Journal of spinal disorders & techniques
-
J Spinal Disord Tech · Apr 2003
Comparative StudyTransdiscal L5-S1 screws for the fixation of isthmic spondylolisthesis: a biomechanical evaluation.
The current study is a biomechanical study using a cadaveric model of L5-S1 spondylolisthesis. The purpose of the current study was to compare, in a cadaveric model of simulated L5-S1 spondylolisthesis, the biomechanical stiffness of transdiscal fixation with traditional pedicle screw fixation, and transdiscal fixation with combined interbody/pedicle screw fixation. The surgical management of L5-S1 spondylolisthesis is a challenge because of the difficulties in achieving a reliable arthrodesis in the face of high mechanical forces. ⋯ There were no differences in stiffness between transdiscal fixation and combined interbody/pedicle screw fixation. In a cadaveric model of simulated L5-S1 spondylolisthesis, transdiscal L5-S1 fixation produced a 1.6-1.8 times stiffer construct than traditional pedicle screw fixation. Further, the stiffness of the transdiscal fixation was equal to that of a combined interbody/pedicle screw fixation.
-
J Spinal Disord Tech · Apr 2003
Comparative StudyEvaluation of descending spinal cord tracts in patients with thoracic cord lesions using motor evoked potentials recorded from the paravertebral and lower limb muscles.
We evaluated the function of the descending spinal cord motor tracts in patients, with and without spinal cord lesion, using motor evoked potentials. We studied 50 normal volunteers and 15 patients with thoracic lesions. The onset latency of the negative waves of motor evoked potentials for the thoracic spines was obtained, and the descending spinal cord conduction time was measured for the thoracic segments. ⋯ The descending spinal cord conduction time from T5-T6 to T11-T12 was also prolonged (p < 0.01) in patients with lower thoracic lesion. The descending spinal cord conduction time from T2-T3 to T11-T12 in patients with smaller motor function scores (<2) was significantly prolonged (p < 0.01) compared with normal subjects and patients with larger function scores. The methods of recording motor evoked potentials from paravertebral muscles with transcutaneous electrical stimulation over occipitocervical junction were useful for evaluating the level and motor function of thoracic cord lesions.
-
J Spinal Disord Tech · Apr 2003
A novel technique for delivery of epidural steroids and diagnosing the level of nerve root pathology.
Transforaminal epidural steroids are a commonly used technique for diagnosis and treatment of nerve root irritation secondary to herniated disc material. The recent reported occurrences of severe complications using the transforaminal technique have led to the search for a novel alternative that is both a safe and accurate method of steroid delivery. The technique described offers improved safety and diagnostic accuracy over traditional transforaminal steroid injections.