Salvage lateral open-wedge high tibial osteotomy for multiplanar deformity after failed cosmetic lateral closed-wedge...

Most failed high tibial osteotomy (HTO) ultimately proceed to conversion to total knee arthroplasty; therefore, revision HTO is rarely performed, and revision lateral open-wedge HTO (LOWHTO) is even rarer. We report a rare and technically demanding case of revision LOWHTO for a complex multiplanar deformity following failed HTO for cosmesis, achieving planned coronal varization and posterior tibial slope reduction with CT-documented decrease in excessive tibial external rotation. This case also describes posterolateral menisco-tibial subsidence (PLMTS) as a hypothesis-generating arthroscopic observation.

A 40-year-old woman presented with worsening right knee pain and an externally rotated gait with subtle foot drag during the terminal stance phase, 20 years after undergoing lateral closed-wedge HTO for cosmesis. Preoperative evaluation revealed excessive valgus deformity (8.2° valgus and MPTA 95.0°), increased PTS (19.6°), excessive tibial external rotation (35.8°), reduced tibiofibular height difference and proximal tibiofibular synostosis. MRI showed intact articular cartilage and meniscus in the knee joint. Diagnostic arthroscopy revealed a qualitatively widened posterolateral compartment gap, which we interpreted as a PLMTS-like finding. Revision LOWHTO was performed with planned coronal varization, posterior tibial slope reduction, and intended axial-plane adjustment. Postoperative arthroscopy demonstrated marked restoration of the previously abnormally widened posterolateral gap. Postoperative assessment showed improvement in MPTA from 95.0° to 87.7°, PTS from 19.6° to 12.0°, and tibial external rotation from 35.8° to 26.1°. At the 1-year follow-up, the patient demonstrated marked clinical improvement with a notable reduction in pain and gait abnormalities.

This case suggests that salvage LOWHTO may be a feasible joint-preserving option for complex multiplanar deformities after failed HTO. When multiple technical maneuvers are appropriately integrated, revision LOWHTO may allow planned coronal and sagittal correction with intended axial-plane adjustment, even in challenging scenarios. Furthermore, this case describes PLMTS as a hypothesis-generating arthroscopic observation associated with unipolar correction of the proximal tibia relative to the fibula, providing additional insight into the biomechanical sequelae of failed lateral closed-wedge HTO.