• BONE-MARROW-PIT OF THE PEDICLE INSIDE OF VERTEBRAL BODY: ITS UTILITY AS ANATOMICAL LANDMARK FOR ANTERIOR APPROACH TO THE CERVICAL SPINAL CANAL

    INTRODUCTION: Vertebral artery laceration by the penetration of the lateral wall of the cervical vertebral body has been known as a serious complication of the anterior approach to the cervical spinal canal. The base of uncinate process has been recommended as an anatomical landmark to designate the location of the lateral corner of the spinal canal, however, it can not become a definitely reliable landmark because it does not locate on the covering roof, i.e. the posterior wall, of the spinal canal. The purpose of this study is to obtain a reliable anatomical landmark in entering the lateral corner of the cervical spinal canal in the anterior approach, definitely avoiding vertebral artery laceration by penetration of the lateral wall of the vertebral body.
  • EFFECTS OF DIFFERENT ORIENTATIONS OF SMITH-ROBINSON ILIAC CREST GRAFTS

    INTRODUCTION: The width of the vertebral body between uncovertebral joints is significantly greater than the depth. The Smith-Robinson graft has a limited width but variable depth when placed in a traditional manner. Rotating the graft 90 degrees in the axial plane may better match the diskectomy site and allow for a larger and possibly stronger graft to be placed. The purpose of this study was to determine if a rotated Smith-Robinson graft is significantly larger and/or stronger than a traditional graft. METHODS: Six embalmed cadaveric cervical spines and matching bilateral iliac crests were dissected and the C5-C6 disc was removed. Beginning 2 cm posterior to the anterior superior iliac spine four sequential Smith-Robinson grafts were taken from each iliac crest allowing for four matched pairs for each cadaver.
  • FOLLOW UP STUDY OF CONSERVATIVE TREATMENT FOR ATLANTO-AXIAL ROTATORY FIXATION

    INTRODUCTION: The subluxation of the atlanto-axial joint is well known as one of the causes of torticollis in children, and an irreducible case is distinguished as an atlanto-axial rotatory fixation (AARF). There have been many cases reported of AARF with several kinds of operative therapy, however few reports in the literature have described the prognosis after conservative treatment. The objective of this investigation is to reveal the prognosis of AARF after conservative treatment. METHODS: Diagnosis of the condition was made based on well-known physical signs as described by Fielding (cock robin position in association with diminished range of motion with muscle spasm) and by characteristic asymmetry of atlantoaxial joint on open mouth anteroposterior radiograph.
  • CERVICAL TRANSFACET VERSUS LATERAL MASS SCREWS: A BIOMECHANICAL COMPARISON

    BACKGROUND: Posterior cervical fixation with lateral mass plates is an accepted adjunctive technique for cervical spine fusions. Altered anatomy due to congenital malformation, tumor, trauma, infection, or failed lateral mass fixation may limit traditional screw placement options. Transfacet screw placement, which has been extensively studied in the lumbar spine, may offer an alternative when posterior cervical fusion is required. PURPOSE: To compare the pull-out strength of screws placed in the cervical lateral masses to that of screws placed across the facet joints.
  • ACTIVE KINEMATICS IN THE UPRIGHT CERVICAL SPINE AS DEMONSTRATED BYREAL-TIME MRI.

    The GE SIGNA SP OpenReal-Time MRI has recently been usedat our institution for the evaluation of cervical spine motionin normal adult volunteers The advantage of this systemisthe ability to accommodate a person in the upright sitting positionandits image acquisitiontime of 1 per second. This allowed for scanningof active flexion/extension of the cervical spine in the upright position. The aim of this study was to determine the segmental motion between flexion and extension of the cervical spine inthe upright loaded position.Ten volunteers were scanned in the GE SIGNA SP Open Real-Time MRI in order to assess the intervertebral motion of the cervical spine.
  • ADENOVIRUS-MEDIATED TRANSFER OF HUMAN TGF-1 ENCODING GENE TO THE RABBIT INTERVERTEBRAL DISC IN-VIVO UPREGULATES PROTEOGLYCAN SYNTHESIS

    INTRODUCTION: Disc degeneration and associated spinal disorders are a leading source of morbidity resulting in substantial pain and suffering and increased health care costs. Although the etiology and pathophysiology of intervertebral disc degeneration are largely unknown, few approaches are available clinically for the treatment or prevention of disc degeneration. Thompson and colleagues showed that addition of recombinant human TGF-β1 to canine disc tissue in culture could stimulate in-vitro proteoglycan synthesis, and they suggested that this growth factor might be used for the treatment of disc degeneration. Although recombinant growth factors have promising therapeutic properties, sustained delivery of the proteins to patients (especially for chronic conditions) would be difficult to accomplish with present technology.
  • THE USE OF BIORESORBABLE CAGES FOR ANTERIOR CERVICAL FUSION IN THE GOAT

    INTRODUCTION: The ideal device for the facilitation of bony fusion in the spine would provide structural support and stability for the interval during which bony growth transpires and then disappears once its presence was no longer needed. Such a device would necessarily have to withstand whatever loads were applied to it until replaced with bone; to resorb over an interval long enough to assure fusion but short enough not to prevent it; to resorb without producing an inflammatory response sufficient to impair fusion; and to produce no local chemical or pH changes sufficient to impair bone growth. Bioresorbable sutures made from various polylactide/polyglycolide polymers have been in clinical use for more than 30 years. Variations in the amino acid ratios of such polymers correspond to known variations in strength and in resorption rate.
  • COMPLICATIONS OF THE ANTERIOR RETROPHARYNGEAL APPROACH IN CERVICAL SPINE SURGERY

    INTRODUCTION: Anterior surgery of the upper cervical spine is a relatively rare occurrence since the majority of cervical spine disorders affect the lower cervical spine. Also, many upper cervical disorders can be effectively managed with a posterior approach. One of the classic anterior approaches to the upper cervical spine entails transoral access and provides direct exposure for anterior decompression of the distal brain stem and upper spinal cord. Prior to this, posterior fusion was the standard technique although this procedure was limited in that cord decompression required the removal of the posterior arch of the atlas without reducing the deformity. The anterior approach allowed for cord decompression and fusion to be performed simultaneously. The transoral approach has been associated with numerous complications including high infection rate, hemorrhage, progressive laryngeal stridor and asphyxiation.