1 Decision making and strategies I top
The choice of an early single-stage versus a multiple-stage surgical approach is based on the individual situation. In general, a staged protocol is used for the majority of high-energy pilon fractures.
Displaced fractures with minimal, closed soft-tissue injury
(Tscherne classification, closed fracture grade 0, rarely grade 1)
When soft-tissue condition is optimal, reconstruction may be achieved by a single-stage open procedure, embracing the classical four steps of Rüedi and Allgöwer: Reconstruction of a fractured fibula followed by reconstruction of the tibial joint surface. Use of autogenous cancellous or corticocancellous bone graft (if necessary) and support by a buttress plate.
Significantly displaced fractures and/or fractures with severe, closed soft-tissue injury
(Tscherne classification, closed fracture grade 2 or 3)
It is generally advisable to proceed in two or more stages:
1) First stage: Closed reduction, fibular reduction and
stabilization, and joint bridging external fixation. Accurate reduction and
stabilization of the fibula re-establishes its proper length, alignment and
rotation. This assists with proper positioning of the posterolateral
tibial articular fragment (from the attachment of the posterior tibiofibular
ligaments) and, in turn, with reduction of the talus relative to the tibial
shaft. With complex fibular fractures, it may be better not to fix the fibula
in the first stage.
Joint spanning external fixation should be remote from the fracture. External fixation pins should avoid the planned future surgical approaches including the neck of the talus.
2) Second stage: Definitive open reconstruction after 5-21 days. Definitive operative treatment of the articular surface should be delayed until the soft tissues have recovered sufficiently to allow definitive reconstruction. Return of skin wrinkles is a good sign of soft-tissue recovery.
Open pilon fractures
These are often very severe injuries that may require plastic surgery for soft-tissue reconstruction. The management includes several stages:
1) Emergency management: Wound debridement and lavage. Fibular stabilization and fixation (if needed and the soft tissues allow). Joint-bridging external fixation.
2) Second stage (within 48 - 72 hours): Soft-tissue coverage (local or free flap). Reconstruction of the tibial articular surface may be possible at the same time and should be considered if the exposure for flap coverage allows.
3) Third stage: Definitive stabilization between the articular segment (joint block) and tibial shaft by internal fixation (or external fixator) is typically delayed until soft-tissue recovery has occurred. However, this may be performed at the time of flap coverage in certain circumstances.
2 Decision making and strategies II topenlarge
The location and the extent of any associated central impaction will determine the optimal surgical approach. Additionally, the size of the anterolateral fragment will influence the surgical access through each approach.
If the medial extension of the anterolateral fragment is limited to the lateral half of the distal tibia, then an anterolateral approach is possible. If the anterolateral fragment extends to the medial malleolus, then an anteromedial approach may provide better access to the central impaction.
Open fractures - anteromedial or anterolateral approach?
For open fractures with the commonly observed associated transverse medial traumatic wound at the distal tibia (see illustration), an anterolateral surgical approach may be preferable to minimize additional dissection beneath the medial traumatized skin. Similarly, a distal tibial fracture with an associated lateral traumatic open wound may be best approached anteromedially. The anticipated incision(s) for ORIF should be considered during initial debridement and external fixation, even though definitive fixation is delayed until soft tissues recover.
Injury radiographic evaluation and its influence on approach and implants
The choice of implants is dependent on the associated metaphyseal comminution, the surgical approach, and the soft tissue envelope as previously described. The associated metaphyseal comminution should be considered and assessed on the injury radiographs. With bending fractures, comminution occurs on the side that fails in compression. Tension failure typically produces a simple transverse fracture plain.
For pilon fractures with a varus deformity, medial metaphyseal comminution is commonly observed and medial buttress plating with a stronger medial implant is necessary. An anteromedial approach is preferable for its application.
For pilon fractures with a valgus deformity, lateral metaphyseal comminution is commonly observed and the medial distal tibia typically fails in tension. In these patterns, lateral or anterolateral buttressing is optimal and medial fixation can be less strong.
Thus, for a pilon with significant initial valgus and lateral and/or anterolateral metaphyseal comminution, an anterolateral approach permits optimal placement of a buttress plate.
The use of locking plates
The choice of whether to use a locking implant is determined by the expected healing time, the surgical approach, and the need for additional compression at the articular surface at the time of reduction. In general, locking implants are unnecessary if plates are placed anterolaterally and medially. Fracture comminution may indicate the need for such supplementary plate fixation.
However, if the associated soft-tissue envelope contraindicates the use of supplementary plate fixation, use of an angular stable (locking) implant may help prevent late deformity and should be considered.
Use of locking plates may also improve stabilization of osteoporotic fractures. Another alternative is supplementary external fixation.
3 Application of a distractor topenlarge
Application of a distractor intraoperatively greatly assists with articular visualization. Additionally, the distractor helps to align several of the major articular fragments. We typically replace a temporary joint bridging external fixator with a distractor during definitive articular surface reduction and fixation.
To apply the distractor laterally, place a 4 mm Schanz pin transversely from lateral to medial into the talar neck, through the surgical incision. A second 4 mm Schanz pin is placed from lateral to medial into the tibial shaft, proximal to the intended plate. The distal pin, anterior to the axis of rotation of the talus, produces ankle joint distraction and plantarflexion, maximizing articular visualization. Place the threaded rod of the distractor posterolaterally, away from the incision.
The course of the anterior compartment neurovascular bundle, and also the superficial peroneal nerve, should be considered during pin placement. Thus the proximal pin should be placed in the anterior half of the tibia. It is important to use blunt dissection and the appropriate soft-tissue protection sleeves during pin placement.
4 Reduction of articular segments top
Articular comminution and impaction
There are multiple commonly observed articular injuries that increase the complexity of C3 pilon fractures. Particularly important are articular comminution and impaction. These processes may produce independent fragments of the articular surface which must be separately reduced and fixed as will be illustrated.
The following description shows reduction and fixation of a central impacted fragment through an anterolateral incision. Similar technique can be used to address such fragments through other approaches.
Cleaning the fracture site
Rotate the anterolateral fragment externally on the anterior tibiofibular ligamentous hinge to allow visualization of the remaining articular segments. The fracture can then be cleaned of early callus and hematoma.
Reduction of the centrally impacted segment
The centrally impacted segment can either be reduced to the posterolateral fragment prior to its reduction, or to the combined and reduced posterolateral and medial fragments.
For the former reduction sequence, the centrally impacted segment is temporarily stabilized to the posterolateral fragment with two small K-wires. If a large defect exists in the metaphysis above the centrally impacted segment, a bone graft can be placed following confirmation of an accurate reduction.
To allow the reduction to be completed, fixation of the central impacted segment must be out of the way of additional articular fragments. K-wires can be inserted from the periphery of the distal tibia or cut short at the fracture surface.
Derotation and preliminary fixation of the combined central and posterolateral fragment
The commonly observed dorsiflexion deformity of the posterolateral fragment must first be corrected.
Place two small (2.5mm) threaded pins or two K-wires directly into the exposed anterior cancellous surface of the posterolateral fragment. Use them as joysticks to correct the dorsiflexion and posterior translation of the posterolateral fragment.
Secure the posterolateral fragment with strategically placed 1.25 mm K-wires. They can be placed from either the anterior tibia into the posterolateral segment, …
…or from the fibula into the posterolateral segment,…
Reduction and preliminary fixation of the medial fragment
Control the medial fragment with small K-wires and manipulate it into position relative to the posterolateral fragment. In this step, the medial K-wires do not yet extend into the posterolateral fragment.
Alternatively, make two small stab incisions and place a large pointed Weber clamp from the posterolateral fragment to the medial fragment.
In order to engage the posterolateral fragment, a small incision is placed at the posterolateral border of the fibula. Dissection continues between the fibula and the peroneal tendons to allow access to the posterior tibia.
Stabilize the medial and posterolateral fragments with 1.25 mm K-wires inserted percutaneously, through the medial fragment and into the posterolateral fragment. These may be the K-wires used for fracture reduction that have been advanced. Place these wires such that they do not interfere with the more anterior reductions.
Stabilization of the central fragment is important to maintain. Wires through the medial fragment may be used to stabilize both major articular fragments. Adequate stability is necessary before removal of the anterior-to-posterior K-wires.
Reduction and preliminary fixation of the anterolateral fragment
Rotate the anterolateral fragment internally to complete the reduction of the pilon. This can be accomplished with dental picks and a large Weber clamp, placed from the posterolateral fragment to the anterolateral fragment. The anterolateral fragment reduction can be confirmed cortically at the junctions with the medial fragment and the intact tibia.
The reduction is confirmed at the articular surface using direct visualization.
Stabilize the reduction with additional 1.1 mm K-wires placed from the anterolateral fragment into the posterolateral segment. These wires will additionally stabilize the centrally impacted segment.
Following the reduction of the anterolateral segment, the articular surface is frequently malreduced. This must be corrected prior to placing any permanent fixation.
This usually requires re-displacement of the anterolateral fragment and correction of the sagittal plane rotational deformity of the combined posterolateral, centrally impacted, and medial segments.
This process is repeated over and over until the fracture is reduced. See also assessment of reduction.
5 Lag screw fixation topenlarge
Before plate fixation, small lag screws can be placed between the major articular fragments. Small cruciate head 2.4 mm cortical screws may be advantageous as they do not interfere with the anticipated plate placement. Special extra-long screws will be necessary. The K-wires can be removed if stable compression of the articular fragments is obtained.
Alternatively, leave the K-wires in place and proceed directly to plate application.
6 Plate fixation top
In C-type fractures, definitive internal fixation often includes lateral and medial plate fixation which span from the articular block to the tibial diaphysis. The distractor may need to be removed to allow plate placement. Additionally, plantarflexion of the foot is frequently necessary.
Options to consider include the number of plates as well as their stiffness, strength, and location. Comminuted areas and osteoporotic fractures may benefit from supplementary plates. If the fibula remains unstable, more stable tibial fixation may be advisable.
Choice of implant
The specific implant is less important than the reduction and the plate function. Non-locking buttressing implants can be used for the majority of pilon fractures. Angular stable fixation, using locking head screws, may avoid the need for a second plate and may reduce the need for bone grafting.
A precontoured L-shaped anterolateral plate (locking or not) may be the ideal implant for the anterolateral approach. If an anterolateral locking plate is used, an additional medial plate may not be necessary. However, if the anterolateral plate is no locking plate, an additional medial buttressing implant is often necessary.
Precontoured plates may often be used without adjustments. However, conventional straight plates must be contoured to fit the bone.
Application of the lateral plate
The plate is slid submuscularly along the lateral cortex of the tibia, deep to the anterior compartment musculature and neurovascular bundle, and anterior to the interosseous membrane.
If lag screws are in place and reduction is stable, the distractor can be removed prior to sliding in the lateral plate in order to facilitate plate placement. However, if the distractor is necessary to maintain length and alignment of the articular block, it may be advisable to leave the distractor in place during plate placement.
Care must be taken during plate placement to ensure that the plate is slid directly against the tibia to avoid damage to the neurovascular bundle.
Distal screw placement in lateral plate
Distally screws are placed from anterior to posterior engaging the major articular fragments. The lateral fluoroscopic image is used to ensure safe, extraarticular screw placements. The number and location of the distal screws is determined by the fracture pattern. Placed appropriately, they can help support central comminuted areas.
Proximal screw placement in lateral plate
Proximally a separate incision (4-6 cm in length) is placed 1 cm lateral to the tibial crest to allow plate adjustment and proximal screw placements.
Fixation of the medial side
Depending on the fracture configuration and location, medial fixation will consist of either
- subcutaneous medial buttress plating,
- or combinations thereof.
The medial plate can be slid subcutaneously through a small (2 cm) incision. The screws through the plate can be inserted through small stab incisions. An additional long surgical exposure of the medial tibia should be avoided.
Prior to closure, reduction and stability must be reconfirmed. See also assessment of reduction.
The joint arthrotomy is repaired. It is imperative that the extensor retinaculum is also repaired to prevent bowstringing of the extensor tendons. The skin is closed with interrupted 3-0 nilon sutures placed in a modified Allgöwer-Donati fashion (Dietz UA, Kuhfuss I, Debus ES, Thiede A (2006) Mario Donati and the vertical mattress suture of the skin. World J Surg; 30(2):141-148).
7 Pearl - Fixation of fractures with proximal extension topenlarge
Fractures with proximal diaphyseal extensions
In selected fracture patterns with a long oblique proximal extension of the posterior, or posterolateral articular fragment, early fixation of this fracture component may be advantageous. Early callus on the large fracture surface may hinder delayed reduction of such fragments.
Early fixation of such an articular fragment with long proximal extension, effectively converts a 43-C pattern into a 43-B pattern, simplifying the delayed articular reconstruction.
Plating the proximal extension
The CT-scan demonstrates where the fracture is located proximally on the posterior tibial surface. This area is exposed through a posteromedial approach. The fracture can be stabilized with lag screws, an antiglide plate, or combinations thereof.
In the illustrated case, fixation of the posterior fragment was performed acutely through a limited posteromedial approach at the time of initial bridging external fixation.
Definitive reconstruction of the articular surface is delayed until the soft tissues allow. The surgical approach and implants are determined based on the remaining fracture configuration.
In the illustrated case, definitive articular reconstruction of the anterior fractures was delayed for 16 days.