In limb salvage surgery for distal femoral osteosarcoma in a skeletally immature child, an expandable/growing prosthesis is preferred. Which biological approach offers an alternative to a metal expandable prosthesis while preserving epiphyseal function?

• A Distraction osteogenesis using an Ilizarov frame to regenerate lost bone
• B Rotationplasty (Van Nes procedure) converting the ankle joint to a functional knee joint ✓
• C Osteoarticular allograft reconstruction preserving the adjacent natural joint
• D Custom hemicortical resection with fibular strut grafting

Explanation

Rotationplasty (Van Nes rotation) is a biological limb-sparing alternative for skeletally immature children with distal femoral tumors. The distal leg is rotated 180° and re-attached so the ankle joint functions biomechanically as a knee joint; a below-knee prosthesis is fitted, providing excellent function. It avoids the complications of expandable metallic prostheses (mechanical failure, multiple lengthening procedures) and preserves neurovascular supply. Osteoarticular allografts have high complication rates (fracture, infection, resorption). Ilizarov distraction is used for intercalary defects, not epiphyseal replacement.

Reference: Maheshwari Essential Orthopaedics, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.