1 Single-stage or multiple-stage surgery? top
Total articular fractures (C-type) require anatomical reduction and stable fixation of the articular surface. Usually, this requires direct reduction of the joint fragments, but indirect reduction and less invasive fixation may be more appropriate for the metaphyseal region. Totally minimally invasive fixation may rarely be indicated when the joint surface fracture is nondisplaced, and perhaps very simple fractures that can be reduced percutaneously and assessed completely reliably with x-ray control.
Most C1 fractures are more accurately reduced through a limited open surgical approach. This involves direct exposure of the joint and minimal extension proximally for plate insertion.
The severity of soft-tissue injury will dictate the choice of timing: early single-stage, or initial provisional fixation and delayed definitive repair. The decision is based on the individual situation and not necessarily on general principles.
Displaced fractures with minimal closed soft-tissue injury
(Tscherne classification, closed fracture grade 0, rarely grade 1)
Reconstruction may be done with a single-stage procedure, similar to the proposals of Rüedi and Allgöwer. This involves complete restoration of the ankle mortise including fibula and tibia. This may require bone grafting and usually a buttress plate. The goal is absolute stability of the joint surface, to permit early motion and achieve healing with anatomical alignment. Assuming a truly minimal soft-tissue injury, the complete reconstruction can be done as soon as preparations are complete.
Grossly displaced fractures and / or fractures with moderate to severe closed soft-tissue injury
(Tscherne classification, closed fracture grade 2 or 3)
To avoid wound healing problems, it is generally advisable to proceed in two or more stages: Closed reduction and joint bridging external fixation in a first stage. After 5-10 days (“skin wrinkling sign”) definitive open reconstruction, respecting the soft tissues, can safely be carried out.
Open pilon fractures
These are very severe injuries often requiring plastic surgery for soft-tissue reconstruction. The management includes the following stages:
1. Emergency management: Wound debridement and lavage. Joint-bridging external fixation. Fibular fixation may also be considered, but rarely adds benefit and may require another incision through badly injured tissue. Open wound management with occlusive dressing (possible antibiotic bead pouch or vacuum dressing)
2. At 48 hours: Second look with repeated lavage (re-dislocation of fracture/joint!) and re-debridement if necessary. Reconstruction of the tibial articular block. Soft-tissue coverage (local or free flap), if possible. Significant delay of coverage increases infection risk.
3. Definitive stabilization: Bridging of the metaphyseal comminution, with or without bone graft. Depending on the individual situation, definitive stabilization with internal or external fixation may be performed together with early soft-tissue closure, or preferably later.
Image shows second look at 48 hours with redislocation of the fracture/joint and repeated lavage at second look operation.
2 Fibula or tibia first? top
The ankle joint involves the tibial-fibular mortise and talus. If the fibula is not properly attached to the tibia, the joint will not be congruent. If there is a fibular fracture, it usually must be repaired. The surgeon must choose whether to do it first or later.
Simple fracture of the fibula
If the fibular fracture is simple, this fracture is fixed as a first step by open reduction and stable plate fixation. This indirectly reduces attached lateral fragments of the tibial articular surface through the usually intact syndesmotic ligaments. ORIF of the articular surface of the tibia and stable meta-diaphyseal fixation then follow.
Complex fibular fracture
Comminuted fibular fractures (a) are difficult to reduce accurately. In such cases it is usually better to reconstruct the tibia first, and use the tibia and talus as guides for positioning the lateral malleolus, if necessary. This usually reduces the fibular fracture indirectly. Since the syndesmotic ligaments are usually intact, gross realignment of the fibula often occurs as the tibia is reduced (b).
The comminuted fibular fracture can often be stabilized with a subcutaneous plate, without exposing the fragments (c) using a long bridging plate (d). It is essential to achieve correct length, rotation, and axial alignment of the fibula.
3 Planning of reduction and fixation top
Preoperative planning is an essential part of the treatment of all distal tibial fractures:
- Obtain good AP and lateral x-rays of both injured and uninjured side; CT if needed
- Careful study of the x-rays and CT scan
- Trace AP and lateral x-rays of normal side
- Identify the individual fracture fragments
- Draw the fracture fragments, reduced, onto the normal tracing
- Consider reduction techniques
- Choose and draw in fixation implants
- Choice of surgical approach
- Prepare list of operative steps
Depending on the location of the articular part of a C1 type fracture, an anteromedial or anterolateral approach is required. The approach may be limited, but sufficient exposure is necessary for direct articular fracture reduction. Plate insertion proximally can be minimally invasive.
Interfragmentary compression with lag screws is the basic technique for reconstruction of articular surface fractures. For C-type fractures, a plate is usually selected to connect the joint surface to the tibial shaft. The preoperative plan should include strategically placed lag screws that do not interfere with the planned plate construct.
Additional interfragmentary lag screws can be placed through the distal holes in the plate. To make this possible, the exact position of the plate must be determined during preoperative planning.
The shape and location of the plate are important for metaphyseal reduction and must be planned preoperatively.
Choice of implant
A variety of precontoured distal tibial plates are available. They usually need slight adjustment of contouring. It is important that the plate be contoured properly before insertion. Longer implants improve load distribution and stability. Only a small number of screws will be needed in the tibial shaft.
A locking or conventional plate can be used. The bone quality, fracture pattern, and length of the distal segment will be the primary determinants. The cost and availability of angular stable fixation and anatomically precontoured plates must also be considered. Well-planned use of conventional fixation remains a reasonable alternative to locking plates in most if not all situations.
4 Reduction and stabilization of the articular segment topenlarge
First the articular segment must be reduced anatomically and either provisionally or definitively stabilized. This can be accomplished with a pointed reduction clamp, K-wires, independent lag screws, or combinations thereof. In the illustration, the articular segment is reduced through a limited anteromedial incision which is also used to place two 3.5 mm cortex screws as lag screws for its fixation.
Applying a distractor may aid the reduction and visualization. Where possible, it should be positioned on the medial side of the leg. Schanz screws are positioned in safe zones of the tibial shaft and talar neck (or the calcaneal tuberosity). In case of previously applied joint-bridging fixator, the already existing Schanz screws can be used. Its tension may need to be adjusted during the procedure.
5 Metaphyseal reduction - First step topenlarge
Adjusting distractor tension
Once the articular block is reconstructed satisfactorily, it must be reduced to the diaphysis. This is done indirectly with fluoroscopic control through manipulation, distraction and plate application. Begin by adjusting the distractor tension for the best alignment. Confirm that rotation and axis alignment (AP and lateral) are satisfactory.
6 Plate insertion top
It is possible to bend a plate before surgery so that it fits satisfactorily on a plastic model. However, it usually will not fit the patient perfectly without further contouring. Important features of the medial distal tibia are its medial concavity, greatest over the metaphysis, and relative external rotation from distal to proximal.
First, make a tunnel for the plate with a blunt instrument, close to the bone.
Next, insert the contoured plate. The anteromedial subcutaneous tibial surface is a typical plate location, but the overlying tissues must be healthy enough to tolerate the procedure.
Before definitive fixation, it is important to confirm that the plate is long enough, and that it is contoured and aligned correctly.
7 Confirm plate position topenlarge
Make a small incision at the proximal end of the plate. This should be well outside the fracture zone, if the plate is long enough. Such an incision is a helpful guide for correct plate positioning. A threaded drill sleeve in the most proximal hole of the plate is a good handle.
Confirm plate position
K-wires can be temporarily placed through screw holes to hold the plate position during fluoroscopy. Using a drill sleeve increases the wire’s stability.
The goal is to position the plate so that bringing it against the bone completes the fracture reduction.
Fluoroscopic assessment of the plate position and reduction requires care, and often several views.
8 Completion of metaphyseal reduction topenlarge
Reduction of the metaphyseal fragment
With the implant positioned correctly, a cortex screw placed at the distal end of the diaphyseal segment should pull the plate to the bone as it is tightened, thus completing the metaphyseal reduction. This assumes correct plate contouring.
Strategic placement of the cortex screw near the fracture - so that positioning the plate recreates the tibial cortical outline - makes the plate act as a reducing tool.
The distractor may need to be adjusted, and manipulation may be needed as well to achieve the desired reduction.
It is important to ensure that the plate is centered on the medial surface of the tibia, so that screws are not too anterior or posterior. Check this with a lateral x-ray. Eccentric screws, particularly if locking head variety, may not provide adequate fixation.
Pitfall - reduction screw compromises insertion of screws for articular fixation
Remember not to place the initial plate reduction screw so that it compromises the insertion of compression screws for articular fixation.
9 Fixation of the distal segment topenlarge
Now the plate can be attached to the distal segment.
This could be done with lag screws or fully threaded cortex or locking head screws. If the articular split needs additional support, use lag screws placed through the plate. Otherwise, the screws serve primarily to anchor the plate and lagging is not necessary. Angular stable fixation provides better stability in osteoporotic bone. In the illustration, cortex screws have been used.
Reduction of the joint should always be confirmed with image intensification or x-rays. See also assessment of reduction.
Pearl - fixation of the distal segment without independent lag screws
As an alternative to placing independent lag screws initially, the articular reduction can be maintained with a pointed reduction clamp, and perhaps K-wires, during manipulation of the distal metaphyseal fracture.
If this strategy is used, the distal plate screws must be lag screws to compress the articular surface.
10 Finish plate fixation topenlarge
Additional screws are now added to obtain the desired stability. Their number and position depends on the individual fracture pattern. At least three screws should be inserted in the diaphyseal segment. Stability is increased with longer plates. It is not necessary to put a screw in every hole.
To enhance stability in certain fracture patterns (eg, oblique or spiral), an additional lag screw can be placed through the plate to compress a non-comminuted metaphyseal fracture. Lag screws should be placed before locking head screws.
Depending upon the bone quality, plate length and fracture stability, conventional or locking head screws are used in the other locations.
X-ray imaging at the end of the operation confirms anatomical restoration of length, alignment and rotation. See also assessment of reduction.