Realignment of postoperative cervical kyphosis in children by vertebral remodeling.
METHODS
This study analyzed radiographically change in the sagittal curvature of the cervical spine after atlantoaxial (C1-C2) posterior fusion in children.


OBJECTIVE
This study clarified the process of spinal remodeling after postoperative cervical deformation in children.


BACKGROUND
Postoperative spinal deformations in children are observed frequently. However, there have been only a few reports on postoperative changes in the sagittal curvature of the cervical spine and spinal remodeling after those changes.


METHODS
Between 1979 and 1991, there was a total of 12 children who underwent C1-C2 posterior fusions. The average age at the time of surgery was 9.8 years. The alignment of the cervical spine was classified into four groups (lordosis, straight, kyphosis, and swan-neck deformity). Radiographic findings suggestive of the remodeling were as follows: 1) new bone formation on the anterior vertebral cortex, and 2) increase in body/canal ratio (BCR). The follow-up period averaged 6.2 years.


RESULTS
Postoperative cervical malalignment (kyphosis or swan-neck deformity) occurred in four patients. In all four patients, new bone formation and increase in BCR at the apex of kyphosis were observed. Therefore, there was gradual improvement of the malalignment by vertebral remodeling. This phenomenon was not observed in eight patients with normal alignment.


CONCLUSIONS
Realignment of postoperative cervical kyphosis by vertebral remodeling was observed in children. The results of this study suggested that remodeling occurred even in the spine, which was similar to the remodeling in long bones.
Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan.
Y
Y
Toyama
M
M
Matsumoto
K
K
Chiba
T
T
Asazuma
N
N
Suzuki
Y
Y
Fujimura
K
K
Hirabayashi
D001268:Atlanto-Axial Joint / Q000601:surgery*; D016723:Bone Remodeling; D002574:Cervical Vertebrae / Q000293:injuries / Q000601:surgery*; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D004204:Joint Dislocations / Q000601:surgery; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D009809:Odontoid Process / Q000002:abnormalities; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011859:Radiography; D013123:Spinal Fusion; D013997:Time Factors