Anterior open wedge high tibial osteotomy for slope correction as a successful method in PCL insufficiency-Radiological and clinical results of a cohort study.

Abstract

The aim of this study was to investigate the clinical and radiological outcomes of anterior open-wedge high tibial osteotomy (AOW-HTO) performed to increase the posterior tibial slope (PTS) in patients with chronic posterior cruciate ligament (PCL) insufficiency and persistent posterior instability. Eleven patients treated between November 2018 and February 2024 were included in this study. All patients presented with chronic symptomatic PCL insufficiency in combination with a reduced PTS, reflected by an increased posterior proximal tibial angle (PPTA), and underwent AOW-HTO for slope correction. Clinical outcomes were assessed using the validated Lysholm Knee Score and Tegner Activity Scale. Scores were recorded retrospectively for the patients' best pre-injury condition, preoperatively at the time of greatest functional impairment and post-operatively at final follow-up. Radiographic evaluation included preoperative, intraoperative and post-operative assessment of the PTS using standardized lateral knee radiographs. Subjective knee stability, patient satisfaction and functional outcomes at follow-up were evaluated using a standardized questionnaire incorporating the Lysholm and Tegner scores. Eleven patients (9 male, 2 female) were included. Mean follow-up was 3.6 ± 1.7 years. The mean preoperative PPTA was 92.2 ± 7.6° (87-111°), which decreased to 83.0 ± 3.9° (80-93°) post-operatively, corresponding to a mean slope correction of 9.2°. AOW-HTO resulted in significant improvements in patient-reported functional outcomes compared with the preoperative condition. The mean Lysholm score improved from 59.0 ± 6.1 points (range, 34-95) preoperatively to 83.0 ± 18.0 points (range, 46-100) at final follow-up (p = 0.0002). Similarly, the mean Tegner activity score increased from 3.0 ± 1.8 (range, 0-7) to 5.3 ± 1.8 (range, 3-8) (p = 0.0004). However, post-operative outcomes remained below the historical pre-injury baseline values. At final follow-up, eight patients reported satisfactory knee stability without episodes of giving way. No patient required secondary PCL reconstruction or additional posterolateral stabilization following osteotomy. Statistical significance was defined as p < 0.05. AOW-HTO resulted in satisfactory subjective knee stability and significant functional improvement in selected patients with chronic PCL insufficiency. Isolated tibial slope correction represents a valid therapeutic approach in the management of complex posterior knee instability. Level IV, therapeutic studies (case series with no comparison group).