The Purpose of this study was to investigate location, the efficacy of diagnostic tools, and risk factors for heterotopic ossification which was a frequent complication in patients with traumatic brain injury(TBI).

Among the fifty-four patients with TBI, heterotopic ossification was developed in twelve patients(22.2%). The most common location was around the hip joint with the incidence of 59.2%. The significant risk factors related to heterotopic ossification were associated long bone fractures and spasticity. The time of diagnosis of heterotopic ossification among six patients was 3.8 months after TBI. Serum alkaline phosphatase levels were elevated in all eight patients with heterotopic ossification within 12 months after injury. All ten patients who took the bone scan reveled increased activity.

In accordance with close clinical observation, serial laboratory tests are needed in patients with TBI at risk of heterotopic ossification. Serial serum alkaline phosphatase measurement, roentgenography and 3 phase bone scan are required for early diagnosis and evaluation of the maturity of heterotopic ossification