1.1 History

The pilon (pharmacist′s pestle, described by the French radiologist Destot in 1911) or tibial plafond (“ceiling” by Bonin) fracture is defined by intraarticular involvement of the distal tibia with metaphyseal extension [1]. Rüedi and All-gower introduced the basic principles of surgical treatment including: reconstruction of the correct length, alignment, and rotation of the fibula; anatomical reconstruction of the articular surface of the tibia; insertion of a cancellous autograft to fill gaps left by impaction and comminution; and stable internal fixation of the fragments by a plate placed on the medial aspect of the tibia [2]. Reports [3–5] have shown mixed clinical outcomes and high complication rates.

1.2 Epidemiology

The pilon fracture accounts for less than 1% of lower limb injuries and 3–10% of tibial fractures [1]. The fracture may occur with low-energy (eg, some skiing injuries) or high-energy trauma like falls from a height or motor vehicle crashes. The pattern of the injury will vary considerably depending on the position of the foot ( Fig 6.8.3-1 ).

1.3 Special characteristics

Pilon fractures are frequently associated with severe soft-tissue injuries that alter the management plan and timing of surgery. Pilon fractures are challenging, especially when they involve multiple articular fragments, impaction, and complex metaphyseal or diaphyseal components. Over the past decade, staging of operative care, newer implants, and less invasive surgical techniques have emerged to improve clinical outcomes.

2.1 Case history and physical examination

A thorough understanding of the mechanism of injury is most important when first assessing a pilon fracture. The amount of soft-tissue injury and the degree of complexity vary widely from low- to high-energy injuries. Comorbidities such as diabetes, neuropathy, peripheral vascular disease, corticosteroid use, osteoporosis, alcohol abuse, or smoking may lead to an increased risk of wound complications and treatment difficulties [3].

Pilon fractures are commonly associated with high-energy trauma: a full trauma evaluation and secondary survey is necessary. Clinical assessment must include the condition of the soft tissues, open wounds, vascular status, and the sensory and motor function of the foot. Special attention is given to any signs of compartment syndrome. Swelling with skin blisters indicates disturbance of skin blood supply caused by severe soft-tissue injury. Closed degloving is common with these injuries. Grossly displaced or dislocated fractures must be reduced immediately and splinted.

2.2 Imaging

Standard AP, lateral, and mortise views of the ankle are taken, while full length x-rays of the tibia show the alignment and the knee above. In select patients, x-rays of the contralateral limb also can be helpful to provide a template for reconstruction of more complex fractures and detect any preexisting anatomical or congenital variants [3].

The injury mechanism can be anticipated from the fibular fracture pattern on x-rays and is divided into compression failure (valgus deformity); tension failure (varus); and axial load (fibula intact). When the fibula is intact, there is a prevalence of severe partial articular (type B) injuries [4]. The axial load injury will result in little translation but substantial distal tibial loading with multiple small fragments of the articular surface and a poor prognosis secondary to cartilage impaction [4, 5]. The direction of displacement can be anticipated from the lateral view showing the pattern of talar displacement (usually anterior) [2].

Computed tomographic (CT) imaging with 2-D and 3-D reconstruction is mandatory to provide information about comminution, the position and number of fragments, and direction of displacement. The CT scan will provide information to plan the best approach for reduction and fixation and it is best obtained after restoring length and mechanical axis to the limb. This will disimpact the talus from the distal tibia allowing better visualization of the articular fragments. Tornetta and Gorup [6] showed that the operative plan and approach was changed in 64% of the patients after CT scans. Additional information was gained in 82% of the patients.

4.1 AO/OTA Fracture and Dislocation Classification

The extraarticular type A fracture often appears simple but may be associated with significant soft-tissue injury. The partial articular type B fracture typically has joint comminution and needs a buttress plate to reduce the articular fragment. The complete articular type C fracture denotes high energy with comminution of the tibiotalar joint, disruption of the syndesmosis, fibular fracture, and tibial metaphysis involvement ( Fig 6.8.3-6 ). It often has severe soft-tissue injury.

4.2 Other key classifications

Topliss et al [9] introduced the idea of six main fragments (anterior, posterior, medial, anterolateral, posterolateral, and diepunch) with two distinct fracture families classified by CT: (1) sagittal fractures that tend to present in varus, with more proximal metaphyseal-diaphyseal dissociation and occurred in younger patients with higher-energy injury; (2) coronal fractures that present in valgus with more distal dissociation and following lower energy trauma in older patients.

5.1 Treatment options

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  Nonoperative:

  
  
  
  
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    – Undisplaced stable closed fracture (43A, B1 or C1)

    
    
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    – Significant comorbidities (excessive risk with surgery)

  
  
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  Operative:

  
  
  
  
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    – Articular step more than 2 mm

    
    
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    – Valgus angulation more than 5°

    
    
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    – Any varus angulation

    
    
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    – Open fractures

    
    
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    – Compartment syndrome

    
    
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    – Vascular injury

    
    
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    – Polytrauma

5.2 Timing

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  Early (less than 24 hours) open reduction and internal fixation (ORIF) for patients with low-energy trauma, minimal soft-tissue injury, and isolated, closed fractures presenting in the first 24 hours [10, 11].

  
  
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  Staged approach (initial reduction with external fixation followed by delayed ORIF):

  
  
  
  
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    – Unfavorable soft-tissue condition: blisters and open fractures

    
    
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    – Patients presenting late or delayed transfers

    
    
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    – Polytrauma patients requiring damage control

    
    
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    – Associated vascular injury

    
    
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    – Lack of experience, facilities, or implants

6.1 Timing of surgery

Timing of surgery is controversial and is determined by the condition of the soft tissues. Simple, closed fractures with minimal soft-tissue injury may safely be definitively stabilized within 24–36 hours [10, 11].

For most patients with soft-tissue damage, the staged or “span, scan, and plan” protocol is used. A joint-spanning external fixator (span) (or alternatively calcaneal traction) is applied followed by limb elevation. The bridging achieves ligamentotaxis of the joint allowing stabilization of the fracture as well as the soft tissue ( Fig 6.8.3-7a–d ). It is left in place until soft-tissue edema has subsided. The skin begins to wrinkle, and the blisters have epithelialized, usually within 7–17 days ( Fig 6.8.3-7e ). This allows detailed radiological assessment (scan) with the fragments in the reduced position. Finally, careful preoperative planning is done (plan) including surgical approach, reduction maneuvers, and definitive fixation.