Posterior Tibial Slope and High-Severity Meniscal Tears With Anterior Cruciate Ligament Injury

Increased posterior tibial slope (PTS) is a known risk factor for anterior cruciate ligament (ACL) injury and incidence of concomitant meniscal tears. However, the effect of PTS on the severity of concomitant meniscal injury has not been investigated.

To characterize the association between PTS and concomitant meniscal injury severity among patients with ACL injury and identify risk factors for high-severity meniscal tears.

Cross-sectional study; Level of evidence, 3.

We retrospectively identified patients who underwent primary ACL reconstruction (ACLR) at a single institution from 2015 to 2021. Patients were excluded if they had a multiligament injury, underwent magnetic resonance imaging (MRI) >12 weeks before surgery, or had >1 year between the injury and surgery. We collected patient demographics, preoperative course, surgical details, and measured medial and lateral PTS. The primary outcome was the presence of a high-severity meniscal tear identified at the time of arthroscopy, defined as a medial or lateral complex, bucket-handle, root, or Zone 3 radial tear. We determined the association between PTS and high-severity meniscal tears using both univariate and logistic regression analyses.

We included 219 patients-47% women, aged 25.3 ± 10.3 years, with a body mass index (BMI) of 25.6 ± 4.5 kg/m²- in the analysis. A total of 41 patients (18.7%) underwent a medial meniscal procedure, 68 patients (31.1%) underwent a lateral meniscal procedure, 42 patients had both medial and lateral meniscal procedures (19.2%), and 68 patients had no meniscal tear (31.1%). The mean medial PTS was 4.3°± 2.8°, and the mean lateral PTS was 5°± 3.1°. The rate of any high-severity meniscal tear was 11.4% or 11% for a high-severity medial or lateral meniscal tear, respectively. BMI was positively associated with medial or lateral high-severity meniscal tears (odds ratio, 1.12 [95% CI, 1.04-1.21]; P = .003). Neither medial nor lateral PTS was associated with high-severity meniscal tears (all, P > .05).

Our study shows that neither medial nor lateral PTS was associated with high-severity meniscal tears in patients undergoing ACLR within 1 year of injury, given the available numbers in this study. While BMI was an independent factor associated with meniscal tear severity, delays in surgery did not increase the odds of severe meniscal tear incidence when taking into account PTS. Our study does not support the use of PTS to alter the timing or indications for ACLR out of concern for an increase in the severity of encountered meniscal tears.