Summary

Patients who were older at the time of ACL reconstruction and had waited more than a year between the injury and reconstruction ran an increased risk of having OA 16 years after reconstruction.

Abstract

Purpose

To determine preoperative predictors of acceptable knee function and the development of osteoarthritis (OA) after anterior cruciate ligament (ACL) reconstruction.

Methods

This study is a long-term follow-up of two previous randomised controlled trials. 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 (IKDC) and the development of OA defined as Kellgren-Lawrence =2. Knee laxity measurements, hop performance, patient-reported outcome and concomitant injuries were determined as variables.

Results

A total of 147 patients (63.7% males) were eligible for inclusion, with a mean follow-up of 16.4±1.3 years. The patients had an average age of 27.9±8.3 years at the time of ACL reconstruction. Half the cohort reported an IKDC score above the PASS cut-off. The presence of a concomitant injury at operation, OR=2.61 (95% CI; 1.10-6.21), p=0.030, and greater preoperative anteroposterior laxity, OR=1.87 (95% CI; 1.05-3.35), p = 0.034, 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=0.046, and older age at reconstruction, OR=2.28 (95% CI; 1.34-3.86), p=0.0023, increased the odds of developing OA at follow-up.

Conclusion

Patients who were older at the time of ACL reconstruction and had waited more than a year between the injury and reconstruction ran an increased risk of having OA 16 years after reconstruction. One in two patients reported acceptable long-term knee function, but no risk
factor for poorer subjective knee function was identified.