• 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.
  • LOAD CARRYING CAPACITY OF THE HUMAN CERVICAL SPINE IN COMPRESSION IS INCREASED UNDER A FOLLOWER LOAD

    INTRODUCTION: The human cervical spine supports the weight of the head (≈50N) and can withstand substantial compressive loads in vivo. The compressive load approaches three times the weight of the head due to muscle co-activation forces in balancing the head in the neutral posture. Compressive load increases during flexion and extension, contact sports, and other activities of daily living, and is estimated to range from 120 N to 1200 N (1, 2). In normal individuals, the cervical spine sustains these loads without damage or instability. However, ex vivo experiments show that the osseoligametous cervical spine buckles in the frontal plane under a small vertical load of 10 N (3). In the sagittal plane, large changes in lordosis occur due to bending at small vertical load levels. This has been a limiting factor in testing a whole ligamentous cervical spine specimen under physiologic loads. For the cervical spine to sustain large compressive loads, the internal shear forces and bending moments must be small.
  • CORRECTION OF CERVICAL KYPHOSIS USING PEDICLE SCREW FIXATION SYSTEMS.

    PURPOSES: The purposes of this report are to investigate the clinical results of correction of cervical kyphosis using pedicle screw fixation and to introduce our surgical techniques. MATERIALS AND METHODS: Between 1991 and 1996, 31 patients with cervical kyphosis were treated using pedicle screw fixation. Causes of kyphosis were old cervical spinal injury in 11 patients, subaxial lesion of RA in nine, cervical spondylosis in five, postlaminectomy kyphosis in three, destructive spondyloarthlopathy in two, and old pyogenic spondylitis in one. Kyphosis caused by flesh spinal injuries or spinal tumors was excluded from this study. Pedicle screw-plates system designed for the cervical spine (CPS) was used in 25 patients.
  • ANALYSIS OF A NEW TECHNIQUE USING BICORTICAL ICBG FOLLOWING CORPECTOMY

    INTRODUCTION: Despite many proposed alternatives to autologous bone grafting for cervical reconstruction, autologous iliac crest bone grafts (ICBG) are still considered the biological and biomechanical standard. Use of tricortical ICBG, however, is a major source of post-operative morbidity. Complications include pain, nerve injury, infection, cosmetic deformity, and anterior superior iliac spine (ASIS) avulsion fracture. In an attempt to reduce this morbidity, the authors report the clinical results of a new technique using bicortical rather than tricortical ICBG in patients undergoing cervical corpectomy.