DDH: Non-Anatomic Positioning of the Acetabulum in THR


- See:
      Total Hip Replacement Menu:
           - total hip in DDH
           - acetabular component menu:
           - crowe classification

- Non Anatomic Positioning of the Acetabulum in DDH: (high hip center)
    - advantages:
          - technically easier than anatomic placement;
          - surgeon can place a small uncemented cup into live host bone and avoid the need for structural autograft;
    - disadvantages:
          - include poor acetabular bone stock, leg length inequality a higher rate of impingement and dislocation, and higher loosening rate;
          - because of illiac bone slopes upward, placement of acetabular component in  the high hip center, means that there will be lateralization of hip center;
          - superior and lateral positioning of acetabular component are strong predictors of acetabular loosening (and may increase femoral loosening as well);
          - abduction may be limited w/ non anatomic positioning;
          - impingement of the femoral neck against the ischium may occur;
    - technical considerations:
          - requires adequate bone stock, and leg length discrepancy less than 3 cm;
          - it is important to avoid lateralization of the acetabular component;
          - it is important to achieve adequate acetabular coverage (50-60 %);
          - coverage is achieved by medialization down to the inner table;
          - it is important to avoid reaming any more of the superior roof than is necessary;
          - consider size of the acetabular components:            
                   - ensure that small size reamers and acetabular shells are available (as small as 36 mm);
                   - corresponding small femoral head sizes need to be available;
          - if the center of acetabulum is medialized more than 1 cm, then an increased offset femoral component should be available (to restore gluteus medius tension,
                   should this be a problem);
                   - a long neck femoral component may be necessary to restore leg lengths;
    - references:
          - Failure of acetabular autogenous grafts in total hip arthroplasty. Increasing incidence: a follow-up note.
          - Proximal placement of the acetabular component in total hip arthroplasty. A long term follow up study
    - case example:

                   



Femoral head autografting with total hip arthroplasty for lateral acetabular dysplasia. A 12-year experience.

Coxarthrosis after congenital dysplasia. Treatment by total hip arthroplasty without acetabular bone-grafting.

Custom-Designed Femoral Prostheses in Total Hip Arthroplasty Done with Cement for Severe Dysplasia of the Hip.

Total hip replacement for coxarthrosis secondary to congenital dysplasia and dislocation of the hip. Long-term results.

Double-chevron subtrochanteric shortening derotational femoral osteotomy combined with total hip arthroplasty for treatment of complete congential dislocation of the hip in the adult. Preliminary report and description of a new surgical technique.

Bateman bipolar hips with autologous bone graft reinforcement for dysplastic acetabula.

Modular noncemented total hip arthroplasty for congenital dislocation of the hip. Case report and design rationale.

Coxarthrosis after congenital dysplasia. Treatment by total hip arthroplasty without acetabular bone-grafting.

Long-Term Results of Total Hip Arthroplasty in Congenital Dislocation and Dysplasia of the Hip.  A Follow-Up Note.

Treatment of osteoarthrosis secondary to congenital dislocation of the hip. Primary cemented surface replacement compared with conventional total hip replacement.

Autogenous bone grafts from the femoral head for treatment of acetabular deficiency in primary total hip arthroplasty with cement: Long term results.

Arthroplasty in high congenital dislocation. 21 hips with minimum five-year follow-up.  

Total hip replacement for coxarthrosis secondary to congenital dysplasia and dislocation of the hip. Long Term Results.    



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

Last updated by Data Trace Staff on Tuesday, May 15, 2012 12:42 pm