Transient bone marrow edema of the foot and ankle and its association with reduced systemic bone mineral density.

BACKGROUND

Transient bone marrow edema in the foot and ankle is an uncommon condition that should be distinguished from early avascular necrosis, stress fracture, or bone bruise. The diagnosis is based on the clinical presentation of pain with weightbearing without a history of trauma, combined with typical findings on magnetic resonance imaging. The etiology is not known, but recent case reports have suggested a possible link to systemic osteoporosis. This study examined the relationship between transient bone marrow edema of the foot and ankle and low systemic bone mineral density.

METHODS

Over a period of 2 years, ten patients (eight women and two men) who were referred to our foot and ankle clinic were diagnosed as having transient bone marrow edema. Their mean age was 59 years. All underwent dual energy X-ray absorptiometry (DEXA) scan and were tested for serum vitamin D levels. The patients were treated with either a controlled ankle motion (CAM) walker or a stiff-soled postoperative shoe and all recovered in 5 to 10 months.

RESULTS

Four patients were found to have osteoporosis and five had osteopenia. Only one patient had normal bone density. Serum vitamin D levels were low in nine patients, and normal in one.

CONCLUSIONS

Our study found a strong association with transient bone marrow edema in the foot and ankle and low systemic bone mineral density, which appears to be due to a vitamin D deficiency. We recommend that, when TBME is diagnosed, patients should be referred for assessment and treatment of their bone mineral density.