Accuracy of Multilevel Registration in Image-Guided Pedicle Screw Insertion for Adolescent Idiopathic Scoliosis

This is a non-final version of an article published in final form in SPINE 35(3): 347-352, 2010.Study Design. Retrospective clinical study. Objective. To assess the accuracy of multilevel registration for skip pedicle screw placement during image-guided, computer-assisted spine surgery, in the setting of adolescent idiopathic scoliosis (AIS). Summary of Background Data. Computerized frameless stereotactic image-guidance has been used recently to improve pedicle screw placement accurately and safety during spine surgery. Because of possible intervertebral motion and usual difference in patients' position between preoperative imaging and surgery, the imaging model and the surgically exposed spine may be significantly discordant. Consequently, current protocols suggested separate registration of each spinal level (single-level registration) before respective pedicle screw placement, a time-consuming process. Moreover, although multilevel registration for lumbar spine has been reported, and that for thoracic spine has not. Methods. A total of 19 patients ( 1 male and 18 females; mean age, 13.9 years) with AIS who underwent multilevel registration for skip pedicle screw placement were included. Variables including surgical time, blood loss, preoperative and 2-year postoperative Cobb angle, correction rate, and postoperative screw position by computed tomography image were evaluated. Mean registration error after point merge and again after surface merge were recorded for each consecutive vertebra of each case. Results. Mean surgical time was 310 minutes ( range, 168-420 min). Mean blood loss 1138 g (range, 300-2300 g). Cobb angle before operation and at 2 years postoperation was 62.4 degrees (43 degrees-100 degrees) and 21.6 degrees (9 degrees-42 degrees), respectively. Mean correction rate 66.2% (39.7%-84.5%). Total 265 screws were inserted with computed tomography-based navigation system. Pedicle violation was observed in only 4 screws (1.5%). No neurovascular complication occurred. After point merge, average Mean registration error of all cases was 1.69 +/- 0.52 mm, and after surface merge was 0.51 +/- 0.16 mm. Conclusion. Multilevel registration may decrease operative time without compromising accuracy of pedicle screw placement afforded by this technique in the setting of AIS.http://journals.lww.com/spinejournal/pages/default.aspx | http://journals.lww.com/spinejournal/pages/default.aspxArticleSPINE. 35(3):347-352 (2010)journal articl

Computer-assisted hemivertebral resection for congenital spinal deformity

No studies have reported on osteotomies utilizing a navigation system in congenital scoliosis surgery. This study aimed to evaluate the surgical outcomes of eight patients with congenital scoliosis or kyphoscoliosis due to hemivertebrae treated by computer-assisted hemivertebral resection using only a posterior approach. Eight consecutive patients (two scoliotics and six kyphoscoliotics) managed by computer-assisted hemivertebral resection using only a posterior approach with transpedicular instrumentation were investigated retrospectively. A CT-based navigation system was used to confirm the positions of the vertebra, spinal cord and aorta in real-time when we inserted a pedicle screw and conducted the osteotomy. The mean patient age at surgery was 18 years (range 11-41 years). The mean follow-up was 46 months (range 18-84 months). Before surgery, the mean kyphotic curve was 55.8A degrees (range 26-83A degrees), and the mean scoliotic curve was 50.0A degrees (range 36-62A degrees). At the final follow-up period, the curves averaged 23.2A degrees (range 15-40A degrees) and 31.6A degrees (range 21-44A degrees), respectively, yielding kyphotic angle corrections of 32.7A degrees (range 11-58A degrees) and Cobb angle correction rates of 36.8% (range 24.1-48.3%). A total of 72 pedicle screws were inserted with the navigation system, and two screws revealed a perforating pedicle. No neurovascular complications occurred. The perforation rate was 2.8%. Hemivertebral resection via a single posterior approach is less invasive than combined anterior and posterior approaches; however, this procedure increases the risk of spinal cord and vascular injuries. Computer-assisted hemivertebral resection enables safe and accurate performance of a hemivertebral resection via a single posterior approach.ArticleJOURNAL OF ORTHOPAEDIC SCIENCE. 16(5):503-509 (2011)journal articl

Evaluation of clinical results and quality of life after surgical reconstruction for rheumatoid cervical spine

BACKGROUND CONTEXT: The EuroQol (EQ-5D) is a widely used comprehensive measure of health-related quality of life. There has been no study that has evaluated the health-related quality of life before and after the surgical reconstruction of rheumatoid arthritis (RA) cervical spine lesions using EQ-5D. PURPOSE: The present study aimed to evaluate the improvement of quality of life before and after surgical reconstruction of rheumatoid cervical spine using EQ-5D, and the surgical outcomes of cervical spine affected by RA. STUDY DESIGN: A retrospective study of the patients who underwent surgical reconstruction of cervical disorders in RA. PATIENT SAMPLE: Twenty-five patients (seven men, 18 women, mean age 62.2 years) who underwent surgical reconstruction of cervical disorders in RA were enrolled. OUTCOME MEASURES: Japanese Orthopaedic Association (JOA) score and EQ-5D. METHODS: Clinical symptoms were evaluated before surgery and at 2 years after surgery by measuring the JOA score. We also investigated health-related quality of life before surgery and outcome at 2 years after surgery using the EQ-5D questionnaire. RESULTS: Mean observation period was 46.3 months. Mean JOA score significantly improved from 9.1 +/- 4.5 points before surgery to 12.4 +/- 2.8 at the 2 years after surgery (p=.0001). All the EQ-5D data were improved at the 2 years after surgery, compared with the data before surgery; especially, pain (p=.005), usual activity (p=.005), mobility (p=.008), and anxiety/depression (p=.02) were significantly improved. Utility weight was 0.37 +/- 0.27 before surgery and 0.56 +/- 0.26 at the 2 years after surgery, showing significant improvement at the 2 years after surgery compared to before surgery (p=.002). CONCLUSIONS: The surgical reconstruction of rheumatoid cervical spine has been demonstrated to improve patients' health-related quality of life.ArticleSPINE JOURNAL. 13(4):391-396 (2013)journal articl

Mid-term results of computer-assisted cervical reconstruction for rheumatoid cervical spines

Study design A retrospective single-center study. Summary and background We routinely have used C1-C2 transarticular and cervical pedicle screw fixations to reconstruct highly destructed unstable rheumatoid arthritis (RA) cervical lesions. However, there is little data on midterm results of surgical reconstruction for rheumatoid cervical disorders, particularly, cervical pedicle screw fixation. Objectives The purpose of this study was to evaluate the mid-term surgical results of computer-assisted cervical reconstruction for such lesions. Methods Seventeen subjects (4 men, 13 women; mean age, 61 +/- 9 years) with RA cervical lesions who underwent C1-C2 transarticular screw fixation or occipitocervical fixation, with at least 5 years follow-up were studied. A frameless, stereotactic, optoelectronic, CT-based image-guidance system, was used for correct screw placement. Variables including the Japanese Orthopaedic Association (JOA) score, Ranawat class, EuroQol (EQ-5D), atlantodental interval, and Ranawat values before, and at 2 and 5 years after surgery, were evaluated. Furthermore, screw perforation rates were evaluated. Results The lesions included atlantoaxial subluxation (AAS, n = 6), AAS + vertical subluxation (VS, n = 7), and AAS + VS + subaxial subluxation (n = 4). There was significant neurological improvement at 2 years after surgery, as evidenced by the JOA scores, Ranawat class, and the EQ-5D utility weight. However, at 5 years after surgery, there was a deterioration of this improvement. The Ranawat values before, and at 2 and 5 years after surgery, were not significantly different. Major screw perforation rate was 2.1 %. No neural and vascular complications associated with screw insertion were observed. Conclusions Subjects with rheumatoid cervical lesions who underwent C1-C2 transarticular screw fixation or occipitocervical fixation using a pedicle screw had significantly improved clinical parameters at 2 years after surgery. However, there was a deterioration of this improvement at 5 years post surgery.ArticleJOURNAL OF ORTHOPAEDIC SCIENCE. 18(6):916-925 (2013)journal articl

Photodynamic Therapy With YAG-OPO Laser for Early Stage Lung Cancer

Photodynamic therapy (PDT) utilizing Photofrin is proving to be effective for the treatment of early stage lung cancers. The effect of PDT utilizing YAG-OPO laser as new light source was evaluated in 26 patients (29 lesions) with early stage lung cancers. YAG-OPO laser is solid state tunable laser which is easy to change wavelength between 620 and 670 nm exciting various kinds of photosensitizers. Moreover, YAG-OPO laser is more reliable, smaller and has less consumables than argon-dye laser or excimer-dye laser. As the result of PDT with YAG-OPO laser, complete remission (CR) was obtained in 82.6% of the 29 lesions, partial remission (PR) in 13.8% and no change (NC) was obtained in 3.4%. We conclude that PDT utilizing YAG-OPO laser is efficacious in the treatment of early stage lung cancers and can achieve complete remission

Toxicoproteomic evaluation of carbon nanomaterials in vitro

Carbon nanotubes (CNTs) have already been successfully implemented in various fields, and they are anticipated to have innovative applications in medical science. However, CNTs have asbestos-like properties, such as their nanoscale size and high aspect ratio (> 100). Moreover, CNTs may persist in the body for a long time. These properties are thought to cause malignant mesothelioma and lung cancer. However, based on conventional toxicity assessment systems, the carcinogenicity of asbestos and CNTs is unclear. The reason for late countermeasures against asbestos is that reliable, long-term safety assessments have not yet been developed by toxicologists. Therefore, a new type of long-term safety assessment, different from the existing methods, is needed for carbon nanomaterials. Recently, we applied a proteomic approach to the safety assessment of carbon nanomaterials. In this review, we discuss the basic concept of our approach, the results, the problems, and the possibility of a long-term safety assessment for carbon nanomaterials using the toxicoproteomic approach.ArticleJournal of Proteomics. 74(12):2703-2712 (2011)journal articl

DJ-1 as a potential biomarker for the development of biocompatible multiwalled carbon nanotubes

Hisao Haniu1, Tamotsu Tsukahara2, Yoshikazu Matsuda3, Yuki Usui4, Kaoru Aoki5, Masayuki Shimizu5, Nobuhide Ogihara5, Kazuo Hara5, Seiji Takanashi5, Masanori Okamoto5, Norio Ishigaki5, Koichi Nakamura5, Hiroyuki Kato5, Naoto Saito6 1Institute of Carbon Science and Technology, 2Department of Integrative Physiology and Bio-System Control, Shinshu University, Matsumoto, Nagano, 3Clinical Pharmacology Educational Center, Nihon Pharmaceutical University, Ina-machi, Saitama, 4Research Center for Exotic Nanocarbons, 5Department of Orthopaedic Surgery, 6Department of Applied Physical Therapy, Shinshu University School of Health Sciences, Shinshu University, Matsumoto, Nagano, Japan Background: In the present study, we investigated whether DJ-1 could serve as a biomarker for assessing the biocompatibility of multiwalled carbon nanotubes (MWCNTs), using the highly purified carbon nanotube, HTT2800. Methods: Using Western blot analysis, we determined DJ-1 protein levels in two different types of cells (one capable and the other incapable of HTT2800 endocytosis). Using quantitative real-time polymerase chain reaction, we also investigated the ability of purified nanotubes to alter DJ-1 mRNA levels. Results: We demonstrated that the DJ-1 protein concentration was reduced, regardless of the cytotoxic activity of intracellular HTT2800. Furthermore, HTT2800 decreased the DJ-1 mRNA levels in a dose-dependent manner. This decrease in DJ-1 mRNA levels was not observed in the case of Sumi black or cup-stacked carbon nanotubes. Conclusion: These data indicate that modification of DJ-1 expression is caused by the cell response to MWCNTs. We conclude that DJ-1 is a promising candidate biomarker for the development of biocompatible MWCNTs. Keywords: multiwalled carbon nanotubes, DJ-1 protein, Western blot, quantitative real-time polymerase chain reactio

Evaluation of CNT toxicity by comparison to tattoo ink

ArticleMaterials Today. 14(9): 434-440 (2011)journal articl