Biomechanical Analysis of the Gracilis and Superficial Third of the Quadriceps Tendons Concerning MPFL Biomechanics

The primary goal of this research is the analysis of the biomechanical performances of most common transplants (distal tendon of m.gracilis and upper third of m.quadriceps femoris) used for the reconstruction of the medial patellofemoral ligament (MPFL). The secondary goal is the comparison of the data obtained from the research with the data available in the literature.The research was conducted on 16 samples of the human tendon, of which there are 8 gracilis tendons and 8 quadriceps tendons. Tensile strength is significantly higher in gracilis tendon (26 MPa - 92 MPa) than in quadriceps tendon (30 MPa - 44 MPa). The extensibility is significantly higher in the quadriceps tendon (10% - 15%) than in the gracilis tendon (13% - 17%). Regarding stiffness (N/mm) there are no significant differences between the groups of gracilis and quadriceps tendons. The module of elasticity is significantly higher in gracilis tendon (235 MPa - 855 MPa) in comparison to quadriceps tendon (239 MPa - 361 MPa).The biomechanical characteristics of the distal surface third of the quadriceps tendon are more favourable than the distal tendon of the gracilis which could prove applicable in operative techniques of reconstruction of the medial patellofemoral ligament when choosing a transplant