• THE MECHANISM OF CERVICAL FACET JOINT BLOCK: A CADAVERIC STUDY

    INTRODUCTION: Facet joint blocks are commonly done procedures in the diagnosis and treatment of axial neck pain. Aprill., et al. have reported relief of axial neck pain with facet injection in patients with evidence of whole motion segment degeneration and disc degeneration alone. They have stated that relief of pain after a facet joint block is a positive confirmation of a painful facet joint. Indeed, the anterior element, the disc, is a potential pain generator. What then is the mechanism by which a posterior element block (facet joint block) relieves anterior element pain or whole motion segment pain? Whatever the mechanism, it must involve the dorsal root ganglion.
  • HYDROSTATIC LOADS WITHIN A CERVICAL INTERBODY FUSION CAGE: AN IN VITRO MODEL

    PURPOSE: Cervical interbody fusion devices offer surgeons another technique to perform interbody spine fusions. Animal and early clinical studies have yiel We hypothesize that hydrostatic forces within the intervertebral fusion cages may provide a stimulus for bone graft revascularization and incorporation within the fusion cage. Hydrostatic lo METHODS: Five human cervical spines consisting of three motion segments were rigidly potted at the cephalad and caudal ends. A 10 mm diameter interbody fusion device (Tapered Cervical Interbody Fusion Device, Sofamor Danek, Memphis, TN) was then inserted, using standard technique, into th 44
  • COMPLICATIONS OF POSTERIOR CERVICAL FUSIONS UTILIZING LATERAL MASS PLATES AND SCREWS

    INTRODUCTION: Previous studies have reported a low complication rate with posterior cervical fusions utilizing lateral mass plates and screws. To verify and test this hypothesis, we review 87 cases of posterior cervical plating using lateral mass screws in 84 patients. Complications and complication rates are identified and compared to earlier reports. METHODS: The complications in 87 consecutive cases from 11/16/93 to 3/17/98 that had been treated by two surgeons with lateral mass screws and plates were identified retrospectively by chart review. Patients averaged 54 years of age with a range of 19 to 85, with an average 12 months of follow up. Fifty-six patients had multiple indications for surgery, and all but 18 required one or more procedures in addition to posterior cervical fusion.
  • RETRO-ODONTOID FIBROCARTLAGINOUS MASS ASSOCIATED WITH ATLANTO-AXIAL INSTABILITY: PATHOGENESIS AND SURGICAL TREATMENT

    INTRODUCTION: Non-tumoral condition at the craniocervical junction is more common than was formerly recognized but it is difficult to diagnose clinically. We treated seven patients who developed retro-odontoido pseudotumor associated with instability of the atlanto-axial joint. Our cases differed a little from what had already been reported by Sze and Crockard. It is intriguing to speculate that mechanical dysfunction and instability may have been the underlying cause of the formation of the fibrous tissue , with hypertrophy of connective tissue elements as the abnormal response to chronic stresses. The advantage of MR imaging of the craniocervical junction is evident and it graphically and dramatically demonstrates the retro-odontoid pseudotumor and it allows repeated pre- and postoperative investigations. The pseudotumor regarded as a new entity which was easily examined by MR imaging when symptoms showed high cervical myelopathy due to atlantoaxial instability.
  • Transcranial Electrical Motor Evoked Potentials (tceMEP) in Anterior Cervical Discectomy and Fusion Surgery: A Comparison Study between Automated and Non-Automated Technologies

    INTRODUCTION: Spinal cord injury resulting in postoperative motor deficits is a serious complication of major spine surgery. Intraoperative electrophysiologic monitoring is performed to assess the functional integrity of the spinal cord in order to recognize and avoid injury. Motor pathways have been successfully monitored using transcranial electrical motor evoked potentials (tceMEP or MEP). A novel system offers automated intraoperative monitoring capabilities that utilize the “threshold-level” alert criteria method which provides more detailed myotome-specific responses, contrasted with the conventional “presence-or-absence” technique which uses a single supramaximal stimulus to obtain responses from one or all myotomes. The automated system then displays this feedback to the end user in a simplified form. The purpose of this study was to compare the automated system to that of conventional, non- automated technology.
  • SURGICAL RESULTS AND COMPLICATIONS OF LAMINOPLASTY FOR CERVICAL COMPRESSION MYELOPATHY IN ELDERLY PATIENTS 70 YEARS OF AGE OR OLDER

    INTRODUCTION: Radiological studies have shown that 75% of people over the age 70 years have evidence of cervical degenerative diseases, which may lead to compression myelopathy. Due to the increasing life expectancy as well as the widespread use of noninvasive imaging methods like MRI, increasing numbers of elderly patients are being presented for decompressive surgery of the cervical spine. Despite the fact, surprisingly few papers have been published with regard to the surgical treatment of cervical compression myelopathy in elderly patients, and it is still controversial whether age is associated with a poor outcome from decompressive surgery.
  • 10 SECONDS TEST (GRIP-AND-RELEASE TEST) -USEFUL NEUROLOGICAL EXAMINATION FOR CERVICAL MYELOPATHY

    INTRODUCTION: Clumsiness of the hands is one of the common symptoms in cervical spondylotic myelopathy (CSM). Crandall (1966) described these clumsy hands as “Slow stiff opening and closing of the fists”. Ono (1987) also mentioned that CSM patients could not grip and release rapidly with the fingers (grip-and release test). Therefore, we hypothesize that the number of grip-andrelease movement in a fixed time may quantitate the severity of spondylotic myelopathy objectively.
  • NEURAL INSTABILITY OF THE LOWER CERVICAL SPINE

    INTRODUCTION: Classical evaluation of the lower cervical spine in the clinic involves assessment of instability based upon extensive work by White and Panjabi[1]. Although their definition of clinical instability addresses the importance of the spine's ability to protect the neural tissue, few studies have specifically examined this role. We define neural instability as the potential for compressive injury to the spinal cord or nerve roots. Since neurologic deficits typically dictate the functional outcome of musculoskeletal injuries, it appears necessary that patient evaluation include a measure of both structural instability as well as neural instability. Examining the cervical spine from the perspective of neural instability will further improve the utility of clinical instability assessment. The purpose of this study is to examine the effect of simulated lesions on lower cervical stability using human cadaver cervical spine specimens. Structural lesions were sequentially introduced to the vertebral column and the resulting changes in neural instability quantified.