• POSTERIOR DECOMPRESSION AND RECONSTRUCTION OF THE CERVICAL SPINE USING PEDICLE SCREW FIXATION SYSTEMS

    PURPOSE: There have been a number of internal fixation procedures for one-stage posterior decompression and stabilization of the cervical spine. The purpose of this study was to analyze the results of 68 patients who underwent one-stage cervical reconstruction using pedicle screw fixation and posterior decompression for primary or salvage surgery. MATERIALS AND METHODS: Between 1991 and 1996, a total of 68 patients who required cervical reconstructed procedure with pedicle screw fixation systems were identified. In all patients, the lamina was removed or laminoplasty was performed for posterior decompression of the spinal cord, or the lamina had been removed by previous decompression surgery. There were 40 females and 28 males, and their average age at the time of surgery was 56.7 years.
  • THE EFFECT OF DISTRACTION – FLEXION INJURIES TO THE LOWER CERVICAL SPINE ON THE VERTEBRAL ARTERIES. AN EXPERIMENTAL STUDY

    INTRODUCTION: The fact that injuries to the vertebral arteries can result in occlusion in closed lower cervical spine trauma is not unknown. On reviewing the literature, injuries of the distraction - flexion type are seen to have a special significance concerning lesions to the vertebral arteries, but a study of the mechanisms which lead to vertebral artery traumatization was not found. AIM OF THE STUDY: An attempt was made to clarify the significance of the various stages of injuries to the lower cervical spine as classified by Allen et al. as to the possibility of traumatization of the vertebral arteries.
  • BIOMECHANICAL EVALUATION OF FIVE DIFFERENT OCCIPITO-ATLANTO-AXIAL FIXATION TECHNIQUES

    INTRODUCTION: Many stabilizing procedures have been reported for craniocervical reconstruction. Recently, new instrumentation using C1-C2 transarticular screw (Magerl) or C2 pedicle screw as a fixation anchor have been developed to provide greater stability. However, few studies have biomechanically evaluated occipitocervical reconstruction methods. Moreover, although stability against anterior shear force is required to prevent anterior translation of C1 in occipitocervical reconstruction, no studies have investigated the stability under anterior translation loading. The purpose of this study was to evaluate the stability provided by five types of occipito-atlanto-axial fixation techniques.
  • EN BLOC LAMINOPLASTY FOR CERVICAL MYELOPATHY AND ACUTE DIFFUSE SPINAL CORD EDEMA – RAPID DECOMPRESSION INDUCES SPINAL CORD EDEMA?

    INTRODUCTION: En bloc laminoplasty is widely preferred to laminectomy for treatment of cervical myelopathy. Nevertheless, there are some complications: we have had five cases of incomplete paralysis with acute diffuse spinal cord edema. This study reviews 204 patients to assess the advantages and examine the complications. MATERIALS & METHODS: Subjects included 145 men and 59 women with a mean age of 57.2 years (range: 23 - 83). There were cervical spondylotic myelopathy (CSM) 155 with underlying conditions: hemodialysis 8; cerebral palsy (CP) 4; rheumatoid arthritis (RA) 4; and disc herniation (HNP) 6 and ossification of posterior longitudinal ligament (OPLL) 43. Operating time was 146.9 ± 52.8 minutes; blood loss was 356.7 ± 290.0 g. Postoperative follow-up ranged from 1 year to 6.1 years ( average: 2.3).
  • SURGICAL PLANNING FOR CERVICAL SPONDYLOTIC DISEASE: ARE MR AND MYELO-CT BOTH NECESSARY?

    INTRODUCTION: A previous presentation at CSRS concluded that when radiologists independently examined MR and Myelogram-CTs (M-CT) of patients with cervical spondylosis, there was poor concordance between the two studies. The present study examines, from the surgeons’ perspective, the utility of obtaining both radiological modalities in the pre-operative work-up for cervical stenosis surgery. METHODS: The MRI and/or M-CT (myelography and CT), clinical information and plain radiographs of 18 patients (average age 56, 9 female, 9 male) with cervical spondylosis requiring surgical decompression, were independently presented to five spine surgeons (four orthopaedic surgeons and one neurosurgeon) on three separate occasions, separated by at least one week.
  • INCREASED SIGNAL INTENSITY OF THE SPINAL CORD ON MR IMAGES DOES NOT PREDICT POOR OUTCOME OF CONSERVATIVE TREATMENT FOR CERVICAL MYELOPATHY

    INTRODUCTION: Increased signal intensity of the spinal cord on MR images (ISI) is considered to reflect various intramedullary lesions including edema, gliosis, and cavity formation. Some authors reported that ISI might reflect irreversible changes of the spinal cord and predict poor prognosis of compressive cervical myelopathy, although this is still controversial. So far, ISI has been studied mainly in relation with surgical outcome. The purpose of this study is to investigate relationships between ISI and the outcome of conservative treatment for cervical myelopathy. MATERIALS AND METHODS: Fifty-two patients with compressive cervical myelopathy were treated conservatively for more than 6 months between 1991 and 1997.
  • DIAGNOSTIC, TEMPORARY EXTERNAL FIXATION OF THE CERVICAL SPINE A five year follow-up

    INTRODUCTION: In the lumbar spine, temporary external fixation has been used to overcome diagnostic problems for identification of painful segments. We adopted this method to the cervical spine to enlarge the diagnostic armamentarium in difficult diagnostic problems with soft tissue injury of the cervical spine in which clinical symptoms differ significantly from objective findings. METHODS: Twenty-six patients with suspected mono-or bisegmental posttraumatic instability of the cervical spine underwent temporary external fixation for diagnostic reasons between 1989 and 1993. Ten females and 10 males were examined. The average age of the patients was 31.6 (19-52) years and the duration of symptoms (accident) was average 3.4 (1 - 10) years.
  • POSTERIOR CERVICAL LATERAL MASS FIXATION WITH A RIGID LOCKING IMPLANT

    OBJECTIVE: To compare the biomechanical stiffness of a standard posterior cervical lateral mass plate (P) to an adjustable posterior cervical lateral mass rod with standard screws (RS) and an adjustable posterior cervical lateral mass rod with rigid locking screws (RL). SUMMARY OF BACKGROUND DATA: Previous studies have demonstrated increased stiffness of posterior cervical mass plate and screw devices (P) in comparison to different posterior wiring constructs and anterior fixation devices. A limitation of posterior cervical plate devices is potential difficulty in aligning screw holes in the plate with the lateral masses. A posterior cervical rod device has been developed to allow flexibility in the positioning of the screws (Synthes, Paoli, PA).