Decreased posterior tibial slope is not a risk factor for posterior cruciate ligament reconstruction failure: A multicentric analysis of 173 cases.

Abstract

To investigate whether posterior tibial slope (PTS) is associated with failure after posterior cruciate ligament reconstruction (PCLR) in a cohort of patients undergoing isolated PCLR and PCL-based multiligament knee injuries (MLKI) reconstruction. The hypothesis was that (1) a reduced PTS is a factor affecting PCLR failures in isolated PCLR, but (2) it is not in the context of PCL-based MLKI. A multicentric retrospective study was conducted across four high-volume knee surgery centres. Patients were contacted to assess the occurrence of additional surgical procedures, knee stability and satisfaction using the simple knee value (SKV). PTS of medial compartment was measured on lateral radiographs. Survival analysis was performed using the Kaplan-Meier method with failure as the endpoint (revision PCL reconstruction, persistent posterior instability documented by a positive posterior drawer test), and Cox regression was used to evaluate the association between PTS and failure. Patients were stratified according to tertiles of PTS distribution (low ≤7°, intermediate 7°-10°, high >10°). Additionally, PTS was compared between failure and non-failure groups using the Mann-Whitney U test (p < 0.05). A total of 173 patients met the inclusion criteria; 24 (13.9%) were considered failures. The overall survival rate was 86.1%, 96% at 2 years, and 70% at 15 years. PTS was slightly higher in patients who failed compared to those who did not (9.1 ± 2.3° vs. 8.0 ± 3.2°; p < 0.05). However, no significant differences in survivorship were observed across PTS tertiles. Kaplan-Meier and Cox regression analyses did not demonstrate a significant association between PTS and failure. PTS was not associated with failure after PCLR. These findings indicate that sagittal tibial alignment alone may have a limited role in determining reconstruction survivorship and do not support routine correction of PTS in primary PCLR. Level IV, retrospective cohort study.