A 45-year-old male has medial compartment osteoarthritis of the knee with 8° of varus alignment and a lateral compartment that is preserved. He wishes to delay arthroplasty. The osteotomy designed to unload the medial compartment by correcting the deformity at the level of the tibial mechanical axis is:
- A Distal femoral varus osteotomy
- B Tibial plateau levelling osteotomy
- C Supracondylar femoral osteotomy to achieve neutral axis
- D High tibial osteotomy (HTO) — medial opening wedge or lateral closing wedge, targeting mechanical axis correction through the lateral 62% point of the tibial plateau (Fujisawa point) ✓
Explanation
High tibial osteotomy corrects varus malalignment at the tibial level, shifting the mechanical axis from the medial to the lateral compartment to unload the arthritic medial side. The 'Fujisawa point' — targeting the mechanical axis to pass through 62–65% of the tibial plateau from medial (i.e., slightly lateral to the centre) — is the accepted overcorrection target, as undercorrection leads to rapid failure. Medial opening-wedge HTO (using a plate and graft) and lateral closing-wedge HTO are the two main techniques; the former avoids fibular osteotomy and is more popular currently. Distal femoral osteotomy is indicated for valgus deformity with lateral compartment OA.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.