Anterior Cruciate Ligament Reconstruction in Patients Older Than 50 Years: A Descriptive Study With Minimum 10-Year Follow-up.

Background: Anterior cruciate ligament (ACL) reconstruction is increasingly being performed in patients >50 years old; however, the long-term outcomes are unclear. Purpose: To analyze the functional results, osteoarthritic progression, reoperation rate, and failure rate at minimum 10-year follow-up in patients >50 years old who have undergone primary ACL reconstruction. Study Design: Case series; Level of evidence, 4. Methods: Included in this study were patients >50 years old who underwent primary ACL reconstruction and had at least 10 years of follow-up data. All patients had instability with limitation of their activities, indicating the necessity of surgical intervention. Patients with revision surgeries, ACL repairs, and nonoperative treatment were excluded. Failure was defined as the presence of revision, high-grade Lachman, positive pivot shift (2+), or subjective instability. The Knee injury and Osteoarthritis Outcome Score (KOOS), subjective and objective functional scores, and osteoarthritic progression were analyzed at final follow-up. Results: A total of 38 patients were identified. The mean age at surgery was 56.8 ± 5.7 years (range, 50.6-70 years). The mean clinical follow-up was 16.2 ± 4.3 years (range, 10.9-23.3 years). The failure rate was 10.5% (4/38): 1 of the 4 patients had a recurrence of instability at 13 years postoperatively and underwent revision with a modified Lemaire extra-articular tenodesis, 1 patient had a positive pivot shift (2+) without subjective instability, and 2 patients underwent total knee arthroplasty. The overall KOOS was 74.2 ± 22.2, and 91.4% of patients were satisfied or very satisfied with the results of the procedure. Radiographic osteoarthritis was identified in 88.5% of patients at final follow-up; however, there was no statistical significance on clinical outcomes ( Conclusion: In patients over the age of 50 years who underwent primary ACL reconstruction, there was a low long-term failure rate and a high level of patient satisfaction, despite osteoarthritic progression in 88.5% of cases. Concomitant meniscal procedures were associated with more severe osteoarthritic progression.