In a patient with a varus deformity of the knee due to medial compartment osteoarthritis, a high tibial osteotomy (HTO) aims to transfer load to the lateral compartment. The ideal target of mechanical axis correction after HTO is:

• A Mechanical axis passing through the center of the knee (Mikulicz line at 50% of tibial plateau width)
• B Full valgus correction to mechanical axis at 75% of tibial plateau width
• C Mechanical axis passing slightly lateral to the center — approximately 62–66% of tibial plateau width from medial border ✓
• D Anatomical correction to 0° tibial plateau slope

Explanation

High tibial osteotomy for medial compartment OA aims to shift the mechanical axis from the diseased medial compartment to the lateral compartment. The optimal target is the Fujisawa point — 62–66% of the tibial plateau width from the medial border (i.e., slightly lateral to the lateral tibial spine). Undercorrection (neutral axis) fails to offload the medial compartment; overcorrection beyond 70% leads to lateral compartment overload and accelerated lateral OA.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.