Outcomes Following Multilevel Cervical Disc Arthroplasty in the Young Active Population.

BACKGROUND: Cervical radiculopathy is a common disorder that portends significant morbidity. The presence of radiculopathy can have a debilitating effect on patients as well as a significant economic impact. Active duty military patients with increased physical occupational demands can be significantly impacted by cervical disease. The resulting disability can have a strong negative impact on operational readiness. Several studies have demonstrated comparably good functional outcomes between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion for single-level disease. To date, no study has specifically evaluated the functional and occupational outcomes following adjacent 2-level CDA in a young, active patient population as represented by the active duty military population. PURPOSE: To evaluate functional and occupational outcomes following adjacent 2-level CDA for cervical radiculopathy in the U.S. military population. We hypothesized that this population would have excellent symptomatic relief at the cost of a low return to duty rate. METHODS: We performed a case series with prospective follow-up of all patients who underwent adjacent two-level CDA at a single institution from 2011 to 2014. Each patient completed the Neck Disability Index questionnaire to assess functional outcome. Primary outcomes of interest were return to active military duty and complications. RESULTS: Follow-up was available for 18 of 21 (85.7%) patients. At an average follow-up of 21.4 ± 11.1 months, 12 patients (66.7%) reported complete symptomatic relief and were able to return to preoperative levels of function. Average self-reported pain score improved from 8.3 preoperatively to 1.1 postoperatively, and average postoperative Neck Disability Index score was 15.5 compared to 37.0 for those who medically retired. Radiographic analysis did not show any evidence of subsidence, migration of hardware, or heterotopic ossification. The average return to duty time was 9.6 weeks. DISCUSSION: We demonstrate that adjacent two-level CDA is capable of providing predictable symptomatic relief and maintenance of a high-demand preoperative level of function for cervical radiculopathy among a population of young and highly active individuals. Adjacent two-level CDA offers significant relief of symptoms with low risk of complication in a young, active, and high-demand cohort such as the U.S. military. Adjacent two-level CDA can be performed with the expectation of improving function, relieving symptoms, returning to preoperative levels of activity, and maintaining operational readiness.

Incidence and epidemiology of cervical radiculopathy in the United States military: 2000 to 2009.

STUDY DESIGN: Epidemiological review of a prospectively collected military database. OBJECTIVE: This investigation sought to determine the incidence of cervical radiculopathy and risk factors for its development within the population of the United States military from 2000 to 2009. SUMMARY OF BACKGROUND DATA: Currently, the epidemiology of cervical radiculopathy remains poorly understood and risk factors for its development have not been reliably defined. METHODS: The military's Defense Medical Epidemiological Database was used to identify all servicemembers diagnosed with cervical radiculopathy (International Classification of Diseases code 723.4) between 2000 and 2009. Demographic data was obtained for all identified individuals including age group, sex, race, military rank, and branch of service. Like data was recorded for all servicemembers within the Armed Forces during the time period under study. The incidence of cervical radiculopathy was calculated and unadjusted incidence rate ratios were determined. Risk factors were analyzed by performing multivariate Poisson regression analysis, controlling for all other factors within the model. RESULTS: Between 2000 and 2009, about 24,742 individuals were diagnosed with cervical radiculopathy among a population-at-risk of 13,813,333, for an incidence of 1.79 per 1000 person-years. Statistically significant differences (P<0.001) in adjusted incidence rate ratios were identified for each successive age group with mutually exclusive 95% confidence intervals. Those age 40 years and above were found to have the greatest risk of cervical radiculopathy. Female sex (P<0.001), White race (P<0.001), senior positions within the rank structure (P<0.001), and service in the Army (P<0.001) or Air Force (P=0.01) were also identified as significant risk factors for cervical radiculopathy. CONCLUSIONS: This study is the first to attempt to define the incidence of cervical radiculopathy and characterize risk factors for its development within an American population. Findings presented here indicate that age is most likely the greatest risk factor for cervical radiculopathy, with female sex, White race, senior military positions, and Army or Air Force service also influencing risk to varying degrees.