Epidemiological trends of spine and spinal cord injuries in the largest Canadian adult trauma center from 1986 to 2006

Abstract

Object In this study the author documents the epidemiology of spine and spinal cord injuries (SCIs) over 2 decades at the largest Level I adult trauma center in Canada. He describes the current state of spine injuries (SIs), their changing patterns over the years, and the relative distribution of different demographic factors in a defined group of trauma patients. Methods Data on all trauma patients admitted to Sunnybrook Health Sciences Centre between 1986 and 2006 were collected from the Sunnybrook Trauma Registry Database. Aggregate data on SIs and SCIs, including demographic information, etiology, severity of injuries (injury severity score [ISS]), and associated injuries, were recorded. The data were analyzed in a main category of spinal fracture and/or dislocation with or without SI and in two subgroups of patients with SIs, one encompassing all forms of SCIs and the other including only complete SCIs (CSCIs). Collected data were evaluated using univariate techniques to depict the trend of variables over the years. The number of deaths per year and the length of stay (LOS) were used as crude measures of outcome. Several multivariate analysis techniques, including Poisson regression, were used to model the frequency of death and LOS as functions of various trauma variables. Results There were 12,192 trauma patients in the study period with 23.2% having SIs, 5.4% having SCIs, and 3% having CSCIs. The SCIs constituted 23.3% of all SIs. The respective characteristics of the SI, SCI, and CSCI groups were as follows: median age 36, 33, and 30 years; median LOS 18, 27, and 29 days; median ISS 29, 30, and 34; female sex ratio 34, 24, and 23%; and case fatality rate 16.7, 16.6, and 21%. Seventy-nine percent of patients had associated head injuries; conversely, 24% of patients with head injuries had SIs. The mean admission age of patients increased by ~ 10 years over the study period, from the early 30s to the early 40s. The relative incidence of SIs remained stable at ~ 23%, but the incidence of SCIs decreased ~ 40% over time to 4.5%. Motor vehicle accidents remained the principal etiology of trauma, although falling and violence became more frequent contributors of SIs. The average annual ISS remained stable over time, but the LOS was reduced by 50% in both the SI and SCI groups. Age, ISS, and SCIs were associated with a longer LOS. The case fatality rate remained relatively unchanged over time. Poisson analysis suggested that the presence of an SCI does not change the case fatality rate. Conclusions Data in this analysis will provide useful information to guide future studies on changing SI patterns, possible etiologies, and efficient resource allocation for the management of these diseases.