HIP REPLACEMENT PROSTHESIS WITH HIGHLY CROSS-LINKED POLYETHYLENE HEAD

摘要

The invention corresponds to a prosthesis for total or surface hip replacement, which comprises a prosthetic femoral head made of highly crosslinked polyethylene, with a diameter of 38 mm to 64 mm, for articulating with a cup or acetabular component made of metal. When the invention is used for total hip replacement, the polyethylene head includes a metal core, which contains the female counterpart (14) on the inside for coupling with the male counterpart (13) of a Morse taper, located at the top end of the femoral component. The use of this type of head for total hip replacement, articulated with an ultra-polished acetabular cup, reduces the risk of luxation, transmits less angular and torque force to the Morse taper than the large metal heads, and avoids problems related with the metal-metal combination or with the use of large metal heads with thin polyethylenes. When the invention relates to surface hip replacement, the highly crosslinked polyethylene femoral head has a lower shank or extension made of polyethylene, with or without inner metal reinforcement (151), or a metal shank built into a metal backing (152). The use of this type of heads for surface hip replacement does away with problems associated with metal-metal surface replacements.