Heterotopic ossification after acute spinal cord injury: early diagnosis and therapy

Heterotopic ossification is a frequent and potentially disastrous complication of acute spinal cord injury. Pathogenesis and etiology are not well described, initial clinical symptoms are uncharacteristic, specific laboratory findings do not exist. Between March 1997 and May 2000 all 290 patients admitted to our facility with acute spinal cord injury underwent standardized sonographic examinations of the soft tissue around the hip joint every three weeks, starting as early as two weeks after injury. In 12% of the patient population characteristic sonographic findings for heterotopic ossification were present while the regular x-ray examination was still unremarkable. Laboratory findings (alkaline phosphatase, C-reaktive protein, anorganic phosphate) were unspecific. Clinical findings were present only in a few patients. All patients underwent radiotherapy consisting of the administration of 5 times 3 Gy to the area as soon as possible. Follow up demonstrated no progression of the heterotopic bone formation in these cases. In conclusion, regular ultrasound examination proved to be a secure, fast and reproducible method for the very early diagnosis of heterotopic ossification after acute spinal cord injury.