Supramalleolar Tibial Osteotomy for the Prevention of Asymmetric Crus Arthrosis: A Case Report

Asymmetric ankle osteoarthritis, whether congenital or posttraumatic, develops from disruption of the mechanical axis and leads to progressive joint degeneration. Supramalleolar osteotomy (SMO) is a joint-preserving procedure that restores alignment and redistributes joint-loading forces. However, conventional fixation often involves bulky implants or external fixators, resulting in excessive surgical trauma, high metal consumption, and prolonged rehabilitation. The optimal fixation strategy for SMO remains a topic of debate. We present a 54-year-old woman with asymmetric ankle osteoarthritis and a 13-degree varus deformity of the tibia. The patient underwent a minimally invasive SMO stabilized with a customized low-profile titanium mini-plate. Postoperative radiographs confirmed restoration of the mechanical and anatomical tibial axes and correction of the varus deformity. At the 2-month follow-up, functional outcomes improved markedly. The AOFAS ankle-hindfoot score increased from 56 preoperatively to 86 postoperatively, the Visual Analog Scale (VAS) for pain decreased from 7/10 to 2/10, and the Foot and Ankle Disability Index (FADI) improved from 58% to 88%. No complications were observed. This case highlights the potential of a customized low-profile mini-plate to achieve stable fixation with minimal implant use and reduced surgical trauma. The approach allowed early mobilization, symptomatic relief, and functional recovery within a short follow-up period. Although the favorable short-term outcome supports the feasibility of this minimally invasive method, further studies with larger cohorts and longer follow-up are needed to validate its effectiveness and cost-efficiency compared with traditional fixation techniques.