Spine
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A retrospective study to evaluate the results of single-level posterior lumbar interbody fusion (PLIF) using the Brantigan I/F cage (DePuy AcroMed Corp., Raynham, MA) filled with a mixture of local morselized autologous bone and bioactive ceramic granules. ⋯ Posterior lumbar interbody fusion using the Brantigan I/F cage with a mixture of local morselized bone and bioactive ceramic granules can yield a solid union with satisfactory regional alignment and adequate disc height without harvest of iliac crest bone.
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An in vitro human cadaveric study comparing the effects of anterior and posterior sequential destabilization conditions on thoracic functional unit mechanics was studied. ⋯ The rib head joints serve as stabilizing structures to the human thoracic spine in the sagittal, coronal, and transverse planes. In anterior scoliosis surgery additional rib head resection after discectomy may achieve greater curve and rib hump correction. The lateral portion of the facet joints plays an important role in providing spinal stability and should be preserved to minimize postoperative kyphotic deformity and segmental instability when performing decompressive wide laminectomy.
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Plain lateral radiographs of the lumbar spines of 607 women (age range 20-87 years) and 633 men (age range 20-92 years) were studied. ⋯ Using the new procedure and the database of reference values, it is possible to measure the height of lumbar discs and concavity of vertebrae objectively and precisely and to compare the results quantitatively with reference values.
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Electrophysiologic recordings were obtained from a lumbar paraspinal nerve or muscle in the anesthetized cat while electrically stimulating a paraspinal nerve or facet capsule in an adjacent lumbar segment. A variety of approaches were used to demonstrate the reflex nature of both the nerve and the muscle response. ⋯ These results indicate that afferent impulses conveyed by the medial branch of the dorsal ramus reflexly altered efferent activity to an adjacent lumbar segment. This intersegmental paraspinal reflex may span at least one or two vertebral segments. The data suggest that electrical stimulation of the facet joint capsule may not have reflexly elicited multifidus activity because neither chemical interruption (intrathecal lidocaine) nor physical interruption (nerve transection) of the presumed reflex pathway diminished or abolished the electromyographic response. Volume conduction of the stimulating currents likely elicited multifidus activity during electrical stimulation of the facet capsule. When using electrical stimulation of neural paraspinal tissues to evoke reflex muscle activity, appropriate control experiments must be performed to clearly demonstrate the reflexive nature of the response.