Autonomic dysreflexia: a possible trigger for the development of heterotopic ossifications after traumatic spinal...

The aim of this study was to investigate the influence of the initial American Spinal Injury Association Impairment Scale (AIS) category and the conversion rate in acute traumatic tetraplegic patients on the development of heterotopic ossifications (HO). The second objective was to prove the hypothesis that tetraplegic patients with autonomic dysreflexia (AD) develop HO more often than patients without AD.

A retrospective analysis from 2002 to 2009 of 330 patients with spinal cord injuries was performed and led to the inclusion of 77 traumatic tetraplegic patients. Clinical data was reviewed to determine the appearance of HO (n = 8) and its possible coincidence with AD during urodynamics. Spearman's correlation coefficient was calculated to test the relationship between HO and initial AIS category or the change in AIS category within 6 weeks. A matched pair (age, neurological level of injury) analysis of two samples (n = 8 with/without appearance of HO; total n = 16) was performed.

The appearance of HO was significantly correlated with an initial AIS A compared to incomplete tetraplegia at baseline (p < 0.017). The conversion of AIS A into incomplete tetraplegia was highly correlated with the incidence of HO (p < 0.003). AD showed a positive correlation with HO (r = 0.97, p = 0.001).

An initial AIS A that converts early into an incomplete tetraplegia constitutes a risk factor for the development of HO. Additionally, AD constitutes an important trigger in the development of HO in acute traumatic tetraplegic patients.