Experimental and Finite Element Investigations on the Biomechanical Effects of Meniscal Tears in the Knee Joint: A Review

Simulated Analysis Ti-6Al-4V Plate and Screw as Transverse Diaphyseal Fracture Implant for Ulna Bone

Transverse diaphyseal fracture is one of the most common fractures caused by accidents. The fracture treatment needs surgery to apply the fixations that matched the bone geometry. This paper aims to reverse engineering of a published bone plate and screw criteria into a three-dimensional (3D) model and analyze them using the finite element method (FEM) in several factors, the bone, the plate, the screw, the unification of plate and screw, and combination all components. This paper conducts two main activities of designing plate and screw based on literature for ulna bone implant and running the FEM to achieve the von Misses stress in the plate, screw, and bone by placing load and constrained area based on the actual use of the implant in the patient. The maximum number in von Misses stress are 5.01855 MPa for bone only, 0.00918 MPa for plate only, 193.304 MPa for screws only, 6.28160 MPa for the assembly screws and a plate, and 761.07 MPa for all unification. All simulation results meet the expectation that the bone analysis is less than the compressive strength of the ulnar bone. Moreover, when applied to the bone, the plate and screw analysis and the assembly also demonstrate a lower number than the yield strength of the properties of the Ti6Al4V materials. All this biomechanical assessment confirms that designs could withstand ulnar bone’s ultimate flexural load and pressure. The finite element analysis (FEA) on the proposed recreated dimension on ulnar plate and screw is expected to accelerate the rehabilitation process of radius ulnar fracture, particularly in the transverse diaphyseal fracture in ulna bone.

Biomechanical Analysis of the Human Knee Joint

Exercise is an indispensable part of human daily life. The knee joint is inseparable from human movement. The knee is relatively fragile and easy to get injuries. Therefore, the biomechanical properties of knee joints were studied. The VICON T40S 3D motion acquisition and analysis system and the AMTI 3D force measurement platform were used to collect the lower limb kinematics and dynamics data of five male volunteers. Then the knee angle and moment of the human body are analyzed, the foot pressure was obtained by force plate, and the ground reaction force was obtained. The results show that: (1) in terms of knee flexion and extension torques, the peak stretching torques occurred in about 25% and 65% of the gait cycles. At the beginning of the gait, which is the flexion moment, the knee joint produces a moment of -24.65 Nmm, 25% of gait cycles reached the maximum peak value of 896.89 Nmm, 65% of gait cycles reached the second peak value of 315.81 Nmm; (2) The change of reaction force in a gait cycle is: when the ground starts to react, the ground reaction reaches 600 N. At normal times, the ground reaction force rapidly rises to the maximum value of 890 N; when the gait is in the middle of a single support phase, the ground reaction force is 462 N; when the ankle joint moves in plantar flexion, the ground reaction force increases to 830 N again; finally, when the toe is lifted off the ground, the ground reaction force quickly drops to zero; (3) in the course of a gait cycle, the spatial and temporal parameter curve distribution of the subjects was consistent, and the difference was not significant (P > 0.05).