A case-control study was performed by Citak et al. (2012) among 132 individuals with traumatic spinal cord injury and 132 controls to determine risk factors for HO. The authors reported that the presence of complete neurological deficit was a major risk factor for HO. Moreover, factors such as spasticity, pneumonia, thoracic trauma, tracheostomy, nicotine use, and urinary tract infection increase patients’ risk for HO (Citak et al. 2012). Contrary to previous belief, the authors reported that patients with fewer comorbidities were also at a higher risk for developing HO. The evaluation of the preceding factors, in combination with early intervention and diagnosis, may reduce incidence of HO or improve a patient’s recovery post-operatively (Citak et al. 2012).
Schuetz et al. (2005) have noted that the symptoms of HO appear 3-12 weeks after spinal cord injury. Individuals with SCI typically present with joint and muscle pain, parasthesias and tissue swelling in the involved region, accompanied by a mild fever (Thomas & Amstutz 1987; Orzel & Rudd 1985; Smith 1998; Shehab et al. 2002). In the initial stages of HO, clinical signs of inflammation are nonspecific (Neal 2003).