Comparative Analysis of Osteotomy Accuracy Between the Conventional and Devised Technique Using a Protective Cutting System in Medial Open-wedge High Tibial Osteotomy

Introduction: Open-wedge high tibial osteotomy (OWHTO) is associated with potential intraoperative problems. For prevention of these problems, we thought that some surgical improvements were required and devised a protective cutting system (PCS). The purposes of this study were (1) to test our devised protective cutting system and (2) compare its accuracy in osteotomy to that of a conventional technique.

Materials And Methods: A comparative study was performed with 19 patients who underwent OWHTO with PCS (group I) and 16 patients who underwent OWHTO using a conventional technique (group II). For the evaluation of osteotomy accuracy, osteotomy lines of the anterior and posterior cortex were analyzed in the 3D surface models [Total (T), Osteotomy (O), Ratio (O/T), Effective osteotomy (E), Deviation direction (DD), and length (DL)]. Analysis of changes of the medial and lateral tibial slope was performed independently, and intraoperative complications were also analyzed.

Results: In the osteotomy line of the anterior aspect, O-anterior and Ratio (O- and T-anterior) showed statistical significance, and a larger osteotomy was observed in group II (p = 0.02 and 0.01, respectively). In the osteotomy line of the posterior aspect, Ratio (O- and T-posterior) and E-posterior showed statistical significance (p = 0.01 and 0.01, respectively). In the comparison between the change of the medial and lateral tibial slope, statistical significance was observed in both groups, and the medial tibial slope showed a larger increase than that of the lateral side (p = < 0.01 and <0.01, respectively). There were more intraoperative complications such as fracture and deviation of the osteotomy plane in group II, and this was more prominent at the posterior aspect.

Conclusions: OWHTO with PCS could improve the accuracy of osteotomies, especially those of the posterior cortex of the proximal tibia, thus resulting in a reduction of intraoperative complications.