[Alignment of the sagittal profile after surgical therapy of nonspecific destructive spondylodiscitis: ventral or ventrodorsal method--a comparison of outcomes]

Abstract

From 1989 to 1998, 129 patients underwent surgery for unspecific spondylodiscitis in the Department of Orthopedics of the Free University of Berlin. Fifty-six of them were followed up, and their clinical and radiological results were evaluated in this study. The surgical results of 40 patients with only ventral removal of a focus and defect coverage with an iliac crest graft were compared to those of 16 with additional dorsal bridging instrumentation by internal fixation. A mean of 2.3 vertebrae were fused in ventral spondylodesis; the mean length of dorsal instrumentation by internal fixation was 3.8 vertebrae. Patients were followed up a mean of 5.1 years after surgery. The mean age of patients was 57.1 years at the time of surgery. Patients were postoperatively mobilized a mean of 5 days after ventrodorsal fusion. A purely ventral procedure required a mean postoperative immobilization period of 3.6 weeks and brace fitting of a mean 8.2 months. There was one case of recurrent spondylodiscitis 25 months postoperatively, which made a revision of the focus necessary. The consolidation rate of the ventral spondylodesis was 84-100% in the different subgroups. A differential view of the spinal areas and ventral fusion segments was used to make a statement about the development of the sagittal spine profile. The segmental position of the spine in the sagittal plane was assessed by comparing the segmental kyphosis angles to normal values in the literature. All subgroups submitted to combined ventrodorsal fusion had a greater preoperative segmental kyphosis angle than those undergoing ventral fusion alone. In marked segmental kyphotic false positioning, the combined ventrodorsal procedure achieved good postoperative repositioning results, and an increase in segmental kyphosis was prevented. Ventral removal of a focus and bone graft spondylodesis seem to be adequate in single-level spondylodiskitis especially in the lumbar spine, but additional dorsal instrumentation should be performed in the case of long ventral fusion.