Metastatic prostate cancer in ossification of the ligamentum flavum--a case report.

BACKGROUND CONTEXT: No previous reports have described a metastatic tumor located in the ossification of the ligamentum flavum (OLF). PURPOSE: To report an extremely rare case of metastatic tumor located in the OLF. STUDY DESIGN: Case report. METHODS: We report a case of a 54-year-old man who sustained paraparesis attributable to spinal cord compression because of OLF in the thoracic spine. RESULTS: The OLF at T3/T4 and T5/T6, together with the laminae of T3-T6, was resected. Histologically, the removed section mainly consisted of mature bone with some elastic fiber and fibrocartilage. Tumor cells with a tubular construction, compatible with metastatic adenocarcinoma, were also observed in the OLF. These findings are consistent with metastatic prostate cancer in the OLF. Eleven months after surgery, the patient showed improvement in gait disturbance and bladder-bowel disturbance that existed before surgery. CONCLUSION: This is the first case of metastatic tumor located in the OLF.

Comparison of enlargement of the spinal canal after cervical laminoplasty: open-door type and double-door type.

The purpose of this study was to compare the degree of enlargement of the spinal canal between two methods of cervical laminoplasty (open-door laminoplasty and double-door laminoplasty) and to determine their appropriate surgical indications based on the results. Tension-band laminoplasty (TBL, one method of open-door type) was performed in 33 patients and double-door laminoplasty (DDL) in 20 patients. The operation level ranged from C2 to C7 in all patients. The width of the spinal canal and the inclination angle of the lamina at the C5 and C6 levels were measured using a computer software program (Image J) and pre- and postoperative CT films. Concerning the degree of enlargement of the spinal canal, the mean expansion ratio at the C5 level was 148.9% in TBL and 148.2% in DDL, and there was no significant difference between them. However, at the C6 level, it was 159.0% in TBL and 140.3% in DDL, which was significantly larger in TBL than DDL (p < 0.05). The increase of inclination angle of the lamina was 11.0° in TBL and 19.0° in DDL at the C5 level, and 9.2° in TBL and 19.3° in DDL at the C6 level. At both the C5 and C6 levels, it was significantly larger in DDL than TBL (p < 0.0001). In conclusion, the appropriate surgical indications of TBL were considered to be (1) cervical spondylotic myelopathy (CSM) combined with hemilateral radiculopathy, (2) severe prominence of ossification of the posterior longitudinal ligament (OPLL), and (3) patients with tiny spinous processes who cannot undergo DDL. Those of DDL were considered to be (1) usual CSM, (2) small and slight prominence of OPLL, (3) CSM combined with bilateral radiculopathy, and (4) cervical canal stenosis combined with instability necessitating posterior spinal instrumentation surgery.

Occipitocervical fusion using a hook and rod system between cervical levels C2 and C3.

We aimed to evaluate the clinical utility and safety of the hook and rod method for occipitocervical fusion. Eleven consecutive patients (3 males, 8 females; 50-78 years old, average 63.8 years; 16-77 months follow-up, average 33.7 months) with unstable lesions at the craniocervical junction who underwent occipitocervical fusion using a hook and rod system were examined. A Compact Cotrel-Dubousset cervical system (Sofamor-Danek, Memphis TN, USA) was used in all patients. The claw mechanism was applied bilaterally between the hook on the C2 lamina and the hook on the C3 inferior articular process. No complications occurred during surgery. Solid bony fusion was obtained in all patients and no patient became clinically worse postoperatively. Occipitocervical fusion using a hook and rod system is a useful procedure that allows decompression of the spinal cord and secure spinal fusion at multiple levels simultaneously.

Chemical sensing plate with a laser-terahertz monitoring system.

A new type of laser-terahertz emission system for noncontact investigations of chemical solutions has been developed. The system monitors terahertz emission from a sensing plate, which consists of silicon oxide and silicon thin film layers on a sapphire substrate. Sensing of chemical solutions with pH values between 1.68 and 10.01 was demonstrated. The amplitude of the terahertz emission from the sensing plate increased with increasing pH value. This change in the amplitude was caused by a change in the depletion layers of the silicon thin film when protons were adsorbed on the surface of the sensing plate. This study demonstrates that full noncontact monitoring of chemical solutions is possible using the laser-terahertz emission system.

Posterior atlantoaxial subluxation due to os odontoideum combined with cervical spondylotic myelopathy: a case report.

In patients with os odontoideum and posterior atlantoaxial subluxation are extremely rare. No reports have described posterior atlantoaxial subluxation associated with os odontoideum combined with cervical spondylotic canal stenosis, both of which require surgical treatment. We report one case of a 75-year-old female who underwent arthrodesis between the occiput and C3 using a hook-and-rod system and also a double-door laminoplasty from levels C3 to C7. The claw mechanism was applied between the C2 lamina and the C3 inferior articular process. The posterior atlantoaxial subluxation was completely reduced by the method that the rod gradually pushed the posterior arch of C1 anteriorly during connection to the occiput. Twelve months after surgery, the patient showed improvement in preoperative clumsiness and gait disturbance, and the latest plain radiographs showed solid osseous fusion, with no loss of correction or instrumentation failure.

Rib length in experimental scoliosis induced by pinealectomy in chickens.

STUDY DESIGN: This study was designed to investigate the difference of rib length of idiopathic scoliosis using experimentally induced scoliosis by pinealectomy in chickens. OBJECTIVE: To find whether the difference of rib length may play a role for the development of scoliosis in pinealectomized chickens. SUMMARY OF BACKGROUND DATA: In experimental and clinical studies, asymmetric growth of the rib has been considered to be one of factors for the development of idiopathic scoliosis. Pinealectomy in chickens consistently produces scoliosis with lordosis, vertebral rotations, and rib humps, which have anatomic characteristics similar to those of human idiopathic scoliosis. METHODS: A total of 30 chickens were divided into two groups: pinealectomy in 15 chickens and sham operation in 15 chickens served as control. The surgeries were performed on the second day after hatching. The chickens in both groups were killed at 3 months of age. The spines were examined radiologically for the presence of a scoliotic curve. Also, the ribs at each level were measured and compared between left and right sides. RESULTS: All pinealectomized chickens that developed scoliosis showed rib humps. In contrast, none of chickens in a sham operation developed scoliosis. In both groups, there were no significant asymmetries in the rib length. CONCLUSION: Our results indicated that rib length was not related to the experimental scoliosis examined in this study. Further study is encouraged to investigate if the asymmetric rib length plays a role in causing or promoting other types of scoliosis, especially in primate or human idiopathic scoliosis.