Transient osteoporosis of the hip in an old woman: a case report

Abstract

Transient osteoporosis of the hip is a rare disease. It mainly affects pregnant women during the third trimester and also adult men. We report the case of an elderly patient who presented this rare pathology. A 65-year-old woman, with type 2 diabetes, with no other medical history, developed over the course of two months mechanical pain in the right hip joint with progressive loss of function, she had no fever and no other rheumatologic sign. She didn’t complain of weight loss or asthenia. Laboratory tests revealed the following results: normal erythrocyte sedimentation rate (ESR): 21mm/h, normal CRP 3.2 mg/l, a deficiency in 25-hydroxy-vitamin D: 18 µg/ml (normal > 30µg/ml). Full blood counts, liver function, renal function, parathyroid hormone and bone remodelling tests were within normal limits. Anteroposterior X-rays of the pelvis and hips showed no anomaly. The ultrasounds of hips showed synovial thickening without joint effusion at the right hip. Magnetic resonance imaging (MRI) of the pelvis showed diffuse homogenous low intensity signal on T1-weighted images and high intensity T2-weighted images of the right femoral head and neck which demonstrate a diffuse bone edema of the head and neck of the right femur, there was no sign of osteonecrosis or stress fracture of the subchondral bone. The diagnosis of Transient osteoporosis of the right hip was retained. A conservative treatment was prescribed, we recommended rest to reduce the load on the femoral head. The use of walking aid device was necessary. Physiotherapy was initiated to reduce pain. Tramadol 100 mg per day, intravenous zoledronic acid 5mg, calcium and Vitamin D were prescribed. The patient was improved and pain free by the fourth week of treatment and she could walk without crutches and up to 01 kilometers without pain or discomfort. Transient osteoporosis of the hip is a rare entity to be considered in old women. The diagnosis is based on MRI findings. This pathology need to be distinguished from avascular necrosis of the femur.