Abstract
Background: The simultaneous occurrence of spina bifida occulta (SBO) and spondylolysis has been noted previously. The occurrence of SBO and spondylolysis are approximately 17% and 5% respectively.
Aims: The aim of this study was to determine the incidence of SBO when a symptomatic spondylolysis has been proven.
Method: Analysis of four years of lumbar spine CT scans was performed. Patients with spondylolysis or spondylolisthesis caused by a pars defect were identified. These patients’ CT images were then reviewed to establish the patients who also had SBO.
Results: In this unit 650 CT scans of lumbar spines were performed in the last five years. Of these scans 100 (15%) were found to have a pars defect. The average age was 34.6. On CT 30 (30%) patients were shown to have SBO. Of the total 23 were under 18 years old and 13 (56%) of these patients had SBO associated with the spondylolysis. In the over 18 year olds 21 (27%) patients had SBO associated with spondylolysis.
On review of the 550 other scans the average age was 51.9 years old. The incidence of SBO within this group is 10%. Only 6% of these patients were under 18. Out of these 33 patients 30.3% (10 patients) had SBO. Over 18 the incidence of SBO was only 8.5%.
Conclusions: Our results indicate that the occurrence of SBO within the group with a spondylolysis is much higher than in the group where no spondylolysis is present. There is higher incidence of SBO in the younger patients with spondylolysis. 56% of paediatric patients with symptomatic spondylolysis will have SBO. Clinicians should be aware of this fact preoperatively to decide on the technique of repair of the symptomatic lysis.
Correspondence should be addressed to: EFORT Central Office, Technoparkstrasse 1, CH – 8005 Zürich, Switzerland. Email: office@efort.org
