title: Halm-Zielke instrumentation for primary stable anterior scoliosis surgery: operative technique and 2-year results in ten consecutive adolescent idiopathic scoliosis patients within a prospective clinical trial.
abstract: Halm-Zielke instrumentation (HZI) was developed to eliminate the disadvantages of Zielke instrumentation (VDS) in terms of lack of primary stability and a kyphogenic effect. HZI is an anterior double-rod system. The system is composed of a lid-plate, which is fixed at the lateral aspect of the vertebral body with two screws, a sunk screw anteriorly and a VDS screw posteriorly. The lid-plate design provides the lowest possible implant profile. The longitudinal components consist of a threaded VDS rod and a solid, fluted rod. Correction is performed with the threaded rod and the solid rod. The solid rod allows internal derotation and relordosation, eliminates the Zielke three-point lever system and augments the system. The fluted design of the rod provides rotatory stability. This is a report of the first ten consecutive adolescent idiopathic scoliosis patients in a prospective clinical trial using HZI with a minimum follow-up of 2 years. Curves ranged from 36 degrees to 77 degrees. Correction of the frontal plane averaged 77.5% and 72.2% postoperatively and at follow-up, respectively. Thoracolumbar kyphosis was present in three patients and corrected in all from an average of +18 degrees to +1.7 degrees at follow-up. Implant-related complications were not observed. All patients were treated without any additional external immobilization. In our opinion, HZI is a major improvement on the original Zielke VDS. It eliminates the kyphogenic effect and provides primary stability.
authors.affiliation: Department of Orthopedic Surgery, Westfälische Wilhelms-University, Münster, Germany.
authors.forename: H F
authors.initials: HF
authors.lastname: Halm
authors.forename: U
authors.initials: U
authors.lastname: Liljenqvist
authors.forename: T
authors.initials: T
authors.lastname: Niemeyer
authors.forename: D P
authors.initials: DP
authors.lastname: Chan
authors.forename: K
authors.initials: K
authors.lastname: Zielke
authors.forename: W
authors.initials: W
authors.lastname: Winkelmann
mesh_terms: D000293:Adolescent; D004867:Equipment Design; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007431:Intraoperative Complications; D009984:Orthopedic Fixation Devices; D011183:Postoperative Complications; D011184:Postoperative Period; D011446:Prospective Studies; D011859:Radiography; D012600:Scoliosis / Q000000981:diagnostic imaging / Q000601:surgery*; D016896:Treatment Outcome