- 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 clamps too close to abdomen, particularly in 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;
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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.
