Spine
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The vertebral levels of dorsal root ganglia innervating the dorsal portion of the L5-L6 intervertebral disc were investigated in rats using a retrograde transport method. The pathways and functions of nerve fibers supplying the dorsal portion of the disc were determined by denervation and immunohistochemistry. ⋯ The dorsal portion of the L5-L6 disc of rats was shown to be multisegmentally innervated by the T13 to L6 dorsal root ganglia. The sensory fibers from T13, L1, and L2 dorsal root ganglia were shown to innervate the dorsal portion of the L5-L6 disc through the paravertebral sympathetic trunks. In contrast, those from the L3-L6 dorsal root ganglia may innervate the dorsal portion of the L5-L6 disc through the sinuvertebral nerves.
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This static, nondestructive, in vitro biomechanical study examines anterior solid rod construct stiffness following the addition of multilevel, threaded cortical bone dowels in a bovine model. A comparison is made with a clinically relevant posterior construct with and without an anterior release. ⋯ Disc space augmentation increased stiffness except in axial rotation, in which values were restored to the intact level. Stiffness was superior to a clinically relevant posterior instrumentation comparison group following anterior release, and was equivalent to a posterior construct without anterior release except in anterior flexion. In addition, the implants enhanced lordosis. Increased rigidity should improve rates of arthrodesis, while maintenance of sagittal alignment may prevent pathologic compensatory curves in adjacent spinal segments. Further research is required to determine the optimal method of achieving structural interspace support.
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Data were collected prospectively on 38 patients who underwent anterior cervical discectomy and fusion for neck pain with no symptoms or signs of radiculopathy or myelopathy. ⋯ A significant decrease in pain, a significant increase in function, and a high degree of patient satisfaction were found with anterior cervical discectomy and fusion for neck pain. Improvements were not affected by worker's compensation status or gender.
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A prospective analysis of the relative influence of pain-specific and performance-specific cognitive variables on lifting tasks using empirically derived measures. ⋯ Data suggest that what patients believed they could achieve accurately determined their actual spinal function, independent of their sense of control over pain or their distress. Approaches to low back disorders emphasizing perceived pain control as a central cognitive determinant of disability were unsupported.