Preoperative and Intraoperative Predictors of Long-Term Acceptable Knee Function and Osteoarthritis After Anterior Cruciate Ligament Reconstruction: An Analysis Based on 2 Randomized Controlled Trials.

Purpose: To determine preoperative predictors of long-term acceptable knee function and the development of osteoarthritis (OA) in long-term follow-up after anterior cruciate ligament (ACL) reconstruction.

Methods: This study is a long-term follow-up of 2 previous randomized controlled trials that included 193 patients who underwent unilateral ACL reconstruction with ipsilateral hamstring tendon or patellar tendon autografts. Patients who suffered multiligament injuries, major meniscal injuries, chondral lesions requiring surgical treatment, or had a previous ACL reconstruction were excluded. Patient demographics, preoperative clinical assessments, and intraoperative findings were used to create stepwise multivariable regression models to determine the patient-acceptable symptom state (PASS) in the International Knee Documentation Committee and the development of OA defined as a Kellgren-Lawrence grade ≥2. Knee laxity measurements, hop performance, patient-reported outcome, and concomitant injuries were determined as variables.

Results: A total of 147 patients (63.7% men) were eligible for inclusion, with a mean follow-up of 16.4 ± 1.3 years. The patients were an average age of 27.9 ± 8.3 years at the time of ACL reconstruction. One-half of the cohort reported an International Knee Documentation Committee evaluation system score above the PASS cutoff. The presence of a concomitant injury at operation (odds ratio [OR], 2.61; 95% confidence interval [CI], 1.10-6.21; P = .030) and greater preoperative anteroposterior laxity (OR, 1.87; 95% CI, 1.05-3.35; P = .034) increased the likelihood of achieving a PASS. A longer period between ACL injury and reconstruction (OR, 2.25; 95% CI, 1.02-5.00; P = .046) and older age at reconstruction (OR, 2.28; 95% CI, 1.34-3.86; P = .0023) increased the odds of developing OA at follow-up.

Conclusions: Patients who were older at the time of ACL reconstruction and had waited >1 year between the injury and reconstruction ran an increased risk of having OA 16 years after reconstruction. One in 2 patients reported acceptable long-term knee function, but no risk factor for poorer subjective knee function was identified. Patients who had a minor concomitant injury and increased preoperative anteroposterior knee laxity had increased odds of reporting an acceptable long-term knee function.

Level Of Evidence: Level II; prospective comparative study.