• 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).
  • COMPARING OUTCOMES OF ANTERIOR CERVICAL DISCECTOMY AND FUSION IN WORKMAN’S COMPENSATION VERSUS NON-WORKMAN’S COMPENSATION POPULATIONS

    INTRODUCTION: The purpose of this study is to analyze the functional outcome of anterior cervical discectomy and fusion (ACDF) between patients who had a work related injury versus patients who did not have a work related injury. METHODS: Eighty consecutive patients undergoing ACDF were analyzed. The same surgeon performed all the surgeries using the Smith-Robinson technique. The indications ACDF were cervical myelopathy or radiculopathy due to herniated nucleus pulposus and /or cervical spondylosis that did not respond to conservative treatments. There were 30 work related injury patients (Group I), and 50 non-work related injury patients (Group II).
  • IS A TITANIUM SPACER A SUBSTITUTE FOR A BONE GRAFT IN DEGENERATIVE CERVICAL SPINE DISEASES? LONG TERM RESULTS IN 279 CONSECUTIVE CASES

    INTRODUCTION: Stabilization of the cervical motion segment after anterior surgical decompression is an accepted surgical procedure. Bony fusion is achieved by inserting an autologous bone graft into the cervical disc space. However, harvesting of bone is related with morbidity (infection, fracture, and pain at the donor site). In the literature a pseudarthrosis rate between 4% and 26% is reported. In order to avoid donor site morbidity and to lower the rate of pseudarthrosis, we inserted an interbody titanium spacer instead of a bone graft. PATIENTS AND METHOD: We performed surgery in 279 consecutive cases with cervical disc degeneration between 05/91 and 12/95. Mean age was 48 yrs (23yrs to 74yrs). Indication was root compression in 83% and radiculo-myelopathy in 13%. Exclusion criteria was previous trauma with instability.