Clinically relevant biomechanics of the knee capsule and ligaments

Abstract

Abstract:The paper describes the concepts of primary and secondary restraints to knee joint stability, and explains systematically how the tibia is stabilised against translational forces and rotational torques in different directions and axes, and how those vary across the arc of flexion-extension. It also shows how the menisci act to stabilise the knee, in addition to load-carrying across the joint. It compares the properties of the natural stabilising structures with the strength and stiffness of autogenous tissue grafts, and relates those strengths to the strength of graft fixation devices. A good understanding of the biomechanical behaviour of these various structures in the knee will help the surgeon in the assessment and treatment of single and multi-ligament injuries.Response to Reviewers: 1. At the end of the Abstract, please add a sentence or two about the … clinical relevance … Authors' response: this has been done 2. The different sections and subsections of the manuscript should not be numbered, e.g. it should be … Introduction and not … 1 Introduction, and this needs to be corrected throughout.Authors' response: this has been done 3. Tables (like table 1 Clinically relevant biomechanics of the knee capsule and ligaments AbstractThe paper describes the concepts of primary and secondary restraints to knee joint stability, and explains systematically how the tibia is stabilised against translational forces and rotational torques in different directions and axes, and how those vary across the arc of flexion-extension. It also shows how the menisci act to stabilise the knee, in addition to loadcarrying across the joint. It compares the properties of the natural stabilising structures with the strength and stiffness of autogenous tissue grafts, and relates those strengths to the strength of graft fixation devices. A good understanding of the biomechanical behaviour of these various structures in the knee will help the surgeon in the assessment and treatment of single and multi-ligament injuries.

Muscle loaded stability reflects ligament-based stability in TKA: a cadaveric study

“…Secondly, the introduction of muscle loads causes more internal femoral rotation and less pronounced, if at all, femoral rollback as flexion progresses. This absence contrasts with the traditional understanding of knee kinematics described by Freeman [7,12]. Their analyses are however limited to passive conditions, under which femoral rollback was also seen in our study.…”

Editorial Commentary: Size Does Matter—Anterior Cruciate Ligament Graft Diameter Affects Biomechanical and Clinical Outcomes

“…9 The actual failure load for a native ACL under injury conditions of valgus loading may be considerably less. 10 If a graft loses strength with healing, how strong should the initial graft be for a successful outcome?…”

Biomechanics and Microstructural Analysis of the Mouse Knee and Ligaments

“…In the human knee, the ACL (2,160 AE 157 N) has been shown to be stronger than that of the MCL (799 AE 209 N) and LCL (392 AE 104 N); in contrast, some studies in the human suggest that the PCL may have a higher tensile strength than the ACL (►Table 1). [25][26][27][28] We observed that the mouse LCL was the weakest and least stiff of the ligaments, with approximately half the strength of the PCL and the MCL, similar to the pattern seen in humans. The MCL and LCL failed by tibial and fibular avulsion, respectively, during biomechanical testing.…”