What is the step-by-step procedure for open reduction and internal fixation (ORIF) using plates for a fracture of the posterior and medial malleolus?

Step-by-Step Procedure for Posterior and Medial Malleolus Fracture Plating

Open reduction and internal fixation (ORIF) with plating is the recommended surgical approach for posterior and medial malleolus fractures to achieve anatomic reduction, restore joint stability, and allow for early functional rehabilitation.

Patient Positioning and Preparation

1. Positioning:

   • Position the patient in an unstable lateral position for the posterior approach
   • Later reposition to supine position for the medial approach without changing sterile covers

2. Preoperative Planning:

   • Review imaging (CT scans) to assess fracture pattern and fragment size
   • Ensure all necessary implants are available (plates, screws, tension band wiring materials)
   • Confirm hemodynamic stability before proceeding with definitive fixation 1

Posterior Malleolus Approach and Fixation

1. Incision and Approach:

   • Make a longitudinal incision between the lateral border of the Achilles tendon and the posteromedial border of the fibula 2
   • Incise the superficial and deep fascia
   • Access the posterior aspect of the fibula through the interval just lateral to the peroneal tendons 3

2. Exposure:

   • Retract the flexor hallucis longus tendon medially
   • Bluntly dissect the flexor hallucis longus muscle belly off the interosseous membrane and lateral side of tibia 2
   • Incise the periosteum to expose the posterior malleolar fracture

3. Fracture Reduction:

   • Debride the fracture site to remove hematoma and loose fragments
   • Lever the posterior fragment distally to remove any loose intra-articular fragments
   • Perform anatomic reduction of the posterior malleolus
   • Hold reduction temporarily with Kirschner wires 2

4. Fixation Options:

   • Option 1: Buttress Plate Fixation

     • Apply a slightly prebent 3-hole buttress plate to the posterior malleolus
     • Place a lag screw through the most distal hole of the plate to close any gaps 2

   • Option 2: Lag Screw Fixation

     • Insert lag screws from posterior to anterior
     • Add a neutralization plate for additional stability in comminuted fractures

   Note: Both techniques provide equivalent outcomes with mean AOFAS scores of 94/100 4

Lateral Malleolus Approach and Fixation (if needed)

1. Incision and Approach:

   • Prepare a full-thickness flap above the peroneal tendons on the fibula
   • Treat according to AO principles 3

2. Fixation:

   • Reduce and fix the fibular fracture with appropriate plate and screws
   • Ensure anatomic reduction of the fibula into the tibial incisura

Medial Malleolus Approach and Fixation

1. Repositioning:

   • Reposition the patient to supine position without changing the sterile covers 3

2. Incision and Approach:

   • Make a medial approach incision over the medial malleolus
   • Carefully dissect down to the fracture site, protecting neurovascular structures

3. Reduction and Fixation:

   • Perform anatomic reduction of the medial malleolus fracture
   • Fixation options:
     • Plate and screw fixation for larger fragments
     • Tension band wiring for smaller fragments or avulsion fractures 5
     • Lag screws for simple fracture patterns

4. Wound Closure:

   • Irrigate all wounds thoroughly
   • Close in layers with attention to the deep fascia
   • Apply sterile dressing and splint

Postoperative Management

1. Initial Period:

   • Immobilization in a posterior splint
   • Elevation to reduce swelling
   • Pain management

2. Weight Bearing Protocol:

   • Six weeks partial weight bearing (20 kg)
   • Early functional exercises, particularly of the flexor hallucis longus muscle
   • Transition to full weight bearing after clinical and radiological follow-up at 6 weeks 3

Clinical Outcomes and Considerations

• ORIF of posterior malleolus results in better reconstruction of the distal articular surface and tibial incisura compared to closed reduction 3
• Anatomic reduction is critical as persistent step-off in the tibiotalar joint is the most important factor in the development of osteoarthritis 2
• Advantages of direct posterior approach include better visualization of the fracture, anatomic reduction, and sound fixation of fragments 2
• Small or comminuted fragments are easier to fix with direct visualization through the posterior approach

This procedure allows for stable fixation of both posterior and medial malleolus fractures, facilitating early functional rehabilitation and reducing the risk of post-traumatic arthritis.