External Fixation for Pelvic Frx



- Discussion and Indications:
    - definitive stabilization of frx may be achieved w/ external fixation in certain rotationally unstable but vertically stable injuries;
    - relative contraindication is iliac wing fractures;
    - antero-posterior compression injuries:
           - external fixation is most applicable to stable "open book" pelvic fractures in which there is intact posterior tension band (APC II & APC III)
           - in the study by Lindahl J, et al (1999), the external fixator failed to give and maintain a proper reduction in six of the eight open-book injuries
    - lateral compression injuries:
           - ex fix is also used for internally rotated injuries;
           - in the study by Lindahl J, et al (1999), ex fixator failed to give and maintain a proper reduction in 20 of the 62 lateral compression injuries
    - vertical shear injury:
           - in the study by Lindahl J, et al (1999), the external fixator failed to give and maintain a proper reduction in 38 of the 40 type-C injuries.
                  - in type-C injuries more than 10 mm of residual vertical displacement of the injury to the posterior pelvic ring was significantly related to poor outcome;
                  - in 14 patients in this unsatisfactory group poor functional results were also affected by associated nerve injuries;
    - vascular injuries:
           - external fixators to contrl hemorrhage
    - suprapubic catheter:
           - external fixator is also preferred to avoid bacterial contamination of pelvic internal fixation when suprapubic catheter is left in place;
    - open frx:
           - in open pelvic fracture or abdominal injury w/ peritoneal contamination, the use of an external fixator allows control of this fracture pattern and decreases the potential infection rate;
    - ref: Failure of reduction with an external fixator in the management of injuries of the pelvic ring. Long-term evaluation of 110 patients. 


- Radiographs:
    -
preop assessment w/ inlet, outlet, & AP views and CT;
    - intra-operative flouroscopy allows assessment of how much force is required to reduce the diastasis and whether there is occult verticle instability of the SI joints (see SI dislocation);


- Technique:
    - positioning:
           - supine on flouro table (the flouro table may need to be turned 180 deg);
           - area of anterior ilium from approx 5 cm above umbilicus to groin is prepped and draped bilaterally;
           - it is helpful, to place a large bean bag perpendicular to the patient's torso, inorder to assist with the reduction;
                  - while the bean bag itself will not maintain a reduction, the edges of the bean bag can be used as a handle for manual reduction;
    - reduction:
           - it is essential that the pelvis be manually reduced as much as possible prior to pin insertion;
                   - manual reduction is used to reduce the pelvis, which can be facilitated w/ use of a bean bag placed at right angles to the table;
           - if pelvis is unstable w/ vertical migration or posterior displacement, then the use of supracondylar femoral pin and the application of 25-30
                   pounds of traction will be necessary to pull the pelvis back down before the rotatory deformity is corrected;
           - another method is to apply a large towel around pelvis and to then tie and then twist ends of towels inorder to apply a compression force across pelvis;
    - selection of pins and frame type
    - technique of pin insertion


- Post Operative Care:
    - any simple frame (rectangular configuration) is suitable to hold this pattern and should be left on for three months;
    - when frame is removed, pelvis should be examined under fluoroscopy to make sure it is stable;
    - wt bearing is appropriate in a unilateral disruption and can usually occur when the patient is comfortable;
    - if both sides are involved, posterior stability must be assessed;
    - if there is no question as to the posterior stability, then wt bearing can be allowed within ten days to two weeks;
    - if instability is present, bed rest or bed-to-chair activity is required for six to 12 weeks;

- Complications:
    - bladder incarceration:
          - may result from the operative reduction of symphysis diastasis;
          - risk factor for bladder incarceration is bladder herniation;
          - consider preoperative CT scan inorder to rule out herniation;
          - ref: Bladder entrapment after external fixation of traumatic pubic diastasis: importance of follow-up computed tomography in establishing prompt diagnosis.
    - in the study by Lindahl J, et al (1999), the authors reviewed 110 patients with an unstable fracture of the pelvic ring who
          had been treated with a trapezoidal external fixator after a mean follow-up of 4.1 years
          - rate of complications was high with loss of reduction in 57%, malunion in 58%, nonunion in 5%;
          - infection at the pin site occurred in 24% and loosening of the pins occurred in 2%;
          - injury to the lateral femoral cutaneous nerve in 2%, and pressure sores in 3%



External fixation of the injured pelvis. The functional outcome.

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.

Unstable fractures of the pelvis treated by external fixation.

The Role of External Fixation in Pelvic Disruptions.

Acute mortality associated with injuries to the pelvic ring: the role of early patient mobilization and external fixation.

Placement of Half-Pins for Supra-acetabular External Fixation: an Anatomic Study.

The subcristal pelvic external fixator: technique, results, and rationale



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

Last updated by Data Trace Staff on Thursday, January 2, 2014 10:15 am