Peri-Implant Fracture After Distal Femur Percutaneous Epiphysiodesis Using Transphyseal Screws.

Percutaneous epiphysiodesis using transphyseal screws (PETS) is a commonly used technique for guided growth. Technical challenges specific to the distal femur include difficulty obtaining a start point, accurately predicting trajectory across the physis, and achieving adequate thread purchase in the epiphysis. A previously unreported complication is peri-implant fracture. We present a case of peri-implant fracture after epiphysiodesis for leg length discrepancy, ultimately treated with retrograde intramedullary nail fixation. We recommend a modified PETS technique and close attention to orthopaedic principles to avoid this unfortunate complication. Key Concepts•Stress riser fractures can occur due to low bone strength and high mechanical stress, cortical defects, changes in stiffness at the ends of a construct, and changes in cross-sectional area of the bone.•Percutaneous epiphysiodesis using cannulated screws (PETS) may be safely used for guided growth of the distal femur when the surgeon can utilize a single start point, with trajectory through the physis at the junction of the lateral and middle thirds, to allow adequate purchase in the epiphysis, and to avoid stress riser creation.•A modified technique utilizing retrograde guidewire placement with antegrade screw placement may help mitigate technical challenges and avoid complication.