Insights into the Function on the Knee Meniscus

Student thesis: Doctoral Thesis

Abstract

The knee menisci are understood to have a variety of roles including load transmission and stability of the knee joint. To date, there has been no exploration of the role of radial tears of the menisci in inducing kinematic changes in knee joint movement. Furthermore, the function of proteoglycans in maintaining mechanical meniscus has not been explored.Load was applied to cadaveric knees in the intact state and following both a 50% and 100% radial tear of the medial (5 knees) or lateral (6 knees) meniscus. A coordinate system was developed to allow analysis of joint kinematics. Concurrently,confined compression techniques were used to apply 10% strain to meniscal samples from cadavers (30 samples) and patients suffering osteoarthritis (36 samples) in solutions of varying ionic concentration. 7 samples from an Actifit meniscal scaffold were also tested in deionised water. Resultant relaxation curves were fit using finite element modelling techniques. Human tissue samples were assayed for proteoglycan content.Radial tears of the meniscus did not induce significant changes in knee joint kinematics.Finite element modelling demonstrated that the electrostatic effect of proteoglycans contributed to ~40% of the stiffness of the meniscus. No significant difference in proteoglycan content was observed between solutions. The Actifit meniscal scaffold is stiffer than native meniscal tissue but displays similar permeability.Although radial tears do not alter the kinematics of the knee joint, there is evidence they result in abnormal loading of articular cartilage and it is hence important that they are repaired where possible. Proteoglycans play a critical role in maintaining stiffness of the meniscus – current repair strategies such as meniscal scaffolds do not attempt to recreate this function and hence may not prevent cartilage degradation. The stiffness of the Actifit meniscal scaffold may help protect a nascent meniscal repair but may also contribute to abnormal joint loading; its similar permeability will help mimic meniscal function.
Date of Award26 Apr 2019
Original languageEnglish
Awarding Institution
  • University Of Strathclyde
SupervisorPhil Riches (Supervisor) & Craig Childs (Supervisor)

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