Risk factors for developing heterotopic ossification in patients with traumatic brain injury

To evaluate the possible risk factors of heterotopic ossification (HO) in traumatic brain injury (TBI) patients.

A total of 151 patients with TBI were included. Demographical variables, laboratory investigations and risk factors for HO including spasticity, walking ability (using Functional Ambulation Category (FAC)), pressure ulcer, neurogenic bladder and systemic infection were recorded.

Fifty-six patients (37.1%) had HO. Time since injury and serum ALP and ESR levels were significantly higher in HO patients than in non-HO patients. Hip (73.2%) and knee (44.6%) were the most commonly involved joints. This study has detected significant associations between FAC scores (FAC 0-1-2 vs. FAC 3-4-5, p < 0.001), degree of spasticity (p = 0.01), pressure ulcer (Absent/Grade 1 vs. Grade 2, 3 and 4, p = 0.001), presence of neurogenic bladder (p < 0.001) and systemic infection (p = 0.002) with the development of HO. According to the final logistical regression analysis, only lower FAC score was independently associated with HO development (p = 0.006).

As lower scores of FAC is an independent risk factor for HO formation and is related to the severity and consequences of injury, ambulation and regular/cautious mobilization of the joints are of paramount importance in the early period of the rehabilitation in TBI patients.