Abstract
<jats:p>Patient-specific instrumentation (PSI)-assisted high tibial osteotomy (HTO) represents a significant advancement in the surgical management of varus knee deformity and medial compartment osteoarthritis. This chapter provides an in-depth, technique-oriented guide covering the full PSI-HTO workflow – from three-dimensional (3D) computed tomography (CT)-based deformity analysis and virtual surgical planning, through computer-aided design (CAD)/computer-aided manufacturing (CAM) guide fabrication, to intraoperative execution, bone gap management, fixation, and rehabilitation. The historical evolution, evidence-based patient selection, biomechanical rationale, comparative performance of PSI against conventional and navigation-assisted techniques, complication management, bone graft selection, long-term survivorship, return-to-sport outcomes, and future directions, including artificial intelligence (AI) and robotic assistance, are all discussed. More than 20 PubMed-indexed references support the evidence base.</jats:p>