A patient undergoes a high tibial osteotomy (HTO) for medial compartment knee osteoarthritis with varus deformity. The principle underlying HTO is to shift the mechanical axis to unload the diseased compartment. The goal is to correct the limb mechanical axis to pass through approximately:

• A The center of the medial tibial plateau
• B 62% of the tibial width from medial to lateral (slight overcorrection into the lateral compartment) ✓
• C The center of the tibial plateau (50%)
• D The lateral tibial spine (75% from medial)

Explanation

In medial opening wedge HTO, the Fujisawa point (62–66% from the medial tibial condyle edge) is the accepted target for the mechanical axis to pass through post-correction. This places a slight overcorrection into the lateral compartment (3–5° of anatomical valgus), which reduces medial compartment load to near zero while not overloading the lateral compartment. Correcting to exactly 50% (neutral) is insufficient to adequately unload the medial side. Over-correction beyond 75% risks lateral compartment arthritis.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.