Atypical fracture of the bowed femoral diaphysis in athletes with prior intramedullary nailing: a Case Study

Abstract

Femoral stress fractures are uncommon and typically appear in athletes or individuals with risk factors that increase mechanical load on the bone. A rare subtype is the bowed femoral shaft fracture (BFSF), caused by abnormally increased tensile stress on the lateral cortex due to diaphyseal curvature. We present the case of a middle‑aged long‑distance runner with a history of femoral fracture in childhood treated with flexible intramedullary nailing, who presented with progressive pain and functional limitation in the left thigh. Radiographs revealed a transverse fracture in an abnormally curved femur, confirmed by computed tomography. Treatment consisted of open reduction and internal fixation with a plate, followed by physiotherapy until consolidation. This case highlights the importance of considering BFSF in adult athletes with residual diaphyseal deformity after childhood femoral fracture, as early diagnosis enables appropriate management.