# Comparative Analysis of Bone Resection Volume and Lateral Overhang in Four Closed-Wedge High Tibial Osteotomy Techniques—A 3D-CT Computational Simulation Study of Eleven Knees

## TL;DR

This study compares four bone-cutting techniques for knee surgery using 3D scans to determine which method removes less bone and reduces overhang.

## Contribution

The study introduces a 3D-CT computational simulation to quantitatively compare resection volumes and lateral overhang in four CWHTO techniques.

## Key findings

- Hybrid CWHTO techniques resulted in significantly smaller bony wedge resection volumes compared to conventional and oblique techniques.
- Conventional techniques showed the largest resected bony wedge volumes and non-overlapping lateral osteotomy surface areas.
- Hybrid techniques preserved more bone stock and reduced lateral overhang compared to conventional methods.

## Abstract

Purpose: This study aimed to quantitatively compare the resected bony wedge volume and evaluate discrepancies in the non-overlapping lateral osteotomy surface areas among four closed-wedge high tibial osteotomy (CWHTO) techniques. Materials and Methods: Eleven knees from 10 patients who underwent high tibial osteotomy at our hospital (2016–2023) were analyzed using preoperative three-dimensional computed tomography. Representative cases were selected based on sex, the presence of proximal tibia vara, and a high joint line convergence angle. A subgroup analysis was then conducted. Surgical simulations were performed on reconstructed bone models using four different CWHTO techniques (conventional, oblique, hybrid 2:1, and hybrid 3:1) at three target angles (12°, 15°, and 18°). Osteotomy surface area and bony wedge volume were calculated and compared. Results: Distal osteotomy surface areas for the oblique, hybrid 1, and hybrid 2 techniques were 91%, 83%, and 72% of the conventional technique, respectively. Resected bony wedge volumes were 86%, 52%, and 38% of the conventional technique, respectively. Volumes decreased in the order of conventional, oblique, hybrid 3:1, and hybrid 2:1. Hybrid techniques showed significantly smaller resection volumes than the conventional and oblique techniques. The non-overlapping lateral osteotomy surface areas for oblique, hybrid 1, and hybrid 2 were 41% (lateral), 22% (medial), and 22% (medial) of the conventional technique, respectively. Only the conventional technique showed a statistically significant difference. Conclusions: Hybrid CWHTO techniques resulted in less bony wedge resection and fewer non-overlapping osteotomy surfaces compared with conventional and oblique techniques. Hybrid CWHTO may offer potential advantages in bone stock preservation and reduced lateral overhanging area.