Surgical outcomes of basilar invagination type B without atlantoaxial dislocation through simple posterior fossa decompression: a retrospective study of 18 cases

Acta Neurochir (Wien). 2023 Oct;165(10):3051-3063. doi: 10.1007/s00701-023-05625-3. Epub 2023 May 24.

Abstract

Background: Basilar invagination (BI) is a common disease in the craniocervical junction (CVJ) area. Posterior fossa decompression with/without fixation is a controversial surgical strategy for BI type B. This study aimed to evaluate the efficacy of simple posterior fossa decompression in treating BI type B.

Methods: This study retrospectively enrolled BI type B patients who underwent simple posterior fossa decompression at Huashan Hospital, Fudan University between 2014.12 and 2021.12. Patient data and images were recorded pre- and postoperatively (at the last follow-up) to evaluate the surgical outcomes and craniocervical stability.

Results: A total of 18 BI type B patients (13 females), with a mean age of 44.2±7.9 years (range 37-62 years), were enrolled. The mean follow-up period was 47.7±20.6 months (range 10-81 months). All patients received simple posterior fossa decompression without any fixation. At the last follow-up, compared with preoperation, the JOA scores were significantly higher (14.2±1.5 vs. 9.9±2.0, p = 0.001); the CCA was improved (128.7±9.6° vs. 121.5±8.1° p = 0.001), and the DOCL was reduced (7.9±1.5 mm vs. 9.9±2.5 mm, p = 0.001). However, the follow-up and preoperative ADI, BAI, PR, and D/L ratio were similar. No patients had an unstable condition between the C1-2 facet joints that was observed in the follow-up CT and dynamic X-ray.

Conclusions: In BI type B patients, simple posterior fossa decompression could improve neurological function and will not induce CVJ instability in BI type B patients. Simple posterior fossa decompression could be a satisfactory surgical strategy for BI type B patients, but preoperative CVJ stability assessment is crucial.

Keywords: BI type B; CVJ stability; Simple posterior fossa decompression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Atlanto-Axial Joint* / diagnostic imaging
  • Atlanto-Axial Joint* / surgery
  • Decompression, Surgical
  • Female
  • Humans
  • Joint Dislocations* / surgery
  • Middle Aged
  • Neck Injuries* / surgery
  • Retrospective Studies
  • Spinal Fusion*
  • Treatment Outcome