Cross-sectional magnetic resonance imaging (MRI) study.
To find out whether different patterns of lumbar disc degeneration related to different physical work types (static vs. dynamic) can be found.
The association of lumbar disc degeneration with physical workload as well as the association of disc degeneration with low back pain (LBP) has been debated controversially. Nevertheless, many of the mainly invasive treatment concepts are based on disc degeneration models.
An MRI study was performed in female subjects aged 45 to 62 years with persistent LBP and in age-matched controls. Subjects (n = 109) were selected from nursing and administrative professions. A questionnaire was used to assess the subjects’ exposure to physical workplace factors. Disc degeneration, disc herniation, nerve root compromise, high intensity zones, endplate changes, and facet joint osteoarthritis were evaluated based on sagittal T1- and T2-weighted as well as axial T2-weighted images.
The two occupational groups could clearly be distinguished by the physical workplace factors: administrative work was associated with predominantly sitting postures whereas nursing work was associated with frequent walking, pushing, pulling, and lifting. Except for endplate (Modic) changes at L5–S1, MRI findings did not differ between the four groups, namely, nurses and secretaries with and without LBP. When analyzing the MRI findings within the two vocational groups, nerve root compromise and endplate changes in the lower lumbar spine were found to be significant (P < 0.05) risk factors for LBP. Disc degeneration, disc herniation, nerve root compromise, and facet joint osteoarthritis were present in more than 50% of the intervertebral spaces studied.
These findings give evidence that in subjects performing nonheavy work, patterns of lumbar disc degeneration are not associated with the job type and characteristic physical loadings.
An MRI study was performed to assess the frequency and pattern of lumbar disc degenerations in four groups: LBP cases and controls exposed to static or dynamic workload. No striking differences between the four groups could be identified, which indicates that factors other than physical loading determine pattern of disc degeneration.
From the *ETH Zurich, Center for Organisational and Occupational Health Sciences ZOA, Zurich, Switzerland; †Orthopaedic University Hospital Balgrist, Zurich, Switzerland; and ‡University Hospital Zurich, Department of Rheumatology and Institute of Physical Medicine, Zurich, Switzerland.
Acknowledgment date: December 21, 2005. First revision date: January 16, 2006. Acceptance date: January 18, 2006.
Supported by the Swiss State Secretariat for Education and Research.
The device(s)/drug(s) is/are FDA-approved or approved by corresponding national agency for this indication.
Federal funds were received in support of this work. No benefits in any form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript.
Address correspondence and reprint requests to Peter Schenk, PhD, ETH Zurich, Center for Organisational and Occupational Health Sciences ZOA, 8092 Zurich, Switzerland; E-mail: email@example.com