Legg-Calvé-Perthes disease following Ender nail fixation of a pediatric femoral fracture.

INTRODUCTION AND IMPORTANCE: Legg-Calvé-Perthes disease (LCPD) sometimes occur in children, however it is difficult to diagnose it at the early stage especially in the cases there are no complaints of symptoms. Femoral shaft fractures in children cause various complications such as leg-length discrepancy, nonunion and malunion, refracture, and osteonecrosis of the femoral head. We presented a rare case in which a pediatric patient developed LCPD after femoral shaft fracture.

CASE PRESENTATION: A healthy 8-year-old boy sustained a left femoral diaphyseal fracture following a pedestrian car accident. Fixation was achieved using retrograde Ender nails; bone union was confirmed at 3 months postoperatively, and the Ender nails were removed at 8 months postoperatively without any problems. Unfortunately, the morphological change of the ipsilateral femoral head and subtle symptoms were missed until the femoral head collapsed. LCPD was successfully treated with intertrochanteric varus osteotomy, which achieved a good clinical result.

CLINICAL DISCUSSION: Although the reason for the ipsilateral LCPD after the femoral shaft fracture is unclear, this case highlights the need for close postoperative follow-up of pediatric femoral fractures resulting from high-energy trauma to prevent the misdiagnosis of this coincidental complication.

CONCLUSION: This case report describes a missed ipsilateral LCPD after a femoral diaphyseal fracture caused by high-energy trauma. Close postoperative follow-up with a detailed assessment and vigilant interpretation of postoperative radiography is imperative to avoid delayed/missed diagnosis of conditions for which early management may provide better outcomes.