PURPOSE: To investigate the factors affecting residual pivot shift after anterior cruciate ligament (ACL) reconstruction. METHODS: This multicentre prospective cohort study included patients who underwent primary ACL reconstruction using an autologous hamstring tendon graft with or without the ACL remnant-preserving technique. Multivariable logistic regression analysis was conducted to identify the factors that influenced residual pivot shift 1 year after ACL reconstruction. Age, sex, body mass index, interval between injury and surgery, preoperative pivot-shift grade, side-to-side differences in anterior knee laxity, hyperextension, lateral and medial meniscus treatments, and ACL reconstruction procedure (remnant-sacrificing single-bundle reconstruction, remnant-sacrificing double-bundle reconstruction or remnant-preserving single-bundle reconstruction) were selected as independent variables in the multivariable model. Patients who underwent additional lateral extra-articular tenodesis or anterolateral ligament reconstruction were excluded. RESULTS: A total of 760 patients, including 394 males and 366 females (average age at surgery, 29.1 years
age range, 14-67 years), were enroled in this study. The postoperative side-to-side difference in anterior knee laxity was 0.8 ± 2.3 mm, and pathological positive results in the pivot-shift test 1 year after ACL reconstruction were observed in 95 patients (12.5%). Factors that significantly affected postoperative positive pivot-shift test results were younger age (odds ratio [OR] 1.71
CONCLUSIONS: Younger age, medial meniscectomy and remnant-sacrificing ACL reconstruction techniques were associated with residual pivot shift 1 year after ACL reconstruction. Identifying risk factors for postoperative residual pivot-shift is important for optimizing treatment decisions. LEVEL OF EVIDENCE: Level II.