摘要 |
Artificial joint prostheses (10,46) are provided whose outer surfaces (20) include a portion wherein areas of surface treatment (24,25,50,68) are interlaced with a screw thread (16,52,60). In certain embodiments, the screw thread (16,52) is interrupted by surface-treated columns (24,25,50) so as to produce an alternating pattern of threaded columns (26,48) adjacent to surface-treated columns. In other embodiments, the surface treatment is applied to the root (62) of the thread (60) so as to form a double helix structure in which the screw thread and the surface treatment follow adjacent helical paths around the outside of the prosthesis. The screw threads provide initial mechanical fixation of the prosthesis to bone and the surface treatment provides long-term fixation through bone or other tissue ingrowth and remodeling. |