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

IntroductionFirst published in 1969, Dwyer instrumentation was the first anterior system for correction of scoliotic deformities of the spine [2]. Major disadvantages of this system were a marked kyphogenic effect, ineffectiveness of derotation, frequent cable fractures with pseudarthrosis and screw pullouts. Ventral Derotation Spondylodesis (VDS), also known as Zielke instrumentation, was developed to preserve the advantages and to eliminate the disadvantages of Dwyer's technique [21]. VDS is the gold standard of scoliosis surgery from the anterior approach [7]. Whereas frontal plane correction and derotation have been reported to be superior to posterior instrumentation techniques, the influence of VDS on the sagittal plane has been a subject of debate during the last two decades. A few authors pointed out that the sagittal plane can be positively influenced with VDS [3,4,21]. However, others have reported a kyphogenic effect [1,11,[13][14][15][16][17][18]20]. Another major disadvantage of VDS is lack of stability, which makes longterm brace or even cast treatment necessary. Screw pullouts, especially at the most superiorly instrumented level and fractures of the threaded rod were reported by several authors [8,13,16,19]. These were associated with painful pseudarthrosis and loss of correction in quite a number of patients. Halm-Zielke instrumentation (HZI) was developed to eliminate the disadvantages of Zielke VDS.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°to 77°. 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°to +1.7°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.

Surgical approaches for the management of idiopathic thoracic scoliosis and the indications for combined anterior-posterior technique

“…His anterior approach and the instrumentation (vertebral body screw, staple, and cable construct) were the prototype for development of subsequent systems. A newer anterior-approach system for the placement of instrumentation in the treatment of scoliotic deformities was proposed by Zielke (as discussed in Halm, et al, [20] and Lowe and Peters [30]) who substituted a single threaded rod and nuts for the cable and introduced a derotator to correct rotation. The rod rotator and the rigidity of the rods were thought to minimize the associated kyphosis that was common when using Dwyer's cables.…”

Comparison of anterior and posterior double-rod instrumentation for thoracic idiopathic scoliosis: results of 141 patients

“…This instrumentation was developed to preserve the efficiency of ventral derotation spondylodesis when a relatively short fusion length corrected scoliosis on the one hand and on the other hand to complete it in such a way that a primary stable instrumentation significantly reduced the rate of breakages and allowed brace-free postoperative care. In addition, kyphogenic effect was to be decreased [8,14,16]. In a prospective study comprising 45 patients with idiopathic scoliosis, Bullmann et al were able to show that a good correction of the scoliotic major curve and the apical rotation were achieved equally by using the Halm-Zielke instrumentation.…”

Relationship of forces acting on implant rods and degree of scoliosis correction

“…These techniques are the rod derotation technique by Cotrel and Dubousset (CD), Ventral Derotation Spondylodesis (VDS), Halm-Zielke Instrumentation (HZI), Simultaneous Double Rod Rotation Technique (SDRRT) and Direct Incremental Segmental Translation (DIST) (Cotrel et al, 1988;Halm et al, 1998;Ito et al, 2010;Wang et al, 2011;Zielke et al, 1982).…”