Role of Osteotomy in ACL and PCL Deficient Patients

1
Role of Osteotomy in ACL and PCL Deficient
Patients

• Satyam Patel Feb. 2007
• mod. from Cole Beavis Nov. 2002

2
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.

3
Natural History of ACL/PCL Deficient Knee

• Literature somewhat difficult to interpret
• Variety of factors influence natural history
• 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

4
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 gt lateral compartment

5
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.

6
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

7
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.

8
Principles of Tibial Osteotomy

9
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

10
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

11
Principles of Tibial Osteotomy

• Anatomic
• Comparison of femoral and tibial shafts
• 5 - 7º valgus
• Mechanical
• Line of ground reaction force transmission
• 0 - 1º varus

12
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

13
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

14
Principles of Tibial Osteotomy

• Type of osteotomy
• Extension Valgus

15
Principles of Valgus Tibial Osteotomy

• Indications for valgus osteotomy
• pain unresponsive to conservative measures
• isolated medial compartment OA
• age lt 60
• no more than 10-15? of varus on WB film
• pre-op ROM gt 90
• lt15? of flexion contracture

16
Principles of Valgus Tibial Osteotomy

• Contraindications
• narrowing of the lateral compartment
• lateral tibial subluxation gt 1cm
• flexion contracture gt 15 degrees
• ROM lt 90 degrees
• gt 20 degrees of correction needed
• large varus thrust
• inflammatory arthritis
• tricompartmental arthritis
• severe patellofemoral disease

17
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
• Fu 5 - 13º
• Vainionppa gt 7º
• Insall 10º
• Keene 7 - 13º
• Most common reason for failure of osteotomy is
  undercorrection

18
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

19
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

20
Valgus Closing Wedge
21
Valgus Closing Wedge

• Lateral wedge resection
• Hinge on medial cortex
• Can resect more bone anteriorly to decrease
  tibial slope (extension type osteotomy)
• ACL deficiency

22
Valgus Closing Wedge

• Benefits
• 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

23
Valgus Opening Wedge
24
Valgus Opening Wedge

• Medially based wedge
• Multiple variations in techniques
• Can incorporate anterior opening wedge
• Increases tibial slope (PCL deficiency)

25
Valgus Opening Wedge

• Advantages
• Useful with medial bone loss or MCL laxity
• Tensions MCL
• Drawbacks
• Limited compression
• Bone graft donor site morbidity

26
Fixation of Osteotomies

• Cast
• Staples
• Plate
• Compression, buttress
• External fixator

27
Osteotomies and ACL / PCL Deficient Knees

28
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

29
Osteotomy and ACL Deficient Knees

• Osteotomy has been used in treatment of
  instability
• Extension type to decrease tibial slope and
  anterior tibial translation

30
Osteotomy and ACL Deficient Knees

• Osteotomy has been used in treatment of
  instability
• Extension type to decrease tibial slope and
  anterior tibial translation

31
Osteotomy and ACL Deficient Knees

• Approach
• Patients with arthritic, ACL deficient knee and
  failing conservative treatment
• 3 groups of patients
• Primary symptom is instability
• Primary symptom is pain
• Both pain and instability

32
Osteotomy and ACL Deficient Knees

• Primarily instability
• Pain Malalignment - ? ACL Reconstruction
• Pain - Malalignment ? Osteotomy and
  Reconstruction
• Pain - Malalignment - ? ACL Reconstruction
• Pain Malalignment ? Osteotomy and
  Reconstruction

33
Osteotomy and ACL Deficient Knees

• Primarily pain
• Instability Malalignment - ? ACL
  Reconstruction
• Instability - Malalignment
  ? Osteotomy
• Instability - Malalignment -
  ? ?Arthroscopic debridement
• Instability Malalignment
  ? Osteotomy and Reconstruction

34
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

35

36
Osteotomy and ACL Deficient Knees

• Technique cont
• 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

37
Osteotomy and ACL Deficient Knees

• Technique contd
• Postop combined procedure
• 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

38

39
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

40
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

41
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

42
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

43
Biomechanical studies

• Am J Sports Med. 2004 Mar32(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)

44
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 ACL-deficient knee.

45
Biomechanical studies

• Am J Sports Med. 2006 Jun34(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

46
Clinical studies

• J Knee Surg. 2003 Jan16(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. 14 valgus HTO ACLR
• No change in instability vs. 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

47
Clinical studies

• 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 --gt stiffness
• 12yr f/u (6-16)
• 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

48
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.

49
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 199624415-426
• 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.

50
References

• Dejour et al, ACL reconstruction combined with
  valgus tibial osteotomy. Clin Ortho 1994
  299220-228
• 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
• ONeil 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)109-118
• Williams et al, Management of unicompartmental
  arthritis in the ACL deficient knee. Am J Sports
  Med 2000 28(5) 749-760

51
Clinical studies

• Z Orthop Ihre Grenzgeb. 2002 Mar-Apr140(2)185-93
  .
• Simultaneous arthroscopic cruciate reconstruction
  and closing wedge osteotomy
• 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 --gt 81 --gt 87 --gt 93)