Establishment of quantitative evaluation method of tendon repair after Achilles tendon rupture using MRI T2 mapping

Research Project

Project/Area Number	16K10884
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Orthopaedic surgery
Research Institution	Chiba University
Principal Investigator	Yamaguchi Satoshi 千葉大学, 国際教養学部, 准教授 (30596953)
Research Collaborator	Watanabe Atuya
Project Period (FY)	2016-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000) Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000) Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000) Fiscal Year 2016: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywords	多血小板血漿 / アキレス腱 / MRI T2mapping / アキレス腱断裂 / 整形外科学 / スポーツ医学
Outline of Final Research Achievements	Three groups were prepared to which high concentration PRP (H-PRP), low concentration PRP (L-PRP) and saline were respectively administered. Each group was administered immediately after the Achilles tendon transection surgery, and MRI and histologic and mechanical evaluation of the tendon repair site were performed 4 and 8 weeks after the operation. The platelet count of the L-PRP and H-PRP were about 3.8 times and 12.8 times higher than that of the whole blood. MRI evaluation was used to measure T2 value. Histological evaluation was performed using Bonner scale. Mechanical evaluation was used to measure the elastic modulus and the linear stiffness. T2 value and Bonner scale were lower in the order of saline, L-PRP, H-PRP, and there was a significant difference. The elastic modulus and the linear stiffness values were higher in the order of saline, L-PRP, H-PRP. Significant correlations were obtained between T2 values and Bonner scale, the elastic modulus and the linear stiffness.
Academic Significance and Societal Importance of the Research Achievements	アキレス腱断裂は人体の中で最も多い腱断裂である。腱修復には時間がかかり、スポーツ復帰まで6-9か月かかる。適切な評価、治療による早期の社会、スポーツ復帰は社会的要請が大きい。現在、臨床で使用可能なアキレス腱断裂後の修復過程を定量的に評価する手法はない。本研究により、修復部の平均T2 値と組織学的な修復スコア、力学的評価（弾性率及び剛性）とは有意に相関することが示され、T2 mapping が臨床で使用可能な腱修復の定量的評価法として有用である可能性を明らかにした。