How to perform a tibial plateau fracture - lateral locking plate technique

Advancing to the Bone Surface

The aim is to achieve safe and effective exposure of the condylar fracture site and facilitate intra-articular access.

1. Locate the proximal part of the tibialis anterior muscle.

2. Detach the tibialis anterior muscle from the tibia from the anterior side to expose the anterolateral surface of the tibia. The detachment is done anteriorly to prevent damage to the deep peroneal nerve that runs posterior to the muscle.
   Avoid detaching the muscle too far posteriorly along the tibia, as in this region the anterior tibial artery traverses through the interosseous membrane. Additionally, be cautious not to place a retractor under the tibialis anterior muscle to prevent damage to the anterior tibial artery.

3. Continue detaching the tibialis anterior muscle distally enough for sufficient evaluation and reduction of the fracture distally.

4. Adjust the retractor to get better visualization of the fracture site and the joint line for the arthrotomy.

Exposing the Articular Surface

The goal is to achieve proper visualization and assessment of the intra-articular aspects of the tibial plateau fracture in addition to identifying common associated injuries, such as meniscal tears or detachment.

1. Palpate the joint line and make a transverse capsular incision just above the proximal tibia, below the lateral meniscus.
   The arthrotomy should not extend too posteriorly to avoid damaging the popliteal tendon.

2. Mobilize the capsule below the meniscus anteriorly and posteriorly.

3. To achieve visibility of the intra-articular surface, elevate the meniscus by placing 2-3 holding sutures on the meniscus. Do not take the bites too posteriorly to avoid damaging the popliteus tendon.

4. Pull the capsule proximally and examine whether the meniscus is detached from the capsule. If so, the meniscus needs to be attached to the capsule during closure.

5. The assistant turns the knee to the varus position while the sutures are pulled proximally. This exposes the articular surface.
   The posterolateral surface is usually hardest to visualize but can be assessed with a dissector.

Reduction of the Fracture

The aim is to restore the normal anatomy of the tibial plateau by repositioning the displaced bone fragments and elevating the depressed segment.

1. In case of an articular surface depression, the depression should be elevated to its anatomical position. This can often be achieved by opening a longitudinal fracture line like a book, and then using, for example, an elevator to reduce the fragments back to their anatomical position.
   If there is residual bone deficit after elevation of the articular surface depression, the empty space can be filled with autogenic or allogenic bone graft or artificial bone.

2. When the articular surface appears flush inside the joint, the reduction can be secured temporarily in place with horizontal K-wires under the articular surface.

3. Reduce the longitudinal fracture line under visual control using condyle reduction forceps, for example.

4. Confirm the reduction with fluoroscopy. The articular surface should be even in AP and lateral views. K-wires should be positioned just under the articular surface. Also, the possible longitudinal fracture line should be aligned in its anatomical position.

Placement of the Locking Plate

The goal is to accurately position the lateral locking plate on the tibia, ensuring the screw holes are correctly aligned for optimal fixation. The plate is designed to restore the anatomy and provide angular stability.

1. Place the locking plate on the tibial surface underneath the tibialis anterior muscle. Make sure that the plate is long enough to extend distally past the fracture line.

2. The plate should be positioned so that the locking screws in the proximal row can be directed under the depressed area of the articular surface. The initial K-wires can be drilled deeper, piercing through the medial side, if they get in the way of placing the locking plate.

3. Fix the plate temporarily in place with a K-wire and forceps.

4. Verify correct placement with fluoroscopy. In the AP view, ensure the locking plate sits nicely on the tibial surface for stability. The proximal part of the plate should be just below the articular surface, providing support but without risking penetration by the proximal screws.
   On the lateral view, the plate should be placed in the midline of the tibia so that the distal screws can be placed securely. Adjust the plate, if necessary.

Plate Fixation

The aim is to secure the plate and the repositioned bone fragments. The screws, inserted below the articular surface, should be of appropriate length and correctly oriented to provide optimal support and stability, and to avoid complications such as intra-articular screw penetration.

1. Depending on the fracture morphology and bone quality, the plate can be initially secured with a cortical screw in the metaphysis-diaphysis area, followed by the locking screws. Alternatively, use only locking screws, starting from the proximal end. If the proximal screws are already in place, do not use a cortical screw, since this can dislocate the fracture.

2. Drill a hole for the screw. Depending on the fracture, the screws should ideally extend to the medial condyle or the medial cortex, but not beyond. Be careful not to drill through the articular surface. To ensure correct orientation of the proximal screws, drill parallel to the K-wires.

3. Measure the length and insert the screw. Manually tighten all screws to avoid damage to the interface between the screw head and the plate.

4. After inserting two proximal screws to provide stability and reduce the risk of rotational instability, place a distal screw.

5. If there is any doubt whether the reduction is still in place, it is advisable to verify the reduction with fluoroscopy.

6. Insert the rest of the screws in place. Depending on the fracture type, aim for a minimum of four screws in the proximal part, with three out of four in the most proximal row, to prevent depression of the articular surface. The second most proximal row should be used without hesitation, especially in cases of osteoporosis. Distal to the fracture line, aim for 3-4 screws to ensure a reliable hold.

7. The distal screws can be inserted with an external drill guide. If this is not available, the distal screws might need a separate skin incision. Fluoroscopy can be used to determine the incision site. If there is risk of compartment syndrome, the initial fascial incision should be extended distally. Carefully expose the plate under the tibialis anterior muscle with a rasp and insert the screws.

8. Verify the fixation with fluoroscopy after all screws are in place. In the AP images, ensure that the articular surface is flush and that the proximal screws do not pierce the articular surface. All screws should extend to the medial cortex to provide optimal fixation. The distal four screws should be placed distal to the fracture.
   In the lateral view, the plate should be placed between the cortices, and the articular surface should be even, with its anatomical aspects restored. This includes the appearance of the medial and lateral condylar surfaces and the tibial slope.

Closure

1. Remove the meniscal holding sutures. If there is a vertical tear in the meniscus, it should be sutured with, for example, PDS No. 0 using the inside-out meniscal repair technique.

2. Attach the joint capsule through the plate holes with Vicryl No. 0, for example.

3. Close the fascia over the proximal plate, using No. 0 Vicryl, for example. The fascia should be closed at least to cover the joint line and the proximal part of the plate to provide a protective layer over the plate. Distally, the plate is covered by the muscle layer.
   Evaluate the risk of compartment syndrome. If the anterior compartment of the leg shows no significant tension or swelling, the fascia can be closed over the muscle area. However, in cases of noticeable swelling and potential compartment syndrome, leave the fascia open over the muscle area. If needed, the fascia can be further opened distally.

4. The subcutis is closed using continuous sutures with 2-0 Vicryl, for example.

5. The skin is closed using single or continuous sutures or with skin staples.

Assessing the Stability of the Knee

The goal is to examine if there are any ligament injuries associated with the proximal tibial fracture which can be difficult to repair during the primary operation but should be identified.

This includes checking the knee's range of motion and testing the integrity of the medial and lateral collateral ligaments, as well as the anterior and posterior cruciate ligaments. Stable endpoints during these tests indicate intact ligaments.