Poster 315: Fifteen-Year Radiographic Follow-Up of a Prospectively Randomized Clinical Trial Comparing Early versus Delayed Anterior Cruciate Ligament Reconstruction.

OBJECTIVES: Post-traumatic osteoarthritis (PTOA) after anterior cruciate ligament (ALC) injury remains a difficult problem. PTOA is considered to be the consequence of an initial mechanical disruption or injury to the cartilage. Recent literature has suggested that 50-60% of reconstructed knees demonstrate post- traumatic arthritis at long term follow up. Several studies evaluating synovial fluid have suggested that inflammatory cytokines present after injury may contribute to post-traumatic arthritis. Therefore, the purpose of this study was to compare the rate of post-traumatic osteoarthritis between acutely reconstructed ACLs (within 21 days) and delayed ACL reconstructions (greater than 6 weeks). METHODS: This study is a retrospective review of a previous prospectively randomized controlled clinical trial where ACL reconstructions were randomized to either early (within 21 days) or delayed (beyond 6 weeks) reconstruction using hamstring autograft. Bilateral weight bearing radiographs were obtained at a minimum of 15-year follow-up. Radiographs were analyzed using the Kellgren-Lawrence classification system by a musculoskeletal radiologist. Seventy patients were enrolled in the study and 1 was excluded because of infection. Therefore, the original study cohort consisted of sixty-nine patients (34 acute, 35 delayed) with an average of 27.3 years at the time of surgery. Follow-up radiographs were obtained for 58 total patients (28 acute, 30 delayed). RESULTS: The average time from injury to surgery in the acute group was 9 days (2-18) and 85 days (42- 192) in the delayed group. At an average follow up of 15.6 years, post-operative radiographs were obtained in a total of 58 patients (28 acute, 30 delayed). In the acute cohort, 53.5% of patients had greater than Grade 3 PTOA compared to 60.0% in the delayed cohort (p=0.1). In the acute cohort, 42.8% (12/28) had Grade 3 PTOA and 10.7% (3/28) had Grade 4 PTOA compared to 46.7% (14/30) Grade 3 PTOA and 13.3% (4/30) Grade 4 PTOA in the delayed cohort (p=0.1). Four patients in the delayed cohort had undergone a total knee arthroplasty compared to 2 patients in the early cohort. In the acute cohort, the average KOOS score was 61.7% in patients with > Grade 3 PTOA compared to 80.6% in those with < Grade 3. In the delayed cohort, in the average KOOS was 56.8% in patients with > Grade 3 PTOA compared to 77.9 in those with < Grade 3. CONCLUSIONS: In conclusion, we found that early ACL reconstruction resulted in no difference in the rate of post-reconstruction osteoarthritis of the knee compared to delayed reconstruction. At fifteen-year radiographic follow-up, both cohorts resulted in high rates of post-traumatic osteoarthritis. Furthermore, patients with greater than Grade 3 PTOA demonstrated worse KOOS scores in both cohorts.