The spine journal : official journal of the North American Spine Society
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Discectomy is a common procedure for treating sciatica. However, both the operation and preceding herniated disc alter the biomechanical properties of the spinal segment. The disc mechanics are also altered in patients with chronic contained herniation. The biomechanical properties of the disc can potentially be restored with an elastomeric nucleus replacement implanted via minimally invasive surgery. ⋯ This study demonstrates that despite having different material properties, a nucleus replacement implant can restore the axial compressive mechanical properties of a disc after a discectomy. The implant carries compressive load and transfers the load into annular hoop stress.
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Review
Causal assessment of occupational carrying and low back pain: results of a systematic review.
Occupational low back pain (LBP) is a common musculoskeletal disorder that results in high healthcare use and a heavy societal burden from morbidity and medical costs. The etiology of LBP is unclear, although numerous physical activities in the workplace have been implicated in its development. Determining the causal relationship between LBP and specific occupational activities requires a rigorous methodological approach. ⋯ This review failed to identify high-quality studies that supported any of the Bradford-Hill criteria to establish causality between occupational carrying and LBP. Based on these results, it is unlikely that occupational carrying is independently causative of LBP in the populations of workers studied.
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Low back pain (LBP) is a common musculoskeletal disorder associated with a considerable social and economic burden within the working-age population. Despite an unclear etiology, numerous physical activities are suspected of leading to LBP. Declaring a causal relationship between occupational activities and LBP remains challenging and requires a methodologically rigorous approach. ⋯ The studies reviewed did not support a causal association between workplace manual handling or assisting patients and LBP in a Bradford-Hill framework. Conflicting evidence in specific subcategories of assisting patients was identified, suggesting that tasks such as assisting patients with ambulation may possibly contribute to LBP. It appears unlikely that workplace manual handling or assisting patients is independently causative of LBP in the populations of workers studied.
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Spontaneous spinal hematoma (SSH) after low-molecular-weight heparin (LMWH) therapy is a rare cause of compressive myelopathy with neurological deficit. Emergent surgical decompression is commonly advocated for optimal neurological recovery. Only three cases of spontaneous spinal subdural hematomas after LMWH therapy have been reported in the literature, and this is the first report of a spontaneous cervical epidural hematoma (EDH). ⋯ LMWH therapy is an important cause of SSH leading to significant neurological deficits. Conservative management is a viable treatment option in patients who demonstrate early and sustained neurological recovery with the cessation of LMWH therapy.
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Achieving fusion across the lumbosacral junction is challenging because of the unfavorable biomechanics associated with ending a fusion at this level. Bicortical placement of S1 pedicle screws can increase the construct stability at the lumbosacral junction; however, construct failure and pseudoarthrosis can still result. Iliac screws have been shown to increase the stiffness of lumbosacral constructs, but disadvantages include difficulty in connecting the iliac screw to adjacent sacral screws, painful screw loosening or prominence requiring removal, and the inability to place the screws in some patients with previous iliac crest autograft harvest. ⋯ Three-dimensional image guidance allows for safe placement of large S2 sacral alar screws that can provide additional biomechanical stability to lumbosacral constructs or serve as an alternate point of sacral fixation when S1 pedicle screws cannot be salvaged or placed in a medial trajectory.