Deep venous thrombosis associated with heterotopic ossification.

The differential diagnosis of the swollen lower extremity in the patient with spinal cord injury includes deep venous thrombosis, fracture, cellulitis, joint sepsis, heterotopic ossification, hematoma formation, and neoplasm. A patient with an asymmetrically swollen limb who was found to have concurrent ipsilateral acute deep venous thrombosis and active heterotopic ossification is described. The diagnostic workup included various laboratory and radiologic studies. Therapy included anticoagulation with heparin and warfarin. To treat the heterotopic ossification, indomethacin, etidronate, and graded range of motion were used. We learned from this patient and several similar cases that acute deep-venous thrombosis and active heterotopic ossification may occur concurrently, and therapeutic anticoagulation did not lead to bleeding within or around the area of active heterotopic ossification. The possibility of a relationship between heterotopic ossification and deep venous thrombosis is presently being studied at our institution.