Is age more than manual material handling associated with lumbar vertebral body and disc changes? A cross-sectional multicentre MRI study.

Objective Conflicting evidence exists to what extent manual material handling (MMH) causes lumbar disc disease, lack of evidence exist that this effect takes place especially at L5-S1 level, where the greatest moment occurs. The aim was to assess if lumbar vertebral body and disc changes are more common in people whose job involves significant MMH and, if so, to evaluate if lumbar vertebral body and disc changes are more prevalent in the lower part of the lumbar spine (L4-L5 and L5-S1). Design Observational, cross-sectional, with quasi-random recruitment. Setting Outpatient radiology units of three large hospitals in northern (Bologna and Brescia) and southern (Bari) Italy. Participants 183 consecutive adult subjects (89 males, 94 females) aged 20-70 years referred by the general practitioner or a specialist for MRI of the lumbar spine. Primary and secondary outcome measures Neuroradiologists (blind to clinical assessment) evaluated the prevalence of intervertebral disc and vertebral body changes in standardised MRI examinations. History of personal and family musculoskeletal diseases and injuries, current and previous MMH at work and during leisure time were assessed by interview and self-administered questionnaire. Results Participants were classified according their occupational exposure to MMH. No association was found between MMH and vertebral body and intervertebral disc changes, whereas age over 45 years was consistently associated with more disc extension beyond the interspace changes, Pfirrmann changes, osteophytes and Modic changes: the association was statistically significant at the conventional 5% level. Conclusions Age, and not MMH, seems to primarily affect the presence of intervertebral disc changes; prospective studies are needed to better explore the relationship between MMH and the possible presence (and level) of lumbar vertebral body and/or disc changes.