Abstract
Introduction: There are few long-term studies after Zielke ventral derotation spondylodesis (VDS). We present a minimum 17 year follow-up study to assess factors predicting distal adjacent disc degeneration.
Material/Methods: Twenty-eight patients with thora-columbar AIS operated in 1982 have been retrospectively evaluated. Mean age 16,3 years, minimum follow-up 15 years. Anterior fusion was performed with rib graft.
Results: Mean pre-op Cobb angle was 65 ± 23°, post-op correction rate was 61,2 ± 12,4%. Mean angulation of end vertebra was 32 ± 10°, post-op corrected to a mean of 8° (correction rate 79%). Mean post-op Th10/L2 kyphosis was 10°. Rod breakage was seen in 17 patients.
Conclusion: Thoracolumbar kyphosis was associated both with proximal implant breakage and with segmental lordosis and degeneration of the distal adjacent segment. Disc angulation in the AP plane seems to be good tolerated. Anterior support with iliac bone graft or cages is expected to overcome these complications.
Correspondence should be addressed to Jeremy C T Fairbank at The Nuffield Orthopaedic Centre, Windmill Road, Headington, Oxford OX7 7LD, UK
