ACL EBM Mixed Bag

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ACL EBM Mixed Bag

• Josh Lewis MD
• 5/2008
• Fairfax Family Practice
• Primary Care Sports Medicine Fellowship

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Primary Questions

• Does ACL reconstruction prevent osteoarthritis?
• Who are the appropriate candidates for ACL
  reconstruction?

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Secondary Questions

• Is there anything better on the horizon?

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Who is a candidate?

• Age
• 1987-Kannus and Jarvinen conservatively treated
  patients mean age 32 years, mean follow-up 8
  years-poor results in non-operative treatment
• 1994-Ciccotti et al reported 83 satisfaction in
  patients mean age 46 treated conservatively. Pts
  required to modify activity

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What about the Foagies?

• Prior to 2006 the oldest studied population
  averaged 44 yearsby Heier et al.
• Barber et al demonstrated similar satisfaction in
  44yo group(91) to 27yo group (89) mean f/u 21
  months
• Dara Torres(at right) set U.S. record in 50m
  Freestyle at age 40

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Age and ACL Reconstruction Revisited-Orthopedics
Jun 2006

• 23 patients of avg age 54yrs(49-64)
• Evaluated at 24mo post-op by validated
  questionnaire, PE, X-ray, KT-1000
• 16 returned for testing, 3 agreed to phone f/u

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Results

• 15 patients had excellent or good results
• 4 patients had fair or poor results
• The above 4 were noted to have moderate to severe
  osteoarthritis

• Mean Lysholm score 92
• Visual analog scale 0.5, satisfaction rating
  100,
• KT-1000 testing 2mm
• ROM 0-135

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Authors Conclusions

• This study should expand the indications for ACL
  reconstruction to 49-64 years of age
• We believe that ACL reconstruction with
  allograftin patients with minimal arthrosis is a
  safe successful and satisfying operation for both
  the patient and the surgeon.

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Study Weaknesses

• No control group
• Too small a sample for statistical significance
• No intention to treat analysis
• No correlation of results to meniscal or chondral
  pathology at initial arthroscopy

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What about those with OA

• ¾ patients with the outcome fair or poor from
  the previous study by Stein et al had moderate to
  severe OA on plain films before surgery

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Retrospective cohort study

• Noyes and Barber-Westin previously reported on 40
  patients who underwent ACL reconstruction with
  severe arthrosis at the time of surgery

• Only 55 were able to return to light athletics
• Pain and instability may have been improved

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Positive results

• Shelbourne/Brenner reported statistically
  significant, improved subjective survey scores in
  52 patients with isolated medial compartment
  arthrosis with chronic ACL deficiency
• At a mean of 10 years post-op, significant
  improvement was noted compared to preoperative
  evaluation

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Summary

• Most studies impaired by small sample group, lack
  of control
• Data is lacking, however there may be select
  patients with OA and chronic ACL deficiency who
  would benefit from reconstruction.

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What if we dont?

• A 2007 case-control study of 38/73 consecutive
  patients from 1998-2003 (Strehl et al)
• Selected for low clinical sx(no giving way), low
  to medium sports activity levels, no additional
  significant structural damage, ability to comply
• Conservatively treated patients followed from 1-8
  yrs, avg 3.4.
• Parameters followed included sports activity,
  subjective knee function, and subjective function
  compared to pre-injury

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Results

• One third of patients had good or very good
  results
• Two thirds of patients required reconstruction
  for persistant symptoms

• Similar results have been borne out in multiple
  studies
• Failure of conservative treatment particularly
  frequent in the active

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Does ACL reconstruction reduce development of OA?

• The American Journal of Sports medicine recently
  reviewed 127 studies
• A formal meta-analysis was impossible secondary
  to poor consistency between recorded variables

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Does ACL reconstruction reduce development of OA?

• The relative risk of developing knee OA after
  ACL rupture is approximately 4.7
• Multiple reports estimate a 50 incidence of OA
  10-20 years after ACL rupture or meniscus tear

• Meniscus injuries are a known risk factor for the
  development of OA
• The incidence of meniscus injury with ACL rupture
  is approximately 50
• This frequency increases with time in an ACL
  deficient knee

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Does ACL reconstruction reduce development of OA?

• Lysholm scores were extracted from 54 published
  studies
• Mean scores trended around 90, between, good
  and excellent
• There was no apparent time dependant trend

• This is inconsistent with long term patient
  reporting

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Does ACL reconstruction reduce development of OA?

• The more recent measure, Knee Injury and
  Osteoarthrotis Outcome score (KOOS) suggests
  different results
• In 8 publications, the trend is that scores peak
  1-2 years after reconstruction

• KOOS scores deteriorate with time after that
  point.

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Does ACL reconstruction reduce development of OA?

• In 2 corresponding cohort studies of 219 male and
  103 female soccer players with ACL rupture about
  75 reported significant symptoms in the affected
  knee

• 42 had radiographic evidence of OA compared to
  4 in the uninjured knee
• Neither study demonstrated a difference between
  conservatively and surgically treated patients

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What about the meniscus?

• Similar story to ACL rupture
• 50 incidence of progression to OA in 15-20 years
• Higher incidence if tear is degenerative

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Mechanism of OA

• There is significant evidence that the initial
  injury sets in motion a cascade of degenerative
  changes in chondral cartilage
• CII degradation appears to be an early event
  following ACL rupture and is unlikely to be a
  direct result of mechanical loading

• Compared to cadaver controls, cartilage s/p ACL
  rupture demonstrates
• Increased cleavage and denaturation of Type II
  cartilage
• Increased proteoglycan content

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Mechanism of OA

• ACL injury changes static and dynamic loading of
  the knee generating increased forces on joint
  cartilage
• Additional injuries tend to accumulate with time,
  particularly to the meniscus

• Reconstruction in young active individuals has
  been shown to provide some protection against
  additional procedures (dunn, lyman)

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ACL reconstruction

• AJSM is in agreement with a recent Cochrane
  review that literature review does not provide
  evidence that ACL reconstruction reduces the rate
  of OA development or improves long term symptom
  outcome

• Additionally there is no indication of a
  decreased rate of OA in recent reports compared
  to older studies

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ACL reconstruction

• Reports do seem to suggest that ACL repair may
  protect against future meniscus injuries
• Although this may be expected to lower the rate
  of OA development, this has yet to be shown

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Risk Factors predicting poor outcome

• Female Sex
• Obese
• Lateral Meniscectomy
• Those with finger joint OA-genetic propensity

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Current areas of Study
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Rotational Kinematics

• Current ACL reconstruction techniques are
  excellent at restoring anterior-posterior
  instability

• Multiple studies have demonstrated decreased
  efficiency at returning rotational kinematics to
  normal

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Rotational Kinematics

• Dayal et al studied 230 patients with knee OA
• Knee laxity and AP semi-flexed radiographs
  obtained at start and 18 months
• Degree of laxity was not found to be predictive
  of progression of OA

• Other studies (Leitze et al, Jonsson et al) have
  found that the presence of a post operative pivot
  shift was predictive of poor outcome
• An abnormal Lachman absent a pivot shift had no
  correlation with outcome measures

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Double Bundle ACL Reconstruction

• Multiple grafts and tibial tunnels used with the
  intent of better approximating the anteromedial
  (AP-stability), and posterolateral (rotational
  stability) bundles of the normal ACL

• While there is significant data suggesting
  improved rotational stability, no study to date
  has demonstrated improved clinical outcome.

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Double Bundle ACL Reconstruction

• Risks include increased potential for
  intraoperative tibial fracture, and increased
  difficulty if revision becomes necessary.

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Take Home Points

• ACL reconstruction is indicated for patients up
  to age 65, and possibly beyond
• ACL reconstruction has been shown to improve
  patient perception of stability

• ACL reconstruction has not been shown to decrease
  progression to OA or improve long term outcomes
• Double bundle reconstructions have not been shown
  to be clinically superior and require further
  study

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References

• Age and ACL Reconstruction Revisited. Stein et
  al, Orthopedics. June 2006. Volume 29 iss
  6(533-537)
• Isolated Anterior cruciate ligament
  reconstruction in the chronic ACL-deficient knee
  with degenerative medial arthrosis. Shelbourne
  KD, Brenner RW. The Journal of Knee Surgery. July
  2007. 20(3)216-22
• Dunn WE, Lyman S, The effect of ACL
  reconstruction on the risk of knee injury. Am J
  of Sports Med. 2004321906-1913
• Dayal et al, The Natural history of
  Anteroposterior laxity and its role in knee OA
  progression. Arthritis and Rheumatism. August
  2005. 52(8) 2343-2349
• Leitz et al, Implications of the pivot shift in
  the ACL deficient knee. Clinical orthopedics and
  related research. July 2005. 436229-236

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References

• Joonsson H et al, Positive pivot shift after ACL
  reconstruction predicts later OA, Acta
  Orthopaedica Scandinavica. Oct 2004. 75(5)594-9
• Sempeles S, ACL reconstructions effectiveness
  questioned in restoring knee function. Bone and
  Joint. January 2005. 11(1)pp1, 3-4