SUMMARY

• A tibial plafond fracture (also known as a pilon fracture) is a fracture of the distal end of the tibia, most commonly associated with comminution, intra-articular extension, and significant soft tissue injury.

• Diagnosis is typically made through clinical evaluation and confirmed with plain radiographs.

• Treatment is generally operative with temporary external fixation followed by delayed open reduction internal fixation once the soft tissues permit.

EPIDEMIOLOGY

• Incidence

  • common

    • 5%-10% of all tibia fractures

    • account for <10% of lower extremity injuries

  • incidence increasing as survival rates after motor vehicle collisions increase

• Demographics

  • average patient age is 35-45 years

  • males > females

ETIOLOGY

• Pathophysiology

  • mechanism

    • high energy axial load (most common)

      • talus is driven into the plafond resulting in articular impaction of the distal tibia

      • falls from height

      • motor vehicle accidents

    • low energy rotational forces (less common)

      • alpine skiing

  • pathoanatomy

    • fracture patterns and comminution determined by position of foot, amplitude of force, and direction of force 

       

      • articular impaction and comminution

      • metaphyseal bone comminution

      • 3 fragments typical with intact ankle ligaments 

        • medial malleolar (deltoid ligament)

        • posterolateral/Volkmann fragment (posterior-inferior tibiofibular ligament)

        • anterolateral/Chaput fragment (anterior-inferior tibiofibular ligament)

• Associated conditions

  • 75% have associated fibula fractures 

     

  • 30% have an ipsilateral lower extremity injury

  • 20% are open fractures

  • 5-10% are bilateral pilon fractures

ANATOMY

• Osteology

  • tibia 

    • distal tibia forms an inferior quadrilateral surface and pyramid-shaped medial malleolus articulates with the talus and fibula laterally via the fibula notch

• Ligaments

  • distal tibiofibular syndesmosis 

    • anterior-inferior tibiofibular ligament (AITFL)

      • originates from anterolateral tubercle of tibia (Chaput) 

      • inserts on anterior tubercle of fibula (Wagstaffe)

    • posterior-inferior tibiofibular ligament (PITFL)

      • originates from posterior tubercle of tibia (Volkmann)

      • inserts on posterior part of lateral malleolus

      • strongest component of syndesmosis

    • interosseous membrane

    • interosseous ligament (IOL)

      • distal continuation of the interosseous membrane

    • inferior transverse ligament (ITL)

CLASSIFICATION

• AO/OTA Classification
  43-A	Extra-articular
  43-B	Partial articular
  43-C	Complete articular

• Ruedi and Allgower Classification
  Type I	Nondisplaced
  Type II	Simple displacement with incongruous joint
  Type III	Comminuted articular surface

PRESENTATION

• Symptoms

  • severe ankle pain

  • ankle deformity

  • inability to bear weight

• Physical exam

  • inspection & palpation

    • ankle tenderness, swelling, abrasions, ecchymosis, fracture blisters, open wounds, and chronic skin/vascular changes

    • examine for associated musculoskeletal injuries

  • motion

    • ankle motion limited

  • neurovascular

    • check DP and PT pulses

      • consider ABIs and CT angiography if clinically warranted

    • look for neurologic compromise

    • check for signs/symptoms of compartment syndrome

IMAGING

• Radiographs

  • recommended views

    • AP

    • lateral

    • mortise

    • full-length tibia/fibula and foot x-rays performed for fracture extension

    • lumbar films if appropriate based on exam

  • findings

    • 4 classic fracture fragments 

      • medial malleolus

      • anterior malleolus = chaput

      • lateral malleolus = wagstaffe

      • posterior malleolus = volkmann

• CT scan

  • indications

    • critical for pre-operative planning

      • articular involvement

      • metaphyseal comminution

      • fracture displacement

    • important to obtain after spanning external fixation as ligamentotaxis allows for better surgical planning 

       

    • fine cuts through the distal tibia

      • 3D reconstructions can be helpful

  • findings

    • ‘Mercedes-Benz’ sign on axials 

TREATMENT

• Nonoperative

  • cast immobilization

    • indications

      • stable fracture patterns without articular surface displacement

      • critically ill or non-ambulatory patients

      • significant risk of skin problems (diabetes, vascular disease, peripheral neuropathy)

    • outcomes

      • intra-articular fragments are unlikely to reduce with manipulation of displaced fractures

      • loss of reduction is common

      • inability to monitor soft tissue injuries is a major disadvantage

• Operative

  • temporizing spanning external fixation across ankle joint 

     

    • indications

      • acute management of most length unstable fractures

        • provides stabilization to allow for soft tissue healing and monitoring

        • capsuloligamentotaxis to indirectly reduce the fracture by tensioning the soft tissues about the ankle

        • keeps fracture fragments out to length

        • fractures with significant joint depression or displacement

        • leave until swelling resolves (generally 10-14 days)

        • not always warranted in length stable pilon fractures

    • outcomes

      • placement of pins out of the zone of injury and planned surgical site is important to reduce infection risks

  • open reduction and internal fixation (ORIF) 

    • indications

      • definitive fixation for a majority of pilon fractures

      • limited or definitive ORIF can be performed acutely with low complications in certain situations

    • outcomes

      • dependent on articular reduction

      • high rates of wound complications and infections are associated with early open fixation through compromised soft tissue

      • ability to drive

        • brake travel time returns to normal 6 weeks after weight bearing 

           

      • fibula fixation

        • not a necessary step in the reconstruction of pilon fractures

        • may be helpful in specific cases to aid in tibial plafond reduction or augment external fixation

        • higher rates of fibula hardware removal 

           

  • external fixation/circular frame fixation alone

    • indications

      • select cases where bone or soft tissue injury precludes internal fixation

    • outcomes

      • thin wire frames and hybrid fixators have high union rate

      • high rates of pin tract infections

      • osteomyelitis and deep infection are rare

      • meta-analysis comparing this method with open reduction and internal fixation found no difference in infection or complication rates between the two groups

  • intramedullary nailing with percutaneous screw fixation 

     

    • indications

      • alternative to ORIF for fractures with simple intra-articular component

    • outcomes

      • minimizes soft tissue stripping and useful in patients with soft tissue compromise

      • high union rates

      • increased valgus malunion and recurvatum seen with IMN compared to plate osteosynthesis

  • primary ankle arthrodesis

    • indications

      • no definitive indications

    • potential indications

      • severely comminuted, non-reconstructable plafond fractures

      • select elderly populations who cannot tolerate multiple surgeries or prolonged immobilization

      • manual laborers

    • techniques

      • plate and screw fixation

      • retrograde intramedullary TTC nail

    • outcomes

      • theorized quicker recovery process and decreased long term pain

      • increases the risk of adjacent joint arthritis including the subtalar joint and midfoot

TECHNIQUES

• Cast immobilization

  • technique

    • long leg cast for 6 weeks followed by fracture brace and ROM exercises

    • close follow-up and imaging needed to ensure articular congruity and axial alignment

• External fixation (temporary and definitive)

  • technique 

     

    • fixator constructs vary with ‘delta’ and ‘A’ frames assemblies being most common

    • 2 tibial shaft half pins outside the zone of injury connected to a single transcalcaneal pin

      • consider trans-navicular pin if associated calcaneal fracture

      • consider connecting fixator to the forefoot 1^st metatarsal to prevent an equinus contracture

    • joint-spanning articulated vs. nonspanning hybrid ring

      • none have been shown to be superior with respect to ankle stiffness

    • can combine with limited percutaneous fixation using lag screws

  • complications

    • pin site drainage

    • pin/wire tract infections

    • pin site fracture

    • ankle stiffness

    • injury to neurovascular structures

    • anatomic articular reconstruction may not be possible, especially with central depression

• Circular frame fixation 

  • technique

    • distraction is the key to reduction

    • proximal fixation

      • tibial shaft is used as a fixation base to reduce the fracture

      • two half-pins in the AP plane with rings in an orthogonal position

      • used to support the distal fixation rings

    • distal fixation 

      • determined by the configuration of the fracture and the soft-tissue injury

      • rings placed at the level of the plafond or calcaneus to distract and reduce the fracture

      • pins should be placed at least 1-2 cm from the joint line in order to avoid possible septic arthritis

      • safe zones for wire placement form a 60-degree arc in the medial-lateral plane 

    • can include limited internal fixation if soft tissues permit

    • consider the need for soft tissue coverage with position of the fixator

    • hydroxyapatite coated pins

      • provides better fixation and decreases frequency of loosening

• Open reduction and rigid internal fixation (ORIF) 

  • timing to definitive surgery

    • once skin wrinkles present, blister epithelization, and ecchymosis resolution (10-14 days)

  • approach(es)

    • single or multiple incisions based on fracture pattern and goals of fixation

    • keep full thickness skin bridge >7cm between incisions

    • positioning of patient dependent on approach(es) being utilized

    • direct anterior approach to ankle 

    • anterolateral approach to ankle 

      • useful with fractures impacted in valgus or with an intact fibula

      • puts the deep peroneal nerve at risk during exposure and dissection in the anterior compartment

      • superficial peroneal nerve at risk during superficial dissection in the lateral compartment 

         

    • anteromedial approach to ankle 

    • medial approach 

    • posteromedial approach 

    • posterolateral approach 

    • lateral approach 

  • technique

    • reduction and fixation

      • goal is for anatomic reduction of articular surface 

      • location of plates/screws are fracture and soft-tissue dependent

      • restore alignment

        • <5-10 degrees varus/valgus

        • <5-10 degrees procurvatum/recurvatum

      • restore length

        • consider provisionally leaving the external fixator in place

      • reconstruct metaphyseal shell

      • bone graft (if warranted)

      • reattach metaphysis to diaphysis

      • fibula fixation if needed

        • can be with intramedullary screw/wire or plate/screw construct

    • postoperative care

      • ankle ROM exercises beginning 2 weeks post-op

      • non-weightbearing for ~6-12 weeks depending on radiographic evidence of fracture consolidation

• Primary ankle arthrodesis

  • approach

    • direct anterior 

  • technique

    • plate and screw fixation

      • debride fibrous tissue, fracture callous, and cartilage

      • small comminuted articular fragments are removed

      • remove talar dome cartilage

      • pack metaphyseal defects and the tibiotalar joint with autologous or allograft bone graft

        • iliac crest

        • demineralized bone matrix

      • optimal position

        • neutral dorsiflexion

        • 5-10° of external rotation

        • 5° of hindfoot valgus

        • 5 mm of posterior talar translation

      • fixation with an anterior plate and screw construct

      • post-op care

        • apply cast or splint for 8 weeks

        • progress weight bearing between 8 and 12 weeks in removable boot

        • full weight bearing with ankle brace at 12 weeks post-op

        • CT at 3 months to assess for successful fusion

    • tibiotalocalcaneal (TTC) fusion with retrograde intramedullary nail

      • sacrifices subtalar joint motion

      • accelerates transverse tarsal joint arthritis

      • immediate weightbearing permissible

COMPLICATIONS

• Wound slough and dehiscence

  • incidence

    • 9-30%

    • wait for soft tissue edema to subside before ORIF (1-2 weeks)

  • treatment

    • free flap for postoperative wound breakdown

• Infection

  • incidence

    • 5-15%

  • risk factors

    • significant soft tissue swelling at time of definitive surgery

    • Increasing fracture severity  

       

  • treatment

    • irrigation and debridement, antibiotics, possible hardware removal

• Malunion

  • incidence

    • 6-14%

  • treatment

    • joint-preserving correction with secondary anatomic reconstruction

    • corrective ankle fusion

• Nonunion 

   

  • incidence

    • 5% of patients undergoing ORIF

    • usually at the metaphyseal junction

  • risk factors

    • metaphyseal comminution

    • open fractures

    • bone loss

    • tobacco use

    • NSAID use

  • treatment

    • must rule out infected non-union (labs to obtain CRP, ESR, WBC)

    • other non-union labs (PTH, calcium, total protein, serum albumin, vitamin D, TSH)

    • rigid fixation with bone grafting

• Post-traumatic arthritis

  • incidence

    • chondrocyte cell death at fracture margins is a contributing factor 

       

    • IL-6 is elevated in the synovial fluid following an intra-articular ankle fracture 

       

    • most commonly begins 1-2 years postinjury

  • risk factors

    • sequalae of cartilage trauma

    • non-anatomic articular reduction

    • mal-alignment

  • treatment

    • first line is conservative management (bracing, injections, NSAIDs, activity modification)

    • total ankle arthroplasty

    • ankle arthrodesis

• Chondrolysis

• Stiffness  

   

  • Present in up to 33% at three years post-injury 

  • risk factors 

    • increasing fracture severity

    • obesity

    • ASA of three or greater

PROGNOSIS

• Poor outcomes and lower return to work associated with

  • lower level of education 

     

  • pre-existing medical comorbidities

  • male sex

  • work-related injuries

  • lower income levels

• Outcomes correlate with severity of the fracture pattern and the quality of reduction

  • at 2 year follow-up, the majority of type C pilon fractures report lower SF-36 scores than patients with pelvic fractures, AIDS, or coronary artery disease

  • clinical improvement seen for up to 2 years after injury 

     

• Return of vehicle braking response time

  • 6 weeks after initiation of weight bearing