Pilon Fractures


Background

Pilon is a French word for pestle, an instrument used for crushing or pounding. [1The first recorded use of the term pilon in the orthopedic literature is in 1911, by Étienne Destot. [2Pilon fractures account for approximately 7% of tibial fractures. Pilon fractures in the distal tibia result from axial forces that can range from low to high energy and produce a spectrum of articular and metaphyseal injuries. These fractures involve the dome of the distal tibial articular surface and extend into the adjacent metaphysis. The fibula may or may not be intact.

Despite the advances that have been made in management, these fractures can be challenging to deal with, especially when associated with significant soft-tissue injury. Although various options are available to treat these fractures, timing of definitive surgery is crucial with respect to the condition of the soft tissues. New developments in the field continue to lead to better outcomes.

The treatment of pilon fractures has evolved over the last century. Conservative management gave way to surgical intervention when implants became available, but poor outcomes led to a return to cast immobilization or limited internal fixation of the fibula only. However, outcomes after nonoperative treatment continue to be poor.

In 1959, Jergesen stated that open reduction and stabilization of severe tibial pilon fractures is impossible. In the early 1960s, the Association for Osteosynthesis/Orthopaedic Trauma Association (AO/OTA) developed general guidelines for the treatment of intra-articular distal tibial fractures, which led to open reduction and anatomic and rigid internal fixation.

Good outcomes were reported when these principles were used for low-energy injuries (eg, those from skiing accidents). However, when the same principles were used to fix high-energy injuries (eg, from motor vehicle accidents), the outcomes were poor, mainly because of soft-tissue complications.

Over the years, the importance of soft tissues and the differences between low- and high-impact energy injuries have become better understood. This has led to the development of newer treatment concepts, which continue to evolve, along with an availability of more advanced surgical options, such as minimally invasive internal fixation implants. [345]

Anatomy

The distal tibia and fibula, along with the ligaments and capsule, help to form the ankle mortise. Any disruption of length, axis, or rotation of the fibula or the tibia can result in an incongruent ankle joint.

The lateral aspect of the distal tibia forms a triangular notch, which is where the fibula articulates. The interosseous and the anterior and posterior tibiofibular ligaments bind these bones together.

The ligaments often avulse fragments from the tibia, such as the anterolateral fragment termed the Chaput fragment and the posterior malleolar fragment termed the Wagstaffe fragment. [6]

The blood supply in the distal leg is provided by branches that arise from the posterior tibial, peroneal, and dorsalis pedis arteries.

The great saphenous vein travels along with the saphenous nerve anterior to the medial malleolus. The small saphenous vein passes posterior to the lateral malleolus. Disruption of the venous system can lead to subsequent chronic venous stasis.

Pathophysiology

Depending on the mechanism of injury and the direction of forces, a wide variety of injury patterns result. At one end of the spectrum are low-energy injuries that follow activities such as skiing and result in minimal soft-tissue injury. The fracture fragments are fewer, have a spiral orientation, and are relatively minimally displaced.

At the other end of the spectrum are high-energy injuries such as a fall from height or a high-speed motor vehicle accident. Such a mechanism can produce significant comminution with multiple displaced fracture fragments and, importantly, a contused or crushed soft-tissue envelope, which could also be breached and open to external contamination through wounds. The fibula is usually fractured in high-energy injuries.

A variable amount of damage can occur to the articular cartilage of the tibia, which can be scuffed, bruised, or fragmented. In severe cases, the weightbearing central dome can be fragmented. The fragments, which can be tiny (~2-3 mm3), are completely broken off and are driven up into the metaphysis of the tibia by the impact. Damage to the talar articular surface can also occur.

Etiology

Pilon fractures occur when the talus is driven into the tibial plafond. The forces that cause fracture fragments in the distal tibial metaphysis, articular and soft-tissue damage, can be vertical, rotational, angular, or a combination of these.

Prognosis

The outcome varies, depending on the following factors:

  • The severity of the injury to bone and soft tissues
  • Delay from injury to presentation, especially in open fractures
  • The patient's general condition and compliance
  • Other associated injuries
  • The surgeon's experience

Low-impact pilon fractures have better outcomes than high-impact pilon fractures. In general, good outcomes can be expected in approximately 60-80% of patients. [7891011]

Many patients continue to improve for many years after the injury. The severity of the injury and the quality of the articular reduction frequently correlate with the development of arthrosis, but radiographic signs of arthrosis have only a weak correlation with clinical outcome [12.

Ankle fusions may be required in approximately 3-27% of patients with posttraumatic arthritis. Nonunion in the distal tibia can be treated with a fibula-pro-tibia plating and bone grafting procedure, as described by DeOrio and Ware. [13Ankle replacement is an option in selected individuals.

Outcomes following an innovative approach using staged posterior tibial plating for the treatment of OTA 43C2 and 43C3 pilon fractures in 9 patients with a separate, displaced, posterior malleolar fragment were compared by Ketz and Sanders to 10 patients with similar fracture patterns treated using standard anterior or anteromedial incisions with indirect reduction of the posterior fragment. [14All 19 patients were available for follow-up at an average of 40 months (range, 28-54 months). The average Maryland Foot Score and American Orthopaedic Foot and Ankle Society (AOFAS) Ankle and Hindfoot score for the first group were 86.4 and 85.2, compared with 69.4 and 76.4 for the later group.

The authors concluded that the addition of a posterior lateral approach offers direct visualization for reduction of the posterior distal fragment of the tibial pilon. [14Although the joint surface itself cannot be visualized, this reduction allows the anterior components to be secured to a stable posterior fragmentat a later date. This technique improved ability to subsequently obtain an anatomic articular reduction based on computed tomography (CT) scans and preservation of the tibiotalar joint space at a minimum 1-year follow-up. [14]

Vidović et al reported on a prospective study involving 21 patients with closed distal tibial and pilon fractures treated with minimally invasive plate osteosynthesis (MIPO). [15Nineteen patients were initially managed with an ankle-spanning external fixator. When the status of the soft tissue had improved and swelling had subsided enough, a definitive internal fixation with MIPO was performed. Patients were invited for follow-up examinations at 3 and 6 weeks and then at intervals of 6 to 8 weeks until 12 months. Mean age of the patients was 40.1 years (range, 19-67 years). Eighteen cases were the result of high-energy trauma and three were the result of low-energy trauma.

By the AO/OTA classification, there were extra-articular and intra-articular fractures, but only simple articular patterns without depression or comminution. [15The average time for fracture union was 19.7 weeks (range, 12-38). Mean range of motion was 10° of dorsiflexion (range, 5-15°) and 28.3° of plantar flexion (range, 20-35°). Three cases were metalwork-related complications. Two patients underwent plate removal at 24 weeks because of plate impingement. There was one case of wound breakdown at 11 weeks. One patient had fracture union with tibial recurvatum of approximately 10°, without functional impairment. Two patients had delayed union.

Vidović et al concluded that MIPO is a reliable method of treatment for distal tibial fractures; it provides a high union rate and good functional outcome with minimal soft-tissue complications. [15Skin impingement remains a common complication with MIPO, but this can be solved by timely plate removal.



History and Physical Examination

Patients involved in high-energy trauma should be treated according to advanced trauma life support (ATLS) guidelines because they may have associated life- or limb-threatening injuries.

Obtain a history of any allergies, intake of medications, past medical history (eg, diabetes mellitusperipheral vascular or neuropathic disease), and events leading to the injury. An understanding of the mechanism of injury may lead to an indication of the forces involved. Also, knowledge of any history of previous trauma in either limb is helpful during restoration.

Clinical presentation varies, depending on the severity of the injury and the duration from the time of the injury. Soft tissues swell rapidly, and tissue tension can produce enormous blisters. The underlying bony fragments may be significantly displaced, threatening the viability of the overlying soft-tissue envelope. Crushing, degloving, bruising, hematomas, and leaving the limb dependent can further compromise soft tissues (see the image below).

Soft-tissue trauma, with blister and area of pressSoft-tissue trauma, with blister and area of pressure necrosis over medial aspect of distal leg, in patient who presented 48 hours after injury.

Classification

The Oestern and Tscherne classification of soft-tissue injury in closed fractures is as follows [16:

  • Grade 0 - Minimal soft-tissue damage, indirect injury to limb (torsion), simple fracture pattern
  • Grade 1 - Superficial abrasion or contusion, mild fracture pattern
  • Grade 2 - Deep abrasion with skin or muscle contusion, severe fracture pattern, direct trauma to limb
  • Grade 3 - Extensive skin contusion or crush injury, severe damage to underlying muscle, subcutaneous avulsion, compartment syndrome

Traumatic wounds can range from a puncture wound, which is usually either medial or lateral, to large injuries with extensive loss of soft tissue.

The Oestern and Tscherne classification for open fractures uses wound size, level of contamination, and fracture pattern to grade open fractures, and is as follows [16:

  • Grade I - Open fractures with a small puncture wound without skin contusion, negligible bacterial contamination, and a low-energy fracture pattern
  • Grade II - Open injuries with small skin and soft-tissue contusions, moderate contamination, and variable fracture patterns
  • Grade III - Open fractures with heavy contamination, extensive soft-tissue damage, and, often, associated arterial or neural injuries
  • Grade IV - Open fractures with incomplete or complete amputations

The Gustilo classification can also be used for open fractures and is as follows [1718:

  • Grade 1 - Skin lesion smaller than 1 cm; clean, simple bone fracture with minimal comminution
  • Grade 2 - Skin lesion larger than 1 cm, no extensive soft-tissue damage, minimal crushing, moderate comminution and contamination
  • Grade 3 - Extensive skin damage with muscle and neurovascular involvement, high-speed injury, comminution of the fracture, instability

Grade 3 Gustilo fractures may be further subclassified as follows [17:

  • Grade 3a - Extensive laceration of soft tissues with bone fragments covered, usually high-speed traumas with severe comminution or segmental fractures
  • Grade 3b - Extensive lesion of soft tissues with periosteal stripping, contamination, and severe comminution due to high-speed traumas; usually requires replacement of exposed bone with a local or free flap as a cover
  • Grade 3c - Exposed fracture with arterial damage that requires repair

Any neurovascular injury must be documented at the time of presentation. Compartment syndrome is a risk in acute injuries; therefore, frequent evaluations are necessary. A systematic and complete evaluation is necessary because other injuries (eg, to the spine or other extremities) may have occurred after a fall from height.

On the basis of the mechanism of injury and the degree of damage to soft tissue and bone, pilon fractures can be divided into two broad categories, low impact and high impact.

Low-impact pilon fractures have the following characteristics:

  • Mechanism - Low-energy rotational force and some axial compression
  • Soft tissue - Little soft-tissue injury
  • Bone - Little articular comminution

High-impact pilon fractures have the following characteristics:

  • Mechanism - High-energy axial compression
  • Soft tissue - Extensive soft-tissue injury
  • Bone - Severe articular and metaphyseal comminution


Laboratory Studies

If patients have preexisting conditions or comorbidities, then appropriate blood investigations are ordered.

Imaging Studies

Plain radiography

Plain radiographs, including anteroposterior (AP), mortise, and lateral views centered over the ankle, help provide an understanding of the fracture fragments and the pattern and facilitate the planning of treatment.

In addition to these radiographs, obtain full-length radiographs of the leg, including the knee and ankle, to help assess alignment and to rule out any other fractures in the limb.

Plain radiographs of the contralateral ankle help provide a template for reconstruction of the ankle. Other areas of the body, such as the spine in the case of a fall from height, [19may require radiographic evaluation, depending on clinical findings.

Two fracture classifications are commonly used, both of them based on the fracture pattern seen on radiographs, the degree of comminution, and displacement of the fragments. [2021]

The Rüedi and Allgöwer classification is as follows:

  • Type A - These are simple cleavage-type fractures with little or no articular displacement (see the first and second images below)
  • Type B: With these, displacement of the articular surface occurs without comminution (see the third and fourth images below)
  • Type C: Intra-articular displacement occurs with marked comminution (see the fifth and sixth images below)
Low-energy pilon fracture in distal tibia with no Low-energy pilon fracture in distal tibia with no significant displacement.
Lateral view of pilon fracture. Lateral view of pilon fracture.
Low-impact pilon fracture with displacement but wiLow-impact pilon fracture with displacement but without significant comminution.
Lateral view of pilon fracture. Lateral view of pilon fracture.
Significant comminution and displacement of fractuSignificant comminution and displacement of fracture fragments in pilon fracture.
Lateral view of pilon fracture. Lateral view of pilon fracture.

The Association for Osteosynthesis/Orthopaedic Trauma Association (AO/OTA) classification (part of a comprehensive classification of long-bone fractures and tibia, numbered 43) is as follows [22:

  • Type A - These fractures are extra-articular and subcategorized as simple (A1), comminuted (A2), or severely comminuted (A3)
  • Type B - These fractures involve only a portion of the articular surface and a single column; subcategories include pure split (B1), split with depression (B2), and depression with multiple fragments (B3)
  • Type C - These fractures involve the whole of the articular surface; they may be categorized as a simple split in the articular surface and the metaphysis (C1), an articular split that is simple with a metaphysis split that is multifragmentary (C2), or a fracture with multiple fragments of the articular surface and the metaphysis (C3)

A type of pilon fracture that is associated with posterior disruption and instability is being recognized as a special entity. This type of pilon fracture requires posterior stabilization and is potentially associated with worse outcomes. Failure to identify this fracture pattern has led to poor clinical outcomes and persistent talar subluxation.

The purpose of a study by Klammer et al was to classify posterior pilon fractures into three primary categories by increasing degree of complexity, as follows [23:

  • Type 1 fractures with a single medially based posterior malleolar fragment can be addressed through a posterolateral approach alone
  • Type 2 fractures, in which the posterior fragment is split with possible posteromedial comminution, may require an additional medial or limited posteromedial approach to assist in reduction and fixation of the posteromedial fragment or separate medial malleolar fracture
  • Type 3 fractures have the fracture line of the posterior malleolus exit the medial malleolus anterior to the posterior colliculus, and an additional anteromedial fragment is present; a medial approach is always necessary for reduction and fixation of the additional anteromedial fragment

Further investigations

Repeat radiographs after application of a spanning external fixator (traction radiographs) will yield a better understanding of the fracture pattern, fracture fragments, and fracture planes. This information is necessary for planning the surgical approach and achieving optimal implant placement and orientation of interfragmentary screws.

Computed tomography (CT) may be necessary in some cases where there is significant comminution or where percutaneous approaches are being planned. It is best obtained after the fracture is stabilized and spanned in an external fixator—a strategy summarized in the dictum "First span, then scan."

This strategy yields a better understanding of the fracture pattern, the degree of comminution, the displacement, and the impaction of articular fragments that may not be evident on plain radiographs. The degree of comminution may indicate severity of damage to articular surface and influence decision-making. This can be valuable in planning the operation (eg, by helping to determine the approach to the fragments and the orientation of the screws).

In a study by Misir et al, 20 orthopedic surgeons compared traction radiographs with CT scans in the evaluation of fracture morphology and consecutive treatment decisions in 12 OTA/AO 43C3 fractures. [24Each observer was required to identify the anterolateral, posterolateral, and medial malleolus fragments and the lateral, central, and medial shoulder comminution zones. They then had to recommend treatment (nonoperative, open reduction and internal fixation [ORIF], closed reduction and external fixation, percutaneous screw fixation, or primary tibiotalar arthrodesis) with the best surgical approach (medial, anterolateral, posterolateral, posteromedial, or combined).

This study analyzed intra- and interobserver reliability, correct identification of fracture fragments and comminution zones on both images, and consistency of treatment recommendations and surgical approaches. [24Treatment and surgical approach recommendations after traction radiographs and CT were similar. The authors concluded that traction radiographs may be a useful alternative to CT in the preoperative planning of pilon fracture repair. Despite less reliable fracture fragment and comminution zone identification on traction radiographs, treatment recommendations and surgical approach were not influenced.

Despite the variations in the mechanism of injury and in the degree or direction of the forces involved, tibial plafond fractures occur in consistent fracture patterns and in the following fracture fragments as a consequence of the presence of ligamentous attachments [25:

  • Anterolateral or Chaput fragment – This fragment remains attached to the fibula through the anterior tibiofibular ligaments and rotated externally and or subluxed and displaced inferiorly; traction and spanning may help with reduction of the subluxation with the help of ligamentotaxis, but if not, the fragment should be manipulated into as nearly anatomic a position as possible to reduce tension over the soft tissues and to help with definitive reduction and fixation at a later stage
  • Anteromedial fragment – The size of the medial malleolar fragment varies, depending on the direction of forces; a spiral force or vertical force causes a large fragment; if there is addition of an angular or adduction force, there may be a separation of the anterior and posterior colliculus
  • Posterior malleolar fragment(s) – These can be posterolateral (Volkmann) or posteromedial or central; the posterolateral fragment is attached to the fibula with posterior tibiofibular ligaments, and the posteromedial fragments are attached to the deltoid ligament; a large posterior malleolar fragment signifies posterior instability
  • Central impaction – A purely vertical force can drive impacted comminuted fragments into the tibial metaphysis completely bereft of any soft-tissue attachments
  • Anterior impaction fragments – These occur when there is a dorsiflexion force; they tend to be multiple and have capsular attachments

Cole et al reported on fracture lines using axial CT scan images in 38 consecutive AO/OTA type 43C3 fractures. [25For each fracture, a map of the fracture lines and zones of comminution was drawn. Each map was digitized and graphically superimposed to create a compilation of fracture lines and zones of comminution. On the basis of this compilation, major and minor fracture lines were identified and fracture patterns were defined. (See the image below.)

CT scan showing axial cut of pilon fracture. CT scan showing axial cut of pilon fracture.

Specifically, a basic Y pattern, constant across all patients, was identified where the stem of the Y went into the fibula incisura. All other fracture lines were considered secondary and these defined the comminution. One hundred percent of major fracture lines involved the tibiofibular joint and all exited medially in two general zones, anterior and posterior to the medial malleolus, best described as a Y-shaped pattern. Therefore, three main fragments existed in every single case. Comminution was present in 36 (95%) of 38 cases, and it was predominantly located centrally and in the anterolateral quarter.

Angiography is required if vascular compromise is suspected.



Approach Considerations

Indications for surgery include the following:

  • Open fracture
  • Displaced fracture - Articular fragments with a gap of more than 2 mm or step of more than 1 mm; rotational malalignment
  • Vascular compromise
  • Compartment syndrome

The presence of soft-tissue swelling and/or blisters, peripheral vascular disease, and/or wound infection are contraindications for extensive surgery (eg, open reduction and internal fixation [ORIF]). External fixation with use of a hybrid frame or a cast can be used in such situations. [26]

Minimally invasive plating techniques have been introduced in the past few years, and these help to minimize soft-tissue trauma and periosteal stripping.

Use of a computed tomography (CT) C-arm intraoperatively may increase the accuracy of articular reduction.

Arthroscopy may be used intraoperatively to aid visualization of the reduction. [2728]

Plating of the fibula is controversial (see Surgical Therapy below).

Initial Management

Prehospital care

Prehospital care depends on other associated injuries, but if an isolated lower limb fracture is suspected, the following steps are important:

  • Check for any neurovascular compromise
  • Correct any gross limb deformity
  • Elevate and support the limb in a temporary splint
  • Cover open fractures with sterile dressings
  • Apply local pressure to control any active bleeding
  • Administer pain-relieving medication

Emergency department care

Prehospital care is administered if not previously instituted.

Antibiotic prophylaxis includes cephalexin for mildly to moderately contaminated wounds, with the addition of an aminoglycoside for highly contaminated wounds. Administer vancomycin and gentamicin if the patient is allergic to penicillin.

Leave fracture blisters intact. Once ruptured, blisters are more likely to become contaminated by skin flora.

For open fractures, obtain a digital photograph for the record before sterile dressings are applied to help minimize the number of times the dressings are taken down before definitive debridement.

Tetanus immunization status should be checked. If the patient has not been immunized or if there is gross contamination, tetanus immunoglobulin should be administered.

Radiographs are obtained and consultations requested (see Consultations below).

Medical Therapy

Pain relief is necessary. Antibiotic prophylaxis is used for open fractures and for internal fixation. Conservative treatment may be indicated in undisplaced fractures, which can be managed with cast immobilization. Some method of prophylaxis for thromboembolic disease must be utilized; however, the optimal protocol is unknown. The method to be employed should be decided on and implemented through discussion with all involved providers. [29]

General Surgical Considerations

Timing of surgery

Poor timing is associated with poor outcomes. Soft tissues must be ready for the second insult dealt by surgery. [26]

The nature and timing of surgery are based on the following:

  • Duration elapsed from the time of injury
  • Condition of the soft tissues
  • Presence of any other additional injuries
  • Presence of open wound or vascular compromise

Open fractures necessitate urgent and thorough debridement. In the case of vascular injury or compromise, vascular surgery is needed to restore blood flow. If adequate soft-tissue cover cannot be achieved, plastic surgery is required.

Stabilization of fracture

Definitive surgery to restore the fragments and stabilize the fracture is delayed to allow soft tissues to recover from the traumatic injury. Adding surgical insult to already injured or compromised soft tissues leads to a higher incidence of wound complications and poor outcomes; therefore, surgical intervention is staged. [30313233]

Preliminary stabilization is usually achieved with an external fixator, with or without fixation of the fibular fracture. [34This is performed in the presence of soft-tissue swelling (see the image below). It helps with pain relief and in the resolution of soft-tissue swelling. It helps dressing changes and wound healing in open fractures. It prevents length-countering contractures in soft tissue, which can make subsequent surgery difficult.

External fixator stabilizing pilon fracture. SwellExternal fixator stabilizing pilon fracture. Swelling has resolved, and blisters have healed.

The aim is to maintain alignment, not necessarily at this stage itself, to accurately reduce the articular surface. When pin-site placement is considered, further surgery (eg, rotational flaps or incisions for ORIF) must be considered. Excessive distraction at the ankle joint is avoided because it can cause traction neuropathy and compartment syndrome.

Definitive surgery is undertaken when the condition of soft tissues is optimized. This is usually when the blisters have epithelized or healed and the skin is wrinkled. Many options for definitive surgery are available; these include the following [3536:

  • ORIF
  • External fixation (either spanning the ankle or not)
  • Limited internal fixation with external fixation
  • Percutaneous plating

Surgical Therapy

Preparation for surgery

Consent is essential and includes a fully informed discussion to explain the nature of the injury; the options, risks, and benefits; the need for bone grafting; the likely rehabilitation plan; the potential for amputation, either acutely or in the future; and the prognosis.

Careful and detailed planning of the procedure, based on findings from radiography and CT, is necessary to anticipate any difficulties and save time. Determine (1) the sequence and strategy for reducing and stabilizing the fragments and (2) the choice of implants and alternatives.

The surgery is performed on a radiolucent table with a fluoroscope and portable radiograph machine available. Antibiotic prophylaxis is administered at the time of anesthesia induction.

Positioning

The procedure is performed with the patient placed supine with a bump under the ipsilateral hip; this allows access to both sides of the ankle. The opposite leg heel is elevated to relieve pressure on the calf and prevent deep vein thrombosis. All bony prominences are padded.

A thigh tourniquet placed after elevation helps achieve exsanguination for a bloodless field. In addition to the extremity, the iliac crest area should be prepared and draped in a sterile fashion in case a bone graft is required.

Choice of surgical approach

The surgical approach depends on the fracture pattern, the method of stabilization, and the implant choice. Essentially, the aim is to restore the tibial articular surface and stabilize the articular block to the metaphysis in an anatomic alignment. Restoration of fibular length may aid in this process. [37]

Percutaneous or minimally invasive fixation

The articular fragments can be reduced by closed techniques or through minimally invasive methods by using Kirschner wires (K-wires) to "joystick" them into position. Once they are aligned, cannulated screws can be inserted under fluoroscopic guidance. This percutaneous technique, as described by Syed and Panchbhavi, can be used in minimally displaced fractures. [38An arthroscope may also be used for visual confirmation that reduction is satisfactory.

If a satisfactory reduction of the articular surface is obtained, the articular block can be stabilized to the metaphysis and held in acceptable anatomic alignment by means of external fixation. However, this method of percutaneous reduction and stabilization is not suitable for fractures with significant comminution or die-punched articular fragments; this would require open reduction (see the images below).

Soft-tissue trauma, with blister and area of pressSoft-tissue trauma, with blister and area of pressure necrosis over medial aspect of distal leg, in patient who presented 48 hours after injury.
Significantly displaced medial malleolar fragment Significantly displaced medial malleolar fragment responsible for area of pressure necrosis.
Lateral radiograph of pilon fracture. Lateral radiograph of pilon fracture.
Necrotic area is excised, and bead pouch covers woNecrotic area is excised, and bead pouch covers wound.
Wound on medial aspect of ankle after 8 days. Wound on medial aspect of ankle after 8 days.
Split skin grafting of wound. Split skin grafting of wound.
Pilon fracture stabilized by minimally invasive tePilon fracture stabilized by minimally invasive technique.
Pilon fracture stabilized with cannulated screws. Pilon fracture stabilized with cannulated screws.
Patient with full active plantarflexion at 2-year Patient with full active plantarflexion at 2-year follow-up after pilon fracture surgery.
Picture at 2-year follow-up after pilon fracture sPicture at 2-year follow-up after pilon fracture surgery showing full active dorsiflexion.
Patient at 2-year follow-up after pilon fracture sPatient at 2-year follow-up after pilon fracture surgery.

A cadaver study by Graves et al evaluated the use of lateral intraoperative fluoroscopy to assess reduction of the tibial plafond articular surface after malreductions were created by displacing a 5-mm osteochondral segment. [39Even on a perfectly lateral fluoroscopic image of the ankle, it was difficult to discern rotational or translational displacement of a 5-mm osteochondral fragment. Thus, even with what appears to be a perfect lateral fluoroscopic view intraoperatively, displacement may still be present. When small osteochondral fragments are present, direct visualization of the articular surface is necessary to confidently establish that an anatomic reduction has been achieved.

Open technique

The location and number of incisions for an open approach is best decided on the basis of the fracture pattern. However, most often, an anteromedial incision overlying the distal tibia just lateral to the tibial crest and following the tibialis anterior tendon provides adequate exposure for open reduction of the tibial articular fragments. Do not create skin flaps, but dissect down to the bone, staying medial to the tibialis anterior and in the fracture plane.

This incision is similar to the incision used in total ankle replacement, and, if reasonable restoration of the ankle is achieved and the ankle becomes arthritic at some point in the future, ankle replacement remains an option. Similarly, just as in total ankle replacement, avoid any tension on the skin. Place one or two deep retractors to open up the deep soft tissue for visualization, but take care to ensure that the retractors do not rest against or apply tension to the skin.

A pilon fracture with a large posterior fragment deserves special attention. Accurate reduction of the posterior fragment, especially the proximal displacement and rotation, can be difficult through anteriorly placed approaches. In such situations, a posteromedial approach between the posterior tibialis and flexor digitorum longus tendons or a posterolateral approach in between the peroneal and the Achilles tendon provides direct visualization not only for anatomic reduction but also for application of a posterior plate, which serves as a buttress.

Reduction of fracture fragments

The anterior lateral and medial fracture fragments are held apart to visualize the impacted central fragments and the posterior fragment. Sometimes, the posterior fragment must be derotated in the sagittal plane and held temporarily with K-wires. If any central fragments are impacted, they must be disimpacted, and the resulting cavity in the metaphysis is grafted with bone using an autogenous graft. This can be augmented with synthetic substances such as calcium sulfate, which will set fast and provide some immediate stability for the screw fixation. Then, the anterolateral fragment and medial fragment are restored and held temporarily with K-wires.

Internal fixation

Cannulated screws over washers can be inserted in the appropriate direction in a lag-screw fashion by using fluoroscopic guidance in different planes to assess proper placement across fracture planes and into intact bone. Once the articular block is adequately reduced, it is stabilized to the metaphysis.

Stability of both the medial and lateral columns is important to prevent a varus or valgus deformity. Also important is stability in the sagittal plane. Often, comminution is present in the anterior cortex of the distal tibial metaphysis and at the junction of the metaphysis and diaphysis. Collapse of the anterior column can result in recurvatum deformity.

Internal fixation, external fixation, or both can be used to provide stability to the medial, lateral, anterior, and posterior columns of the tibia. [4041The choice of fixation depends on the condition of the soft tissues and the experience of the surgeon. [42]

For internal fixation, a low-profile contoured plate can be introduced over the medial aspect of the tibia through the existing exposure and advanced percutaneously proximally into the metaphysis, thus limiting the soft-tissue stripping over the bone and limiting soft-tissue injury (see the images below). A smaller anterolateral tibial plate may also be necessary to reduce and hold the anterolateral column out to length.

Pilon fracture showing significant comminution andPilon fracture showing significant comminution and displacement.
Lateral radiograph of pilon fracture. Lateral radiograph of pilon fracture.
External fixator stabilizing pilon fracture. SwellExternal fixator stabilizing pilon fracture. Swelling has resolved, and blisters have healed.
External fixator maintaining improved alignment ofExternal fixator maintaining improved alignment of pilon fracture.
Alignment in lateral view of pilon fracture, stabiAlignment in lateral view of pilon fracture, stabilized in external fixator.
CT scan showing multiple fragments in articular doCT scan showing multiple fragments in articular dome of pilon fracture.
CT scan showing axial cut of pilon fracture. CT scan showing axial cut of pilon fracture.
Minimally invasive plating technique performed as Minimally invasive plating technique performed as second stage in treatment of pilon fracture.
Lateral view after minimally invasive plating of pLateral view after minimally invasive plating of pilon fracture.

A study by Yenna et al found that distal tibia extra-articular fractures stabilized with anterolateral or medial locking plate constructs demonstrated no statistically significant difference in biomechanical stiffness during compression and torsion testing in a saw-bone pilon fracture model. [43]

Locking contoured plates have threads within the screw holes that engage heads of screws to create a fixed-angle construct that improves fixation in osteopenic bone and multifragment fractures. They also have a broader distal end, providing more than a single hole along the width of the plate and thus providing additional purchase in the shorter distal cancellous metaphyseal fragment.

External fixation

An external fixator can also be used to stabilize and align the reconstructed articular block to the metaphysis. The fixator may span the ankle joint and incorporate the foot to give additional stability to the reconstruction, but this limits ankle movement.

A nonspanning fixator allows for early range of motion and cartilage nutrition, and it limits arthrofibrosis. A variety of external fixator frames are available, but a hybrid fixator is commonly used. [4445]

The wires used should be inserted carefully so as not to damage any tendons or neurovascular structures. [46Usually, one wire is passed through the articular block from posterolateral to anteromedial, starting just anterior to the fibula or through the fibula if the fibula is not plated. To avoid injury to peroneal tendons and the sural nerve, it should not be started posterior to the fibula. A second wire is passed in a posteromedial-to-anterolateral direction, starting in the posteromedial aspect of the tibia anterior to the neurovascular bundle.

The wires are placed parallel to and approximately 20 mm proximal to the ankle joint. Olive wires can be used to aid compression across fracture planes or to hold alignment. A ring is attached to the proximal aspect of these wires.

Two 5-mm half pins are inserted in the tibia proximal to the fracture in a sagittal plane. Carbon fiber rods link the half pins to the ring, and the attachments are tightened after reduction of any malalignment, which is checked using fluoroscopy and confirmed with plain radiography.

Fibular plating

Fibular fracture fixation is also important. It may be used to restore the length of the lateral column of the tibia indirectly via ligamentotaxis on the Chaput fragment anterolaterally and the Wagstaffe fragment posteriorly. It also provides additional strength to the entire reconstruction, especially if some screws are directed into the tibia and through the fibular plate. It helps to prevent valgus deformity. [47]

The incision to fix the fibula should be positioned slightly posterior to the lateral aspect in order to maximize the width of the skin bridge between this incision and the one on the tibia.

Problems can arise with the fibular plating. A straight or noncontoured plate can push the tibial articular fragment medially and can resist reduction.

Anatomic restoration of length, contour, and axial rotation of the fibula can be challenging in cases of severe comminution or segmentation of the fibula. Restoration of fibular length is difficult without plating the fibula. However, when an external fixator is used in such a way that it incorporates and distracts the talus, it can indirectly restore fibular length by applying traction on the fibula through the intact talofibular ligaments.

Also, some overall symmetrical shortening of both the tibia and fibula is acceptable. In fact, shortening is preferred if restoration of the leg length by just a few centimeters means a more extensive surgery with devitalization of fracture fragments.

Biz et al reported a retrospective, observational, case series study on medium-long-term radiographic and clinical outcomes after surgical treatment of intra-articular tibial pilon fractures by three different techniques. [48 In this study, 94 articular pilon fractures (34 type 43-B, 60 type 43-C) were evaluated with a mean follow-up of 56.34 months (range, 33-101) after either ORIF (n = 63 [67%]), MIPO (n = 17 [18.9%]), or EF (n = 14 [14.1%]).

According to Ovadia and Beals' criteria, good results were reported in 61 cases (64.89%), fair results in 26 (27.66%), and poor results in seven (7.45%). [48Mean AOFAS score was 82.41 for MIPO, 79.83 for ORIF, and 50.57 for EF. Early or late complications were noted in 39 patients (41.49%). Radiographic outcomes were inversely proportional to the fracture comminutions and were statistically different between internal and external osteosynthesis but comparable between ORIF and MIPO techniques. On the other hand, clinical outcomes were closely related to soft-tissue conditions and the anatomic reconstruction of the joint.

Wound closure

Meticulous soft-tissue handling is important throughout the surgery. The anterior joint capsule is closed, but the anterior tibial fascia is left open to prevent postoperative compartment syndrome.

Skin should be closed under no tension. The tibial wound is closed first. The preferred technique is an Allgöwer modification of the Donati stitch that uses nylon or polypropylene suture and that has the knots on the lateral flap of the tibial wound.

If necessary, the fibular wound can be left open and closed after a few days. Sterile dressings are used to cover incisions and wounds, but the pin sites for a frame are left open.

A well-padded, below-knee, posterior splint reinforced with two side splints is applied with the ankle held at 90°.

Postoperative Care

Vascularity and sensation in the toes is documented in the immediate postoperative period.

Postoperative analgesia is administered as required, usually with a patient-controlled device. Another alternative is the continuous popliteal block, which is also used for anesthesia at the time of surgery. Given that compartment syndrome is a clinical diagnosis, the role of regional anesthesia must be considered carefully; it may interfere with the ability to detect compartment syndrome.

The leg is kept elevated. Regular observations are made to ensure early detection of a compartment syndrome. Active exercises are encouraged, and antithrombotic measures are instituted as necessary.

Patients are discharged home when comfortable. They should not bear weight on the operated leg until advised to do so.

Complications

The rate of severe complications after ORIF of tibial plafond fractures ranges from 10% to 55%; some of these complications can lead to amputation. [726]

Soft-tissue complications include the following:

  • Wound dehiscence
  • Superficial skin necrosis at suture line
  • Full-thickness skin loss
  • Wound infection
  • Damage to superficial nerves, neuroma, hypersensitivity, or chronic regional pain syndrome

Bony complications include the following:

  • Pin-track infection
  • Avascular necrosis of fragments devitalized by injury or surgery
  • Malunion leading to deformities; these can be in single or multiple planes such as a varus, valgus, recurvatum, procurvatum, rotation, or shortening of the tibia and/or the fibula
  • Articular incongruity
  • Posttraumatic arthritis

Implant-related complications include the following:

  • Loosening
  • Failure or breakage of metal
  • Infection

Sommer et al performed a study aimed at defining parameters that could better assess the reduction quality and at investigating the influence of reduction quality on functional outcomes. [49Patients with unilateral pilon fracture of AO/OTA type 43-B or 43-C were consecutively recruited to the study and followed for 2 years after surgery. Postoperative radiographs of the injured and contralateral joints were evaluated and 13 radiologic parameters measured by two independent surgeons. The reliability of the measurements for each parameter was assessed by the Intraclass Correlation Coefficient (ICC), and four parameters with the highest ICC scores were deemed most reliable and were selected for further analysis.

Functional outcome was assessed by using the Foot and Ankle Ability Measure (FAAM) for daily living and sports activities. [49The four most reliable radiologic parameters, together with three possible baseline confounders (age, AO/OTA fracture type, and open vs closed injury), were subjected to both univariate and multivariate analysis for their association with the FAAM scores. Secondary outcome measures, including pain, ankle range of motion (ROM), quality of life (QoL), and adverse events, were also reported.

Length of the lateral malleolus (LLM), anterior distal tibia angle, anterior talar shift, and length of the medial malleolus had the highest reliability scores on ICC assessment (0.76, 0.72, 0.58, and 0.45, respectively). [49Only LLM exhibited a statistically significant association with the 2-year FAAM results. At 2-year follow-up, the injured joints achieved an average ROM of 70.7% as compared with the contralateral joints, and patients did not regain preinjury QoL overall. Multivariate analysis showed that LLM (independent of age, AO/OTA fracture type, and open vs closed injury) was a reliable indicator of reduction quality and a prognostic factor for patient outcome in pilon fracture surgery.

Consultations

Consult an orthopedist.

Consult a plastic surgeon when soft tissues are lost, compromising cover over exposed bone and/or tendons.

Consult a vascular surgeon. Blood flow to the foot may be compromised in the case of severe deformity. If it is not restored and/or if an open wound with vascular injury is present, angiography may be necessary along with involvement of the vascular surgeon.

Long-Term Monitoring

Pin-site care requires daily irrigation and regular removal of any crust to prevent pin-site infection.

The incision sites are inspected at 1 week, and sutures are removed when incisions have healed, in approximately 2 weeks. The temporary splint is changed to a cast at this stage.

Depending on the stability and type of fixation, ankle range-of-motion exercises are started as soon as feasible.

Fracture alignment and healing are checked with serial radiography.

Weightbearing is not commenced until plain radiography demonstrates evidence of bony healing.

In patients with preexisting peripheral neuropathy, such as patients with diabetes mellitus for more than 10 years, prolonged protection in a removable cast or a boot is necessary to prevent late displacement, refracture, or both.