Purpose

To identify preoperative risk factors for ipsilateral ACL reinjury following ACLPR with a minimum follow-up of 5-years.

Methods

This prospective cohort study evaluated the outcomes of the first 113 consecutive patients with proximal ACL tears who underwent ACL primary repair (ACLPR) by a single surgeon, at minimum 5-year follow-up. Assessment included knee laxity testing, Pivot shift test, and a standardized patient interview to evaluate any potential for ipsilateral reinjury. To identify preoperative risk factors for ipsilateral reinjury, univariate and multivariate logistic regression models were used. Preoperative risk factors included demographic (sex, age, BMI, activity level, surgery delay) and clinical variables (pivot shift grade, concomitant injuries).

Results

Outcomes were assessed for 107 patients (median age 35.5 years, IQR 22.4-43.1) at the final follow-up (median 6.0 years, IQR 5.3-7.0). Six patients (5%) were lost to follow-up. Analysis of preoperative risk factors showed that younger age significantly affected ACLPR survival negatively (p = 0.002), with a 12.5% reduction in the risk of failure for each additional year of age. Additional demographic (sex, BMI, activity level, surgery delay) and clinical characteristics (pivot shift grade, concomitant injuries) did not show a significant impact on the survival of the ipsilateral ACL following ACLPR over a minimum 5-year follow-up.

Conclusion

Age is identified as a significant risk factor for ACLPR reinjury, with a 12.5% decreased risk of failure for each additional year of age, indicating that younger patients experience higher rates of reinjury.