KSSTA - 2026-09-21 - Journal Article
The association between passive anterior tibial subluxation and anterior cruciate ligament reconstruction failure.
Gao YT, Shi WL, Zhong YF, Wen T, Qiu LF, Zhou SP, Ma Y, Liu P, Wang HJ, Wang J, Gong X, Wang C, Wang JQ
Topics
Key Takeaway
Primary lateral PATS (OR 1.166) and lateral tibial slope (OR 1.193) independently predict ACL reconstruction graft failure, with moderate discriminative ability (AUC 0.682 and 0.668 respectively).
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Summary
This study asked whether preoperative passive anterior tibial subluxation (PATS) on MRI predicts ACL graft failure and how PATS changes longitudinally. In 262 propensity score-matched patients, primary lateral PATS (OR 1.166) and lateral tibial slope (OR 1.193) independently predicted graft failure with AUCs of 0.682 and 0.668. Graft failure patients showed significant longitudinal progression of both L-PATS and M-PATS, while female sex and medial meniscus injury were also independently associated with PATS increase over time.
Key Limitation
The moderate AUC values (0.668–0.682) indicate that L-PATS and LTS alone have limited standalone predictive power, and no threshold PATS value was validated to guide surgical decision-making.
Original Abstract
PURPOSE
Increased passive anterior tibial subluxation (PATS) has been observed in patients with failed anterior cruciate ligament (ACL) reconstruction (ACLR). However, whether primary PATS is associated with future risk of graft failure and how PATS evolves over time remain unclear. This study aims to determine whether PATS measured at the time of the primary ACL injury is associated with graft failure and to characterize the longitudinal changes in PATS among patients with and without graft failure.
METHODS
A retrospective review was conducted on patients who underwent primary ACLR between January 2019 and December 2023. A total of 131 patients with graft failure were propensity score-matched to 131 controls with intact grafts at a minimum 48-month follow-up (age, 28.9 ± 7.7 years; 61 females [23.3%]). Primary magnetic resonance imaging (MRI) evaluation was performed for all patients before primary ACLR. Secondary MRI evaluation was performed before revision surgery for the failure group (median [interquartile range {IQR}], 31.0 [19.1-58.0] months) and at 24 months post-operatively for the control group (median [IQR], 24.9 [23.9-27.4] months). Multivariable logistic regression and receiver operating characteristic curve analysis were performed to evaluate factors associated with graft failure. Multivariable linear regressions were performed to identify factors associated with longitudinal changes in PATS between the primary and secondary MRI evaluations. Statistical analyses were performed using R software.
RESULTS
Significantly higher lateral (L-PATS) and medial (M-PATS) PATS at both the primary and secondary MRI evaluations were observed in the failed ACLR group compared with the control group (all p < 0.05). Patients with graft failure demonstrated significant longitudinal progression of PATS compared to those with intact grafts (p < 0.05). Primary L-PATS (odds ratio [OR], 1.166; p < 0.001) and lateral tibial slope (LTS) (OR, 1.193; p < 0.001) were identified as factors independently associated with graft failure, demonstrating moderate discriminative ability (area under the curve [AUC], 0.682 and 0.668). Graft failure, female sex and medial meniscus injury were independently associated with longitudinal increases in PATS (all p < 0.05).
CONCLUSIONS
Increased L-PATS measured at the time of the primary ACL injury was associated with an increased risk of graft failure. Patients who experienced graft failure demonstrated significant longitudinal increases in both L-PATS and M-PATS compared to those with intact ACLR.
LEVEL OF EVIDENCE
Level III.