The experience of dynamic fixation with nitinol implants for degenerative diseases of the spine

Introduction. The works related to using Nitinol possessing thermomechanical memory, superelasticity, and self-regulating compression, appeared at the end of XX century, the implants biochemically and biomechanically compatible with body tissues developed for anterior and posterior fixation of the spine. Purpose. To study the results of using Nitinol fixators in the surgery of degenerative-and-dystrophic diseases (DDD) of the spine in its cervical and lumbar parts. Methods. 71 cases of such surgeries analyzed in order to study the experience of using Nitinol fixators in surgeries for DDD of the spine. DDD of the spine combined with osteoporosis in 33.8 % of patients. In 83.1 % instability occurred which resulted in developing different ultrasound syndromes of vertebral artery pathology in patients with DDD of cervical spine revealed by color duplex scanning (CDS). Results. Intrabody fixators (in 28 patients), looped ties of Nitinol (40), and their combinations (3) used. When the indications determined for Nitinol implants use in interventions, not only general clinical indications considered but four technical ones as well: performing surgery with resection of one or more vertebral arches, or resection of articular processes, for spinal canal stenosis in the absence of radicular canal stenosis, in the presence of instability in one or more vertebral-motor segments (VMS) revealed before surgery, or in case of instability development possibility postoperatively, the deformity of vertebral bodies when DDD of the spine combined with its osteoporosis. The analysis of catamnestic data demonstrated a good result of using Nitinol implants. Conclusion. The dynamic fixation using Nitinol implants is one of the possible options of performing surgery for DDD of the spine which allows to provide neurovascular structure decompression accompanied by resection of one and more vertebral arches or resection of articular processes with maintaining minimum mobility of VMS, without its instability, in one or more VMS, when revealed before surgery, as well as in case of moderate deformity of vertebral bodies for the spine osteoporosis with compression of spinal canal neurovascular structures. The procedure of neck vessel CDS gives the possibility to assess hemodynamics in vertebral arteries, and the adequacy of surgical intervention in the cervical spine.