Vertebral body resection

Vertebral body resection for locally advanced lung cancer can be performed with acceptable morbidity and mortality rates, and with improved long-term survival, when combined with chemotherapy and radiation. A consensus has not been reached on either the optimal extent of vertebral resection or the optimal treatment regimen. Should total vertebrectomies be the standard of care for all patients, even those with minimal spine involvement? Can the extended operative times and multiple incisions and anatomic limitations that place some of the mediastinal organs at risk be justified for potential improvement in local control, or are the quicker and potentially safer endolesional resections appropriate for these tumors? Is local control, and ultimately survival, improved when additional chemotherapy and radiation therapy is given up front, or is an uninterrupted course of a higher dose of concurrent chemotherapy and radiation therapy following surgery preferred? Ideally, these questions will be answered by means of prospective randomized trials; however, because of the small number of patients who actually present with vertebral body involvement by lung cancer, physicians may have to rely on phase 2 studies and series reports from high-volume institutions to guide their treatment algorithms in the future.     

Vertebral histiocytosis-X causing spinal cord compression

An unusual case of spinal cord compression caused by histiocytosis-X of the vertebral body of T-7 was recently operated upon in our department; the case was diagnosed during the operation by means of the squash-smear cytologic technique. Characteristic cytologic features were the presence of sparse eosinophilic leukocytes containing mature, multilobed nucleai and sharp, rather coarse, cytoplasmic granules; abundant histiocytes with round to oval, sometimes indented nuclei and finely granular cytoplasm; and giant, multinucleated cells, as those seen in granulomatous lesions. These cytotypes were grouped to form a monotone, but highly characteristic pattern. We think the reported picture is diagnosic of the pathologic entity under discussion.     

Vertebral body resection and lumbar corpectomies

Corpectomies in the lumbar spine are unique operations with important and well-deserving nuances that determine their ultimate safety and efficacy. Lumbar vertebral resections are indicated in deformity and non-deformity settings. For deformities, they are reserved for those that are severe and rigid. Infections, fractures, and tumors that compromise the weight-bearing capacity of the anterior and middle columns of the spine are also indicated for lumbar vertebrectomy. Anterior column structural support is required in non-deformity situations and may be accomplished with the use of polymethyl methacrylate (PMMA) cement, osseous strut grafts (i.e. allografts/autograft), or titanium cages (static vs. expandable). The newest generation of cages have wide, rectangular footprints that span the apophyseal ring and provide a sound biomechanical environment and minimize the risk of cage subsidence compared to those with circular footprints. Neural decompression and placement of structural support can be accomplished by a variety of surgical approaches. While a traditional anterior approach is the gold-standard for lumbar vertebrectomies, minimally invasive lateral approaches and a posterior-only approach are viable management strategies. Supplemental fixation is also required and may be achieved with anterior-only instrumentation, posterior-only instrumentation, and circumferential instrumentation. In the review to follow, an evidence-based approach will be used to outline appropriate indications, surgical technique, and concomitant reconstructive and stabilization options for lumbar corpectomies. The discussion to follow ideally will help optimize outcomes for patients treated with vertebral resection and lumbar corpectomies in the lumbar spine.     

Vertebral column resection for complex spinal deformity

Vertebral column resection is a powerful tool in the management of complex spinal deformity. Indications for VCR include rigid or focal, angular kyphosis or coronal deformity, hemivertebrae, and post-tuberculous spinal deformity. We review the approach to the patient with complex spinal deformity, VCR surgical technique, intraoperative considerations and outcomes reported in the literature.     

Vertebral body replacement with expandable titanium cages

OBJECTIVES: The aim of vertebral body replacement is the stabilisation and restoration of the anterior column of the spine with removal of the diseased region. We present our results of stabilisation, pain reduction and neurological improvement using vertebral-body replacement systems METHODS: Between April 1997 and December 2002, 53 patients with malignant vertebral destruction or instability due to traumatic and osteoporotic fracture were treated. We evaluated the results after vertebrectomy and vertebral body replacement by using expandable titanium cages in a retrospective study. RESULTS: The average follow-up time was 18.9 +/- 19.9 months. The mean operation time was 173.2 +/- 77.4 minutes. Intraoperatively, we saw no implant-related complications. Perioperatively, complications appeared in 18 patients (34.0 %). 4 of them were severe, with 2 patients dying. In the total follow-up, 16 patients died, 10 of them (62.5 %) due to tumour progression. Pain reduction was reported in 52.7 %, neurological improvement in 48.0 %. One patient had a loosening of his posterior instrumentation in the further follow-up due to tumour growth with dislocation of the cage and a deterioration of his neurological deficit. CONCLUSION: By using vertebral body replacement systems, sufficient stabilisation of the vertebral column, pain reduction and neurological improvement can be achieved with an acceptable perioperative risk.     

Velocity-dependent ankle torque in rats after contusion injury of the midthoracic spinal cord: time course

Progressive neurophysiological changes in the excitability of the pathways that subserved ankle extensor stretch reflexes were observed following midthoracic contusion. The purpose of the present study was to determine the nature and time course of velocity-dependent changes in the excitability of the ankle stretch reflex following T(8) contusion injury. These studies were conducted in adult Sprague-Dawley rats using a 10-g 2.5-cm weight drop onto the exposed thoracic spinal cord (using an NYU injury device and a MASCIS protocol). Velocity-dependent ankle torques and triceps surae EMGs were measured in awake animals over a broad range of rotation velocities (49-612 deg/sec) using instrumentation and protocol previously reported. EMGs and ankle torques were measured before and at weekly intervals following injury. Statistical tests of the data included within group repeated measures ANOVA and between group one-way ANOVA comparisons with time-matched control animals. An alternating pattern of significant increase followed by significant decrease in velocity-dependent ankle torque was observed during the first postinjury month. An increase of 33% in the peak torque and 24% in peak EMG magnitude at 612 deg/sec was observed in the first week. EMG burst amplitudes, that were timed-locked to the dynamic phase of the rotation, were observed to increase and decrease in a manner, which indicated that the changes in torque included stretch-evoked active contractions of the ankle extensors. During the second and third postinjury months, consistent 24-40% increases in the peak torques and 17-107% increases in the EMG magnitudes at the highest velocity were observed. No significant increases in torques were observed in the slowest rotation velocity in these periods.     

Vertebral body index and bone mineral density in women with spinal fractures: 66 probands compared with controls

The bone mineral density (BMD) was measured in 61 women with compression fractures of the spine and 66 normal pre-menopausal women. Radiographs of the lateral spine were also obtained and the vertebral body index (VBI) was measured in the region L2-L4. Women with spinal fractures had lower BMD and VBI values. Using both BMD and VBI, 3 regions of fracture risk were defined. All but 2 of the fracture patients were in the moderate- or high-risk region for fracture.     

Vertebral body MRI related to lumbar fusion results

The evaluation of continued pain after a technically successful posterolateral lumbar spine fusion is often challenging. Although the intervertebral disc is often a source of low back pain, abnormal endplates may also be a focus of pain, and possibly a source of continued pain after a posterolateral fusion. MRI allows noninvasive evaluation for disc degeneration, as well as for abnormal endplates and adjacent vertebral body marrow. Previous studies have found inflammatory marrow changes, adjacent to abnormal endplates, associated with disc degeneration in low back pain patients. In this study, preoperative MRI scans in 89 posterolateral lumbar fusion patients were reviewed, by an independent radiologist, to determine whether vertebral body marrow changes adjacent to the endplates were related to contined pain. Independent chart review and follow-up telephone interview of all patients at a 4-year follow-up (mean) formed the basis for the clinical results. Vertebral body MRI signals consistent with inflammatory or fatty changes were found in 38% of patients, and always occurred adjacent to a degenerated disc. Inflammatory MRI vertebral body changes were significantly related to continued low back pain atP = 0.03. We conclude that posterolateral lumbar fusion has a less predictable result for the subset of degenerative disc patients with abnormal endplates and associated marrow inflammation. More research is needed to determine the biological and biomechanical effects of a posterolateral fusion upon the endplate within the fused segments. If indeed further study supports the hypothesis that abnormal endplates associated with inflammation are a source of pain, then treating the endplates directly by anterior fusion may be a preferred treatment for this subset of degenerative patients.