The phenomenon of vertebral body drift in neurofibromatosis and its implications for surgical safety

S. Rajasekaran, B. T. Pushpa, Karuppanan Sukumaran Sri Vijay Anand, Ajoy Prasad Shetty, Rishi Mugesh Kanna, Charanjit Singh Dhillon

April 2022, pp 1 - 6 Original Article Read Full Article

First Online: 01 April 2022

Objective

To report on the phenomenon of body drift in neurofibromatosis scoliosis and discuss its implication on surgical safety.

Materials and methods

Ten dystrophic neurofibromatosis scoliosis (NF) and ten adolescent idiopathic scoliosis (AIS) were studied by radiographs, CT, and MRI. The curve characteristics and a detailed analysis of the morphology of the apical and three adjacent vertebral segments above and below were done. The coronal alignment and the presence of a drift of the vertebral body in relationship to the lamina were carefully studied in both groups and compared.

Results

The mean cobb angle in the NF group was 77.6°, and 63.7° in the AIS group. All the studied vertebra in the NF group had extensive pedicle changes, which were more severe at the apical and periapical regions. Body drift was noted in 29 vertebral segments, with 9/10 of apical segments showing a significant drift. The body drift was associated with significant pedicle dystrophic changes and was independent of the curve magnitude. In comparison, in AIS, no body drift was noted despite a larger deformity and more severe vertebral rotation.

Conclusion

The ‘body drift’ phenomenon was unique to neurofibromatosis scoliosis and was secondary to severe pedicle morphology changes. This was present even in curves less than 60° and could result in cord injury while instrumenting the concave pedicle. Therefore, a thorough preoperative assessment and planning by a 3D CT are mandatory.

Read Full Article