• 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.