Risk Factors for Heterotopic Ossification in Patients With Spinal Cord Injury A Case-Control Study of 264 Patients

Study Design. Case-control study. Objective. We designed a case-control study to analyze the risk factors associated with the development of heterotopic ossification (HO) in patients with traumatic spinal cord injury. Summary of Background Data. Patients with spinal cord injury have a high risk of developing HO, although the exact etiopathogenesis is still unknown. Several factors are known to be potential risk factors. However, we are not aware of any large clinical studies evaluating the risk factors for HO. Methods. Patients who were treated for a traumatic spinal cord injury in our hospital, and who subsequently developed HO, were identified by querying the electronic database at our hospital from 2002 to 2010. One hundred thirty-two patients and 132 controls were included. Our primary outcome measures were the risk of developing HO according to whether the patient had experienced a complete spinal cord lesion according to American Spinal Injury Association Impairment Scale; tetraplegia or paraplegia; cervical, thoracic, or lumbar injury; severe chest trauma; and the time interval between injury and surgery. Secondary risk factors explored were patient age; sex; presence and number of comorbidities; length of hospital and intensive care unit stay; associated traumatic injuries; presence of spasticity, pressure ulcers, deep venous thrombosis, and urinary tract infection; and pulmonary complications, such as pneumonia and necessity of tracheostomy. Results. Patients with associated spasticity and thoracic trauma, complete lesion, pneumonia, presence of tracheostomy, and urinary tract infection had a higher risk of developing HO. Conclusion. Adequate management of potential risk factors could help reduce the overall incidence of HO and outcome in patients with traumatic spinal cord injury.