• LOOSENING AT SCREW-BONE JUNCTION IN MULTI-LEVEL ANTERIOR CERVICAL PLATE CONSTRUCT

    INTRODUCTION. High failure rates of up to 50% have been reported for long anterior cervical spine plates (Philips et al. 1997, and Swank et al. 1997). The failures of multi-level anterior plates were mostly at the vertebra-screw-plate junction at the inferior end of the construct (O'Brein et al. 1996, and Vaccaro et al. 1995). We hypothesize that the failure is a result of large relative motion between the instrumented vertebral body and the anterior plate. The purpose of the study was to investigate such motions in response to physiological and fatigue loads for one- and three-level corpectomies stabilized with anterior cervical plates.
  • THE VALIDITY OF CLINICAL TESTS IN THE DIAGNOSIS OF CERVICAL MYELOPATHY

    INTRODUCTION: Cervical myelopathy has several etiologies and presentations. Whatever the etiology, the physical signs on presentation are often few and subtle. Recognition of cervical myelopathy is essential, as it has important therapeutic implications. The purpose of this study was to test the validity of eight (8) physical exam signs in the diagnosis of cervical myelopathy. METHODS: Consecutively and prospectively, fifty-one (51) patients with symptoms referable to the cervical spine were evaluated by MRI and neurologic exam. All patients had a standard neurologic exam. Specifically, neurological signs including hyper-reflexia, hypo-reflexia, clonus, asymmetrical clonus, Hoffmann’s sign, Lhermitte’s sign, manual muscle testing and Babinski reflex were evaluated for the purposes of this study.
  • MULTIMODAL SPINAL CORD MONITORING PROMISES ACCURATE NEUROLOGICAL EVALUATION FOR INTRAMEDULLARY SPINAL CORD TUMOR SURGERY

    INTRODUCTION: Extirpation of intramedullary spinal cord tumor causes various neurological complications that can not be detected by single monitoring method. For the accurate evaluation of neurological function, we have performed multimodal spinal cord monitoring; (1) evoked compound muscle action potentials after transcranial repetitive electrical stimulation (Muscle MEPs), (2) evoked spinal cord potentials after transcranial electrical stimulation (Spinal MEPs), and (3) evoked spinal cord potentials after spinal cord stimulation (ESCPs). The purpose of this study is to ascertain the relationship between the changes of the monitoring responses and postoperative neurological outcome, and to clarify their clinical usefulness.
  • WAVES OF CELLULAR APOPTOSIS IN MODERATE SPINAL CORD INJURY (SCI) IN THE RAT

    Cell loss following SCI is greater than expected given the severity of injury. This secondary cell death is apoptotic, having many of the features of programmed cell death (PCD) that occurs during development. In an effort to approach the extensive long tract demyelination that occurs chronically after SCI, focus by several groups has been on delayed, up to 14 days, PCD in oligodendrocyte populations, occurring at a distance from the lesion epicenter after controlled contusion SCI. In contrast, we have reported that after severe (50 gm·cm force) SCI, apoptosis occurred in 4 distinct cellular compartments, including neuronal, and even motoneuronal cells, with peak PCD in 3 of these compartments at day 3 after injury.
  • INCREASED FUSION RATES WITH CERVICAL PLATING FOR TWO-LEVEL ACDF

    INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) has a high fusion rate, however, the pseudarthrosis rate increases with two-level surgeries. The use of cervical plating can provide increased stability and may allow for better healing and subsequent fusion. The purpose of this study was to compare the results of two-level ACDF in a large group of patients with and without cervical plating. METHODS: 60 consecutive patients having two-level anterior cervical discectomy and fusion by the senior author between 1990-1996 were entered into the study.
  • THE RELATIONSHIP BETWEEN DISC DEGENERATION AND MORPHOLOGIC CHANGES IN THE INTERVERTEBRAL FORAMEN OF THE CERVICAL SPINE: A CADAVERIC MRI AND CT STUDY.

    INTRODUCTION: The pathogenesis of cervical spondylosis involves degenerative changes in the intervertebral disc and subsequent morphologic changes in the zygapophyseal joints and intervertebral foramen. Nerve root compression in the intervertebral foramen is a frequent sequela of cervical spondylosis. The purpose of this study is to investigate the relationship between disc degeneration and morphologic changes in the intervertebral foramen, including the effect on the nerve root. MATERIALS AND METHODS: Seven fresh frozen human cadavers were dissected from C1 to T1, preserving the ligaments, capsules, intervertebral disc, and the neural structures.
  • RADIATION EXPOSURE USING INTRAOPERATIVE FLUOROSCOPY FOR ANTERIOR CERVICAL DISKECTOMY AND FUSION

    INTRODUCTION: The use of intraoperative fluoroscopy, in place of standard radiographs in anterior cervical decompression and fusion surgery, has received little attention and appears to be used by a minority of surgeons on a consistent basis. Identification of the appropriate level is not only necessary for a positive outcome, but is the standard of care. From personal experience, I found that the use of intraoperative fluoroscopy increased surgeon confidence and reduced operating room time. I undertook this study in an effort to determine the risks of radiation exposure using fluoroscopy to the operating surgeon and the surgical team, as well as its impact on efficiency, cost, and surgeon confidence.
  • RADIOGRAPHIC COMPARISON OF PLATED VERSUS UNPLATED FUSIONS FOR SINGLE ACDF

    INTRODUCTION: The use of plates in single level anterior discectomy and fusion has been the source of ongoing debate. The success rates of unplated single level fusions is quite high and many advocate this as the procedure of choice. The use of a plate is thought to improve stability at the fusion site and increase fusion rates, allow earlier mobilization, and may help prevent graft extrusion and collapse. This study is a review of the elective single level primary ACDF’s performed by the senior author. From 1990 to 1994 unplated ACDF was performed, and routine plating was used from 1994 to 1997. The purpose of the study is to determine if there is a difference in fusion rates and final alignment between plated and unplated fusions.