Abstract
Study Design
An observational study in patients with congenital spinal deformity.
Objective
To review the relationship between hemivertebrae and the posterior spinal elements in congenital spinal deformity.
Summary of background data
The vertebral body anomalies of congenital scoliosis have been classified and their natural history is well known. More recently a variety of posterior element anomalies have been classified. The relationship between posterior and anterior structures is important when posterior excision of a hemivertebrae is undertaken.
Methods
Patients recorded as having congenital spinal deformity were identified from a database. All available imaging was obtained and reviewed with particular reference to posterior element anatomy as visualised on CT or MRI scans.
Results
In total 36 patients with congenital spinal deformity were identified and their imaging was reviewed. 29 hemivertebrae were identified in 24 patients. Clear images were obtained of the posterior elements in 18 cases. 9 isolated hemilaminae (as visualised on coronal CT or MRI) were seen in 8 patients with associated hemivertebrae. In 7 of 9 cases the hemilamina was found to be one level cranial to the hemivertebrae and in the remaining 2 cases it was at the same level.
Conclusion
When planning excision of a hemivertebra, whether this is performed by a posterior approach or by combined anterior and posterior surgery, care must be taken to avoid wrong level surgery. Pre-operative assessment with CT and MRI scans is essential. The surgeon must be aware of the high possibility that the posterior element anomaly may be proximal to the vertebral body anomaly both when considering how to excise the hemivertebra and for planning the fixation levels.
Statement of interests: The authors declare that they have no competing interests.
