Long-term Outcomes of ACL Reconstruction and Posterior Tibial Slope Correction: A 20-Year Retrospective Analysis

Abstract

Background: Despite advancements in surgical techniques, the recurrence rate of anterior cruciate ligament (ACL) rupture after reconstruction remains between 2% and 20%. An increased posterior tibial slope (PTS) is associated with higher ACL rupture and reconstruction failure rates.

Hypothesis: Anterior closing wedge high tibial osteotomy (ACW-HTO) combined with ACL reconstruction will result in a lower rate of failure and better functional outcomes for patients with excessive PTS.

Study design: Case series; Level of evidence, 4.

Methods: The study was conducted on patients who underwent ACW-HTO combined with ACL reconstruction between 2000 and 2020. Inclusion criteria included knee anterior and lateral rotatory instability, ACL rupture, and PTS (≥12°). Exclusion criteria included follow-up <2 years, normal tibial slope, multiligament knee injuries, significant valgus/varus deformity, and Kellgren-Lawrence stage >2 symptomatic osteoarthritis. Primary outcome measures included the International Knee Documentation Committee (IKDC) score, Tegner activity scale score, Self Knee Value, patient satisfaction, and laxity measurements. Radiographic assessments measured PTS on true lateral views of the entire tibia. The surgical goal was to achieve a PTS between 4° and 10°. A subgroup analysis was performed according to the time from surgery (±10 years) and the postoperative correction of the PTS (4°-10°).

Results: The study included 27 patients (23 men, 4 women), with a mean age of 33.4 ± 8.5 years and a mean follow-up of 7.7 ± 5.2 years. No graft failures were reported. Significant improvement was observed in side-to-side anterior laxity (9.9 ± 3.1 mm preoperatively to 1.4 ± 1.2 mm postoperatively; P < .001). The mean IKDC score improved from 59.3 ± 23.0 to 75.8 ± 24.4 (P = .037), and the Tegner activity scale score improved from 3.6 ± 2.6 to 5.9 ± 2.9 (P = .037). The mean PTS decreased from 15.9° ± 2.8° to 5.5° ± 3.7° postoperatively (P < .0001). Overall, 25.9% of patients required reoperation, mainly for hardware removal. There were no statistical differences in both subgroup analysis concerning patient-reported outcome measures and satisfaction.

Conclusion: ACW-HTO combined with ACL reconstruction shows promising long-term outcomes, significantly reducing PTS and improving knee stability and function with an acceptable complication rate.

Keywords: anterior closing wedge high tibial osteotomy (ACW-HTO); anterior cruciate ligament (ACL); graft failure; posterior tibial slope (PTS).