Material properties of the human posterior knee capsule

• Published in: Bio-medical materials and engineering Vol. 25; no. 2; p. 177
• Main Authors: Rachmat, H H, Janssen, D, Verkerke, G J, Diercks, R L, Verdonschot, N
• Format: Journal Article
• Language: English
• Published: Netherlands 2015
• Subjects: Aged; Aged, 80 and over; Biomechanical Phenomena; Cross-Sectional Studies; Elastic Modulus - drug effects; Female; Humans; Joint Capsule - drug effects; Joint Capsule - physiopathology; Knee - anatomy & histology; Knee Joint - drug effects; Male; Models, Biological; Stress, Mechanical; Tensile Strength - drug effects; material properties; tensile test; posterior knee capsule; three-dimensional knee model; Cross sectional area
• ISSN: 1878-3619
• DOI: 10.3233/bme-151268

There is considerable interest to develop accurate subject-specific biomechanical models of the knee. Most of the existing models currently do not include a representation of the posterior knee capsule. In order to incorporate the posterior capsule in knee models, data is needed on its mechanical properties.
To quantify the mechanical properties of the human posterior knee capsule through semi-static tensile tests.
Fifteen posterior knee capsule specimens (5 knees, 3 male, 2 female; age 79.2±7.9 years) were used to perform tensile tests. A medial, central and lateral specimen was taken from each knee. The cross-sectional area was measured, after which semi-static tensile tests were performed to quantify the material properties.
The stiffness of the capsule was randomly distributed over the regions. The global Young's modulus and yield strength was 8.58±10.77 MPa and 1.75±1.89 MPa, respectively. A strong correlation (ρ=0.900) was found between Young's modulus and yield strength. The location of failure was not associated with smallest cross-sectional area or highest strain.
The results suggest that the posterior knee capsule does not have a systematic (medial-central-lateral) distribution of material properties. The posterior capsule may play an important role in knee joint mechanics, particularly when in hyper extension.