Faculty Profiles - Saito Taichi

The trend of treatment and conveyance system for upper extremity replantation in Japan: A nationwide population-based study from the Japan trauma data bank

Saito, T., Nezu, S., Matsuhashi, M., Nakahara, R., Shimamura, Y., Noda, T., Yumoto, T., Nakao, A., Ozaki, T.

Journal of Orthopaedic Science 26 ( 2 ) 271 - 275 2021

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: In Japan, microsurgical skill development and a system to transfer patients to an appropriate hospital for upper extremity amputation have been promoted; however, information about trends of replantation is limited. Therefore, the aim of this study was to clarify the trends in the treatment for upper extremity amputation using the Japan Trauma Data Bank (JTDB). METHODS: Data derived from JTDB (2004-2015) were used to quantify trends in the volume of replantation for upper extremity amputation including finger amputation. Trauma was diagnosed based on the Abbreviated Injury Scale code; a subgroup of patients who underwent replantation was delineated. We investigated patient demographics, infection rate, and characteristics of treating facilities. RESULTS: A total of 1240 patients underwent upper extremity amputation. Among these, 510 (41.1%) underwent replantation, and the rate of replantation did not change over the study period. The average age of patients who underwent or did not undergo replantation was 45.5 and 47.2 years, respectively. The proportion of the patients who were transferred to another hospital for treatment significantly decreased between 2004 (28.5%) and 2015 (16.3%) (P < 0.01). Time taken for transfer from the accident site to hospitals increased. The rate of patients who underwent replantation differed among different hospitals; however, higher-volume hospitals were more likely to perform replantation. CONCLUSION: The rate of patients transferred to another hospital decreased between 2004 and 2015; however, the rate of patients who underwent replantation remained unchanged. This suggests that the number of patients who were transported directly from the accident site to an appropriate hospital has increased, whereas the indication for care in each hospital remains unchanged. Common criteria for amputations are needed to address the differing rates of replantation among hospitals.

DOI： 10.1016/j.jos.2020.03.006

Relationship between clinical outcomes and nerve conduction studies before and after surgery in patients with carpal tunnel syndrome International journal

Ise, M., Saito, T., Katayama, Y., Nakahara, R., Shimamura, Y., Hamada, M., Senda, M., Ozaki, T.

BMC Musculoskeletal Disorders 22 ( 1 ) 882 - 882 2021

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Nerve conduction study (NCS) is the only useful test for objective assessment of carpal tunnel syndrome (CTS). However, the relationship between pre- and postoperative NCS and clinical outcomes was unclear. This study aimed to determine whether pre- and postoperative (6 months) NCS could predict patient-oriented and motor outcomes (6 and 12 months postoperatively) in patients with CTS. METHOD: Of the 85 patients with CTS, 107 hands were analyzed from March 2011 to March 2020. All patients underwent open carpal tunnel release and were examined using the disabilities of the arm, shoulder and hand (DASH) questionnaire and grip strength (GS) preoperatively and 6 and 12 months postoperatively. Moreover, NCS was examined preoperatively and 6 months postoperatively. Distal motor latency (DML) and sensory conduction velocity (SCV) were the parameters used for NCS. The correlation coefficient between NCS and DASH or GS was calculated. A receiver operating characteristic curve was utilized to determine the NCS threshold value to predict DASH and GS improvement. RESULTS: The average scores of GS preoperatively and 6 and 12 months postoperatively were 21.3, 22.3, and 22.8, respectively. On the other hand, the average scores of DASH preoperatively and 6 and 12 months postoperatively were 28.8, 18.3, and 12.2, respectively. The average NCS scores (DML and SCV) preoperatively/6 months postoperatively were 7.3/5.4 and 27.8/36.7, respectively. Preoperative NCS did not correlate with DASH and GS. Postoperative SCV correlated with the change in grip strength (6-12 months, r = 0.67; 0-12 months, r = 0.60) and DASH (0-12 months, r = 0.77). Moreover, postoperative DML correlated with the change in DASH (6-12 months, r = - 0.33; 0-12 months, r = - 0.59). The prediction for the improvement of GS/DASH achieved a sensitivity of 50.0%/66.7% and a specificity of 100%/100%, at an SCV cutoff score of 38.5/45.0 or above. The prediction for improvement of GS/DASH achieved a sensitivity of 83.3%/66.7% and a specificity of 100%/66.7% at a DML cutoff score of 4.4/4.4 or below. CONCLUSION: NCS at 6 months postoperatively can be used to predict the improvement of clinical outcome after 6 months postoperatively in patients with CTS.

DOI： 10.1186/s12891-021-04771-y

Differences between the root and horn cells of the human medial meniscus from the osteoarthritic knee in cellular characteristics and responses to mechanical stress

Okazaki, Y., Furumatsu, T., Kamatsuki, Y., Nishida, K., Nasu, Y., Nakahara, R., Saito, T., Ozaki, T.

Journal of Orthopaedic Science 26 ( 2 ) 230 - 236 2021

Language：English Publishing type：Research paper (scientific journal)

BACKGROUND: Many histological, mechanical, and clinical studies have been performed on the medial meniscus posterior root attachment, as it often tears in patients with osteoarthritic knee. Medial meniscal root repair is recommended in clinical situations; however, to date, no studies have examined the differences between meniscal root and horn cells. The aim of this study was, therefore, to investigate the morphology, reaction to cyclic tensile strain, and gene expression levels of medial meniscal root and horn cells. METHODS: Meniscal samples were obtained from the medial knee compartments of 10 patients with osteoarthritis who underwent total knee arthroplasty. Root and horn cells were cultured in Dulbecco's modified Eagle's medium without enzymes. The morphology, distribution, and proliferation of medial meniscal root and horn cells, as well as the gene and protein expression levels of Sry-type HMG box 9 and type II collagen, were determined after cyclic tensile strain treatment. RESULTS: Horn cells had a triangular morphology, whereas root cells were fibroblast-like. The number of horn cells positive for Sry-type HMG box 9 and type II collagen was considerably higher than that of root cells. Although root and horn cells showed similar levels of proliferation after 48, 72, or 96 h of culture, more horn cells than root cells were lost following a 2-h treatment with 5% and 10% cyclic tensile. Sry-type HMG box 9 and α1(II) collagen mRNA expression levels were significantly enhanced in both cells after 2- and 4-h cyclic tensile strain (5%) treatment. CONCLUSIONS: Medial meniscal root and horn cells have distinct morphologies, reactions to mechanical stress, and cellular phenotypes. Our results suggest that physiological tensile strain is important to activate extracellular matrix production in horn cells.

DOI： 10.1016/j.jos.2020.02.015