ABSTRACT
<p><b>OBJECTIVE</b>To explore the safety and efficacy of the insertion of screws into fused C1-occipital condyle(CC)complex without image guidance in atlantal-cervical nonsegmentation patients.</p><p><b>METHODS</b>The occipital condyle junction was fixed posteriorly in 10 basilar invagination patients with atlantal-cervical nonsegmentation using polyaxial titanium screws(3.5 mm)inserted unicortically into the CC complex and C2 pedicles,followed by fixation to a 3 mm rod. Drilling was guided by anatomic landmarks. The entry point was at the center of posterior surface of the CC complex. The angle of medicalization was 10-15 degrees. In the sagittal plane,the angle for maximal superior screw angulation was also 10-15 degrees. The screw length to obtain unicortical purchase was 16 to 22 mm. CT scans were obtained before and after the surgery. The length,width,and height of CC complex were measured on computed tomography(CT)preoperatively. The position of screws and the condition of fixation were analyzed on postoperative CT scan. Postoperative complications were recorded. The mean follow-up was(30.2±4.38)months(range: 24-36 months).</p><p><b>RESULTS</b>The width,length,height of left side CC complex were(7.96±2.23)mm,(16.06±2.73)mm,and(13.76±2.06)mm,and the width,length,height of right side CC complex were(7.84±1.38)mm,(16.66±2.58)mm,and(12.81±2.62)mm. No fracture was identified. There was no screw malposition or neurovascular complication related to screw insertion. No screw loosening or construct failure was observed during the follow-up.</p><p><b>CONCLUSIONS</b>In patients with atlantal cervical nonsegmentation,the CC complex screws can be safely inserted assisted by microscope without image guidance. Occipital condyle junction fixation using polyaxial CC complex screws is feasible and can be a good alternative where other fixation techniques are not satisfactory.</p>
Subject(s)
Humans , Bone Screws , Cervical Vertebrae , General Surgery , Microscopy , Neck , Spinal Diseases , General Surgery , Spinal Fusion , Methods , Tomography, X-Ray ComputedABSTRACT
<p><b>OBJECTIVES</b>To review the preliminary clinical experience with high-field-strength intraoperative magnetic resonance imaging (iMRI) suite with neuronavigation system in the pituitary adenoma operation with transsphenoidal approach.</p><p><b>METHODS</b>From March 2009 to December 2010, 31 patients [range, 29 - 76 years, mean age (47 ± 11) years]of pituitary adenoma were operated with transsphenoidal approach and intraoperatively with a movable 1.5 T high-field-strength iMRI suite in combination with neuronavigation system. Tumor size was 1.8 - 7.3 cm, mean (3.5 ± 1.2) cm. Twenty-five cases were non-functional pituitary adenoma, 4 cases were prolactin-secreting pituitary adenoma, 2 cases were growth hormone-secreting pituitary adenoma. Thirty patients' resection with transnasal transsphenoidal approach were performed, one patient with transoral transsphenoidal approach was performed.</p><p><b>RESULTS</b>In 12 cases of 30 patients who planed to totally remove tumor, iMRI had revealed residual lesions and resulted in the change of the surgical strategy, 2 invasive cavernous sinus cases no further resection of the tumor because of internal carotid artery encasement, the other 10 cases resected further, eventually. Finally, 8 cases were totally removed. The ratio of total removal tumor was enhanced to 86.7% (26/30) from 60.0% (18/30). There was no perioperative mortality.</p><p><b>CONCLUSIONS</b>High-field-strength iMRI suite with neuronavigation system provides valuable information of tumor resection that allows intraoperative modification of the surgical strategy. It could be very helpful to maximize the resection of the pituitary adenoma and minimize the injury to neurological function.</p>