Transforaminal lumbar interbody fusion (TLIF) using an implanted cage is the gold standard surgical treatment for disc diseases such as disc collapse and spinal cord compression, when more conservative medical therapy fails. Titanium (Ti) alloys are widely used implant materials due to their superior biocompatibility and corrosion resistance. A new Ti-6Al-4V TLIF cage concept featuring an I-beam cross-section was recently proposed, with the intent to allow bone graft to be introduced secondary to cage implantation. In designing this cage, we desire a clear pathway for bone graft to be injected into the implant, and perfused into the surrounding intervertebral space as much as possible. Therefore, we have employed shape optimization to maximize this pathway, subject to maintaining stresses below the thresholds for fatigue or yielding. The TLIF I-beam cage (Fig. 1(a)) with an irregular shape was parametrically designed considering a lumbar lordotic angle of 10°, and an insertion angle of 45° through the left or right Kambin's triangles with respect to the sagittal plane. The overall cage dimensions of 30 mm in length, 11 mm in width and 13 mm in height were chosen based on the dimensions of other commercially available cages. The lengths ( After shape optimization, a final design with
Recent anthropometric studies have suggested that current design of total knee arthroplasty (TKA) does not cater to racial anthropometric differences. The purpose of this study was to investigate the exact sizing and rotational landmarks of the distal femur collected and its gender differences from a large group of healthy Southern Chinese using 3D-CT measurements, and then compare these measurements to the five total knee prostheses conventionally used in China. This study evaluated distal femoral geometry in 85 healthy Southern Chinese, included 39 females (78 knees) and 46 males (92 knees) with a mean age of 33.9 years，a mean height of 164.7 cm and a mean weight of 59.9 kg. The width of the articular surface as projected onto the transepicondylar line(ML), anteroposterior dimension (AP), the dimensions from medial/lateral epicondyle to posterior condylar (MEP/LEP) were measured. A characterization of the aspect ratio (ML/AP) was made for distal femur. The angles between the tangent line of the posterior condylar surfaces, the Whiteside line, the transepicondylar line, and the trochlear line were measured. The sulcus angle and hip center-femoral shaft angle were also measured [Fig. 1]. The data were compared with the five total knee prostheses conventionally used in China. In analyzing the data, best-fit lines were calculated with use of least-squares regression. The dimensions are summarized as the mean and standard deviation. Comparisons of dimensions between males and females were made with use of the two-sample t test. A p value of <0.05 indicated a significant effect.Background
Methods
The purpose of this study was to investigate the morphology characteristic of proximal femur of Chinese people. 170 healthy Southern Chinese hips being measured using 3D computer tomographic, in order to improve prosthesis design and preoperation plan of total hip arthroplasty. This study measured proximal femoral geometry in 85 healthy Southern Chinese, included 39 women (78 hips) and 46 men (92 hips) (mean age: 33.9 y, mean height: 164.7 cm, mean weight 59.9 kg). Medullary canal morphology measurements, include: the position of isthmus, medial-lateral(ML) and anteroposterior(AP) medullary canal diameter of isthmus and 20 mm, 10 mm, 0 mm, −20 mm, −160 mm, −200 mm upon less trochanter(LT) (medullary canal height, MCH), canal flare index(CFI), aspect ratio(ML/AP), epiphysis-shaft angel (ES angel) (a posterior bow in the metapysis in lateral view). Exterior morphology measurements include: femoral head offset, ML and UD diameter, femoral head position(FHP) from LT, height of the femoral head center from the tip of the great trochanter(GT)(FHCH), femoral neck and head anteversion angle, femoral neck-shaft angle, neck length, neck width, intertrochanteric length (Fig 1, Fig 2). And then we use student's t–test to compare means, linear regression and correlation to analysis these data's relationship, p value <0.05 indicated a significant effect.Background
Methods
Recent anthropometric studies have suggested that current design of total knee arthroplasty (TKA) does not cater to racial anthropometric differences. The purpose of this study was to investigate the exact sizing and rotational landmarks of the distal femur collected from a large group of healthy Southern Chinese using three dimensional computer tomographic measurements, and then compare these measurements to the known dimensions from Caucasian populations. This study evaluated distal femoral geometry in 125 healthy Southern Chinese, included 58 women (106 knees) and 67 men (134 knees) with a mean age of 35.2±8.11 years, a mean height of 165.5±7.94 cm, and a mean weight of 61.7±9.56 kg. The width of the articular surface as projected onto the transepicondylar line(ML), anteroposterior dimension (AP), the dimensions from medial/lateral epicondyle to posterior condylar (MEP/LEP)were measured. A characterization of the aspect ratio (ML/AP) was made for distal femur[Fig. 1]. The angles between the tangent line of the posterior condylar surfaces, the Whiteside line, the transepicondylar line, and the trochlear line were measured. The sulcus angle and hip center-femoral shaft angle were also measured. Known dimensions from Caucasian populations were compared with the morphologic data collected in this study[Fig. 2]. In analyzing the data, best-fit lines were calculated with use of least-squares regression. The dimensions are summarized as the mean and standard deviation. The differences of rotational landmarks and sizing between the Southern Chinese and Caucasians were assessed with use of the Student t test. A p value of <0.05 indicated a significant effect.Background
Methods
