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Wheeless' Textbook of Orthopaedics
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Radiographic Evaluation of the Acetabular Cup




- Discussion:
    - acetabular component loosening:
    - osteolysis
    - polyethylene wear:
    - component position:
    - Paprosky classification
    - acetabular component flexion:
          - to measure postoperative cup position, a standing true lateral view of the operated hip allowed direct measurement of cup flexion;
          - cross table lateral:
                  - to measure anteversion, draw a line tangential to the face of the cup and a line drawn perpendicular to the horizontal plane;  
                  - note that supine cross table lateral radiographs may be unreliable for measuring acetabular component anteversion since
                        the amount of flexion in the contra-lateral hip will affect the amount of pelvic tilt (and anteversion);
          - Lowenstein lateral radiograph:
                  - provides a lateral view of the acetabular subchondral bone and the cup after implantation
                  - modified Lowenstein lateral radiograph is similar to an oblique radiograph of the pelvis;
                  - patient is turned onto the affected hip at least 45° and as much as necessary to allow the lower limb to be
                        in abduction and external rotation and to be flat on the x-ray table;
    - assesment of posterior column:
          - in cases of acetabular loosening, the integerty of the posterior column may determine whether or not allografting is required;





Acetabular revision in total hip replacement with a press-fit cup.

Extra-large press-fit cups without screws for acetabular revision.

A simplified method to determine acetabular cup anteversion from plain radiographs.

Sensitivity and specificity of plain radiographs for detection of medial-wall perforation secondary to osteolysis.

Functional Pelvic Orientation Measured from Lateral Standing and Sitting Radiographs.





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