Long-term fate of C3-7 arthrodesis: 4-level ACDF versus cervical laminectomy and fusion.

BACKGROUND: Cervical spondylotic myelopathy (CSM) most commonly occurs at the C3-7 levels and is successfully treated by multilevel anterior cervical discectomy and fusion (ACDF) or cervical laminectomy and fusion (CLF), but no procedure has clearly demonstrated superiority. Most prior investigations comparing approaches are limited by marked heterogeneity in the composition of the study groups. This investigation compares ACDF versus CLF surgery specifically at C3-7 in terms of long-term neurological outcome and the fate of the adjacent levels. METHODS: Over a twelve-year period, surgeries to treat CSM at C3-7 by ACDF or CLF were retrospectively reviewed. Demographic/clinical data were recorded, pre/postoperative modified Japanese orthopedic association scores (mJOA) were calculated, and any complications were noted. RESULTS: Of 781 cervical surgery patients, 15 underwent C3-7 ACDF and 49 CLF. There were no differences in patient characteristics or pre/postoperative mJOA scores. Mean follow-up was 52 and 44 months for the anterior and posterior groups, respectively. A complication occurred in 3/15 (21%) of the anterior and 14/49 (28%) of the posterior group. No infections occurred in ACDF patients, but there were three in CLF patients. Pseudoarthrosis occurred in two ACDF patients, neither associated with symptoms. Four in the CLF group had asymptomatic pseudoarthrosis; two others needed reoperation for kyphosis at the inferior level. CONCLUSIONS: Long-term neurological improvement occurs following C3-7 ACDF and CLF to a similar degree. While not statistically significant, fewer complications, were seen following ACDF. The absence of symptomatic adjacent segment degeneration (ASD) following ACDF in this series raises a question for further study whether the statistical likelihood of ASD changes once the C3-7 levels are already fused.

4-Point C2 Fixation for Occipitocervical Fusion: Technical Case Report.

BACKGROUND: Occipitocervical fusion is an important surgical procedure to treat instability of the upper cervical and craniocervical junction. Fixation to the dense cortical bone of the occiput, contemporaneously typically accomplished with a plate and screws, is known to be strong and durable, but there are many competing methods used to secure an adequate number of fixation points of sufficient strength at the cervical end. Extension of hardware to the midcervical region to acquire additional fixation points, however, results in loss of subaxial motion segments and additional potential morbidity. The C2 vertebra is unique in that its morphology and dimensions permit fixation with longer screws than are typically possible to place in the midcervical lateral masses. Translaminar and pars screw techniques, both commonly used to achieve C2 fixation, are not mutually exclusive, as their respective trajectories are considerably different and engage different portions of the bony anatomy. METHODS: We describe a novel, 4-point C2 fixation technique for OC fusion that may avoid the need to extend fusion to the subaxial spine. RESULTS: This technical note illustrates how 4-point C2 fixation can be employed in occiptocervical fusion. CONCLUSIONS: 4-point fixation of C2 combining translaminar and pars screw placement is technically feasible and may be a suitable strategy to spare subaxial motion segments in OC fusion procedures. Futher investigation may establish its applicability to additional surgical procedures.

Postoperative lumbar spine MRI: How well does a radiology report that raises suspicion for infection correlate with true clinical infection?

INTRODUCTION: Interpretation of a lumbar spine MRI in the immediate postoperative period is challenging, as postoperative tissue enhancement and fluid collections may be mistaken for infection. Radiology reports may use ambiguous language, creating a clinical problem for a surgeon in determining whether a patient needs treatment with antibiotics or revision surgery. Moreover, retrospective criticism of management in instances of a true infection may lead to medicolegal ramifications. METHODS: A retrospective review of patients undergoing posterior-approach lumbar decompressive surgery with or without fusion over a 30-month period identified those undergoing postoperative MRI within 10 weeks of surgery. Patients initially operated upon for infection were excluded. The MRI reports were analyzed for language describing findings suspicious for infection and those of these with true infections were identified. RESULTS: Of 487 patients undergoing posterior lumbar spine decompression surgery, 68 (14%) had postoperative MRI within 10 weeks. Of these, the radiology reports raised suspicion for infection in 20 (29%), of which 2 (10%) patients had a true infection. Two patients underwent reoperation for new motor deficit from seroma/hematoma. Of 63 patients who had MRI to evaluate complaints of back and/or leg pain without new motor deficits, the MRI significantly altered management in 3 patients (4.8%). CONCLUSION: Radiology reports of postoperative lumbar spine MRIs frequently use language that raises suspicion for infection; but it is uncommon, however, that these patients harbor true infections. A radiology report describing possible infectious findings may not be considered significant without corroboration with other laboratory and clinical data.

Bilateral paraspinal muscle flap closure technique for reduction of wound complications from posterior thoracolumbar spinal fusion: results of a series of 716 patients.

OBJECTIVE: Wound complications such as surgical site infection (SSI) and dehiscence are among the most common complications of thoracolumbar spinal fusion surgery and are particularly prevalent in patients with risk factors such as obesity, diabetes, smoking, malignancy, and multilevel and/or revision procedures. A specialized wound closure technique with muscle flap mobilization, which reduces tension at the wound edges and increases the bulk of vascularized tissue in the midline, can be employed as a salvage procedure to manage wound complications. The authors evaluated the effectiveness of prophylactic muscle flap closure for reducing SSI in patients with risk factors for wound complications who undergo thoracolumbar fusion surgery. METHODS: A retrospective review of thoracolumbar fusion surgeries over a 15-year period was conducted in a group of patients at risk for wound complications to compare outcomes of patients who underwent prophylactic muscle flap closure with outcomes of patients who had conventional wound closure. Patients were selected for specialized closure based upon a protocol adopted during the study period. Patients were excluded if they had active infections or underwent tubular retractor-mediated decompression and did not have open surgery with a midline incision. RESULTS: Of 716 patients, wound closure was performed in 455 patients using conventional closure and in 261 using muscle flap closure. There were no significant differences in the ratios of male to female patients, with 251 men and 204 women with conventional closure and 133 men and 128 women with muscle flap closure, but the muscle flap patients were older than the conventional closure patients, with mean ages of 65.2 versus 62.9 years (p < 0.005). Indications for surgery in the muscle flap group and the conventional group, respectively, were metastatic disease in 44 (17%) and 32 (7%) patients; trauma in 10 (4%) and 14 (3%) patients; and degenerative disease, including spondylolisthesis, spondylolysis, and stenosis, in 207 (79%) and 409 (90%) patients, with more muscle flap patients having metastasis (p < 0.00001). Patients having muscle flaps had significantly higher rates of diabetes, smoking, and revision surgery, and a higher mean BMI and number of operative levels. The serum albumin level was slightly lower in the muscle flap group (p < 0.047). The wound infection rate was significantly lower in the muscle flap group (0.4%) compared with the conventional closure group (2.4%) (p < 0.033). CONCLUSIONS: Prophylactic muscle flap closure significantly lowers the rate of SSI in patients undergoing thoracolumbar spinal fusion who harbor risk factors for wound complications, with even fewer infections seen than in a group of patients without similar risk factors. Given the success of the technique, consideration of wider use for thoracolumbar fusion cases, even those without a high level of complexity, may be warranted.

Improved Cosmetic Outcome With Bilateral Paraspinal Muscle Flap Closure Following Cervical Laminectomy and Fusion.

BACKGROUND: Poor cosmetic results following cervical laminectomy and fusion (CLF) are rarely considered in assessing surgical complications. Atrophy from muscle denervation and posterior bone loss may result in a sunken appearance; relative tension may lead to wide, unsightly scars. Paraspinal muscle flaps are routinely employed by plastic surgeons for closure of wound infection and dehiscence. OBJECTIVE: To assess clinical and cosmetic results of CLF with/without a paraspinal muscle flap closure technique. METHODS: A retrospectively collected cohort analysis was undertaken for a 12-yr period in CLF patients. During the study period, a paraspinal muscle flap closure technique was adopted. Wounds were inspected for scar width and depth using a scale devised to categorize the posterior neck contour. Minimum follow-up was 12 mo. RESULTS: Of 159 patients, 94 wounds were evaluated of which 34 had muscle flap closure. There were no differences in age, sex, body mass index, mJOA scores, diabetes status, or number of spinal levels treated. Mean follow-up was 18.6 (12-48) and 49.8 (12-130) mo in the muscle flap and conventional closure groups respectively; contour scores were 1.20 vs 2.65 (P < .00001) and scar width was 2.8 vs 4.9 mm (P < .0001). No patient had a wound complication in the muscle flap group and 4 (7%) in the conventional closure group. CONCLUSION: Paraspinal muscle flap closure of CLF improved cosmetic appearance in terms of wound contour and scar width. Further investigation is needed to determine any effect upon wound infection and dehiscence rates.

Myelopathy from Intradural Extramedullary Metastasis as an Initial Presentation of Metastatic Melanoma.

The incidence of metastatic melanoma (MM) has been steadily rising, and it is the third most common metastatic lesion to the central nervous system (CNS). Spinal intradural extramedullary (IDEM) MM is rare, and it is associated with coexisting or antecedent brain metastasis. Metastatic disease to the CNS is a complication of advanced disease, and it generally occurs months to years after initial diagnosis and treatment. We describe the first case of an initial presentation of MM, presenting as cervical myelopathy secondary to spinal cord compression from IDEM spinal metastasis. Further work-up revealed additional lesions in the temporal lobe and cauda equina region as well as a scalp lesion that was presumed to be the primary site. MM should be considered in the differential of myelopathy secondary to a spinal intradural mass, particularly in those with a history of or risk factors for melanoma.

Protein kinase M zeta synthesis from a brain mRNA encoding an independent protein kinase C zeta catalytic domain. Implications for the molecular mechanism of memory.

Protein kinase M zeta (PKM zeta) is a newly described form of PKC that is necessary and sufficient for the maintenance of hippocampal long term potentiation (LTP) and the persistence of memory in Drosophila. PKM zeta is the independent catalytic domain of the atypical PKC zeta isoform and produces long term effects at synapses because it is persistently active, lacking autoinhibition from the regulatory domain of PKC zeta. PKM has been thought of as a proteolytic fragment of PKC. Here we report that brain PKM zeta is a new PKC isoform, synthesized from a PKM zeta mRNA encoding a PKC zeta catalytic domain without a regulatory domain. Multiple zeta-specific antisera show that PKM zeta is expressed in rat forebrain as the major form of zeta in the near absence of full-length PKC zeta. A PKC zeta knockout mouse, in which the regulatory domain was disrupted and catalytic domain spared, still expresses brain PKM zeta, indicating that this form of PKM is not a PKC zeta proteolytic fragment. Furthermore, the distribution of brain PKM zeta does not correlate with PKC zeta mRNA but instead with an alternate zeta RNA transcript thought incapable of producing protein. In vitro translation of this RNA, however, generates PKM zeta of the same molecular weight as that in brain. Metabolic labeling of hippocampal slices shows increased de novo synthesis of PKM zeta in LTP. Because PKM zeta is a kinase synthesized in an autonomously active form and is necessary and sufficient for maintaining LTP, it serves as an example of a link coupling gene expression directly to synaptic plasticity.