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

<b>Purpose</b>: 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. <b>Materials and Methods</b>: 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. <b>Results</b>: 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. <b>Conclusions</b>: 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.