597 - Occipital Cervical Fusion in the Setting of Prior Suboccipital Craniec...

#597 Occipital Cervical Fusion in the Setting of Prior Suboccipital Craniectomy: Technique Report and Case Series

Pediatric Spine

Poster Presented by: S.M. Spitz

Author(s):

S.M. Spitz (1)
R. Felbaum (1)
F.A. Sandhu (1)

(1) Georgetown University Hospital, Medstar Health, Neurosurgery, Washington, DC, United States

Abstract

Introduction: A subset of patients that have undergone a suboccipital craniectomy for Chiari I malformation may develop a recurrence of symptoms in the setting of glacial craniocervical instability. This is demonstrated radiographically by a decrease in the obtuseness of the clival-axial angle (CAA) with resultant neurologic dysfunction related to deformative stress injury to the neuraxis. The authors present use of the “Inside-Out” technique for occipital cervical fusion (OCF) that overcomes the difficulties inherent to occipital plate fixation in the setting of patients with a suboccipital craniectomy defect in order to restore a more anatomical CAA.

Methods: Retrospective data of the senior author (F.A.S.) was reviewed demonstrating 3 pediatric patients that underwent an occipital cervical fusion utilizing the “Inside-Out” technique for progressive symptoms of cervicomedullary compression and occipital headaches associated with a decreased CAA after a prior suboccipital decompression and C1 laminectomy for Chiari 1 malformation. Pre and postoperative sagittal reconstructed CT images of the craniocervical junction were performed in all patients to determine the amount of CAA correction after OCF. A normal CAA was deemed to be greater than 150° based on previously published reports in the literature.

Results: Three (2 female, 1 male) pediatric patients (mean age: 13.6 years) with a prior suboccipital craniectomy and C1 laminectomy and progressive symptoms of cervicomedullary dysfuction and occipital headaches underwent an OCF employing the “Inside-Out” technique. Fixation to C1 and C2 was done in all cases as was the use of rib autograft. The average preoperative CAA of 129.6° was corrected to 158° postoperatively (average correction 38.3°). There were no complications from the procedure or hardware. Rigid fixation and fusion were achieved in all cases without the need for halo immobilization. All patients reported resolution of their preoperative symptoms at 6 months follow up.

Conclusion: The “Inside-Out” method of occipital-cervical fusion in a setting of pediatric patients with a prior suboccipital craniectomy defect may be a safe and effective technique for correcting the clival-axial angle, while treating craniocervical instability.