Agisilaos Aligizakis

Treatment of unstable thoracolumbar and lumbar spine injuries using Cotrel-Dubousset instrumentation.

STUDY DESIGN In this prospective study, the results of treating unstable thoracolumbar and lumbar injuries with Cotrel-Dubousset instrumentation were investigated. OBJECTIVE To determine the pain and work status of the patients, to evaluate neurologic status, and to assess the efficacy of instrumentation in the short term. SUMMARY OF BACKGROUND DATA Short-segment pedicle screw construct is the method of choice for reduction and stabilization of unstable thoracolumbar spinal injuries. Many investigators have recently reported a high rate of instrument failure. In this study, the use of segmental transpedicular fixation two levels above the kyphosis decreased instrument failure and sagittal collapse. METHODS Thirty patients, who had unstable thoracolumbar and lumbar spinal injuries, underwent application from a posterior approach of Cotrel-Dubousset instrumentation two levels above and one below at the thoracolumbar junction and short segment fixation in the lumbar area. Radiologic parameters were evaluated before and after surgery. RESULTS The mean follow up was 31 months (range, 25-49) months. There were statistically significant differences between the pre- and postoperative values in all radiologic parameters. Neurologic status improved in 70% of the patients, with a mean Frankel grade of 1.3 grades. CONCLUSIONS Cotrel-Dubousset instrumentation provided spinal stability in unstable injuries, forming a rigid construct and restoring physiologic thoracolumbar and lumbar postural contours because of its highly corrective effect in the sagittal profile with no loss of correction.

Complications and problems related to pedicle screw fixation of the spine.

This retrospective study analyzes the complications and the problems developed during and after pedicle screw fixation in patients with spinal disorders and trauma. One hundred twelve patients were treated using the Cotrel-Dubousset pedicle screw fixation system for degenerative disease (57 patients), trauma (42 patients), infection (eight patients), and tumor (five patients) of the lumbar or thoracolumbar spine. The average age of the patients was 47 years and the average followup was 35 months. Forty-seven general complications were seen in 41 patients (36.5%). In addition, hardware failures were observed in 12 patients (10.7%), junctional problems were seen in five patients (4.5%), problems in the instrumented segments were seen in 39 patients (34.7%), and problems of balance occurred in five patients (4.5%). Although the rate of the reported complications was high, the final outcome of the patients was not affected significantly. Placement of the pedicle screws in the thoracolumbar and lumbar spine is a technically demanding procedure. It should be used by experienced and qualified surgeons who are aware of the pitfalls associated with its use.

Treatment of closed unstable metacarpal fractures using percutaneous transverse fixation with Kirschner wires.

BACKGROUND The vast majority of metacarpal bone fractures are stable and are treated conservatively; however, when surgical intervention is to be preferred, many different operative procedures have been described. The purpose of this prospective study was to assess the anatomic and functional outcome of percutaneous transverse fixation with Kirschner wires (K-wires) of closed metacarpal neck, shaft. and intra-articular fractures of the base of the fifth metacarpal. METHODS Twenty-four consecutive patients with 25 closed metacarpal fractures were treated with this technique between 1999 and 2001. Under fluoroscopy, closed reduction and osteosynthesis with three K-wires, one proximally and two distally, was performed on the fracture site. All patients were reviewed clinically and radiologically after 3 weeks, 6 weeks, and 3 months. RESULTS The postoperative dorsal angulation ranged from 0 to 3 degrees. No measurable metacarpal shortening was observed. Callus formation was obvious in all fractures at 6 weeks. No complications were recorded, and all patients were cosmetically and functionally satisfied. CONCLUSION Treatment of closed metacarpal neck, shaft, and intra-articular fractures of the base of the fifth metacarpal with percutaneous transverse pinning, using two K-wires distally and one proximally, has shown excellent functional and anatomic outcome.

Gertzbein and load sharing classifications for unstable thoracolumbar fractures.

From 1996 to 1998, 30 consecutive patients with Level 1 thoracolumbar spinal injury were classified and treated according to the Gertzbein classification and the load sharing classification. A posterior short segment pedicle screw implant was used in 21 patients; anterior decompression with strut grafting and application of the Kaneda device was used in three patients; and six patients were treated with short posterior instrumentation and an anterior strut graft. The average followup was 32 months (range, 24–50 months). The clinical outcome was satisfactory in 22 of 30 patients. Five of nine patients had neurologic improvement. Radiographic imaging findings showed a slight loss of reduction, but the clinical outcome of the patients was not affected. No pseudarthrosis and no implant failures were recorded. The Gertzbein classification correlates the type of fracture with the degree of mechanical instability and neurologic lesion. The load sharing classification correlates fracture comminution and displacement with mechanical stability and implant failure. Patient selection is a fundamental component for a successful outcome. The best candidates for surgery are cooperative patients who require spinal mobility, patients who are able to tolerate a two-stage reconstruction, and patients in good general health.

Posterior compact Cotrel-Dubousset instrumentation for occipitocervical, cervical and cervicothoracic fusion

The authors report on 32 consecutive patients with instability at the craniocervical, cervical and cervicothoracic regions suffering from various pathologies, who were treated with posterior instrumentation and fusion using the posterior hooks-rods-plate cervical compact Cotrel-Dubousset (CCD) instrumentation alone or, in three patients, in combination with anterior operation. The patients were observed postoperatively for an average of 31 months (range 25–44 months) and evaluated both clinically and radiographically using the following parameters: spine anatomy and reconstruction, sagittal profile, neurologic status, functional level, complications and status of arthrodesis. All patients but one (who died) achieved a solid arthrodesis based on plain and flexion/extension roentgenograms. Cervical lordosis (skull–C7) and cervicothoracic kyphosis (C7–T2) was improved by instrumentation towards a physiological lateral curve by an average of 33% (P<0.05) and 28% (P<0.05) respectively. Anterior vertebral olisthesis was reduced in the craniocervical and cervicothoracic region, by 73% and 90% respectively. At final follow-up there was an improvement of the neurologic Frankel status by an average of 1.2 grades and of myelopathy in 75% of the operated patients. Good to excellent functional results were seen in 77% of the operated patients, while acute and chronic pain was reduced by an average of 2.4 grades, on a scale of 0–3, in operated patients. No neurovascular or pulmonary complications arose from surgery. There was no significant change in lateral spine profile and olisthesis at the latest follow-up evaluation. There were no instrument-related failures. One patient requested hardware removal in the hope of reducing postoperative pain in the cervicothoracic region. The poor and fair results were related to the lack of improvement of neurologic impairment and myelopathy. The results of this study demonstrate that cervical CCD instrumentation applied in the region of the skull to the upper thoracic region for various disorders is a simple and safe instrumentation that restores lateral spine alignment, improves the potential for a solid fusion and offers sufficient functional results in the vast majority of the operated patients. However, the use of hooks in spinal stenosis is contraindicated.

Levels of bone collagen markers in preterm infants: relation to antenatal glucocorticoid treatment

Although the beneficial effects of antenatally administered glucocorticoids are well documented, data on the potential of adverse consequences are limited. The objective of this study was to determine the effects of antenatally administered glucocorticoids on biochemical markers of bone metabolism of 55 preterm infants with a gestational age of 24–34 weeks who were enrolled in the study. Neonates were divided into two groups according to antenatal exposure to corticosteroids. There were no significant differences between the groups in clinical characteristics and anthropometric variables. We studied blood levels of osteocalcin (OC), carboxy-terminal propeptide of type I procollagen (PICP), and carboxy-terminal telopeptide of type I collagen (ICTP) at the time of delivery, on postnatal day 10, and at 2 and 4 months of life. Comparing the groups, we found statistically significant reduction in PICP levels at birth in corticosteroid-exposed neonates (P < 0.05). The levels of bone markers increased progressively on the first days of life. There were no significant differences between groups in bone markers at 10 days or at 2 and 4 months of life. We found no significant difference for bone markers between groups of infants exposed to single or repeated maternal corticosteroid treatments. In summary, antenatal glucocorticoid treatments are suggested to have a negative impact on fetal bone formation as reflected by low PICP levels at birth. However, this negative effect on bone markers seems to be a temporary effect that subsides on the first days of life and afterward.