2025 ISAKOS Congress in Munich, Germany

2025 ISAKOS Biennial Congress Paper


Clinical Outcomes Following ACL Reconstruction With Slope Reducing High-Tibial Osteotomy: A Matched Case-Control Study

Walter Richard Lowe, MD, Houston, TX UNITED STATES
Alfred Mansour, Houston, TX UNITED STATES
Griffin Reyes, MD, Houston UNITED STATES
Jacquelyn Kleihege, PT, MPT, Houston, Tx UNITED STATES
Steven Higbie, DPT, Houston, TX UNITED STATES
Maddie Eastman, DPT, Houston UNITED STATES
David Suarez, DPT, Houston UNITED STATES
Brian Randall Duncan, PT, DPT, Houston, TX UNITED STATES
Lane Bailey, PT, PhD, DPT, CSCS, Houston, TX UNITED STATES

McGovern Medical School, University of Texas Health Sciences Center, Houston, TX, UNITED STATES

FDA Status Not Applicable

Summary

This is the first matched case control study to investigate outcomes following ACL reconstruction with SRO. The results suggest that SRO in the setting of ACL reconstruction is effective at correcting malalignment, restoring objective and self-reported function.

Abstract

Background

Elevated posterior tibial slope (≥12o) has been identified as an anatomic risk factor contributing to increased anterior cruciate ligament (ACL) reinjury rates. Slope reducing high tibial osteotomy (SRO) has been suggested as a surgical means to modify this risk factor, although there are few clinical trials examining its’ safety and clinical effectiveness in patient samples.

Hypothesis/Purpose: To compare functional performance and graft reinjury rates between patients undergoing ACL reconstruction with a SRO versus matched controls undergoing isolated ACL reconstruction.

Study Design: Matched Case-Control Study

Methods

A retrospective matched-case control study was conducted utilizing a single surgeon ACL reconstruction database. Eligible participants were 18-50 years old who received SRO and ACL reconstruction (‘ACL+SRO’ group). Participants were matched to a cohort of patients undergoing isolated ACL reconstruction (‘Isolated ACL’ group) based on age, gender, and ACL revision status. Exclusion criteria consisted of contralateral knee injury within two years of surgery, isolated coronal-plane high tibial osteotomy, and multi-ligamentous knee injury. Patient demographics and surgical data were obtained, including pre/postoperative posterior tibial slope (o). Data were obtained at return to sport and included knee range of motion deficits, single-leg balance, single- leg hop testing, and self-reported IKDC-2000 (International Knee Documentation Committee) and ACL-RSI (Anterior Cruciate Ligament Return to Sport After Injury) scores. Average follow-up for obtaining graft failure rates, return to sport rates, and self reported function via the Single Assessment Numeric Scale (SANE) score for the total sample was at 26.5mo ±5.6mo (range 9-42 mo). Generalized Linear Models and Chi-Square analyses were conducted to compare groups with an a-priori alpha level of .05.

Results

Of the 1,978 patients in the ACL registry, 46 met the study criteria and were included in the analyses (ACL+SRO group, n = 23; Isolated ACL group, n = 23). Baseline comparisons revealed that the ‘ACL+SRO’ group was heavier (200.9 ±35.1 vs 179.7 ±33.9 lbs, P = .001). The mean preoperative posterior tibial slope was 17.0o ±2.7o33 and was corrected to 7.0o ±2.2o following SRO (mean diff: -10.0o, P <.001). The ‘ACL+SRO’ group demonstrated longer time to return to sport (P < .001) and lower ACL-RSI scores (P = .027). At the follow-up assessment, there were no statistical differences in SANE score (85.3 ±7.3 vs 88.5 ±9.3, P = .349), graft reinjury rate (4.3% vs 0.0%, P = .876), rate of return to sport (87.0% vs 91.3%, P = .932), or level of return to sport between groups with 43.5% (n = 10) of the ‘ACL+SRO’ group returning to a level I or II cutting and pivoting sport versus 56.5% (n = 13) in the isolated ACL group (P = .656).

Conclusion

The SRO in the setting of ACL reconstruction appears effective at correcting malalignment, and restoring objective and self-reported function. This procedure also allows a majority of patients to return to prior levels of sporting activities. To our knowledge, this is the first comparative study examining the return to sport and follow-up outcomes of this population to a matched isolated ACL reconstruction cohort. While these data do provide evidence for ongoing investigation, it is important to note that this study is underpowered for detecting difference in reinjury rates, therefore, we recommend the performance of larger clinical trials to confirm these results.