Effect of Infratuberosity Anterior Closing Wedge Osteotomy for Posterior Tibial Slope Correction on Patellar Height in Patients Undergoing Revision ACL Reconstruction

Abstract

Background: An excessive posterior tibial slope (PTS) is a risk factor for anterior cruciate ligament (ACL) rupture or rerupture, and it can be managed by an anterior closing wedge high tibial osteotomy (ACW-HTO). The effect of slope‐changing osteotomies on patellar height is poorly described after infratuberosity ACW-HTO. Purpose: To assess the effect of ACW-HTO on patellar height using an infratuberosity approach. Study Design: Case series; Level of evidence, 4. Methods: Patients who underwent ACW-HTO between January 2019 and March 2024 were assessed for eligibility. Among 98 cases, 94 knees were analyzed with a complete radiographic assessment for the patellar height evaluation. Patellar height was measured on lateral radiographs according to the Caton-Deschamps index (CDI), Insall-Salvati index (ISI), and Blackburne-Peel index (BPI). The change in patellar height was assessed postoperatively, as were the rates of cases with a postoperative difference <0.3, <0.5, or >0.5 points of the respective index. The change in patellar height category (baja, normal, or alta) after correction of the PTS was also evaluated. Results: In univariate analysis, no significant difference was found between pre- and postoperative radiographs for the patellar height indices (differences for ISI: +0.1 ± 0.1, P = .18; CDI: +0.1 ± 0.1, P = .41; BPI: +0.1 ± 0.2, P = .52). The patellar height variation was +0.5 points in only 1 case for CDI, and it was <0.5 points in all other cases (98.9%). Five cases (5.3%) exhibited a postoperative change in patellar height category when measured by the ISI (3 moved up a category, 2 moved down a category; P = .65). Eight cases (8.5%) changed category according to the CDI (6 moved up a category, 2 moved down a category; P = .14). Twelve cases (12.7%) changed category according to the BPI (7 moved up a category, 5 moved down a category; P = .55). Conclusion: Infratuberosity ACW-HTO for tibial slope correction did not lead to significant changes in patellar height. However, slight variations in both directions were possible in a small portion of patients.