Reverse shoulder arthroplasty for Japanese ~Optimal implant strategy based on anatomical study~

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K17988
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56020:Orthopedics-related
• Research Institution: Chiba University
• Principal Investigator: Hashimoto Eiko 千葉大学, 医学部附属病院, 助教 (30836747)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 逆置換型人工肩関節置換術 / 関節窩傾斜 / 3D補正CT / 動作解析

Outline of Final Research Achievements

Optimal implant strategies for reverse shoulder arthroplasty were examined by analyzing scapula morphology, biomechanical analysis, and finite element analysis related to postoperative complications, such as dislocations and acromial stress fractures, based on disease characteristics, especially with attention to the Japanese populations. The baseplate positioning with superior inclination has a significant negative correlation with clinical outcomes. We should ensure the correct baseplate positioning with less than 10 degrees of superior inclination to obtain good clinical outcomes after reverse shoulder arthroplasty. Additionally, the repair of the subscapularis tendon and adequate lateralization of the implant are necessary to avoid postoperative complications by biomechanical and finite element analysis.

Free Research Field

医学（整形外科学）

Academic Significance and Societal Importance of the Research Achievements

反転型人工肩関節全置換術が欧米の諸外国に10年以上遅れて、本邦に2014年に導入された。導入10年を迎え、一次修復不能な 広範囲腱板断裂や腱板断裂性肩関節症などを適応とし、良好な短中期成績が徐々に報告される一方で、日本人の体格差によるインプラントサイズのミスマッチやコンセプトの改良の必要性が明確となった。本研究において、適応疾患の疾患特性を踏まえて肩甲骨形態やサイズを解析し、術後合併症（脱臼や肩峰骨折）の動作解析と応力分布を検証することで最適な人工関節デザインやサイズ、設置を日本人に特筆して解明を試みた。これらの研究結果を踏まえて、今後さらに長期的な成績の改善が期待できる。