Journal of neurosurgery. Spine
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OBJECT Spinal metastasis is common in patients with cancer. About 70% of symptomatic lesions are found in the thoracic region of the spine, and cord compression presents as the initial symptom in 5%-10% of patients. Minimally invasive spine surgery (MISS) has recently been advocated as a useful approach for spinal metastases, with the aim of decreasing the morbidity associated with more traditional open spine surgery; furthermore, the recovery time is reduced after MISS, such that postoperative chemotherapy and radiotherapy can begin sooner. ⋯ CONCLUSIONS In the authors' opinion, MISS techniques should be considered the first choice for the treatment for patients with spinal metastasis and myelopathy. MISS is as safe and effective for spinal cord decompression and spine fixation as traditional surgery, and it also reduces the impact of surgery in critical patients. However, further studies are needed to confirm these findings.
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OBJECT Low bone mineral density in patients undergoing lumbar spinal surgery with screws is an especially difficult challenge because poor bone quality can severely compromise the maximum achievable purchase of the screws. A relatively new technique, the cortical bone screw trajectory, utilizes a medialized trajectory in the caudocephalad direction to engage a greater amount of cortical bone within the pars interarticularis and pedicle. The objectives of this cadaveric biomechanical study were to 1) evaluate a cortical screw system and compare its mechanical performance to the traditional pedicle screw system; 2) determine differences in bone quality associated with the cortical screw trajectory versus the normal pedicle screw insertion technique; 3) determine the cortical wall breach rate with both the cortical and traditional screw trajectories; and 4) determine the performance of the traditional screw in the cortical screw trajectory. ⋯ The incidence of cortical wall breach with the cortical or traditional pedicle screw trajectories was not significantly different. CONCLUSIONS The data demonstrated that the cortical trajectory provides denser bone that allows for utilization of smaller screws to obtain mechanical purchase that is equivalent to long pedicle screws placed in traditional pedicle screw trajectories for both normal- and low-quality bone. Overall, this biomechanical study in cadavers provides evidence that the cortical screw trajectory represents a good option to obtain fixation for the lumbar spine with low-quality bone.
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OBJECT Heterotopic ossification (HO) after cervical arthroplasty is not uncommon and may cause immobility of the disc. To prevent HO formation, study protocols of clinical trials for cervical arthroplasty undertaken by the US FDA included perioperative use of nonsteroidal antiinflammatory drugs (NSAIDs). However, there are few data supporting the use of NSAIDs to prevent HO after cervical arthroplasty. ⋯ Patients who used selective COX-2 NSAIDs had nonsignificantly less HO than those who used nonselective COX-2 NSAIDs. The clinical outcomes were not affected by the use of NSAIDs or the kinds of NSAIDs used (selective vs nonselective COX-2). However, the study was limited by the number of patients included, and the efficacy of NSAIDs in the prevention of HO after cervical arthroplasty may need further investigation to confirm these results.
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OBJECT The cervical interfacet spacer (CIS) is a relatively new technology that can increase foraminal height and area by facet distraction. These offer the potential to provide indirect neuroforaminal decompression while simultaneously enhancing fusion potential due to the relatively large osteoconductive surface area and compressive forces exerted on the grafts. These potential benefits, along with the relative ease of implantation during posterior cervical fusion procedures, make the CIS an attractive adjuvant in the management of cervical pathology. ⋯ The ANOVA of the Ishihara index and cervical lordotic angle did not show a statistically significant difference in degree of change in cervical lordosis among patients with a different number of levels of CIS insertion (p = 0.25 and p = 0.96, respectively). CONCLUSIONS In the authors' experience of placing CISs in more than 100 levels, they found no evidence of significant loss of cervical lordosis. The long-term impacts of these implants on fusion rates and clinical outcomes (particularly radiculopathy and postoperative C-5 palsies) remain active areas of interest and fertile ground for further studies.
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OBJECT Most cases of traumatic spondylolisthesis of the axis (hangman's fracture) can be treated nonoperatively with reduction and subsequent immobilization in a rigid cervical collar or halo. However, in some instances, operative management is necessary and can be accomplished by using either anterior or posterior fusion techniques. Because open posterior procedures can result in significant blood loss, pain, and limited cervical range of motion, other less invasive options for posterior fixation are needed. ⋯ This technique may be appropriate, depending on circumstances, for all L-E Type I and II hangman's fractures; however, the degree of associated ligament injury and disc disruption must be accounted for. Percutaneous fixation is not appropriate for L-E Type III fractures because of significant displacement and ligament and disc disruption. This report is meant to serve as a feasibility study and is not meant to show superiority of this procedure over other surgical options.