Summary
This study demonstrates that Increased medial and lateral PTS are significant predictors of tibial tunnel widening following ACL reconstruction using hamstring tendon autografts.
Abstract
Posterior tibial slope (PTS) has been implicated in tunnel widening following anterior cruciate ligament reconstruction (ACLR), yet its precise impact remains unclear. Additionally, the influence of lateral extra-articular tenodesis (LET) and meniscal root injuries on tunnel widening has not been well established.
Purpose
To evaluate the effect of medial and lateral PTS, LET, and meniscal root injuries on tibial and femoral tunnel widening following ACL reconstruction using a hamstring tendon autograft.
Methods
A total of 307 patients who underwent primary ACLR with a hamstring tendon autograft were included. Tibial and femoral tunnel diameters were measured immediately postoperatively and at a two-year follow-up by measurements made on standard radiographs. Posterior tibial slope was assessed using long lateral radiographs. Univariate and multivariate regression models were used to identify predictors of tunnel widening.
Results
At two years, the mean tibial tunnel diameter increased from 9.46 ± 1.00 mm postoperatively to 11.35 ± 1.55 mm (p < 0.001) and the mean femoral tunnel diameter increased from 9.27 ± 0.83 mm to 11.52 ± 1.63 mm (p < 0.001). Univariate analysis demonstrated that increased medial and lateral PTS were significantly associated with tibial (p < 0.0001) and femoral (p < 0.0001) tunnel widening. Meniscal root injuries (p = 0.0024) and higher BMI (p = 0.0127) were also associated with increased tunnel widening. In multivariate regression, medial PTS (ß = -0.321, p < 0.0001), lateral PTS (ß = -0.137, p = 0.0356), addition of LET (ß = 0.2207, p = 0.0257), and meniscal root injuries (p = 0.0024) remained independent predictors of tunnel widening.
Conclusion
Increased medial and lateral posterior tibial slopes, the addition of LET and the presence of meniscal root injuries are significant independent predictors of tibial and femoral tunnel widening following ACL reconstruction with a hamstring graft. These findings highlight key anatomical and surgical factors influencing postoperative tunnel remodeling and emphasize the importance of considering these variables in ACLR planning.