Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima City, Hiroshima, 734-8551, Japan.
Department of Orthopaedic Surgery, Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima City, Hiroshima, 734-8551, Japan; Medical Center for Translational and Clinical Research, Hiroshima University Hospital, 1-2-3 Kasumi, Minamiku, Hiroshima City, Hiroshima, 734-8551, Japan.
J Orthop Sci. 2023 Sep;28(5):1093-1098. doi: 10.1016/j.jos.2022.06.016. Epub 2022 Jul 19.
Medial malleolar osteotomy has been widely performed for posteromedial osteochondral lesions of the talus (OLT) to expose the lesion. In osteochondral fragment fixation, bioabsorbable pins should be inserted as perpendicular as possible to obtain the rigid fixation. However, the exposure of the lesion may depend on the osteotomy angle, which affects the pin insertion angles. This study aimed to analyze the relationship between pin insertion and osteotomy angles in the medial malleolar osteotomy.
Twenty-four ankles of 23 patients were included. The malleolar bisector angle which was calculated from radiographs and actual osteotomy angles were measured on radiographs, and the pin insertion and osteotomy angles were measured using MRI. The intersection angle was defined by the tangential line of the tibial plafond and medial malleolar articular facet, and the bisector of this angle was defined as the malleolar bisector angle. The relationship between pin insertion and osteotomy angles was analyzed.
There was no significant difference between the actual osteotomy (55.7° ± 6.6°) and malleolar bisector angles (57.4° ± 4.3°) on the radiograph. There was a significant correlation between pin insertion and osteotomy angles (rs = 0.601). The pin insertion angle (54.3° ± 5.9°) in the lower actual osteotomy angle than the malleolar bisector angle was smaller than those in the higher actual osteotomy angle (63.4° ± 8.2°).
This study showed the osteotomy angle affected pin insertion angle. The osteotomy angle should not be smaller than the malleolar bisector angle at medial malleolar osteotomy to insert pins as perpendicular as possible for fixation of posteromedial OLTs.
内侧踝骨切开术已广泛应用于距骨后内侧骨软骨病变（OLT）以暴露病变。在骨软骨碎片固定中，生物可吸收钉应尽可能垂直插入以获得刚性固定。然而，病变的暴露可能取决于切开角度，这会影响钉插入角度。本研究旨在分析内侧踝骨切开术中钉插入与切开角度的关系。
纳入 23 名患者的 24 例踝关节。从 X 线片上计算出踝骨平分线角度，在 X 线片上测量实际切开角度，在 MRI 上测量钉插入角度和切开角度。交点角度由胫骨平台和内踝关节面的切线定义，该角度的平分线定义为踝骨平分线角度。分析钉插入与切开角度的关系。
X 线片上实际切开角度（55.7°±6.6°）与踝骨平分线角度（57.4°±4.3°）无显著差异。钉插入角度与切开角度之间存在显著相关性（rs=0.601）。实际切开角度低于踝骨平分线角度的钉插入角度（54.3°±5.9°）小于实际切开角度较高的钉插入角度（63.4°±8.2°）。
本研究表明切开角度会影响钉插入角度。在内侧踝骨切开术时，切开角度不应小于踝骨平分线角度，以尽可能垂直地插入钉固定后内侧 OLT。
