Combined open decompressive laminectomy and vertebroplasty for treatment of thoracolumbar fractures retrospective review of 41 cases.

BACKGROUND: Vertebral compression fractures are common, and can occur concomitantly in patients with symptomatic degenerative stenosis. Less commonly, complicated vertebral body fractures may involve retropulsion of bone into the spinal canal, resulting in stenosis with myelopathy and/or radiculopathy. Decompression of the neural elements can lead to destabilization and progressive kyphotic deformity. Laminectomy combined with open vertebroplasty provides a way to decompress the neural elements and stabilize the anterior columns in patients who cannot tolerate extended surgical time or complications associated with instrumentation and fusion. The authors describe the combination of decompressive laminectomy and open transpedicular vertebroplasty as a means to decompress neural elements and simultaneously stabilize the anterior vertebral column. METHODS: Forty-one patients with a total of 51 thoracolumbar fractures were included in this retrospective case review. A decompressive laminectomy was performed first, followed by vertebroplasty using an open transpedicular approach. For subjective assessment of outcome, the patients were assessed using the Oswestry Low Back Disability Questionnaire and additional questions pertaining to the patient's condition. RESULTS: Out of 51 fractures, there were 15 burst fractures and 36 compression fractures. Fracture levels ranged from T12 to S1. The average follow-up period was 27 months (range, 0.5-60 months). The mean post-operative Oswestry score was 16 (range, 0-39), and all patients except for one were subjectively pleased with the results of the procedure and said they would recommend it to others. All patients were able to return to all routine activities of daily living. CONCLUSIONS: The authors' cases indicate combining open decompressive laminectomies with vertebroplasty can be an effective treatment for patients with complicated thoracic and lumbar fractures without involving bone fusion or spinal instrumentation and with good long-term outcomes.

Minimally invasive implantation of epidural spinal cord neurostimulator electrodes by using a tubular retractor system. Technical note.

The authors describe a novel technique for the implantation of multipolar epidural spinal cord neurostimulator electrodes with the aid of a tubular retractor system. Spinal cord neurostimulation is used as a neuroaugmentive tool for treating chronic intractable pain syndromes. Minimally invasive placement of the multipolar neurostimulator electrodes may allow for shorter hospital stays and less postoperative pain associated with the incision.

Stretching and breaking characteristics of cerebrospinal fluid shunt tubing.

OBJECT: Cerebrospinal fluid (CSF) shunt system malfunction due to silastic tubing fracture necessitates revision surgery in shunt-dependent individuals. The goal of this study was to examine the mechanical stretching and breaking characteristics of new and used CSF shunt tubing catheters to determine if any inherent physical properties predispose the tubing to fracture. METHODS: Fifty-millimeter segments of new and retrieved (used) CSF shunt tubing were stretched to 120 mm in a hydraulic press to determine modulus values (modulus = stress/strain) and to measure permanent tubing deformation imparted by the applied stress and strain. Similar 50-mm tubing segments were also stretched in an electromechanical material testing system until fracture occurred; the force and strain needed to break the tubing was recorded at the time of failure. The results demonstrate that shunt tubing with a greater cross-sectional area requires greater force to fracture, and that catheters become weaker the longer they are implanted. Barium-impregnated shunt tubing, compared with translucent tubing. appears to require less applied stress and strain to break and may fracture more easily in vivo. The variety of modulus values obtained for the new catheters tested indicates that the various companies may be using materials of different quality in tubing manufacture. CONCLUSIONS: A CSF shunt catheter design that incorporates tubing with a greater cross-sectional area may lead to fewer fractures of indwelling catheters and a reduction in shunt revision surgery.

Role of Na(+)-Ca(2+) exchanger after traumatic or hypoxic/ischemic injury to spinal cord white matter.

BACKGROUND CONTEXT: Spinal cord injury is a devastating condition in which clinical disability results from demyelination of white matter tracts. Changes in glial-axonal signaling, and enhanced Ca(2+) channel activity with excessive accumulation of intracellular Ca(2+), is a common phenomenon after hypoxia/ischemia or mechanical trauma to spinal cord dorsal column white matter tracts leading to irreversible injury. PURPOSE: In the present study we examined the role of Na(+)-Ca(2+) exchanger (NCX) at physiological temperatures after hypoxia/ischemia and compressive injury to spinal cord dorsal column white matter in vitro. STUDY DESIGN: A 30-mm length of dorsal column was isolated from the spinal cord of adult rats, pinned in an in vitro recording chamber (maintained at 37 degrees C) and injured by exposure to a hypoxic atmosphere for 60 minutes or compressed with a modified aneurysm clip (2-gm closing force) for 15 seconds. The functional integrity of the dorsal column was monitored electrophysiologically by quantitatively measuring the compound action potential (CAP) with glass microelectrodes. RESULTS: The mean CAP decreased to 49.5 +/- 5.7% and 49.4 +/- 2.6% of control (p<.05) after hypoxia/ischemia and compressive injury, respectively. KB-R7943, a potent, selective NCX reverse mode inhibitor, significantly promoted greater recovery of CAP amplitude to 82.0 +/- 10.0% and 70.8 +/- 10.7% of control (p<.05) after hypoxic/ischemic or compressive injury to dorsal column white matter, respectively, when applied at 10 microM concentration. Bepridil (Research Biochemical Inc., Natick, MA, USA) (a less selective NCX inhibitor), when applied at 10 microM and 50 microM concentration promoted CAP amplitude recovery only to 46.8 +/- 7.8% and 29.9 +/- 3.3% of control, respectively, after hypoxic/ischemic injury to dorsal column white matter. Western blot analysis identified NCX presence with positive immunolabeling of 160 kD and 120 kD NCX proteins in the spinal cord white matter. CONCLUSION: In conclusion, at physiological temperature NCX activation plays an important role in intracellular calcium overload after hypoxic/ischemic and compressive injury to spinal cord dorsal column white matter in vitro.