Design On Novel Three-Dimension Prothesis Structure

The artificial joint replacement is to repair damaged joints caused by disease or tumor, solve pain, deformity and dysfunction, reconstruct a near normal function of joints, and has to be one of areas where it's taken great place in investment and development of orthopedic surgery in the recent 30 years. However, in many joints of a human body, the activities of the shoulder joint is the biggest, so shoulder joint replacement surgery has become a hot research.The shoulder joint on the market in China mainly comes from Europe and the United States at present, and the design of those mainly depends on theirselves' anatomy parameters of shoulder joint. UNIVERSE 3-D, their Mainstream products, its characteristic is taken as follows: humerus tilt angle adjust consecutively range from 125 to 140 degrees, the surface of humerus front and back retortion angle adjust range consecutively from +15 to -15 degrees, offset distance is 3.5mm, have 5 changing angle 0, 45, 90, 135 and 180. UNIVERSE 3-D adapt to individual requirements basically. However, chinese shoulder anatomical parameters are different to Westerners anatomical parameters in addition that Chinese accepted the replacement surgery have higher ratio complication than occidental for discomfort. So the study and design of the shoulder joint adapted to Chinese is concerned by more and more experts and scholars in China.With the comparison of the shoulder joint anatomy parameters between Chinese and foreigners, we can get the conclusions that Chinese shoulder joint radius of curvature,ROC, inner offset , articular surface arc are smaller than westerners while back offset, inclination angle, IA, maximum supero-inferior height, MSIH inward is bigger than westerners. In order to change the circumstances that lots of Shoulder Prosthesis used in the domestic major hospitals are imported, the new shoulder prosthesis design was proposed so as to adapt to Chinese people's physique anatomical features and the functional requirements of campaign and improve the Clinical results. Also the fees spent on shoulder replacement will be decreased. The shoulder prosthesis structure was designed innovatively.The theme is based on the Chinese shoulder joint anatomy parameters and a new type shoulder prosthesis is designed on the basis of a two-tooth structure. This new shoulder prosthesis can achieve the adjustment of the proximal humerus reverse angle from -20 o to +20 o, the eccentricity can be adjusted between 2.5 mm and 4.0 mm, the proximal humerus articular surface tilt angle and the proximal humerus reverse angle can be adjusted repeatedly. The surgery process is simple and easy to operate. Phantom materials was analyzed and the selection materials principle was made in the paper. Choosing titanium alloys as the shoulder prosthesis material, modeling in UG 2.0 environment, the model was simplified and the equation about different Circumstances force was listed and the force bared on these parts was calculated. The structure analysis of shoulder prosthesis was done and the result showed that maximum stress that the shoulder prosthesis bared was 471.7Mpa. The part that bared maximum stress is circle plate, allow able Stress of the choosed material is 550Mpa, so meet the need of the structural strength. This new shoulder prosthesis can meet the structre intension, the chosen materials can meet the need of structural performance.