Lower lumbar back pain occurring with transient hip osteoporosis: complication of prolonged suffering and neck of femur fracture in a 24-year-old pregnant patient.

Six days after a normal delivery, a 24-year-old woman with atraumatic lumbosacral pain radiating to the left groin was referred to the orthopaedic surgeon due to worsening pain and impossible load bearing on the left lower limb. Standard pelvic radiographs revealed an unstable displaced left neck of femur (NOF) fracture. A CT scanner and MRI showed diffuse osteopaenia of the left proximal femur and the corresponding acetabulum. A diagnosis of transient osteoporosis of the hip (TOH) complicated by a pathological displaced subcapital NOF fracture was established. The patient underwent total hip arthroplasty without complication and recovered excellent function after rehabilitation. Awareness of the differential diagnosis of TOH in pregnancy, a high index of suspicion and early MRI to make an early diagnosis and to prevent devastating fracture complications are mandatory.