Object An increasing emphasis is being placed on the preservation or restoration of neutral upright sagittal spinal alignment in both deformity surgery and routine spinal operations. Sagittal spinal alignment is becoming recognized as an important predictor of a patient’s outcome after spinal surgery. In this literature review, the authors analyze data obtained from previously published studies conducted to evaluate neutral upright sagittal spinal alignment from the occiput to the pelvis in asymptomatic adults. Methods A review of the English-language literature was conducted to identify studies conducted to evaluate neutral upright sagittal spinal (occiput–pelvis) alignment in asymptomatic adult volunteers with no spinal disease. The authors identified 12 articles that met the strict primary inclusion criteria of the current study. From these articles, 23 angles and displacements were selected to depict neutral upright sagittal occiput–pelvis alignment. Pooled estimates of the mean and variance were calculated for angles and displacements that met secondary inclusion criteria. The greatest variation in the regional spinal curves occurred in the cervical spine from C-2 to C-7, whereas the greatest focal angulation in the spine occurred from L-4 to S-1. Sagittal spinal balance was maintained in a narrow range for alignment of the spine over the pelvis and femoral heads. Conclusions Neutral upright sagittal occiput–pelvis alignment in asymptomatic adults has been well studied regionally. Despite a wide variation in the undulating lordotic and kyphotic regional curves from the occiput to the pelvis, sagittal spinal balance is maintained in a narrower range for alignment of the spine over the pelvis and femoral heads.

Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) remains a significant cause of mortality and morbidity; however, the etiology is, as yet, unknown, despite intensive research efforts. Research in this laboratory indicates that bilirubin and oxidative stress may be responsible by leading to formation of bilirubin oxidation products (BOXes), so we investigated changes in bilirubin concentration and oxidative stress in vitro, and in cerebral spinal fluid (CSF) from SAH patients. Non-SAH CSF, a source of heme oxygenase I (HO-1), and blood were incubated, and in vitro bilirubin production measured. Cerebrospinal fluid from SAH patients was collected, categorized using stimulation of vascular smooth muscle metabolism in vitro, and information obtained regarding occurrence of vasospasm in the patients. Cerebral spinal fluid was analyzed for hemoglobin, total protein and bilirubin, BOXes, malonyldialdehyde and peroxidized lipids (indicators of an oxidizing environment), and HO-1 concentration. The formation of bilirubin in vitro requires that CSF is present, as well as whole, non-anti-coagulated blood. Bilirubin, BOXes, HO-1, and peroxidized lipid content were significantly higher in CSF from SAH patients with vasospasm, compared with nonvasospasm SAH CSF, and correlated with occurrence of vasospasm. We conclude that vasospasm may be more likely in patients with elevated BOXes. The conditions necessary for the formation of BOXes are indeed present in CSF from SAH patients with vasospasm, but not CSF from SAH patients without vasospasm.

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Object The standard treatment for lumbosacral tethered cord syndrome (TCS) in adults is surgical detethering. In patients with recurrent TCS, additional detethering operations are associated with increased risk of complications and subsequent scar formation. The authors studied the effect of undertaking a vertebral column subtraction osteotomy (VCSO) at the thoracolumbar junction to shorten the vertebral column and reduce neural element tension. Methods A model of TCS, developed in fresh-frozen human cadavers, was evaluated in three experiments. In Experiment 1, VCSO of 20 to 25 mm was performed at the T11–12 level. The vertebral column was sequentially shortened and the reduction in tension was measured separately in the terminal filum and the L-1 to S-3 or S-4 nerve roots. In Experiments 2 and 3 the reduction in tension was measured in the spinal cord after a VCSO and after simulating a traditional detethering operation. Vertebral column shortening produced tension reduction in all experiments. Tension decreased to less than 0.6 g in the terminal filum, L1–S3/4 nerve roots, and spinal cord after closure of a 20- to 25-mm VCSO. The mean ± standard deviation of the Δtension/Δdistance was −0.242 ± 0.019 g/mm for the terminal filum, −0.246 ± 0.019 g/mm for the lumbar nerve roots, and −0.216 ± 0.040 g/mm for the sacral nerve roots. A simulated traditional detethering operation required significant neural element release (detethering) to achieve spinal cord tension reduction equivalent to VCSO. Conclusions A VCSO significantly reduced neural tension at the thoracolumbar junction. This novel procedure may provide an alternative to traditional surgical detethering when scarring is excessive and the risk of complications and retethering are high.