Multicenter ACL Revision Study (MARS)

Injury to the anterior cruciate ligament (ACL) results in a threat to an active lifestyle and exposes the patient to risk of osteoarthritis. ACL reconstruction is typically chosen by individuals to allow a return to their previous work and sports activities. The results of primary ACL reconstruction have in general been good at restoring functional stability. Primary ACL reconstruction has a graft failure rate ranging from approximately 2%-8%. Consensus amongst surgeons and low-level evidence (retrospective case series) indicate a worse outcome following revision ACL reconstruction compared to primary reconstruction. The typical surgeon performs less than 10 revision ACL reconstructions per year. Thus, the ability of any single surgeon or small group of surgeons to accumulate enough cases to effectively analyze predictors for worse outcome is impossible.

With this in mind, the Multi-Center ACL Revision Study (MARS) group was established as a multi-center surgeon group to perform a prospective longitudinal cohort analysis of revision ACL reconstruction. This is a mixed group of academic and private practice physicians and has been supported and endorsed by the American Orthopedic Society for Sports Medicine (AOSSM).

This study focuses on the predictors for ACL revision outcome at 2, 6,10 and 20 years following a patient's revision ACL reconstruction. This will be accomplished by three Specific Aims. Specific Aim 1 will determine the independent predictors of patient-reported quality of life, utilizing a general (SF-36) and knee-specific (Knee Injury and Osteoarthritis Outcome Score - KOOS) validated outcome instrument. Specific Aim 2 will determine the independent predictors of sports function utilizing three validated outcome instruments (the Marx activity level, International Knee Documentation Committee Subjective form - IKDC, and the KOOS sports and recreation subscale). Specific Aim 3 will identify those independent modifiable predictors measured at the time of the revision ACL reconstruction associated with symptoms of knee osteoarthritis at up to 20 years post-surgery. Symptoms will be quantified using the validated survey instrument the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Once the predictors for these worse outcomes are identified, surgeons can be educated in potential modifiable variables to improve the outcome.

Inclusion criteria

• All ACL-deficient candidates presenting to the clinic, between the ages of 12† and 65, scheduled to have a revision ACL reconstruction by a participating (MARS Study) surgeon.
• All participants must have undergone a primary ACL reconstruction in the past and are currently identified as having experienced failure of their primary ACL reconstruction, as defined by either MRI, knee laxity (KT > 5mm), a positive pivot shift or Lachman's, functional instability, and/or by arthroscopic confirmation.
• All ACL-deficient patients seeking a revision ACL reconstruction that have either partial (Grade I or II) and/or complete (Grade III) simultaneous ligamentous injuries to the collateral ligaments (MCL or LCL) and/or the posterior cruciate ligament (PCL) will also be included.
• Non-operative treatment of patients with ACLR failure are also eligible to participate.
• The following graft types will be the only ones accepted for inclusion:

• any autograft
• Fresh-frozen allografts from a single donor source (Musculoskeletal Transplant Foundation (MTF); Edison, NJ). These grafts should consist of either:

• bone-patellar tendon-bone
• tibialis anterior/posterior
• achilles tendon

Exclusion criteria

• Patients presenting with prior infection, arthrofibrosis, or regional pain syndrome.
• Subjects will be excluded if their allograft source does not come from MTF.
• Patients unwilling or unable to complete their repeat questionnaire two years after their initial visit.