- Pre Reduction Evaluation:
    - frx-dislocation usually confirmed by a single AP x-ray;
    - rule out: assoc acetabular, femoral head, or femoral neck frx;
         - these must be recognized prior to reduction;
         - femoral head: for assoc frx;
         - acetabulum: presence, size, and location of fragments;
              - Judet View
              - evaluate post. wall frx ( > 40% is Unstable)
              - injured side is elevated to 45 deg w/ pt supine, to demonstrate posterior acetabular rim in profile;
         - femoral neck: r/o non-displaced frx that might displace when Closed Reduction is attempted;
    - CT scan should be performed in all cases to identify intra articular fragments or associated fractures such as femoral head fractures;
         - CT would be indicated prior to reduction if radiographs show a posterior wall frx ( > 40% implies Unstable frx-dislocation);

- Post Reduction Evaluation:
    - need to assess stability following either closed or open reduction;
    - CT can assist in assessment of stability after reduction of posterior dislocations of the hip;
         - stability is inversely proportional to the size of the posterior acetabular fragment;
         - fragments involving < 25% of acetabular wall do not affect hip stability, while those involving > 40% result in instability

Changes on magnetic resonance images after traumatic hip dislocation.