- Discussion:
- femoral offset is measured from the distance between the center of the femoral head and a line drawn down center of femoral shaft;
- lateralization of the femoral shaft restores offset, reduces femoropelvic impingement, and increases abductor tension.
- lateralization also increases the lever arm for the abductor muscles;
- note that increasing offset may have the unwanted effect of increasing rotational torque on the stem (leading to
aseptic loosening);
- offset may be increased by:
- increasing stem varus from the typical 135 deg;
- shifting the neck trunion medially;
- increasing modular neck length (which will also increase verticle offset and leg length);
- references:
-
Effect of femoral component offset on polyethylene wear in total hip arthroplasty.
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A relationship between stem orientation and function following total hip arthroplasty.
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Femoral component offset. Its effect on strain in bone-cement.
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The anatomic basis for the concept of lateralized femoral stems: a frontal plane radiographic study of the proximal femur.
-
Effect of femoral offset on range of motion and abductor muscle strength after total hip arthroplasty.
-
Reconstructed Hip Joint Position and Abductor Muscle Strength After Total Hip Arthroplasty.
