A 45-year-old patient with a healed femoral shaft fracture complains of knee pain and instability 8 months later. X-ray shows callus but the limb has 15° varus angulation. The complication best explaining the knee symptoms is:

• A Refracture at original site
• B Myositis ossificans around the knee
• C Volkmann's ischaemic contracture
• D Malunion with altered joint biomechanics causing medial compartment overload ✓

Explanation

Varus malunion of a femoral shaft fracture shifts the mechanical axis medially, overloading the medial tibiofemoral compartment and causing accelerated osteoarthritis and medial collateral ligament strain presenting as knee pain and instability. This is a late complication of malunion rather than non-union. Myositis ossificans typically follows muscle trauma and presents as painful mass. Volkmann's contracture is a compartment syndrome sequela affecting the forearm, not the knee following femur fracture.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.