees ).
– Under A-P and combined loads, no differences were detected in A-P translation
or in situ forces in the cruciates (intact versus osteotomy)
Biomechanical studies
• Results suggest that small increases in tibial slope do
not affect A-P translations or in situ forces in the cruciate
ligaments.
• However, increasing slope causes an anterior shift in
tibial resting position that is accentuated under axial
loads.
• This suggests that increasing tibial slope may be
beneficial in reducing tibial sag in a PCL-deficient knee,
whereas decreasing slope may be protective in an ACLdeficient knee.
Biomechanical studies
• Am J Sports Med. 2006 Jun;34(6):961-7.
• 10 cadaveric knees: valgus HTO + anatomic double bundle ACL
reconstruction
• Anterior tibial translation and internal rotation decreased by 2mm
and 2 degrees at low flexion angles vs. ACL intact knees
• In-situ forces in posterolateral graft became 56-200% higher than
those in the posterolateral bundle of the intact ACL
• N.B. - may overconstrain knee and result in high forces in
posterolateral graft, predisposing to graft failure
Clinical studies
• J Knee Surg. 2003 Jan;16(1):9-16
• 26 Patients with ACL insufficiency, symptomatic medial OA, varus
– 14/26 recreational athletes - minimum 2 year follow-up
• 12 valgus HTO alone
vs.
• No change in instability vs.
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14 valgus HTO + ACLR
grade 1 lachman 11/13
negative pivot 12/13
No ROM deficit
same
OA progression
OA progression
Overall 23/26 patients able to play recreational sports
Good or excellent results seen more often in HTO + ACLR group
Clinical studies
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Knee 2004 Dec; 11(6):431-7
29 patients (30 knees) retrospectively reviewed
Previous single-stage ACLR + valgus HTO
19/30 had previous medial meniscectomy
2/30 major complications --> stiffness
12yr f/u (6-16)
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5/30 had progressed one arthritis grade
14/30 returned to intensive sports
11/30 played moderate sports
Avg. difference in anterior tibial translation (vs. Normal side) was 3mm
Osteotomy and ACL Deficient Knees
• Summary
– Active patients with ACL deficiency and unicompartmental
arthritis may benefit from ACL reconstruction, osteotomy or
combination with improved pain and return to recreational
activities
– Radiographic (& clinical) progression of OA may be delayed
or may be unchanged.
Osteotomy and PCL deficient knees
• Long-term data regarding the outcome of PCL deficiency vs. PCL
reconstruction vs. PCL reconstruction & osteotomy is lacking.
• Short term follow-up reveals better knee scores and less subjective
sense of instability. Am J Sports Med 1996;24:415-426
• In the presence of varus deformity and decreased tibial slope
correcting the varus deformity and increasing the tibial slope (e.g.
anteromedial opening wedge) decreases the amount of posterior tibial
sag.
• This should theoretically decrease the amount of quads force required
to pull tibia anteriorly and thereby decrease rate of onset of
patellofemoral arthritis.
• Valgus HTO unloads medial compartment and decreases medial OA.
References
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Dejour et al, ACL reconstruction combined with valgus tibial osteotomy. Clin
Ortho 1994 299:220-228
DeLee JC ed. Orthopaedic Sports Medicine. Pg 1401-1441
Fu F ed. Knee Surgery. Pg 859-876
Larson et al, PCl reconstruction: associated extra-articular procedures. Tech
Ortho 2001 16(2):148-156
Noyes et al, High tibial osteotomy in ligament reconstruction for varus
angulated ACL deficient knees. Am J Sports Med 2000 28(3):282-296
O’Neil and James, Valgus osteotomy with ACL laxity. Clin Ortho 1992 278:
153-9
Vogrin et al, Biomechanics of PCL deficient knee. Tech Ortho 2001 16(2):109118
Williams et al, Management of unicompartmental arthritis in the ACL deficient
knee. Am J Sports Med 2000 28(5); 749-760
Clinical studies
• Z Orthop Ihre Grenzgeb. 2002 Mar-Apr;140(2):185-93.
• Simultaneous arthroscopic cruciate reconstruction and
closing wedge osteotomy
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4/96 - 12/00 58 patients (avg. 33 y.o.)
49 ACL , 7PCL, 2 ACL & PCL
Avg. 7deg correction (mean malalignment 5 deg)
13 patients also had osteochondral allograft
2 had implantable collagen meniscus
Lysholm score (66 --> 81 --> 87 --> 93)