External Fixation

Franklin Chen and David M. Kalainov

Indications

1. Unstable extra-articular fractures with metaphyseal comminution

2. Unstable intra-articular fractures

3. Fractures requiring re-reduction after initial closed treatment

4. In conjunction with open reduction and internal fixation for intra-operative distraction or as supplemental fixation

5. Open fractures with extensive soft tissue injury

Contraindications

1. Stable fractures amenable to cast immobilization

2. Associated ipsilateral fractures prohibiting secure placement of fixator pins

3. Patient noncompliance or severe coexisting medical illness

Preoperative Preparation

1. Standard AP/lateral/oblique plain radiographs

2. Identify fracture pattern and degree of comminution.

3. Evaluate entire extremity for associated injuries (e.g., scaphoid fracture, distal radioulnar joint instability, median nerve contusion/compression).

4. When initially treating a fracture by closed reduction and casting, obtain frequent radiographic follow-up to assess for fracture displacement.

Special Instruments, Position, and Anesthesia

1. Supine position

2. Hand table

3. Upper extremity pneumatic tourniquet

4. Standard or mini-fluoroscopy unit

5. Routine orthopedic instruments

6. External fixation systems are abundant. Familiarize yourself with one system and understand its capabilities and limitations.

7. Ensure availability of internal fixation plates, K-wires (0.045- and 0.062-in), and a powered wire driver if supplemental fixation is anticipated.

8. Small Bennett and Hohman retractors are helpful for soft-tissue retraction. A Freer elevator is useful not only for retraction but also for periosteal elevation.

9. The procedure can be performed under regional or general anesthesia.

10. Prepare the iliac crest if autogenous bone grafting is anticipated.

Tips and Pearls

1. K-wires can provide additional stability to the fracture. Recent studies have suggested that K-wire supplementation may allow for earlier fixator removal and wrist motion.

3. Preoperative antibiotics should be administered prior to tourniquet inflation.

4. The fixator should be positioned to minimize interference with thumb motion. In addition, AP and lateral radiographic views of the distal radius should be unobstructed by the pins, connecting bars, and clamps.

5. Although no universal criteria have been established, in general, loss of reduction with radial shortening greater than 5 mm, radial inclination less than 15 degrees, sagittal angulation more than 15 degrees dorsal or more than 20 degrees volar, or articular incongruity greater than 2 mm should prompt one to consider abandoning cast treatment. Some authors have suggested 10 degrees as the acceptable upper limit for dorsal angulation.

6. Remember that the frame is only as strong as its weakest link; there is no need to use larger diameter pins in the radius if smaller ones are used in the metacarpal.

7. Inform the patient of the common potential complications associated with distal radius fractures and the use of external fixation.

8. If signs of worsening median nerve compression are present, perform a concurrent carpal tunnel release. Carpal tunnel pressures have been shown to increase with progressive wrist flexion in the treatment of Colles’ fractures.

9. Have available an appropriate wrench or similar instrument for postoperative adjustment and tightening of the frame in the follow-up period.

What To Avoid

1. Do not place the pins percutaneously. This may increase the risk of cutaneous sensory nerve injury.

2. Do not leave the wrist in over-distraction as this will greatly increase the potential for finger stiffness and delayed union.