Material parameters identification of 3D printed titanium alloy prosthesis stem based on response surface method.

3D printed Titanium alloy is widely used as a material of artificial joints and its mechanical properties is a key factor for improving operation results. Because the elastic modulus of the 3 D printed titanium alloy specimen was related to the size of the metal blank. It is very difficult to identify mechanical parameters by traditional mechanics experiments.

Mechanical behavior of a titanium alloy scaffold mimicking trabecular structure.

Background: Additively manufactured porous metallic structures have recently received great attention for bone implant applications. The morphological characteristics and mechanical behavior of 3D printed titanium alloy trabecular structure will affect the effects of artificial prosthesis replacement. However, the mechanical behavior of titanium alloy trabecular structure at present clinical usage still is lack of in-depth study from design to manufacture as well as from structure to mechanical function.

Mechanical Roles in Formation of Oriented Collagen Fibers.

Collagen is a structural protein that is widely present in vertebrates, being usually distributed in tissues in the form of fibers. In living organisms, fibers are organized in different orientations in various tissues. As the structural base in connective tissue and load-bearing tissue, the orientation of collagen fibers plays an extremely important role in the mechanical properties and physiological and biochemical functions.

Effect on Chest Deformation of Simultaneous Correction of Pectus Excavatum with Scoliosis.

Objective: This paper is to understand the effect of simultaneous correction of pectus excavatum with scoliosis and to provide some useful information for clinical orthopedic surgery design.

Methods: The method of a three-dimensional reconstruction has been used to the reconstruction of the chest model of pectus excavatum with scoliosis, and the numerical stimulation has been conducted to the process of minimally invasive correction. Three kinds of correction methods have been considered in the numerical simulation, stretch spine, stretch spine and minimally invasive correction at the same time, and release stretch spine after stretch spine and minimally invasive correction of pectus excavatum at the same time.

Effects of Pectus Excavatum on the Spine of Pectus Excavatum Patients with Scoliosis.

Background: There is high risk in the correction surgery of pectus excavatum with scoliosis because of the lack of the correction mechanism of pectus excavatum with scoliosis. This study performed a comprehensive analysis about the impact that pectus excavatum had on scoliosis and elaborated its biomechanical mechanism in pectus excavatum patients with scoliosis.

Methods: 37 pectus excavatum patients were selected.

On mechanical mechanism of damage evolution in articular cartilage.

Superficial lesions of cartilage are the direct indication of osteoarthritis. To investigate the mechanical mechanism of cartilage with micro-defect under external loading, a new plain strain numerical model with micro-defect was proposed and damage evolution progression in cartilage over time has been simulated, the parameter were studied including load style, velocity of load and degree of damage. The new model consists of the hierarchical structure of cartilage and depth-dependent arched fibers.

Correction: Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis.

[This corrects the article DOI: 10.1371/journal.pone.

Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis.

Objective: To investigate the biomechanical effects of the lumbar posterior complex on the adjacent segments after posterior lumbar interbody fusion (PLIF) surgeries.

Methods: A finite element model of the L1-S1 segment was modified to simulate PLIF with total laminectomy (PLIF-LAM) and PLIF with hemilaminectomy (PLIF-HEMI) procedures. The models were subjected to a 400N follower load with a 7.

Numerical Simulation and Clinical Verification of the Minimally Invasive Repair of Pectus Excavatum.

Objective: In this article we proposed a modeling method by building an assembled model to simulate the orthopedic process of minimally invasive surgery for pectus excavatum and got the clinical verification, which aims to provide some references for clinic diagnoses, treatment, and surgery planning.

Methods: The anterior chest model of a 15-year-old patient was built based on his CT images; and his finite element model and the Nuss bar were created. Coupling of nodal displacement was used to connect bones with cartilages of the anterior chest.

Numerical simulation research to both the external fixation surgery scheme of intertrochanteric fracture and the healing process, and its clinical application.

In this paper, the single arm external fixation of intertrochanteric fracture healing process after surgery was simulated to obtain a postoperative fracture healing and stress distribution in the external fixator. Firstly CT images of intertrochanteric fracture are reconstructed into the femur solid model. Then based, the external fixator is installed on the model, which lastly formed a finite element model of unilateral external fixation for intertrochanteric fracture.