• RELATIONSHIP BETWEEN SPINAL-CORD DEFORMATION AND NEUROLOGICAL DEFICIT IN POST-REDUCTION CERVICAL-SPINE INJURIES

    INTRODUCTION: The mechanisms leading to the deleterious effects of severe spinal-cord injury are complex and multifactorial. Neurological deficit may stem from the initial insult to the cord or from secondary effects such as ischemia, hemorrhage, and/or edema. Our study examined the relationship between the severity of neurological deficit in cervical-spine injuries and the degree of post-reduction spinal-cord deformation. METHODS: We reviewed MRI scans and medical charts of patients with cervical spine injuries admitted to Harborview Medical Center between January 1995 and February 1997.
  • ARTHRODESIS FROM SYNERGISTIC COMBINATIONS OF BONE SUBSTITUTES AND INTERBODY FUSION CAGES

    INTRODUCTION: The integration of two technologies, interbody fusion cages and osteopromotive bone substitutes, has lead to a synergistic method of promoting arthrodesis after anterior cervical discectomy. Traditionally, bone grafts have been harvested from the iliac crest but the possibility of donor site morbidity or insufficient quantities have been among the key factors in the research and development of osteopromotive bone substitutes. At the forefront of this technology is rhBMP-2. In addition, the osteopromotive properties of a 15 sequence amino acid peptide, P15, has recently been shown to illicit promising osteopromotive behavior when coupled with hydroxyapatite granules. The Alpine cervical goat model has proven to be an aggressive animal model for examining the healing of fusions using bone grafts, instrumentation, or bone substitutes.
  • INITIAL EXPERIENCE WITH ENDOSCOPIC POSTERIOR CERVICAL LAMINOFORAMINOTOMY FOR THE TREATMENT OF CERVICAL RADICULOPATHY

    The initial experience with 24 patients with cervical radiculopathy secondary to cervical disc herniations treated utilizing an endoscopic posterior cervical laminoforaminotomy is presented. The procedure was modified from the traditional Scoville type with the addition of a paramedian muscle splitting approach and endoscopic visualization. Sixteen males and eight females were involved in the initial series. Only patients with single level symptoms refractory to conservative therapy and MRI or CT imaging confirming a corresponding lateral or foraminal lesion were considered. The series consisted of 8 C-5/6, and 16 C-6/7 lesions, 16 of these occurring on the left and 8 on the right.
  • AGE RELATED CHANGES IN APOPTOTIC RATE IN THE MURINE INTERVERTEBRAL DISC

    RELEVANCE TO MUSCULOSKELETAL CONDITIONS: The role of aging in the etiology of disc degeneration is not fully understood. Apoptosis (programmed cell death) may play an important role in this process.  The current study examines the relation of aging to the apoptotic index and the distribution of cells undergoing apoptosis in intervertebral discs. INTRODUCTION: Intervertebral discs undergo age-related degenerative changes. There are numerous factors involved in disc degeneration, such as declining nutrition, loss of viable cells, cell senescence, post-translational modification of matrix proteins, accumulation of degraded matrix molecules, and fatigue failure of the matrix to name a few. Apoptosis may be a major cause of disc degeneration and also a possible “common pathway” for other effecting processes. Therefore, we chose to study the trends of apoptotic index in relation to age in an animal model.
  • MANAGEMENT OF TYPE II ODONTOID FRACTURES: A CASE-CONTROL STUDY

    Odontoid fractures are common spinal injuries which occur relatively more frequently in elderly patients. Halo immobilization of odontoid fractures results in about a 70% successful fusion rate. Case series have attempted to predict which individuals will fail halo immobilization. Unfortunately these reports are limited to retrospective Class III studies which carry little statistical significance. We have constructed a case-control study of the treatment of type II odontoid fractures with halo immobilization. Concomitant medical conditions, the amount of fracture displacement, and the direction of fracture displacement were all controlled.
  • 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.