Comparative morphometric study of the sigmoid sinus sulcus and the jugular foramen

Objective To compare the right and left sides of the same skulls as far as the described landmarks are concerned, and establish the craniometric differences between them. Method We carried out measurements in 50 adult dry human skulls comparing both sides. Results The sigmoid sinus width at the sinodural angle level was larger on the right side in 78% of the cases and at the level of the digastric notch in 72%. The jugular foramen width was also larger on the right side in 84% of the cases. The sigmoid sinus distance at the level of the digastric notch was larger on the right side in 64% of the cases, and the sigmoid sinus distance at the level of the digastric notch to the jugular foramen was larger on the right side in 70% of the cases. Conclusion Significant craniometric differences were found between both sides of the same skulls

Posterior cervical foraminotomy: anatomic study in cadavers

OBJECTIVE: This study was designed to use different segments of the cervical spine in cadavers to determine how much lateral mass should be resected for adequate foraminal decompression. METHODS: Six cadavers were used. The region of the cervical spine from C1 to the C7-T1 transition was dissected and exposed. The lateral mass of each vertebra was measured bilaterally before the foraminotomy in the following segments: C2-C3, C3-C4, C4-C5, C5-C6 and C6-C7. The procedure was performed with a high-speed drill and through surgical microscopy. Three foraminotomies were performed (F1, F2, F3) in each level. Lateral masses were measured after foraminotomy procedures and compared to the initial measurement, creating a percentage of lateral mass needed for decompression.. The value of the entire surface was defined as 100%. RESULTS: There was a statistical difference between the amounts of the resected lateral mass through each foraminotomy (F1, F2, F3) at the same level. However, there was no statistical significant difference among the different levels. The average percentage of resection of the lateral masses in F2 were 27.7% at C2-C3, 24.8% at C3-C4, 24.4% at C4-C5 and 23.8% and 31.2% at C5-C6 and C6-C7, respectively. In F3, the level that needed greater resection of the lateral masses was C6-C7 level, where the average resection ranged between 41.2% and 47.9%. CONCLUSION: In all segments studied, the removal of approximately 24 to 32% of the facet joint allowed adequate exposure of the foraminal segment, with visualization of the dural sac and the exit of the cervical root

A new expansive two-open-doors laminoplasty for multilevel cervical spondylotic myelopathy: technical report and follow-up results

The laminoplasty technique was devised by Hirabayashi in 1978 for patients diagnosed with multilevel cervical spondylotic myelopathy. Objective: To describe an easy modification of Hirabayashi’s method and present the clinical and radiological results from a five-year follow-up study. Method and Results: Eighty patients had 5 levels of decompression (C3-C7), 3 patients had 6 levels of decompression (C2-T1) and 3 patients had 4 levels of decompression (C3-C6). Foraminotomies were performed in 23 cases (27%). Following Nurick`s scale, 76 patients (88%) improved, 9 (11%) had the same Nurick grade, and one patient worsened and was advised to undergo another surgical procedure. No deaths were observed. The mean surgery time was 122 min. Radiographic evaluation showed an increase in the mean sagittal diameter from 11.2 mm at pretreatment to 17.3 mm post surgery. There was no significant difference between pretreatment and post-surgery C2-C7 angles. Conclusions: This two-open-doors laminoplasty technique is safe, easy and effective and can be used as an alternative treatment for cases of multilevel cervical spondylotic myelopathy without instability