Transient osteoporosis of the hip in pregnancy: the orthopaedic management of bilateral neck of femur fractures in the third trimester.

Transient osteoporosis of the hip (TOH) is a rare cause of pelvic pain in the third trimester of pregnancy and post partum. Although several cases have been reported in literature, its aetiology is poorly understood. The diagnosis is commonly missed in pregnancy, as the presenting symptoms can be vague, and the risks of radiographic imaging deter clinicians from pursuing investigation. In extreme cases, this pathology presents with neck of femur fractures, with no current guidelines on optimal management. We describe the case of a 24-year-old woman who presented with bilateral neck of femur fractures at 34 weeks gestation. Following an emergency caesarean section, operative management consisted of bilateral closed reduction and internal fixation using dynamic hip screws. Postoperative radiographs demonstrated failure of fixation on the left side, which was revised to a complex primary arthroplasty. This case demonstrates both the diagnostic and management challenges associated with TOH.