The changing role for neurosurgeons and the treatment of spinal deformity

Spinal deformity has classically and historically been studied by those in the discipline of orthopedic surgery. This may be attributable to the orthopedic interventionalists' experience with osseous fixation for long-bone and other skeletal fractures. Neurosurgeons have maintained a long-standing interest in complex cervical spinal disorders, and their interest in the larger field of complex spinal deformity has been expanding. An understanding of spinal deformity disorders, biomechanics, bone biology, and metallurgy is necessary before clinical, teaching, and research activities can be undertaken within neurosurgery. The authors describe basic and advanced concepts of spinal deformity management with cases to illustrate teaching points.     

Childhood cancer survivors: an at-risk cohort for ankle osteonecrosis

We aimed to determine if the ankle is at risk for corticosteroid-induced osteonecrosis as a cause of pain in a cohort of childhood cancer survivors. We retrospectively reviewed magnetic resonance imaging scans of the ankle in patients treated at our institution between 1993 and 2003. Among the 15 patients who met study criteria, 20 of 30 (67%) ankles were involved. Older children had the highest incidence of the disease. The tibial metaphysis, epiphysis, and talus were the most frequent sites of osteonecrotic lesions. Ten patients were symptomatic with extended weightbearing activity. Surgery was required in four with continued amelioration of pain at last followup (17-44 months). As early detection and intervention lead to prevention of ankle morbidity, childhood cancer survivors would benefit from a prospective multi-institutional study that would provide understanding of ankle osteonecrosis and development of effective interventions. Level of Evidence: Prognostic study, Level II-1 (retrospective study).     

Methanococcus vannielii selenium-binding protein (SeBP): chemical reactivity of recombinant SeBP produced in Escherichia coli

A selenium-binding protein (SeBP) from Methanococcus vannielii was recently identified, and its gene was isolated and overexpressed in Escherichia coli [Self, W. T., Pierce, R. & Stadtman, T. C. (2004) IUBMB Life 56, 501-507]. SeBP and recombinant SeBP (rSeBP) migrated as approximately 42-kDa species on native gels and as approximately 33-kDa species on SDS gels. rSeBP consists of identical 8.8-kDa subunits, each containing a single cysteine residue. rSeBP isolated in the absence of reducing agents contained oxidized cysteine (89%) and very little bound selenium (0.05 eq or less per subunit). Complete reduction of the oxidized cysteine residues in rSeBP with Tris(2-carboxyethyl)phosphine required addition of a denaturant, such as 1 M guanidine-hydrochloride. With selenite as the selenium source and the isolated reduced protein as sole reductant, binding of one selenium per tetramer under anaerobic conditions required four cysteine thiol groups, one on each subunit. In the corresponding reaction, with reduced glutathione (GSH), equimolar amounts of selenodiglutathione (GSSeSG) and glutathione disulfide are formed from selenite and 4 GSH. At GSH-to-selenite ratios >4:1, conversion of GSSeSG to a perselenide derivative, GSSe(-), occurs. However, with the reduced rSeBP as sole electron donor in the reaction with selenite, further conversion of the R-SSeS-R product apparently did not occur. Prior alkylation of the cysteine thiol groups in reduced rSeBP prevented selenite reduction and selenium binding under comparable conditions.     

New symptomatic vertebral compression fractures within a year following vertebroplasty in osteoporotic women

BACKGROUND AND PURPOSE: Percutaneous vertebroplasty has been performed in the United States in an increasing volume since the mid-1990s. The purpose of this study is to analyze the risk of a new symptomatic vertebral compression fractures within 1 year of having an acute/subacute fracture treated with vertebroplasty. METHODS: A retrospective analysis was performed in which 253 female patients were found to have acute/subacute vertebral compression fractures secondary to osteoporosis treated with percutaneous vertebroplasty. Occurrences of new symptomatic vertebral compression fractures were recorded for a year following initial vertebroplasty. RESULTS: Fifty-five patients (21.7%) of the 253 osteoporotic women with one or more initial fractures experienced a new symptomatic vertebral compression fracture within 1 year. CONCLUSION: Roughly one-fifth of osteoporotic women with acute/subacute fracture treated with vertebroplasty will have a subsequent fracture within 1 year.     

Intradiskal extravasation with low-volume cement filling in percutaneous vertebroplasty

BACKGROUND AND PURPOSE: Adjacent fracture formation after percutaneous vertebroplasty has been reported in literature. The purpose of this study was to determine whether intervertebral disk extravasation is related to adjacent fracture formation in low-volume cement-filling vertebroplasty. METHODS: A retrospective analysis of 308 patients having vertebroplasty was undertaken. Anteroposterior and lateral procedural fluoroscopy radiographs were analyzed for mild, moderate, or severe disk extravasation. Symptomatic refracture location relative to the presence or absence of extravasation was analyzed on follow-up fluoroscopy radiographs. RESULTS: Of the 308 patients in the study, 81 patients had disk extravasation at a total of 85 vertebral levels; 40 levels had mild extravasation, 38 levels had moderate extravasation, and 7 had severe extravasation. Of the 40 levels with mild extravasation, 6 new adjacent fractures occurred next to the disk leakage. Of the 38 with moderate extravasation, 6 new adjacent fractures occurred. Of the 7 levels of severe extravasation, only one new adjacent fracture occurred. Hence, a total of 13 adjacent fractures occurred next to disk extravasation; 13 nonadjacent fractures also occurred in the patients with disk extravasation. In the patients without disk extravasation, 28 adjacent and 24 nonadjacent subsequent fractures occurred. The average available cement volumes injected into vertebral bodies causing disk leakage ranged from 4.78 to 5.60 mL. CONCLUSIONS: With low-volume cement-filling percutaneous vertebroplasty, we cannot conclude (level of significance alpha = .05) that for patients who have a new fracture there is significance between the location of the fracture and the occurrence of disk extravasation.     

Twenty months' routine use of a new percutaneous tracheostomy set using controlled rotating dilation

After a favorable trial period, we introduced the new percutaneous tracheostomy set, PercuTwist, in February of 2002 for our routine procedures. Over the next 20 mo, 90 procedures were performed with minimal complications. To prospectively evaluate this experience, we collected information on reasons for unit admission, operators' previous experience, the duration of prior tracheal intubation, the time needed for the procedure, the grading of the difficulty, the amount of bleeding, and the complications of the procedure. Twenty-two of 90 (24.4%) procedures were performed by senior consultants with experience; 68 of 90 (75.6%) were safely performed by intensive care residents under close bedside supervision. The mean time needed for the procedure was 13 min 7 s. In only one procedure during the entire study was any difficulty observed during the insertion process. This occurred because the initial skin incision was too small. However, no major bleeding or complications were encountered.     

Efficacy of multiple intraarterial papaverine infusions for improvement in cerebral circulation time in patients with recurrent cerebral vasospasm

OBJECT: Cerebral vasospasm that is caused by aneurysmal subarachnoid hemorrhage and that is refractory to maximal medical management can be treated with selective intraarterial papaverine infusions. The effects of single papaverine treatments on cerebral circulation time are well known. The purpose of this study was to assess the efficacy of multiple, repeated papaverine infusions on the cerebral circulation time in patients with recurrent vasospasm. METHODS: A retrospective study was conducted in 17 patients who received multiple intraarterial papaverine infusions in 91 carotid artery (CA) territories for the treatment of cerebral vasospasm. Cerebral circulation times were measured from the first angiographic image, in which peak contrast was seen above the supraclinoid internal CA, to the peak filling of cortical veins. Glasgow Outcome Scale (GOS) scores assessed 12 months after discharge were reviewed. Cerebral circulation times in 16 CA territories were measured in a control group of 11 patients. Seventeen patients received a total of 91 papaverine treatments. Prolonged cerebral circulation times improved after 90 (99%) of 91 papaverine treatments. The prepapaverine mean cerebral circulation time was 6.54 seconds (range 3.35-27 seconds) and the immediate postpapaverine mean cerebral circulation time was 4.19 seconds (range 2.1-12.6 seconds), an overall mean decrease of 2.35 seconds (36%, p < 0.001). Recurrent vasospasm reflected by prolonged cerebral circulation times continued to improve with subsequent papaverine infusions. Repeated infusions were just as successful quantitatively as the primary treatment (mean change 2.06 seconds). The mean cerebral circulation time in the control group was 5.21 seconds (range 4-6.8 seconds). In five patients a dramatic reversal of low-attenuation changes was detected on computerized tomography scans. The mean GOS score at 12 months after discharge was 3.4. CONCLUSIONS: The preliminary results indicate that multiple intraarterial papaverine treatments consistently improve cerebral circulation times, even with repeated infusions in cases of recurrent vasospasm.     

Cutaneous sarcoidosis at sites of previous laser surgery

A 33-year-old patient was referred for evaluation and treatment of enlarging scars in areas where full-face carbon dioxide (CO2) laser resurfacing had been performed previously. The patient denied any systemic illness and was in good health at the time of presentation. This is a case report of isolated sarcoidosis limited to the skin associated with CO2 laser resurfacing.