Morphological changes of adjacent vertebrae after posterior hemivertebrae resection and unilateral short segment fixation:Retrospective cohort study 

Abstract

Background To investigate the morphological changes in the adjacent vertebrae in patients with congenital scoliosis caused by hemivertebra treated by posterior hemivertebra resection with unilateral short segment fixation. Methods A retrospective cohort study was conducted. From 2000 to 2023, 26 pediatric patients with scoliosis caused by a single hemivertebra were included in our institution. They were treated with posterior hemivertebra resection and unilateral short-segment fixation. The preoperative, postoperative, and final follow-up imaging parameters were measured separately, such as the main curve Cobb angle, correction rate, the height of the convex and concave side of the vertebral body, and bilateral pedicle distance (BLPD). All patients had at least 60 months of follow-up. Results The patient was followed up for 68.81 ± 8.11(60–82)months. The preoperative main curve Cobb angle: 36.32°±11.36°, postoperative main curve Cobb angle: 12.29°±7.41°, with a mean correction rate of 66.3%.The main curve Cobb angle at the last follow-up: 12.59°±7.42°, with a loss rate of 2.3%. Preoperative height of proximal vertebral body on convex side: (1.14 ± 0.48) cm,height of proximal vertebral body on concave side: (1.15 ± 0.50) cm, BLPD: (2.58 ± 1.11) cm, height of distal vertebral body in convex side: (1.26 ± 1.89) cm, height of distal vertebral body in concave side: (1.13 ± 0.45) cm, BLPD: (2.83 ± 0.93) cm; Postoperative height of proximal vertebral body in convex side: (1.83 ± 0.49) cm,height of proximal vertebral body in concave side height: (1.58 ± 0.39) cm, BLPD: (2.86 ± 0.77) cm, height of distal vertebral body in convex side: (1.88 ± 0.46) cm,height of distal vertebral body in concave side height: (1.59 ± 0.32) cm, BLPD: (3.31 ± 0.99) cm; At the final follow-up,the height of proximal vertebral body in convex side: (2.01 ± 0.60) cm, height of proximal vertebral body in concave side: (1.89 ± 0.49) cm, BLPD: (3.20 ± 0.78) cm, height of the distal vertebral body in convex side: (2.25 ± 0.50) cm, height of distal vertebral body in concave side: (1.90 ± 0.32) cm, BLPD: (3.58 ± 0.90). The postoperative and final follow-up parameters were significantly difference(P < 0.05) compared with preoperative parameters. No complications such as neurological injury, infection, and internal fixation failure occurred during the follow-up. Conclusion Posterior hemivertebrectomy with unilateral short-segment fixation and fusion can effectively remove the factors leading to deformity and correct the spinal alignment. Morphological changes in the vertebrae adjacent to the hemivertebrae are observed on long-term follow-up, with a tendency to from wedge-shaped or irregular-shaped vertebrae to a typical vertebra. It is a safe and effective treatment for congenital scoliosis caused by hemivertebra.