Transient osteoporosis of the hip: A case report.

We report a case of transient osteoporosis of the hip (TOH) in a 59-year-old man including the clinical presentation, diagnostic studies, management and clinical progress. TOH is a rare self-limiting condition that typically affects middle-aged men or, less frequently, women in the third trimester of pregnancy. Affected individuals present clinically with acute hip pain, limping gait, and limited ranges of hip motion. TOH may begin spontaneously or after a minor trauma. Radiographs are typically unremarkable but MR imaging studies yield findings consistent with bone marrow edema. TOH is referred to as regional migratory osteoporosis if it travels to other joints or the contralateral hip. TOH often resembles osteonecrosis but the two conditions must be differentiated due to different prognoses and management approaches. The term TOH is often used interchangeably and synonymously with transient bone marrow edema.