Comparative analysis of osteotomy accuracy between the conventional and devised technique using a protective cutting system in medial open-wedge high tibial osteotomy

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. 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. 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. 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.