Summary

Infra-tuberosity anterior closing-wedge high tibial osteotomy for tibial slope correction does not lead to significant changes in patellar height

Abstract

Background

An excessive posterior tibial slope (PTS) is a risk factor for anterior cruciate ligament (ACL) rupture or re-rupture, 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 infra-tuberosity ACW-HTO. the aim was to assess the effect of ACW-HTO on patellar height using an infra-tuberosity approach.

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 patients with a postoperative difference < 0.3, < 0.5, or > 0.5 of the respective index. The change in patellar height category (Baja, normal, or alta) after correction of the posterior tibial slope 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 = 0.18; CDI: 0.1 ± 0.1, p = 0.41; BPI: 0.1 ± 0.2, p = 0.52). The patellar height variation was 0.5 points in only one case for CDI, and it was < 0.5 in all other cases (98.9%). Five patients (5.3 %) exhibited a postoperative change in their patellar height category when measured by the ISI (3 moved up a category, 2 moved down one, p = 0.65). Eight patients (8.5%) changed category according to the CDI (6 moved up a category, 2 moved down one, p = 0.14). Twelve patients (12.7 %) changed category according to the BPI (7 moved up a category, 5 moved down one, p = 0.55).

Conclusion

Infra-tuberosity anterior closing-wedge high tibial osteotomy for tibial slope correction does not lead to significant changes in patellar height; variations in both directions are possible but remain less than 0.5 points due to the osteotomy performed below the anterior tibial tuberosity and the preservation of the extensor apparatus.