2.1. D-Hole Violation Simulation Study
rheumatoid arthritis, compartment osteoarthritis, lateral tibial subluxation, stroke, infection, Parkinson’s disease
RHEUMATOID ARTHRITIS, INFLAMMATORY ARTHRITIS, EROSION, OSTEONECROSIS, STROKE, INFECTION, PERIPHERAL VASCULAR DISEASE, GOUTY ARTHRITIS, JOINT INFLAMMATION
This study was approved by the Institutional Review Board (IRB) of the authors’ institution (No.2007-085-1141). Radiological information of patients with medial compartment osteoarthritis and varus alignment who underwent MOWHTO between February 2011 and June 2019 were retrospectively reviewed. The exclusion criteria included the following conditions: loss of lateral compartment joint space, lateral tibial subluxation of 1 cm or more, medial tibial plateau erosion of 2–3 mm or more, knee flexion angle of less than 90 degrees, correction angle greater than 20 degrees required, inflammatory arthritis such as rheumatoid arthritis or gouty arthritis, presence of peripheral vascular disease, joint inflammation due to infection or osteonecrosis, and patients with stroke, Parkinson’s disease, or other neurological conditions. Preoperative teleradiograms and CT scans of the lower extremity were analyzed.On the preoperative radiographs, tibial length, tibial width, medial proximal tibial angle (MPTA), and hip–knee–ankle angle (HKAA) were measured. Tibial length was defined as the distance between the center of the intercondylar eminence of the proximal tibia and the center of the inferior articular surface of the distal tibia, while tibial width was defined as the distance between the most medial point and the most lateral point of the tibial plateau. Tibial width was measured on both preoperative radiographs and CT scans, with the tibial length measured on radiographs being multiplied by the ratio of the tibial width measured on the CT scans and radiographs. Lower extremity CT scans were acquired using a 64-channel multi detector CT, with images taken while the knee was extended. Digital Imaging and Communications in Medicine (DICOM) data were exported to a Picture Archiving and Communication System (PACS), and the 3D multiplanar reconstruction function of PACS DICOM Viewer was used to reconstruct images and derive the virtual osteotomy plane.The virtual osteotomy plane (VOP) was defined as an inclined line starting just above the pes insertion on the medial surface of the proximal tibia and extending toward the proximal tibiofibular junction. The proximal segment length (PSL) was defined as the distance between the starting point of the VOP and the medial corner of the tibial articular surface (