Table 1.
Baseline data of the hip joint capsule specimens.
Mean values ± standard deviation are given in the captions for all tested tissue samples (∑).
Fig 1.
Preparation and material testing setup for the investigation of the stress-strain properties of the ilio-, ischio- and pubofemoral ligaments.
(A) Partially plastinated ligaments of hip capsule. (B) Attached partially-plastinated tissue sample to the testing machine (C) Example of a stress-strain curve. The elastic modulus was represented by means of a secant modulus. It was calculated as ratio of Δσ10% (last 10% of stress values) and according strain values Δε: elastic modulus = Δσ10% / Δε.
Fig 2.
The ligaments of the hip capsule revealed similar mechanical properties except of significant differences in the cross-sectional area.
Hip capsules of 17 cadavers were used and dissected related to their anatomical origin. From these tissue samples 17 ilio-, 9 ischio- and 17 pubofemoral were investigated regarding their elastic modulus, strain and cross-sectional area. (A) The cross-section of the iliofemoral ligament (IL) is significant higher compared to ischio- (IS) or pubofemoral (PF) ligament (* indicates p<0.05 adjusted p values: IF vs. IS 0.0016, IF vs. PB <0.0001, IS vs. PB >0.999). (B) Analysis of strain values revealed non-significant differences between the hip capsule ligaments. (C) Elastic Modulus was generated related to the strain and stress values measured over ten cycles and present no significant differences between iliofemoral, ischiofemoral and pubofemoral ligament.
Table 2.
Investigation of gender-specific differences of the hip capsule ligaments regarding strain, cross section and elastic modulus.
No statistical differences were determined (p>0.05).
Table 3.
Investigation of side-specific differences of the hip capsule ligaments regarding strain, cross section and elastic modulus.
No Statistical differences were determined (p>0.05).
Fig 3.
The ligaments of the hip joint capsule have a lower elasticity and less variation compared to the iliotibial tract (* indicates p<0.0001).