Femoral Component Offset:

- Discussion:
    - see acetabular component, reestablishment of acetabular floor, and component position;
    - see: preoperative and post operative radiographic eval
    - femoral offset is measured from the distance between the center of the femoral head and a line drawn down center of femoral shaft;
    - 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;
                    - references:
                           - Are Gender-specific Femoral Stems Needed?
                           - The effectiveness of dual offset stems in restoring offset during total hip replacement
                           - Do post-operative changes of neck-shaft angle and femoral component anteversion have an effect on clinical outcome following uncemented total hip arthroplasty?
           - lateralization:
                    - shifting the neck trunion medially;
                    - lateralization of the femoral shaft restores offset, reduces femoropelvic impingement, and increases abductor tension.
                    - lateralization also increases the lever arm for the abductor muscles;
                    - lateralization may be required with medialization of the cup
                    - 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.
                            - Benefit of cup medialization in total hip arthroplasty is associated with femoral anatomy
                            - The anatomic basis for concept of lateralized femoral stems: a frontal plane radiographic study of proximal femur.
                            - Total hip replacement: increasing femoral offset improves functional outcome



- references:
           - Total hip replacement: increasing femoral offset improves functional outcome.
           - A relationship between stem orientation and function following total hip arthroplasty.
           - Femoral component offset. Its effect on strain in bone-cement.
           - 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.
           - The influence of femoral offset on health-related quality of life after total hip replacement
           - Managing Length and Stability: The Role of the Modular Neck
           - Effect of femoral offset on pain and function after total hip arthroplasty.
           - Total hip arthroplasty: leg length inequality impairs functional outcomes and patient satisfaction.
           - Femoral offset: Anatomical concept, definition, assessment, implications for preoperative templating and hip arthroplasty
           - The effect of femoral offset modification on gait after total hip arthroplasty



Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Thursday, November 24, 2016 1:22 pm