Transforaminal lumbar interbody fusion: prognostic factors related to retention in an active duty military population.

Little information is available regarding patient-based factors that may influence results following transforaminal lumbar interbody fusion (TLIF) in younger, high-demand individuals. A query of all TLIF procedures performed on active duty military personnel at our institution was conducted for the time period 2005 to 2008. Data was abstracted, including age, gender, military rank, preoperative diagnosis, complications, and ability to remain in the military. Favorable outcome was defined as the ability of the patient receiving TLIF to remain on active duty, without medical separation (Medical Evaluation Board [MEB]), at a minimum of 1 year postsurgery. Univariate analysis was conducted to identify potential risk factors for MEB. Factors with a univariate p value <0.2 were included in multivariate analysis and sensitivity testing to identify independent predictors of outcome. The cohort included 143 patients with an average age of 36.3 years and mean follow-up of 34.9 months. Younger age (odds ratio 0.93 per year increase in age; 95% confidence interval 0.87, 0.98) and Junior Enlisted rank (odds ratio 6.42; 95% confidence interval 2.20, 18.74) were found to increase the risk of MEB, and these relationships were maintained in the sensitivity analyses. These findings highlight the potential role of activity level and sociodemographic status in outcomes after TLIF in a military population.