Transient osteoporosis: an unusual presentation of hip pain in a trail runner.

We present a case of transient osteoporosis of the hip in a 38-year-old recreational trail runner. Shortly after a trail running competition, he developed acute hip pain, functional disability and an antalgic gait. Diagnosis was made with MRI showing bone marrow oedema, plain radiographs demonstrating osseous demineralisation and bone scintigraphy showing uniform radioactive uptake. Treatment included off-loading of the anatomical site for 6 months until symptom resolution, analgaesia, Vitamin D, bisphosphonates and pulsed electromagnetic field therapy. He recovered fully and returned to running activities 8 months after initial presentation. Transient osteoporosis of the hip is rare but benign, self-limiting condition; however, awareness and exact diagnosis are important as runners often present with hip pain and other more serious pathologies such as avascular necrosis or stress fractures need to be excluded.