Comparative Analysis of Three Different Cervical Lateral Mass Screw Fixation Techniques by Complications and Bicortical Purchase : Cadaveric Study

OBJECTIVE: The purpose of this study is to compare the incidence of possible complications of cervical lateral screw fixation and the achievements of bicortical purchase using the Roy-Camille, Magerl and the modified methods. METHODS: Six fresh-frozen cervical spine segments were harvested. The Roy-Camille technique was applied to C3 and C4, and the Magerl technique was applied to C5, C6, and C7 of one side of each cadaver. The modified technique was applied to the other side of each cadaver. The nerve root injury, violation of the facet joint, vertebral artery injury, and the bicortication were examined at each screwing level. RESULTS: No vertebral artery injury was observed in any of the three methods. One nerve root injury was observed in each cervical spine segment using the Roy-Camille method (8.3%), the Magerl method (5.6%), and the modified method (3.3%). Facet joint injuries were observed in two cervical spinal segments using the Roy-Camille method (16.7%) and three with the Magerl method (16.7%), while five facet joint violations occurred when using the modified method (16.7%). Bicortical purchases were achieved on ten cervical spinal segments with the Roy-Camille method (83.3%) and Magerl method (55.6%), while twenty bicortical purchases were achieved in the modified method (66.7%). CONCLUSION: The advantages of the modified method are that it is performed by using given anatomical structures and that the complication rate is as low as those of other known methods. This modified method can be performed easily and safely without fluoroscopic assistance for the treatment of many cervical diseases.

Role of Multislice Computerized Tomographic Angiography in Vasospasm Following Aneurysmal Subarachnoid Hemorrhage

OBJECTIVE: We evaluate the role of multislice computerized tomographic angiography(MCTA) in the diagnosis of intracranial vasospasm following subarachnoid hemorrhage(SAH) in patients suspected of having vasospasm on clinical ground. METHODS: Between October 2003 and June 2005, patients with ruptured cerebral aneurysms of the anterior circulation clipped within 3 days of the onset were included. We performed follow-up MCTAs in patients who were suspected to have vasospasm on transcranial doppler sonography(TCD) findings and clinical grounds. Based on the clinical presentation of symptomatic vasospasm, we investigated the correlation between clinical, TCD, and MCTA signs of vasospasm and evaluated the role of MCTA in vasospasm. RESULTS: One hundred one patients met the inclusion criteria and symptomatic vasospasm developed in 25 patients (24.8%). We performed follow-up MCTAs in 28 patients. MCTA revealed spasm in the vessels of 26 patients. The sensitivity of MCTA was 100%. Among the 26 patients with MCTA evidence of vasospasm, 3 patients had TCD signs of vasospasm after symptomatic vasospasm presentation. Another 3 patients with symptomatic vasospasm had no TCD signs of vasospasm in daily serial recordings. Six other patients without symptomatic vasospasm showed MCTA evidence of vasospasm (false positive result) but these patients had also positive TCD signs of vasospasm. Volume rendering(VR) images tended to show significantly more exaggerated vasospasm than maximum intensity projection(MIP) images. The mean cerebral blood flow velocity of both proximal segment of the middle cerebral artery (M1) was significantly correlated with each reduced M1 diameter on MCTA (P<0.05). CONCLUSION: MCTA could be a useful tool for evaluation and planning management of critically ill patients suspected of having vasospasm; however, more randomized controlled trials are necessary to assess these points definitively.

Cavernous Angioma of the Oculomotor Nerve

Cavernous angiomas of the cranial nerves are rarely reported. We report a case of a 33-year-old man affected by a cavernous angioma originated in the oculomotor nerve with it's palsy. Preoperative radiological findings are difficult to differentiate it from meningioma or neurinoma. Postopertive pathological report discloses it as cavernous angioma. We discuss radiological, pathological features and management of this vascular lesion of the cranial nerve.