Orthopedic implant with self-reinforced mantle

An orthopedic implant having a rigid stem dimensioned to be received in the intramedullary cavity of a bone;

• and a self-reinforced polymeric mantle tightly encasing at least a portion of the length of said stem;
• said mantle being composed of fibers of PMMA that are longitudinally oriented in predetermined directions relative to said stem with each fiber being of a diameter within the range of about 5 to 500 .mu.m and having longitudinally-oriented molecular chains that provide said fiber with a heat relaxation ratio for length of no less than about 6 to 1;
• adjacent fibers of Said mantle having contacting surfaces fused together and which interlocks said fibers against relative movement;
• a plurality of said fibers being arranged into strands in which the fibers of each strand are generally uni-directional;
• said strands extending in selected directions along and about said stem and being arranged to provide multiple layers with the strands of different layers extending in different directions;
• said strands of each layer being interwoven and arranged so that the fibers of each such layer extend in predetermined directions relative to said stem;
• said fibers of different layers of said mantle extending in different directions than those of adjacent layers.