Acetabular reconstruction ring for plastics hip joint cup hold

摘要

The reconstruction ring has an elliptical opening (3) for the joint cup plus an anatomical cranial rim (4) for maximal bone compass and with bone-facing surfaces roughened to roughness (R2) of 40-60 micron. The screw holes (5) in the rim (4) area should be in slot form and are spread round an angle of 90 degrees, leaving the remainder of the ring (1) undrilled. The shape of the holes (5) ensures virtually totally countersunk screw heads and the ring seat (2) matches the diameter of the inserted joint cup. The ring preferably is flattened off (9) arcuately at a shallow angle to the entry plane (10).