Occupational influences on Spondylolysis and Spondylolisthesis in a cohort of 18-year-old male military conscripts

Abstract

BackgroundThe reported prevalence of spondylolysis (SL) in the adult population is 6–7%. Data concerning adolescent-onset spondylolisthesis (SLS) and the impact of certain activities on it is scarce. We examined the risk of clinical progression of SL and SLS as a function of primary severity and occupational strain among military recruits.MethodsBased on the Israel defense Force (IDF) central human resources database, we identified 1521 18-year-old males inducted to the IDF with SL/SLS between the late nineteen nineties and early two-thousands. We followed changes in the SL/SLS status during the 3 years of obligatory military service. Disease severity was classified as Cat2: radiological findings of SL without clinical findings; Cat3: painful SL or asymptomatic grade 1 SLS; Cat4: grade 1 SLS with pain; Cat5: Grade 2 SLS. The soldiers were subdivided into the following occupational categories: administrative, combat, maintenance, and driving. The purpose was to compare the progression rates in different medical categories and job assignments.ResultsThere were 162 recruits in Cat2, 961 in Cat3, and 398 recruits in Cat4. The overall progression rate to Cat5 (grade 2 SLS) was 1.02%. Significant progression rates were seen amongst administrative soldiers with a relatively higher risk of progression from Cat4 (painful-grade-1 SLS: 2.2%) vs. Cat3 (asymptomatic SLS: 0.5%, relative risk = 4.7, p < 0.02). Other occupational categories did not exhibit significant progression rates.ConclusionProgression of SL/SLS was highest in Cat4, i.e. for recruits already diagnosed with painful SLS (i.e. with a more severe baseline disorder). Progression did not correlate with military occupation. We recommend further follow-up studies that include, aside from progression rates, incidence rates of newly diagnosed grade 2 SL during military service.