What is the step-by-step procedure for treating a posterior malleolus fracture with plating?

Posterior Malleolus Fracture Fixation by Plating: Step-by-Step Procedure

The posterior approach with direct visualization and buttress plating is the preferred surgical technique for posterior malleolus fractures as it provides superior clinical outcomes compared to anterior-to-posterior screw fixation.

Preoperative Planning

1. Imaging Assessment

   • Obtain standard ankle radiographs (AP, lateral, mortise views)
   • CT scan is essential for complex injuries like posterior malleolar fractures to assess fragment size, displacement, and comminution 1
   • MRI may be considered if radiographs are negative but clinical suspicion remains high 1

2. Surgical Indication Evaluation

   • Consider fragment size (fragments >25% of the articular surface typically require fixation) 2
   • Assess for ankle instability, articular displacement, and tibiotalar subluxation 3
   • Evaluate for associated syndesmotic injury

Surgical Procedure

Step 1: Patient Positioning and Approach

• Position patient prone or in lateral decubitus position
• Use a posterolateral approach through the interval between the flexor hallucis longus and peroneal tendons 4
• This approach provides direct visualization of the posterior malleolus fragment 4

Step 2: Fracture Exposure

• Make a longitudinal incision approximately 10 cm in length, centered at the level of the ankle joint
• Identify and protect the sural nerve
• Develop the interval between the peroneal tendons laterally and the flexor hallucis longus medially
• Retract the flexor hallucis longus medially to expose the posterior aspect of the distal tibia and fracture site

Step 3: Fracture Reduction

• Remove any interposed soft tissue or hematoma
• Reduce the posterior malleolar fragment anatomically under direct visualization
• Confirm reduction with fluoroscopy
• Temporary fixation can be achieved with K-wires

Step 4: Fixation with Buttress Plate

• Select an appropriately sized posterior buttress plate (T-shaped distal radius plate or one-third tubular plate)
• Position the plate on the reduced posterior malleolus
• Secure the plate with appropriate screws:
  • Place at least 2 screws in the distal fragment
  • Place 2-4 screws in the proximal fragment
• For fractures involving >25% of the articular surface, plate fixation provides more stable fixation than screws alone 2

Step 5: Syndesmotic Assessment

• After posterior malleolus fixation, assess syndesmotic stability
• In 82% of cases, syndesmotic stability may be achieved after proper posterior malleolar fixation without requiring additional syndesmotic screws 4
• If instability persists, place syndesmotic screws as needed

Step 6: Associated Fracture Management

• Address associated lateral and medial malleolar fractures as needed
• Lateral malleolus can be approached through the same incision or a separate lateral approach
• Medial malleolus may require a separate medial approach

Step 7: Wound Closure

• Irrigate the wound thoroughly
• Close the deep fascia with absorbable sutures
• Close subcutaneous tissue and skin in layers
• Apply sterile dressing and splint

Postoperative Management

1. Immediate Postoperative Care

   • Elevate the extremity to reduce swelling
   • Maintain non-weight bearing status for 4-6 weeks 1
   • Monitor for wound complications

2. Follow-up Protocol

   • Clinical and radiographic follow-up at 2 weeks and 4-6 weeks 1
   • Assess for maintained reduction and early signs of healing
   • Begin progressive weight bearing at 6 weeks if healing is adequate

3. Rehabilitation

   • Early range of motion exercises to prevent stiffness
   • Progressive weight bearing as tolerated after 6 weeks
   • Full weight bearing typically by 10-12 weeks

Outcomes and Complications

• Anatomical reduction is critical for successful outcomes 4
• Posterolateral plating demonstrates superior clinical outcomes compared to anterior-to-posterior screw fixation 5
• Potential complications include:
  • Wound healing problems (though rare with proper technique) 4
  • Post-traumatic arthritis
  • Malunion or nonunion
  • Hardware irritation requiring removal

Technical Pearls

• Direct visualization through the posterolateral approach allows for anatomical reduction of the posterior malleolus 4
• Buttress plating provides more stable fixation than screws alone for fragments involving >25% of the articular surface 2
• Proper fixation of the posterior malleolus may restore syndesmotic stability and eliminate the need for syndesmotic screws in many cases 4
• Trauma-trained surgeons are more likely to choose antiglide plate fixation compared to screw-only fixation 6

This approach allows for direct visualization, anatomical reduction, and stable fixation of posterior malleolar fractures with few complications, leading to improved clinical outcomes.