- See:
-
operative considerations for hip dyplasia
-
acetabular component revision:
- Discussion:
- restoration of the normal hip center in acetabular reconstruction encourages restoration of normal biomechanics;
- medial placement:
- moving hip center medially improves efficiency of hip abductors and will reduce forces acting on the hip in the coronal plane;
- in osteoarthritis, acetabulum is often overgrown by osteophytes that push femoral head laterally, superiorly, and posteriorly;
- inorder to re-establish optimal hip mechanics, the hip center must be placed medially, inferiorly, and anteriorly;
- lateral placement:
- placing the socket laterally creates increased joint reactive forces;
- lateral placement leads to uncoverage of the superior acetabular cup (or inappropriate abduction of the cup to achieve coverage);
- anterior placement:
- this will reduce saggital plane resultant forces about the hip and improves efficiently of the hip extensor muscles;
- superior placement:
- placing it directly superior requires the use of a long neck prosthesis to restore abductor moment arm;
- may slightly improve efficiency of extensor muscles but may have a more significant negative effect on hip abductor muscles;
Secondary total hip replacement after fractures of the femoral neck.
Current status of acetabular fixation in primary total hip arthroplasty.
Failure of the Mecring screw-ring acetabular component in total hip arthroplasty. A three to seven-year follow-up study.
The definition and measurement of acetabular orientation.
DW Murray.
JBJS. Vol 75(2)-B. 1993. p 228-232.
