소형위성 RISESAT의 광센서기술과 1 kg급 광송신기에 의한 광통신 실험

Kuwahara, Toshinori,Fujita, Shinya,Sato, Yuji,Tomio, Hannah,Sakai, Morokot,Kunimori, Hiroo,Takenaka, Hideki 한국광학기기산업협회 2019 光學世界 Vol.175 No.-

Compression Myelopathy due to Proliferative Changes around C2 Pars Defects without Instability

Tetsuya Kimura,Toshinori Sakai,Fumitake Tezuka,Mitsunobu Abe,Kazuta Yamashita,Yoichiro Takata,Kosaku Higashino,Koichi Sairyo 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.3

We report a case with compression myelopathy due to proliferative changes around the C2 pars defects without instability. A 69-yearold man presented with progressive clumsy hands and spastic gait. Plain radiographs showed bilateral spondylolysis (pars defects) at C2 and fusion between C2 and C3 spinous processes. Dynamic views revealed mobility through the pars defects, but there was no apparent instability. Computed tomography showed proliferative changes at the pars defects, which protruded into spinal canal. On magnetic resonance imaging, the spinal cord was compressed and intramedullary high signal change was found. A diagnosis of compression myelopathy due to proliferative changes around the C2 pars defects was made. We performed posterior decompression. Postoperatively, symptoms have been alleviated and images revealed sufficient decompression and no apparent instability. In patients with the cervical spondylolysis, myelopathy caused by instability or slippage have been periodically reported. The present case involving C2 spondylolysis is extremely rare.

Complete Resolution of a Case of Calcific Tendinitis of the Longus Colli with Conservative Treatment

Fumitake Tezuka,Toshinori Sakai,Ryo Miyagi,Yoichiro Takata,Kosaku Higashino,Shinsuke Katoh,Koichi Sairyo,Natsuo Yasui 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.5

Acute calcific tendinitis of the longuscolli is a self-limiting inflammatory condition caused by calcium hydroxyapatite deposition in the longuscolli tendon. Although several case reports have described its radiological presentation, few reports provide detailed chronological accounts through symptomatic and radiologic resolution. A 59-year-old woman presented with severe neck pain and stiffness of a few days duration as well as moderate discomfort when swallowing. Lateral radiographs revealed a large calcium deposit anterior to the C1–C2 joint and swelling of the prevertebral soft tissue from C1 to C5. CT and magnetic resonance imaging showed fluid in the retropharyngeal gap.A soft collar and non-steroidal anti-inflammatory drug were prescribed, without antibiotics. At 4 months after presentation, the calcium deposit and all symptoms had resolved completely. Although this disease is comparatively rare, physicians should keep it in mind when a patient presents with acute severe neck pain.

Vacuum Phenomenon of the Sacroiliac Joint: Correlation with Sacropelvic Morphology

Yoichiro Takata,Kosaku Higashino,Masatoshi Morimoto,Toshinori Sakai,Kazuta Yamashita,Mitusnobu Abe,Akihiro Nagamachi,Koichi Sairyo 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.4

Study Design: A radiologic study of sacropelvic morphology and vacuum phenomenon of sacroiliac joint in subjects unrelated to low back pain. Purpose: The aim of this study is to describe the relationship between sacropelvic morphology and vacuum phenomenon of the sacroiliac joint. Overview of Literature: Lumbopelvic alignment and sacropelvic morphology are associated with the pathomechanisms of various spinal disorders. The vacuum phenomena of the sacroiliac joint (SJVP) are often observed in clinical practice, but the relationships between these phenomena and sacropelvic morphology have not been investigated. This study examined the prevalence of SJVP in computed tomography (CT) images and the relationship between sacropelvic morphology and SJVP. Methods: We analyzed multiplanar CT images of 93 subjects (59 men, 34 women). Pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and lumbar lordosis (LL) were measured using the three-dimensional reconstruction method. The prevalence of SJVP in multiplanar CT images were reviewed. Roland-Morris Disability Questionnaire (RDQ) scores and the modified Japanese Orthopedic Association (JOA) score, which focuses on subjective symptoms and restriction of activities of daily living, were also obtained from all the subjects. Results: Thirty-six of the 93 subjects had SJVP (39%), with marked female predominance (91% women, 8.5% men). Men with SJVP had significantly lower PI than men without SJVP (35.1° vs. 46.3°, p <0.05). There was no correlation between SJVP and the modified JOA or RDQ scores. Conclusions: These data suggest that differences in sacropelvic morphology can influence the biomechanical environment and contribute to SJVP in men. Presence of SJVP did not affect JOA or RDQ scores.

Radiation Exposure to the Hand of a Spinal Interventionalist during Fluoroscopically Guided Procedures

Kazuta Yamashita,Hisanori Ikuma,Takuya Tokashiki,Takashi Maehara,Akihiro Nagamachi,Yoichiro Takata,Toshinori Sakai,Kosaku Higashino,Koichi Sairyo 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.1

Study Design: Prospective study. Purpose: During fluoroscopically guided spinal procedure, the hands of spinal surgeons are placed close to the field of radiation and may be exposed to ionizing radiation. This study directly measured the radiation exposure to the hand of a spinal interventionalist during fluoroscopically guided procedures. Overview of Literature: Fluoroscopically guided spinal procedures have been reported to be a cause for concern due to the radiation exposure to which their operators are exposed. Methods: This prospective study evaluated the radiation exposure of the hand of one spinal interventionalist during 52 consecutive fluoroscopic spinal procedures over a 3-month period. The interventionalist wore three real-time dosimeters secured to the right forearm, under the lead apron over the chest, and outside the lead apron over the chest. Additionally, one radiophotoluminescence glass dosimeter was placed under the lead apron over the left chest and one ring radiophotoluminescence glass dosimeter was worn on the right thumb. The duration of exposure and radiation dose were measured for each procedure. Results: The average radiation exposure dose per procedure was 14.9 μSv, 125.6 μSv, and 200.1 μSv, inside the lead apron over the chest, outside the lead apron over the chest, and on the right forearm, respectively. Over the 3-month period, the protected radiophotoluminescence glass dosimeter over the left chest recorded less than the minimum reportable dose, whereas the radiophotoluminescence glass ring dosimeter recorded 368 mSv for the thumb. Conclusions: Our findings indicated that the cumulative radiation dose measured at the dominant hand may exceed the annual dose limit specified by the International Commission on Radiological Protection. Spinal interventionalists should take special care to limit the duration of fluoroscopy and radiation exposure.

Vertebral Lateral Notch as Optimal Entry Point for Lateral Mass Screwing Using Modified Roy-Camille Technique

Norio Yamamoto,Hirofumi Kosaka,Kosaku Higashino,Masatoshi Morimoto,Kazuta Yamashita,Fumitake Tezuka,Fumio Hayashi,Yoichiro Takata,Toshinori Sakai,Akihiro Nagamachi,Koichi Sairyo 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.2

Study Design: Retrospective study of 37 consecutive female patients with cervical spondylotic myelopathy who underwent reconstructed computed tomography (CT) scanning of the cervical spine. Purpose: The purpose of this study was to investigate whether the vertebral lateral notch of the cervical spine is an effective landmark to determine the entry point for lateral mass screwing. A modified Roy-Camille technique was used to determine the entry point associated with the lateral notch of the cervical spine. Overview of Literature: The Roy-Camille technique has been a popular technique for the posterior fixation of the cervical spine. A problem with this technique is determining the entry point on the lateral mass via visual inspection, such as in cases with degenerative or destructive cervical facet joints. Methods: Thirty-three female patients with cervical spondylotic myelopathy underwent reconstructed CT scanning of the cervical spine. Overall, 132 vertebrae from C3 to C6 were reviewed using reconstructed CT. The probable trajectory using a modified Roy- Camille technique was determined using reconstructed CT scans, and the optimal entry point was identified. Horizontal and vertical distances from the vertebral lateral notch were measured. Results: The entry point determined using the modified Roy-Camille technique was significantly superior and medial compared with that determined using the conventional Roy-Camille technique. At C3 and C4 levels, the entry point using the modified technique was 1.4 mm below and 4.4 mm medial to the lateral notch, and at C5 and C6 levels, it was 2.3 mm below and 4.9 mm medial to the lateral notch. Conclusions: The vertebral lateral notch of the cervical spine was an effective landmark to determine the entry point for lateral mass screwing. The modified Roy-Camille technique proposed here may prevent surgical complications and poor outcomes.