An analysis of the results of Dwyer and Zielke instrumentations in the treatment of scoliosis.

From 1974 to the end of 1985, 76 operations for correction of scoliosis by the anterior approach using the techniques of Dwyer and Zielke were carried out. This review reports the results of follow-up examination of 55 patients. Differences concerning etiology of curvatures and age of patients are considerable. Twelve patients underwent operation with the Dwyer instrumentation; in the remaining 43 patients the Zielke instrumentation (VDS) was used. Complications were rare and could be managed easily. In the Dwyer group an average correction of 78% could be obtained; the results obtained with the VDS instrumentation were slightly better, with 87% correction of curvatures. With reference to pelvic obliquity, both methods produced similarly good results of 70% and 73% respectively. As for stability, the VDS system is superior to the Dwyer technique; it also offers the possibility of derotation and better lordosis.