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Wheeless' Textbook of Orthopaedics
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Pelvic Frx: Selection of Pins and Frame Type





- Pin Diameter and Length:
    - pins should be at least 5 mm in diameter (such as the Orthofix 6/5 mm self tapping screws);
    - resistance to cephalad displacemnt could be approximately doubled by using 5 mm vs.
            4 mm half pins for iliac wing fixation, & is further enhanced by adding a second
            pin group in each ilium between anteroinferior and superior iliac spines;
            - smaller pelves, however, require 4-mm pins to avoid comminution of
                  iliac wing & loss of purchase;
            - osteoporotic pelvis in the elderly patient may not hold pins well.
    - pin length:
            - use pins with adequate length, to allow for postoperative swelling and the
                  need for anteriorization of the frame;

- Frame Type:
    - it is helpful to construct the frame prior to surgery;
    - consider using a double frame construct;
            - this will allow for postoperative manipulation of one frame without losing
                    the reduction (since the second frame is in place);
            - avoid placing cross bars between the two frames since this will complicate
                    postoperative frame manipulation;
    - care must be taken to avoid placing the clamps too close to abdomen, particularly
            in the acute situation in which abdominal distension will cause frame impingement;
            - always build into the frame the option of increasing the frame's girth inorder
                    to allow for postoperative frame manipulation should swelling occur;



-------------------------------------------
External fixation of unstable Malgaigne fractures: the comparative
      mechanical performance of a new configuration.

Anatomic and radiographic considerations in the placement of anterior
      pelvic external fixator pins.

Biomechanical testing of new and old fixation devices for vertical shear
      fractures of the pelvis.









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