In a patient with post-traumatic medial compartment knee osteoarthritis and a varus deformity of 12°, high tibial osteotomy (HTO) is planned. The goal of HTO is to shift the load-bearing axis to the lateral compartment by correcting the mechanical axis. The recommended overcorrection target is to achieve a mechanical axis passing through:

• A The center of the knee (50% of tibial width)
• B The lateral border of the tibial plateau
• C The lateral femoral condyle
• D 62% of the tibial width (slightly lateral to center — Fujisawa point) ✓

Explanation

The Fujisawa point (62.5% of tibial width from medial side) is the recommended target for mechanical axis correction in HTO for medial compartment OA. Slight overcorrection into valgus transfers load-bearing to the relatively preserved lateral compartment. Crossing through the center (50%) is insufficient; passing through the lateral border is excessive overcorrection and risks lateral compartment overloading. This 62% target is the standard taught in orthopaedic texts and corresponds to a post-operative mechanical axis of 2–3° valgus. Opening wedge HTO (medial) or closing wedge HTO (lateral) can achieve this; opening wedge is more popular as it preserves fibula and avoids peroneal nerve risk.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.