Fifteen-Year Radiographic Follow-up Comparison of Early Versus Delayed ACL Reconstruction: A Retrospective Review of a Previous Prospective Randomized Clinical Trial

Background: Posttraumatic osteoarthritis (PTOA) after anterior cruciate ligament injury and reconstruction (ACLR) is a prevalent cause of long-term disability. Few studies have compared the effect of ACLR timing on the development of PTOA.

Purpose/hypothesis: The purpose of this study was to compare the rate of PTOA at a long-term follow-up between patients who underwent early ACLR (<21 days after injury) versus delayed ACLR (>6 weeks after injury). The authors hypothesized that patients who underwent early ACLR would have lower rates of PTOA compared with the delayed ACLR cohort.

Study design: Cohort study; Level of evidence, 2.

Methods: The authors contacted patients from a previous prospective randomized controlled trial who were randomized to undergo either early (<21 days) or delayed (>6 weeks) ACLR with hamstring tendon autografts. Weightbearing radiographs were obtained at a minimum 15-year follow-up, and radiographic PTOA was evaluated using the Kellgren-Lawrence (K-L) classification system. The prevalence of pathologies was compared between the early and delayed groups using appropriate testing, and logistic regression was used to evaluate for associations with failure-a K-L grade of ≥2 or conversion to total knee arthroplasty (TKA).

Results: At a mean follow-up of 15.6 years, radiographs were obtained for 58 (28 early, 30 delayed) of the original 69 (84.1%) patients. High rates of PTOA (K-L grade ≥2) were observed in the early (82.1%) and delayed (86.7%) cohorts (P = .634). Two (7.1%) patients in the early cohort converted to TKA compared with 4 (13.3%) patients in the delayed cohort (P = .44). Surgical timing did not affect arthritis severity (P≥ .4), and no factors predicted developing radiographic PTOA in either cohort (P > .2). Increased time from injury decreased the odds of failure in the early ACLR cohort (odds ratio, 0.79; P = .041).

Conclusion: In this study, >80% of patients who underwent ACLR with hamstring tendon autografts had radiographic evidence of PTOA at a mean 15.6-year follow-up, with no difference in the prevalence or severity of PTOA between the early and delayed groups. In addition, 11% of patients had converted to TKA by the time of the final follow-up, and the conversion rate did not differ according to the timing of ACLR.