Pilon Fractures

 

Introduction

  • Intra-articular fractures of the distal tibia resulting from an axially-loaded talus
  • Pilon is a French word meaning ‘pestle’; here, the talus is the pestle and the tibial plafond is the mortar
  • 1% of all lower limb fractures, 7% of tibial fractures
  • average age 35-45 years
  • males > females
  • 5-10% bilateral

 

Mechanism

  • axial +/- torsional force
  • axial load drives the talar dome into the distal tibia
  • ankle position influences the pattern of injury
  • fibula is usually also fractured
  • normally high-energy trauma e.g. fall from height, RTC
  • associated with significant soft tissue injuries
  • low-energy twisting injury in osteoporotic bone

 

Pathoanatomy

Fracture pattern:

  • articular impaction and comminution
  • metaphyseal bone comminution
  • 4 common fragments based on ligament attachments: 
    • medial malleolar (deltoid)
    • posterolateral / Volkmann fragment (PITFL)
    • anterolateral / Chaput fragment (AITFL)
    • anterior distal fibula / Wagstaffe (AITFL)

Soft tissue envelope:

  • thin and constrained
  • blood supply comes mostly from an anastamotic network from the posterior tibial and anterior tibial arteries
  • surgical planning is critical for timing and approach

 

Classification

Ruedi and Allgower

  1. undisplaced cleavage fractures
  2. displaced fracture fragments with minimal comminution
  3. high degree of comminution and displacement

 

AO Classification (43)

  1. extra-articular
  2. partial articular
  3. total articular

 

Assessment

Clinical

  • Look
    • inability to bear weight
    • deformity
    • soft tissues, blisters, open wounds
    • associated injuries
  • Feel
    • tenderness
    • check DP and PT pulses (consider ABIs and CT angiography if concerns)
    • neurologic compromise
    • compartment syndrome
  • Move
    • other joints

Radiological

  • Plain radiographs
  • CT scan (after initial stabilisation) – “span, scan and plan”
    • essential – likely to change the surgeon’s plan
    • look for 4 classic fracture fragments

 

Management

 

Non-operative (cast immobilisation)

Indications:

  • low-energy, undisplaced articular fractures
  • high risk or non-ambulatory patients

 

Operative management

Urgent management

  • multiply-injured patients assessed and managed using ATLS principles
  • open fractures managed as per BOAST guidelines
  • bridging external fixator until soft tissues settle (~10-14 days) prior to…
  • open reduction and internal fixation

Early fibular fixation (+/- ex-fix) was historically advocated to help maintain length, alignment and rotation. However, this can compromise later surgical approaches or fragment manipulation.

 

Definitive Management

Timing is crucial:

  • once soft tissues / blisters have settled
  • aim to minimise further soft tissue trauma
  • after careful planning of surgical approaches
  • d/w colleagues in trauma MDT
  • d/w plastics if soft tissue / coverage concerns

 

Goals of treatment

  • anatomical reduction of articular surface
  • restore length (use fibula as a guide)
  • reconstruct metaphyseal shell
  • bone graft or void filler
  • connect metaphysis to diaphysis

 

Surgical Approaches

Factors affecting choice of surgical approach:

  • presence of an open wound
  • residual fracture blisters
  • location of key fracture fragments
  • surgeon’s preference
  • can use a combination of direct or minimal approaches, allowing for above factors and decent skin bridges

 

Open reduction and internal fixation

  • Restoration of the articular surface:
    • open the anterior articular fragments to visualise the central and posterior fragments
    • individual articular fragments are reduced from posterior to anterior
    • provisional reduction performed with K-wires
    • definitive fixation with screws
  • Plate fixation:
    • low-profile plates to connect the articular fragment to the tibia
    • valgus fracture patterns with lateral compression (coronal patterns) are better fixed with anterolateral plating
    • varus fracture patterns with medial compression (sagittal patterns) are better stabilized with medial buttress plates

 

Controversy exists regarding fibular fixation:

Ruedi and Allgower recommended fixing the fibula first to restore the length of the lateral column. However, in cases of severe fibular comminution, restoring the length is difficult.

In case of using an anterolateral approach, care should be taken to leave at least 6 cm skin bridge from the fibular incision.

Rouhani et al. and Williams et al. found no clinical difference in patients treated with ankle-bridging external fixation, with or without fibula plating. The plating group suffered more wound complications, and the non-plating group had more incidence of angular malunion.

 

Indications for external fixation with or without limited ORIF

  • severely comminuted fractures
  • large articular fragments reducible by ligamentotaxis
  • open fractures with significant soft-tissue injury
  • patients with significant co-morbidities
  • longer-term frame treatment requires MDT approach for pin-site management

 

Indications for primary ankle arthrodesis

  • severely comminuted, non-reconstructable plafond fractures
  • low demand populations who cannot tolerate multiple surgeries
  • manual labourers
  • techniques include:
    • plate and screw fixation
    • retrograde intramedullary TTC nail

 

Outcomes

  • depend on:
    • associated soft tissue injury
    • accuracy of the articular reduction
  • 40% of workers lose employment
  • high incidence of post-traumatic arthritis often develops quickly
  • delayed / non-union increase with fracture severity
  • wound problems / infection

 

 

EMQ Test:

For each of the following scenarios select the most appropriate option from the list below:

A. ORIF

B. Intramedullary nail and fibula fixation

C. Isolated fibular fixation

D. Fibular fixation and a spanning external fixator

E. Spanning external fixator

F. Anterolateral approach

G. Posterolateral approach

H. Anteromedial approach

I. Anterior approach

J. Lateral approach

 

 

1. Which approach has superior access to a Chaput–Tilleaux fragment in Pilon fractures?

2. Which approach has superior visualisation of articular fragments?

3. In Pilon fractures with an intact lateral column which is the best technique for maintaining position until soft tissues improve?

 

 

 

Answers

1-F    The Chaput–Tilleaux fragment represents the fragment avulsed from the tibia by the anterior inferior tibio-fibular ligament and is therefore best visualized with an anterior lateral approach.

2-I      The anterior approach would give the best access to visualise medial and lateral articular fracture fragments.

3-E     External fixation should be considered for all pilon fractures as a staged process until soft tissues are recovered sufficiently to allow for definitive fixation.

 

 

References​

Marsh JL, Saltzman CL. Axial-loading injuries: tibial plafond fractures. In: Bucholz RW, Heckman JD, Court-Brown CM, eds. Fractures in Adults. Ed 6. Vol 2. Philadelphia, PA: JB Lippincott; 2006:2203–2234

Sirkin M, Sanders R, DiPasquale T, Herscovici D Jr. A staged protocol for soft tissue management in the treatment of complex pilon fractures. J Orthop Trauma. 1999;13:78–84

Sommer C, Ruedi TP. Tibia distal (pilon). In Ruedi TP, Murphy WM, eds. AO Principles of Fracture Management. New York, NY: Thieme; 2000:543–560

Assal M, Ray A, Stern R. Strategies for surgical approaches in open reduction internal fixation of pilon fractures. J Orthop Trauma 2015;29:69-79

Leung F, Kwok HY, Pun TS, Chow SP. Limited open reduction and Ilizarov external fixation in the treatment of distal tibial fractures. Injury 2004;35:278-283

Pollak AN et al. Outcomes after treatment of high-energy tibial plafond fractures. J Bone Joint Surg [Am] 2003;85-A:1893-1900

Sands A et al. Clinical and functional outcomes of internal fixation of displaced pilon fractures. Clin Orthop Relat Res 1998;347:131-137

Jacob N et al. Management of high-energy tibial pilon fractures, Strat Traum Limb Recon (2015) 10:137–147.

Papadokostakis G, Kontakis G, Giannoudis P, Hadjipavlou A (2008) External fixation devices in the treatment of fractures of the tibial plafond: a systematic review of the literature. J Bone Joint Surg Br 90(1):1–6

Leung F, Kwok HY, Pun TS, Chow SP (2004) Limited open reduction and Ilizarov external fixation in the treatment of distal tibial fractures. Injury 35(3):278–283

Watson JT, Moed BR, Karges DE, Cramer KE (2000) Pilon fractures: treatment protocol based on severity of soft tissue injury. Clin Orthop Relat Res 375:78–90

Topliss C, Jackson M, Atkins RM (2005). Anatomy of pilon fractures of the distal tibia. J Bone Joint SurgBr, 87-B, 692–697

Rüedi TP, Matter P, Allgöwer M. Intra-articular fractures of the distal tibial end [in German]. Helv Chir Acta. 1968;35:556–582