Very long-term osteoarthritis rate after anterior cruciate ligament reconstruction: 182 cases with 22-year' follow-up.

Background: Few data are available on the 20-year outcomes of anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to assess the prevalence and risk factors of knee osteoarthritis at least 20 years after ACL reconstruction.

Hypothesis: Factors associated with progression to knee osteoarthritis include meniscal lesions, level of physical activity, injury-to-surgery time, body mass index, residual laxity, tunnel position and cartilage injury.

Material And Methods: One hundred and eighty two patients were included in a multicentre retrospective study conducted in the setting of a SoFCOT symposium. Females contributed two-thirds of the study population. ACL reconstruction was performed arthroscopically in 82% of cases, and a bone-patellar tendon-bone transplant was used in 92.8% of cases. Mean age at surgery was 26±7years. Clinical outcomes were assessed based on the objective and subjective IKDC scores and on the KOOS. Radiographic evidence of osteoarthritis was classified according to the IKDC. Factors evaluated for their ability to predict progression to osteoarthritis included age, sex, body mass index, level of physical activity, injury-to-surgery time, meniscectomy, cartilage injury, tunnel position and residual laxity.

Results: At last follow-up, the objective IKDC score was A (normal) for 48%, B for 35%, and C or D for 17% of the knees. The mean subjective IKDC score was 82.7±13.1. Moderate-to-severe osteoarthritis was present in 29% of cases. The following risk factors for osteoarthritis were identified: medial or lateral meniscectomy, residual laxity, age >30years at surgery, and engaging in a pivoting sport. Meniscectomy was a major contributor to the development of osteoarthritis (17% of knees without vs. 46% with meniscectomy). Finally, the ACL re-tear rate was 13%.

Conclusion: ACL reconstruction provides satisfactory knee stability. The risk of subsequent osteoarthritis depends chiefly on the status of the menisci. Residual laxity is also associated with the development of osteoarthritis.

Level Of Evidence: IV, retrospective cohort study.