Composite femoral implant having increased neck strength

摘要

A femoral implant for a hip prosthesis includes a shaft oriented in a longitudinal direction and a neck extending from said shaft at an acute angle theta to the longitudinal direction. The implant includes a plurality of layers of fibers in a matrix, wherein the fibers are substantially unidirectional in each respective layer. The implant is made from a stack of layers of the matrix so that the direction of fibers is unbalanced. At least 50% of the fibers are oriented in the theta direction and the remainder of said fibers are oriented in directions other than the theta angle.