HALM-ZIELKE INSTRUMENTATION (MUNSTER ANTE RIOR DOUBLEROD SYSTEM) AS AN ADVANCED TECHNIQUE OF ZIELKE-VDS - SURGICAL TECHNIQUE AND PRELIMINARY-RESULTS

Introduction and Aim of the Study: Halm-Zielke Instrumentation (HZI), in german speeking countries also named the Munster Anterior Doublerod System, was developed to eliminate the disadvantage of VDS-Zielke in terms of lack of primary stability. Additionally sagittal plane contro l should be improved. Within a prospective clinical trial it was exami ned, if HZI fulfilled these demands. Methods: HZI is an anterior doubl erod system with a two screw per vertebral body fixation. The longitud inal components consist of a threaded VDS-rod and a solid rod. 12 cons ecutive patients with idiopathic scoliosis and curves ranging from 36 degrees to 77 degrees were treated with HZI. Results: Correction of th e frontal plane averaged 75% and 73,8% postoperatively and at follow-u p, respectively. Derotation averaged 49,3%. Thoracolumbar kyphosis was present in four patients and always completely corrected. Implant rel ated complications were not noted. All patients were treated without a ny additional external immobilisation. Conclusion: The aim of improvem ent of VDS in terms of primary stability and control or improvement of the sagittal plane was completely achieved.