Ankle Fractures

Open Reduction and Internal Fixation

Scott D. Cordes

Classification

Danis-Weber AO classification is based on the level of the fibula fracture: Type A, infrasyndesmotic; Type B, transsyndesmotic; Type C, suprasyndesmotic.

Indications

1. Displaced lateral malleolus fracture associated with deltoid ligament disruption resulting in medial joint space widening

2. Unstable trimalleolar fractures

3. Any combination of bony and/or ligamentous injury that disrupts the integrity of the ankle mortise

Contraindications

1. Nonviable soft tissue envelope

2. Anatomic reduction and the ability to maintain that reduction

3. Although best results can be seen with open reduction and internal fixation in all age groups, clinical judgment must be used in the face of advanced age, systemic disease, and severe osteopenia.

4. Acute surgical management of open grade III B ankle fractures remains controversial. However, lesser grade open fractures can be stabilized acutely after satisfactory thorough irrigation and debridement.

5. Fracture blisters are associated with increased complication rates, presumably related to significant underlying soft tissue damage. The exact timing of surgery in patients with fracture blisters remains controversial.

Preoperative Preparation

1. Perform a systemic evaluation that includes examination of both malleoli, fibular shaft, proximal fibula, deltoid ligament, and syndesmosis.

2. Obtain appropriate extremity radiographs including anteroposterior (AP), lateral and mortise views of the ankle joint. Any shift of the talus within the mortise implies instability and must be recognized.

3. Assess the skin, soft tissues and neurovascular status of the extremity.

Special Instruments, Position, and Anesthesia

1. The procedure can be done with general, epidural, or spinal anesthesia.

2. Position patient supine on either a standard operating room table (if intraoperative plain radiographs are planned) or a radiolucent table (if intraoperative fluoroscopy is planned).

3. Pad all bony prominences.

4. A sand bag placed under the ipsilateral buttocks aids in internal rotation of the leg. Internal rotation enhances exposure of the distal lateral fibula.

5. A tourniquet should be placed on the upper thigh.

6. Instruments: complete small screw fragment set (3.5-mm cortical screws, 4.0-mm cancellous screws and ⅓ semitubular plates). Optional: cannulated 3.5- to 4-0-mm screws are useful for medial malleolus fracture fixation.

Tips and Pearls

1. If a circumferential cast has been previously applied, bivalve it in the preoperative area. This minimizes dust contamination in the operating room. The bivalved cast can be left in place for support and protection until the patient is anesthetized. However, if the condition of the skin needs to be inspected, the anterior half of the cast can be removed.

2. If both the lateral and medial malleolus require open reduction and internal fixation, stabilize the fibula first.

3. Whenever possible, use an interfragmentary screw to enhance fixation in oblique fibula fractures (Fig. 36–3).

4. Carefully review an intraoperative radiograph obtained after completion of the open reduction and internal fixation. Check for proper hardware placement, satisfactory fracture reduction, proper ankle mortise spacing, and syndesmotic ligament integrity. Make necessary changes or proceed with wound closure once these findings have been reviewed.

What To Avoid

1. While bone reduction clamps are useful in holding a fracture in anatomic alignment prior to internal fixation, avoid using excessive force with these instruments which could cause further fracture comminution.

2. Avoid excessive soft tissue stripping. Limit soft tissue dissection to what is needed to assist reduction and obtain adequate visualization.

3. Avoid missing syndesmotic ligament disruptions. The more proximal the fibular fracture extension, the higher the index of suspicion should be.

4. Respect the articular confines of the ankle mortise. Avoid screw penetration into the ankle joint especially during fixation of distal fibular or medial malleolus fractures.

5. Avoid missing a “Maisonneuve” fracture (proximal fibular fracture associated with ankle instability). Tenderness anywhere along the fibular shaft on examination warrants radiographs of the entire fibula.

Postoperative Care Issues

1. After surgery, the extremity is placed in either a posterior mold or a formal cast. The mold or cast is normally removed 2 to 6 weeks after surgery depending on the quality of the internal fixation and bone.

2. Commonly, the extremity is placed in a short leg brace after the mold or cast is discontinued. The brace can be intermittently removed to allow commencement of ankle range-of-motion exercises.

3. Initially, most patients are allowed to ambulate non-weight-bearing (NWB).

4. Depending on the stability of the fixation and quality of the bone, protected weight bearing can be advanced approximately 6 weeks after surgery. This is dependent on radiographic evaluation and clinical symptoms.

Operative Technique

1. Transport the patient to the operating room. Position the patient on a radiolucent table. (A standard operating table can be used if plain radiographs are planned for later in the case to evaluate hardware position; however, the author prefers using a radiolucent table in conjunction with fluoroscopy.) Care should be taken to ensure that the patient’s position allows adequate clearance for the fluoroscopy.

2. After adequate anesthesia is achieved, remove the previously bivalved cast.

3. Place a tourniquet around the proximal thigh.

4. Prepare and drape the foot, ankle, and distal leg. The drapes should cover both sides of the surgical table.