Increased Posterior Tibial Slope and Lateral Extra-articular Tenodesis Are Independently Associated With Revision ACL...

Increased posterior tibial slope (PTS) has been associated with higher revision rates after anterior cruciate ligament reconstruction (ACLR). Whether the addition of lateral extra-articular tenodesis (LET) mitigates the risk associated with increased PTS is unclear.

To determine the prevalence of increased PTS (≥12°) in a young high-risk primary ACLR population and evaluate whether LET is associated with lower revision rates in patients with increased PTS.

Cohort study; Level of evidence, 3.

This study included patients aged ≤25 years undergoing primary ACLR across 3 high-volume centers with ≥2 years between surgery and data collection. PTS was measured on lateral radiographs for medial and lateral plateaus. Primary analyses consisted of 4 prespecified multivariable logistic regression models with different PTS operationalizations as continuous predictors per 1° increase (medial PTS, lateral PTS, the maximum [PTSmax], and the lateral-medial difference), adjusted for patient and surgical covariates including graft type, with surgical center as a fixed effect. Secondary analyses used PTS dichotomized at 12°; revision rates were compared between isolated ACLR and ACLR with LET, with the treatment effect quantified as absolute risk reduction and number needed to treat.

A total of 780 patients were included; 84 (10.8%) underwent revision ACLR. Increased PTS (≥12°) was present in 28.2% of patients and more common in those requiring revision (38.6% vs 27.0%; P = .03). In patients with PTSmax ≥12°, revision occurred in 21.0% without LET and 9.2% with LET (absolute risk reduction, 11.8% [95% CI, 2.3%-21.3%]; number needed to treat, 9); in patients with PTSmax <12°, revision occurred in 13.2% without LET and 5.4% with LET (absolute risk reduction, 7.8% [95% CI, 3.0%-12.6%]; number needed to treat, 13). In the 4 prespecified multivariable models with PTS as a continuous predictor, LET was independently associated with substantially lower odds of revision ACLR (odds ratio [OR], 0.37; 95% CI, 0.22-0.62; P < .001). Lateral PTS (OR, 1.09 per 1° increase; 95% CI, 1.00-1.18; P = .04) and PTSmax (OR, 1.09; 95% CI, 1.00-1.19; P = .04) were independently associated with revision ACLR. The lateral-medial PTS difference was not associated with revision ACLR.

In a young high-risk primary ACLR population, increased PTS was present in nearly 30% of patients. LET was associated with a lower risk of revision irrespective of PTS, while increased PTS was independently associated with revision ACLR.