A study on reducing cold flow damage for improving longevity of hip prosthesis

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K12689
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 90120:Biomaterials-related
• Research Institution: The University of Kitakyushu
• Principal Investigator: Cho Changhee 北九州市立大学, 国際環境工学部, 教授 (70364148)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 人工股関節 / UHMWPEライナー / コールドフロー（cold flow） / 有限要素法

Outline of Final Research Achievements

Wear and failure of UHMWPE after total joint replacement are major factors restricting the longevity of artificial joints. Generations of cold flow into screw holes are frequently observed in retrieved UHMWPE liners of hip prostheses. In this study, we focused on the existence of screw hole in the acetabular cup, use of screw or cap, condition of screw hole, simultaneous occurrence of cold flow and impingement, polyethylene thickness, and screw hole diameter as factors influencing the wear and failure of the liner due to generation of cold flow. Computer simulations of the generation of cold flow using the finite element method were performed. The results of this study confirmed that these are significant factors influencing the wear and failure of the liner in the hip prosthesis after total hip replacement. Therefore, it is necessary to change designs related to these factors in order to decrease the wear and failure of the liner and to increase the longevity of hip prosthesis.

Free Research Field

生体機械工学

Academic Significance and Societal Importance of the Research Achievements

人工股関節の摩耗や破損などの損傷発生問題は臨床現場から緊急な解決策が要求されている。この問題が改善されれば、人工股関節の更なる耐用性が確保できる。次世代型長寿命人工股関節の開発が実現できれば、一回の置換手術のみで一生使用することが可能となり、再置換手術を受ける必要がなくなる。またこれは、患者の肉体的・精神的・経済的な負担の軽減にもつながる。本研究の成果は、人工股関節の更なる耐用性確保および性能向上に貢献できるものと確信する。また、人工股関節におけるコールドフロー発生に関する研究の活性化や、最適形状設計による人工股関節の損傷の低減化に関連する研究の発展に貢献できるものと確信する。