Introduction: Condylar screws have been recently introduced as a technical resource in the context of craniocervical fusion. This presentation reflects the experience in our institution.
Methods: 24 patients underwent craniocervical fusion at our institution between September 2012 and April 2013. Condylar screws were used in all cases for occipitocervical fixation. An original modified condylar screw trajectory called the Lateral Pars Occipitalis (LPO) was used a rescue technique whenever adequate condylar screw trajectory was not possible. The instrumentation used was the Danek Vertex system by Medtronic to supplement the arthrodesis. C2 rhizotomy was performed in all patients for optimal exposure. Aside from the very first case in which neuronavigation was used, screw insertion was guided by fluoroscopy and confirmed by intra and post-operative CT scan.
Results: Out of 48 total condylar screws, 38 were inserted at conventional condylar trajectories and 10 were LPO rescue screws. No permanent hypoglossal nerve compromise was noted. One patient had faint fasciculations on the left side of the tongue immediately post-operatively, which subsequently disappeared by the second postoperative day. The only permanent complication of the series was a thromboembolic event in the left dominant vertebral artery in the absence of any visible intraoperative compromise, stable neuro-monitoring, and without abnormal screw trajectories. All patients experienced clinical improvement postoperatively.
Conclusions: We report a single institution series of condylar screws used in the context of craniocervical fixation. In our experience, condylar screw placement is a user-friendly technique with a quick learning curve, and has a reasonably low short-term complication rate. Long-term patient follow-up for this case series to examine arthrodesis and complication rates are necessary.
Patient Care: The techniques described here may allow for better craniocervical fixation in patients with former or associated suboccipital decompression.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the technique of condylar screws for craniocervical fusion
2) Better understand the surgical anatomy of the craniocervical junction
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3. Uribe JS, Ramos E, Vale F. Feasibility of occipital condyle screw placement for occipitocervical fixation: a cadaveric study and description of a novel technique. J Spinal Disord Tech 2008;21:540-46.
4. Uribe JS, Ramos E, Baaj A, Youssef AS, Vale FL. Occipital cervical stabilization using occipital condyles for cranial fixation: technical case report. Neurosurgery 2009;65:E1216-E17.
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