Occult Femoral Neck Fracture Misdiagnosed as Septic Arthritis: A Case Highlighting Diagnostic Challenges in Busy Emergency Settings.

Occult femoral neck fractures are a diagnostic challenge in busy emergency settings, especially when initial imaging is unremarkable. Confounding clinical features, temporary response to analgesia, and raised inflammatory markers can lead to misdiagnosis, delaying definitive care. We present a case of a 52-year-old male who initially presented with right hip pain following a fall. His radiographs were unremarkable, and he was discharged after pain control. He re-presented three days later with worsening hip pain, inability to weight bear, and confusion. Raised inflammatory markers led to a presumptive diagnosis of septic arthritis, but a computed tomography (CT) scan ultimately revealed a basicervical femoral neck fracture. The patient underwent successful open reduction and internal fixation (ORIF). This case underscores the importance of maintaining a high index of suspicion for occult fractures, especially in patients with persistent or worsening pain and early representation. It also highlights the limitations of plain radiography in hip trauma. CT or magnetic resonance imaging (MRI) should be considered when clinical signs are incongruent with imaging findings.