We reviewed seven children with torticollis due to refractory atlanto-axial rotatory fixation who were treated in a halo vest. Pre-operative three-dimensional CT and sagittal CT imaging showed deformity of the superior articular process of C2 in all patients. The mean duration of halo vest treatment was 67 days (46 to 91). The mean follow-up was 34 months (8 to 73); at the latest review six patients demonstrated remodelling of the deformed articular process. The other child, who had a more severe deformity, required C1-2 fusion. We suggest that patients with atlanto-axial rotatory fixation who do not respond to conservative treatment and who have deformity of the superior articular process of C2 should undergo manipulative reduction and halo-vest fixation for two to three months to induce remodelling of the deformed superior articular process before C1-2 fusion is considered.
It is accepted that the development of scoliosis has a close relationship with physical growth, but the aetiology and mechanism of the disease remain unknown. Few studies have assessed the bone microarchitecture and histomorphological findings in vertebrae. After the occurrence of scoliosis, those include secondary changes caused by mechanical compression. It is important to investigate those data in the period prior to the occurrence of scoliosis.
Study Two: Sixty female Broiler chickens were divided into three groups: the control group (group C, n=20), the sham operation group (group S, n=20), and the pinealectomy group (group P, n=20). Each group was then subdivided into two groups according to the time of sacrificing: 3 days after the operation (group 3-C, 3-S, 3-P, n=10), and six days after the operation (group 6-C, 6-S, 6-P, n=10). Decalcified thin sagittal sections were made using a tartrate-resistant acid phosphatase (TRAP) stain. Histological examinations of the growth plate, trabecular structure and osteoclast number were performed.
Study Two: Nine out of ten chickens in group 6-P showed scoliosis deformity, while the presence of scoliosis was unclear in any of chickens in group 3-P. The osteoclast number increased significantly in group 3-P, compared to groups 3-C and 3-S, and the trabecular thickness was greater in group 3-P than in groups 3-C and 3-S. There was no significant change in the growth plate or in other aspects of the trabecular structure, except for trabecular thickness, in any of the groups. The results of study one showed that the change of microarchitecture might be caused by Wolff’s law and was the secondary response to the scoliotic deformity. Therefore, it was difficult to clarify the cause of scoliosis using micro CT. In study 2 we found that the number of osteoclast increased in pinealectomised chickens after 3 days postoperatively, just before scoliosis began to develop. We also found there was no change in the growth plate. These outcomes suggest that there are no relationships between changes in the growth plate and the development of scoliosis. However, the change in osteoclast number may have a relationship with the development of scoliosis through changes in bone modelling.
