POSTERIOR INTERNAL FIXATION WITH SHAPE-MEMORY TIGHTENING CLAMPS IN THE TREATMENT OF LOWER CERVICAL VERTEBRA ANTERIOR DISLOCATIONS

Abstract

Objective. To analyze adaptation of shape-memory dynamical clamps to anatomical and morphological features of the cervical spine. Material and Methods. Fifty five patients with lower cervical spine dislocations were operated on by posterior fixation with tightening clamps. In 14 (25.0 %) patients the open reduction of dislocated vertebra and posterior clamp fixation were accompanied by the anterior fusion with a porous NiTi implant, while 42 (75.0 %) patients underwent only posterior operation. The treatment results in patients with spinal cord injury were evaluated using A.H. Martins criteria and ASIA/IMSOP scale. Delayed results were estimated 1–5 years after operation in 42 (75.0 %) patients. Results. Treatment results were assessed as good in 88.1 % of cases. Radiological examination revealed a decrease in disc height at injured and adjacent levels not more than 1 mm; instability, or kyphotic deformity were not registered. Implant area did not include the signs of resorption or osteosclerosis. Neurological disorders caused by posttraumatic spinal cord cyst were observed in one (2.4 %) patient in 1.5 years after surgery. In 4 (9.5 %) patients who underwent anterior and posterior fixation the treatment results were assessed as fair. Patients disability period was 96 ± 38 days. Conclusion. Two-axial fixation with coupled tightening clamps of shape-memory material provides the reliable stabilization of the injured vertebral motion segment. Preliminary posterior fixation for unstable injury facilitates the optimal performing of anterior interbody fusion with porous implants and ensures its absolute stability.