Ten year follow-up of hemivertebrae treated by anterior convex epiphysiodesis and posterior concave distraction

Introduction: Anterior convex epiphysiodesis and posterior concave distraction has not been previously described in the literature for the treatment of thoracolumbar hemivertebrae. We describe our experience with long-term follow-up. Method: Six consecutive patients with a mean age of 3.4 years were operated on with this technique. Levels of fusion extended two levels above and below the hemi-vertebra, while the instrumentation span the full length of the curve. Further concave distraction was carried out when there was evidence of loosening of the hooks. Results: The average follow-up was 10.8 years (range 8 to 14). The mean Cobb angle before surgery was 49°, and at the latest follow-up was 26°. There was a mean 41% improvement in the scoliosis. In 5 of these cases, this correction was achieved immediately after surgery and did not significantly change despite repeated distraction. Conclusion: The addition of concave distraction provided better correction than convex epiphysiodesis alone. It is technically easier and safer than hemivertebra excision in the correction of such deformities. This method of treatment is recommended for patients with single fully segmented hemivertebrae located at the thoracolumbar junction that has a significant deformity.