Lateral meniscal status, chronicity of anterior cruciate ligament (ACL) deficiency, and initial graft tension were associated with abnormal knee laxity after anatomical ACL reconstruction

Purpose

Graft failure or recurrence of instability without obvious trauma remains one of the problems following anterior cruciate ligament (ACL) reconstruction. This retrospective study aimed to identify risk factors for abnormal knee laxity after anatomical ACL reconstruction.

Methods

A total of 291 patients who underwent primary anatomical ACL reconstruction were included in this study. Sex, age, body mass index (BMI), time to surgery, medial meniscal status, lateral meniscal status, graft materials, initial graft tension protocol, preoperative and postoperative pivot shift test and side-to-side differences in anterior tibial translation using the arthrometer were reviewed. Abnormal knee laxity was defined as constituting one or both of the following criteria: (i) a side-to-side difference of ≥3 mm by arthrometer; and (ii) a positive pivot shift test, being “glide,” “clunk”, or “gross”.

Results

Abnormal knee laxity occurred in 30 patients (10.3%) at a median follow-up of 25 months. Results of univariate analysis indicated that a higher likelihood of abnormal knee laxity was associated with female sex, greater BMI, longer time to surgery, higher initial graft tension protocol, and lateral meniscus resection. Multivariate logistic regression analysis showed that abnormal knee laxity was significantly associated with time to surgery [1-month increase; odds ratio (OR), 1.01], higher initial graft tension protocol (vs. lower tension; OR, 3.5), and lateral meniscus resection (vs. intact and repaired lateral meniscus; OR, 12.8).

Conclusion

Higher initial graft tension protocol, chronicity of ACL deficiency, and lateral meniscus resection were risk factors for abnormal knee laxity after anatomical ACL reconstruction.

Level of evidence

Level III retrospective prognostic study.