Diagnostic challenge of occult subtrochanteric femoral fracture in an elderly patient with negative initial MRI: a case report.

Introduction and importance: Occult fractures of the proximal femur represent a significant diagnostic challenge in elderly patients when initial imaging is negative. Delayed diagnosis can lead to fracture progression and increased morbidity. This case highlights the limitations of initial imaging and the importance of maintaining a high index of suspicion in elderly patients presenting with persistent hip pain and an inability to bear weight. Case presentation: A 76-year-old female with a background of hypertension and type 2 diabetes mellitus presented with a 3-day history of progressive left hip pain and inability to bear weight, with no history of trauma. Initial pelvic radiographs and an MRI of the pelvis were negative for fracture. The patient condition was managed conservatively with observation. However, 20 days later, her symptoms worsened, and she developed ecchymosis over the thigh. Repeat radiography revealed a left subtrochanteric femoral fracture. The patient was medically optimized with a blood transfusion and subsequently underwent intramedullary nailing of the femur, 31 days after the initial presentation. Discussion: This case demonstrates that occult fractures may not be detected on initial MRI with elderly patients at higher risk. Persistent or worsening symptoms should prompt repeated imaging. Clinical judgment remains paramount in guiding further investigation and treatment. Surgical stabilization using intramedullary fixation remains the gold standard for subtrochanteric fractures. Conclusion: In elderly patients presenting with persistent hip pain and an inability to bear weight, an occult femoral fracture must be strongly considered, even when initial imaging results are negative. Repeat imaging and prompt surgical intervention are essential.