A synthetic 3-benzothiepin derivative, TAK-778, promotes osteoblast differentiation. If a mixture of TAK-778 and β-tricalcium phosphate (β-TCP) can be a substitute for autografts used for packing interbody fusion cages, donor-site related complications should be avoided. The lumbar vertebrae from L1 to L5 were exposed in 8 dogs using a posterolateral approach, and discectomy and interbody cage fusion were performed in three disc spaces. In group A, the cage was filled with autograft bone, in group B with β-TCP, and in group C with β-TCP and TAK-778. The lumbar spine was excised at 16 weeks post-surgery, and mechanical, microradiographical and histological evaluations were made. The microradiographical and histological examinations revealed four fusions in eight operations in group A (50.0%), three in group B (37.5%), and five in group C (62.5%). The mean percentage of trabecular bone area in the cages was 53.4% in group A, 45.6% in group B and 64.4% in group C. Although the effect was not significant, addition of TAK-778 to β-TCP had some beneficial influence and there was a trend toward an improved fusion status in cages filled with β-TCP and TAK-778. β-TCP combined with TAK-778 could be used as a substitute for autografts in clinical spine surgery, especially for those patients who are anticipated to have a poor graft bone status.

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The idiopathic meralgia paresthetica is well known and was related with plenty of etiologies; however the bilateral meralgia paresthecia (BMP) after spine surgery, as unexpected complications, has sparsely been reported in the literature. The objetive of this study is to describe the BMP and to evaluate the prevalence in the setting of low thoracic and lumbar spine surgery. During the 10-years-period from 1991 through 2001, data from every patient harboring surgical procedure on the low-thoracic, lumbar and/or sacral spine were evaluated. Eighty three patients were collected. A total of 59 patients, as having markedly sensory disturbance or younger than 15 year-old, were excluded from the study. Among the remaining 24 patients, we found five cases (20, 8%) in which the BMP appeared postoperatively. The BMP was characterized by the postopertive onset of bilateral exquisite sensory disturbance upon the antero-lateral region of the thigh. All of them were young (average age of 27 years), and slender (median of Body Mass Index : 21.22 Kg/m^2). Tumor removal was done for three patients and cord untethering was performed for other two patients. All patients recovered completely with conservative management for 1, 5 to 11 months. In conclusion, we reported five cases of BMP after spinal surgery in prone position. Young slender patients are at risk in contrast to idiopathic meralgia. It may be avoided by improving frame system and meticulous attention but can happen due to anatomical variation of the LFCN.

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Object. We studied the changes in neurological status and radiological features of 16 patients undergoing the anterolateral partial vertebrectomies (ALPVs) with the use of beta-tricalcium phosphate (beta-TCP) for multilevel ossification of the posterior longitudinal ligament (OPLL) in the cervical spine during a 1-year follow-up. Methods. There were 11 male and 5 female patients. The patients' ages ranged from 37 to 81 years (mean 63 years). In ALPV the uppermost site was C2-C3 in 6 patients and the lowermost was T1-T2 in 1 patient. The site of ALPV consecutively ranged from 3 to 7 levels (mean 4.3). Beta-TCP was implanted into the site of the vertebrectomy with the exception of the two vertebral bodies (upper and lowermost) for each patient. The Neurosurgical Cervical Spine Scale (NCSS) was used to assess the patient's neurological status. The cervical lateral X-ray was used to measure the cervical curvature and the range of motion (ROM). A computed tomography scan was used to evaluate the degree of ossification of beta-TCP. Results. No patient showed any deterioration in neurological status during a 1-year follow-up. Twelve out of 16 patients showed an acceptable improvement (NCSS rate of improvement &ge;50%) and 6 patients showed a satisfactory improvement (NCSS rate of improvement 100%) at a 1-year follow-up. There was no significant change in the cervical curvature but ROM decreased by 23% as an average at a 1-year follow-up (p<0.0001, paired t-test). All beta-TCPs for each patient promoted new bone formation at a 6-month follow-up and were replaced by the compact bone with remodelling of the vertebral column at a 1-year follow-up. Horner's syndrome occurred in 2 patients but improved within a few months postoperatively. Conclusions. ALPV with the use of beta-TCP may be acceptable as a radical treatment for multilevel OPLL in the cervical spine.

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The superior ablation ability of the Erbium : YAG laser (Er : YAG laser) for hard tissue has recently become clear, and it might have some potential as a hard tissue cutting device under endoscopic application, because the laser energy of the Er : YAG can be transmitted through a special fiber. However, the action of this laser wavelength in bone is basically a photothermal effect, so before using this Er : YAG laser system clinically, it is necessary to assess the degree of heat which it generates in cutting target bone. We cut lower jaw of a pig with a conventional turn cutting diamond bar and then with the Er : YAG laser energy and measured the heat generated. It was significantly low in the Er : YAG laser compared with the conventional turn cutting apparatus. These features suggest that the Er : YAG laser has potential for application as a bone cutting device available for use in minimally aggressive spinal surgery.

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The etiology of syringomyelia associated with trauma remains unknown. Moreover, no single procedure for the treatment of this entity has been consistently successful, leading to the publication of many alternative procedures. As our surgical procedure of choice, we have selected subarachnoid reconstruction in those cases of traumatic syringomyelia with a tethered spinal cord, in which MRI shows the posterior shift of spinal cord and its attachment to the dura mater. The surgical procedure involves an osteoplastic laminotomy with beads and microsurgical lysis between the dura and the adhesive arachnoid membrane associated with posttraumatic inflammation (i. e., untethering). Then we perform fenestration in the normal arachnoid membrane at the rostral and caudal sites of adhesive arachnoid membrane. An expanded polytetrafluoroethylene sheet (Gore-Tex sheet^[○!R]) is inserted and fixed to the the inner part of the dura mater to maintain CSF flow between the two fenestrations. We have to date performed this subarachnoid reconstruction procedure in two cases of traumatic syringomyelia with a tethered spinal cord. Postoperative neurological deterioration did not occur in either case, and postoperative MRI in both cases demonstrated the collapse of the syrinx. These results suggest that subarachnoid reconstruction should be the procedure of choice for traumatic syringomyelia with a tethered spinal cord.

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Transpedicular vertebroplasty for the repair of osteoporotic vertebral compression fracture has become popular in recent years because that the procedure is minimally invasive, and rapid postoperavie pain relief is obtained. However, extrusion of the injected material beyond the confines of the vertebral body is not rare. Therefore transpedicular vertebroplasty for the treatment of osteoporotic vertebral collapse in which bone fragments protrude into the spinal canal is considered to be a contraindication because of the increased risk of leakage of the material into the epidural space and consequent narrowing of the spinal canal. For two such cases, we injected bioactive bone substitute, calcium phosphate cement (CPC), through a small hole made in the lateral wall of the vertebral body. There was no leakage of the material and pain relief was achieved immediately after the operation. Vertebral collapse was arrested during the follow-up. The procedure of new vertebroplasty is described in this paper. Under general anesthesia the patient is placed in a lateral position. The lateral wall of the collapsed vertebra is exposed through the extrapleural approach. If the spinal cord is compressed by the protruded bone fragments, decompression before vertebroplasty is an option. A small hole is made in the lateral cortical bone of the vertebral body. The cancelous bone is curettaged to make a cavity which is filled with the material. CPC is injected into the cavity through the hole. Patients are allowed to walk, or sit in a chair without wearing a girdle after at least 3 days bed rest. The advantages of this method are as follows. 1) It is possible to decompress the spinal cord and simultaneously perform the vertebroplasty. 2) The bone substitute is injected safely and securely without leakage. 3) As both spinal fixation and bone grafting are not necessary, postoperative care is easy without wearing a girdle. 4) Immediate pain relief is obtained postoperatively.

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Ulnar nerve compression at the elbow is sometimes encountered in neurosurgical clinical practice. Early surgery is very important, since the effect of surgery depends on the duration of the symptoms and the presence of muscle atrophy. Operative management includes three major categories : simple decompression, medial epicondylectomy and anterior transposition. However, it is controversial which option is the most effective. We report our experience in 32 cases of subcutaneous anterior transposition of the ulnar nerve. Recurrence can be prevented by suturing the band together beneath the nerve and covering the nerve entirely in the subcutaneous fatty tissue. When ulnar nerve and spinal cord lesions coexist, diagnosis from neurologic and radiologic findings can be difficult. Therefore, electorophysiologic studies have become important in such cases.

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Spinal intramedullary cavernomas are a relatively rare entity and these natural histories concerning hemorrhage rates are unknown. The authors report a case of thoracic intramedullary cavernoma with recurrent hemorrhage in a short interval from initial hemorrhage and discuss the timing of surgery for this lesion. A 27-years old woman was admitted because of rapid progressive myelopathy of bilateral lower extremities. MR images of the thoracic spine demonstrated an intramedullary hemorrhagic lesion at the T-9 level. Nine days later, she became sudden-onset paraparesis during menses. MRI demonstrated new hemorrhage at the T6-T9 level. Although she underwent total resection of the cavernoma with intramedullary hemorrhage, her neurological deficits did not recover at all. In patients with spinal cavernoma demonstrating symptomatic hemorrhage, early surgical intervention should be taken into consideration to prevent catastrophic outcome.

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An unusual case demonstrating initial symptoms of recurrent headaches which was due to a hemorrhagic spinal myxopapillary ependymoma was presented. A 31-year-old woman kinder garden teacher visited an orthopedic clinic complaining of a sudden severe headache followed by low back pain and left leg sciatic pain after picking-up a child. Diagnosis was lumbar disc herniation. With conservative treatment manifestations diminished shortly, and she returned to her occupation. Seven months later, she complained of the same symptoms while running with children. A magnetic resonance image demonstrated a hemorrhagic tumor in the lumbosacral lesion and she was sent to our institution. As spinal fluid was hemorrhagic, subarachnoid hemorrhage due to the spinal tumor was considered. The tumor was totally resected without neurological deficits, and the histological diagnosis was myxopapillary ependymoma. Ependymomas are known for the risk of hemorrhage, however subarachnoid hemorrhage due to spinal tumors are rare. Shear stress due to motional changes between the spinal column and the surface of the tumor attached to the filum terminal may have caused mechanical trauma causing damage to the blood vessels on the surface of the tumor which created subarachnoid hemorrhage.

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