Increased prevalence of HLA-B27 in patients with ectopic ossification following traumatic spinal cord injury.

The histocompatibility antigen HLA-B27 was determined in 43 patients with post-traumatic spinal cord injury (SCI). The prevalence of B27 was significantly increased in the SCI patients with ectopic ossification. Five of 21 patients with ectopic bone had B27 compared to none of the 22 patients without ossification (P = 0.021). This finding indicates that HLA-B27 is a genetically determined risk factor for the development of heterotopic ossification following injury to the central nervous system. Future studies may determine that HLA-typing can identify a group of patients at a high risk of a disabling complication of SCI who should be treated prophylactically to prevent ectopic bone.