Lumbar disc degeneration in relation to occupation.

OBJECTIVES

The aim was to study risk factors of lumbar disc degeneration demonstrable with magnetic resonance imaging (MRI) with special emphasis on occupational load and back accidents.

METHODS

The subjects in this cross-sectional study were 53 machine drivers, 51 construction carpenters, and 60 municipal office workers aged 40-45 years. Data on possible risk factors were available from current structured questionnaires and for 4 and 7 years in retrospect. The prevalence of lumbar disc degeneration L2/L3-L5/S1 was determined with MRI.

RESULTS

An increased risk was found for posterior disc bulges among the carpenters and for anterior disc bulges among the machine drivers, but decreased signal intensity was not related to occupation. Car driving was also associated with anterior disc bulges. All signs of disc degeneration were related to a history of back accidents. Disc degeneration was not related to body height, overweight, smoking, or the frequency of physical exercise.

CONCLUSIONS

Occupational load affects the risk of disc degeneration of the lumbar spine. Accidental back injuries and motor vehicle driving are associated with an increased risk of disc degeneration. Anterior and posterior disc bulges seem to be related to different types of physical loads.