20 Year Outcomes of ACL Reconstruction with Hamstring Tendon Autograft. Does Age Matter?

INTRODUCTION: The purpose of this study was to document the prospective longitudinal outcome of ‘isolated’ anterior cruciate ligament (ACL) ruptures treated with anatomical endoscopic reconstruction using hamstring tendon autograft over 20 years. Long term outcomes were compared between those undergoing ACL reconstruction age 18 or less and those >18 years the time of surgery. METHODS: A total of 100 consecutive men and 100 consecutive women with ‘isolated’ ACL rupture underwent four-strand hamstring tendon reconstruction with anteromedial portal femoral tunnel drilling and interference screw fixation by a single surgeon. At the time of ACL reconstruction 39 participants were aged 18 or less, 81 were aged 19 to 25 and 80 were over 25. Reviews were performed pre-operatively and at 1, 2, 7, 15 and 20 years post-operatively. Outcomes included further ACL injury, clinical examination, subjective and objective scoring systems, and radiological assessment. RESULTS: Further ACL injury occurred in 55 of the 200 patients (28%), 37 ruptured the ACL graft and 22 ruptured the contralateral ACL. ACL graft rupture was significantly increased in the young; 39% in those aged 18 or less, 21% of those aged 19-25 and 6% of those over 25 years (p=0.001). Participants with a posterior tibial slope of 12 degrees or more sustained a further ACL injury in 65% of cases. Moderate to severe radiological degenerative change was evident in 14% at 20 years. Outcomes were not statistically different between those aged 18 or less and those >18 years for the variables of IKDC subjective score (p=0.98), rate of return to preinjury activity level (p=0.32), current activity level, or degree of radiological degenerative change at 20 years (p=0.65). CONCLUSIONS: ACL reconstructive surgery in patients with an ‘isolated’ rupture using this technique was associated with good long term outcomes and does not appear to cause osteoarthritis, regardless of age. However further ACL injury after ACL reconstruction is significantly more common in the young and those with a high posterior tibial slope. **This study was performed with support from AOA Research Foundation