A high tibial osteotomy (HTO) performed for medial compartment osteoarthritis of the knee aims to achieve a post-operative mechanical axis passing through what percentage of the tibial plateau width (from medial to lateral)?

• A 50% (neutral mechanical axis through the centre of the knee)
• B 80% (lateral compartment edge) to maximally unload the medial compartment
• C 30% (medial to neutral) for conservative partial correction
• D 62% (Fujisawa point — slightly lateral to centre) to achieve modest valgus overcorrection ✓

Explanation

Fujisawa et al. established that the optimal target for HTO is to position the mechanical axis at the 62–65% point of the tibial plateau width (measured from medial to lateral). This slight overcorrection into valgus unloads the diseased medial compartment while preventing excessive lateral overload. Overcorrecting beyond 70% shifts too much force laterally. The HTO is most effective in younger, active patients (<65 years) with isolated medial OA and good lateral compartment.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.