Initial spinal epidural hematoma symptoms mimic artery dissection.

An elderly patient with upper back pain and hypertension was diagnosed as having spontaneous spinal epidural hematoma (SSEH) after excluding artery dissection. The initial symptoms of SSEH mimic those of artery dissection, and the symptoms of spinal damage frequently appear later. Physicians should, therefore, be mindful of SSEH.

Cervical spinous process bifurcation is not useful as a landmark in posterior cervical spine approach.

BACKGROUND: In the posterior cervical spine approach, the form of the cervical spinous process tip is one important landmark for level determination. However, it is still controversial whether the most caudal level of the bifurcated spinous process is C5 or C6 in previous reports. METHODS: The study samples consisted of 47 bleached bones and 3 fixed bodies for anatomical practice. According to the classification of Okuwa, patients who showed remarkable bifurcation of the spinous process tip were regarded to have "remarkable bifurcation", those who showed unclear indentation in the spinous process tip to have "slight bifurcation", and those who showed no bifurcation and no indentation to have "lack of bifurcation". RESULTS: The spinous process tips from C2 to C5 bifurcated in 26 out of 50 cervical spines (52%), and those from C2 to C6 in 20 (40%). There was no significant difference in the frequency of bifurcation of the spinous process tip between males and females. CONCLUSION: The results of the present study indicate that it does not seem useful to use bifurcation of the cervical spinous processes for anatomical landmarks.

[Clinical anatomy of lumbar spine].

Three elements contribute to the neurologic symptoms of the lumbar spine or its multiplicity from an anatomical viewpoint. The first element is the problem of neural tissue. The second element is the bone or the soft tissue existing around the circumference of the neural tissue. The third element is the correlation of the above two. In other words, the neural tissue as content is too large or the adjacent tissue as container is too narrow or else an aberration in the correlation of the aforesaid is involved. Therefore, it is necessary to study those three elements to comprehend the neurologic symptoms of the lumbar spine.

Necessity of rib head resection for anterior discectomy in the thoracic spine.

STUDY DESIGN: The relation between the rib head and the thoracic disc was investigated anatomically. OBJECTIVES: To clarify the necessity of rib head resection in thoracoscopic discectomy using the anterior approach. SUMMARY OF BACKGROUND DATA: When using the transthoracic anterior approach, the rib head must often be resected. However, there are no reports in which the relation between the rib head and the interspinal disc has been investigated. METHODS: The distance between the inferior margin of the superior vertebral body and the superior margin proximal to the rib (hereafter, "rib index") was measured. RESULTS: The rib index shows negative value in T2-T9 levels, while zero in Tl0 level and positive value T11-T12. The rib index of the fifth to ninth ribs in men was significantly smaller than those in women. CONCLUSIONS: The surgeon should anticipate full removal of the rib head if operating at T9 and only partial resection below that level.

An anatomic study of the lumbar plexus with respect to retroperitoneal endoscopic surgery.

STUDY DESIGN: The distribution of the lumbar plexus was analyzed using cadavers. OBJECTIVE: To clarify the safety zone to prevent nerve injuries with respect to retroperitoneal endoscopic surgery. SUMMARY OF BACKGROUND DATA: Surgical approaches to the retroperitoneal space vary among surgeons. Recently, retroperitoneal endoscopic surgery has been applied to various spinal disorders. When the psoas major muscle is separated during retroperitoneal endoscopic surgery, there is a potential risk of injury to the lumbar plexus or nerve roots. However, there is sparse knowledge regarding the relationship between the greater psoas muscle and the lumbar plexus. METHODS: A total of 30 cadavers were analyzed. Six lumbar spines of the cadavers were cut in parallel with the lumbar disc space. Each axial section was photographed and captured into a computer. The distribution of the lumbar plexus was analyzed using computer images. The positions where the genitofemoral nerve emerged on the abdominal surface of the psoas major muscle were analyzed using 24 cadavers. RESULTS: L2/3 and above, all parts of the lumbar plexus, and nerve roots were located from the dorsal fourth of the vertebral body and dorsally. The genitofemoral nerve descends obliquely forward through the psoas major muscle, emerging on the abdominal surface between the cranial third of the L3 vertebra and the caudal third of the L4 vertebra. The safety zone of the psoas major muscle to prevent nerve injuries, excluding the genitofemoral nerve, is at L4/L5 and above. CONCLUSIONS: The safety zone, excluding the genitofemoral nerve, is at L4-L5 and above.