Transarticular screw fixation augmented with interspinous wiring technique for atlantoaxial instability was analyzed to provide immediate multidirectional rigid fixation and increase likelihood of fusion of C1-2 for atlantoaxial instability in several biomechanical studies. Transarticular screw fixation eliminates anterior, posterior translation at C1-2 and reduce flexion and extension movement. 13 patients with atlantoaxial instability were operated with posterior atlantoaxial facet screws fixation augmented with an interspinous C1-2 strut graft and posterior wire fixation technique. One patient died postoperatively from cardiac problem. All surviving patients restored C1-2 alignment and stability without complication due to instrumentation and osseous unions have developed even 2 cases of screw breakage developed. This technique was analyzed to be superior to wiring or clamp fixation biomechanically and leads to success without external orthosis in several series. But precaution is needed to avoid the vertebral artery injury.
Humans ; Orthotic Devices ; Transplants ; Vertebral Artery

BACKGROUND:Lumbar spine fractures treated conservatively or operatively may result in severe kyphotic deformity. Reliable operation plan should be made to prevent the development of delayed kyphosis in unstable lumbar spine fracture. STUDY DESIGN: Between September 1995 and March 1997, twelve cases with highly unstable lumbar spine fractures (7 according to'Load-sharing classification score') or fracture-dislocations were operated with combined retroperitoneal and posterior approach. The patients underwent anterior corpectomy, interbody fusion and short segment fixation with posterior transpedicular screws(1 level above and 1 level below). All patients were operated on the same day except one case. The patients were followed-up at least 12 months and mean follow-up period was 17.2 months after operation. The kyphotic angle was measured by Salter's method preoperative, immediate postoperative and at 12 months. RESULTS: There were 9 cases of burst fractures and 3 cases of fracture-dislocations. The mean kyphotic angle was 24degrees preoperatively, -5degrees postoperatively and -2degrees at 12 months follow-up. This means the patients regained normal lumbar lordosis after the operation and maintained on long term follow-up. There was no case of pseudoarthrosis or delayed kyphosis development during follow-up period. CONCLUSIONS: Highly unstable lumbar spine fracture with high load-sharing classification score could be treated to achieve normal lumbar lordosis immediate postoperatively and prevent kyphotic deformity on long-term follow-up evaluation with combined approach.
Animals ; Classification ; Congenital Abnormalities ; Follow-Up Studies ; Humans ; Kyphosis ; Lordosis ; Pseudarthrosis ; Spine*