ORIF - Conventional plating

Split depressed partial articular fractures of the medial plateau are uncommon. These injuries are often secondary to high-energy forces and represent a fracture-dislocation variant. Varus or varus hyper extension mechanisms are typically implicated. Meniscal tears, articular incongruity, malalignment, condylar widening, knee joint instability, and posterolateral corner injuries are all indications for surgical management. Significant soft-tissue injury is very common with these injury patterns. Compartment syndrome, and vascular and nerve injuries (peroneal) must be expected, monitored and ruled out.

In order to illustrate the difficulties that may be encountered, we have included a full discussion under the respective sections.

Main steps in treatment include the following:

1. Temporary reduction and immobilization until definitive surgery (eg, external fixator) typically dictated by resolution of soft-tissue injury
2. Adequate preoperative planning (need for bone graft, approach(es), number and type of implants, sequence of reduction and fixation, additional equipment)
3. Medial sub-meniscular arthrotomy and joint distraction allow articular visualization and reduction
4. Anatomical reduction of the articular surface with disimpaction of fracture fragments
5. Bone grafting of the epiphyseal/metaphyseal defect once the fragments are disimpacted and the articular component elevated
6. Definitive stable fixation performed with the buttress screw plate technique

Posterolateral corner repair and/or fibular head fixation may be indicated. Primary repair of cruciate ligament avulsions should also be considered. Acute, subacute, or delayed ligament reconstruction or augmentation may be required.

Surgery should be delayed until full recovery of soft tissues (swelling, blisters, abrasions, etc). This usually takes 3–10 days.

Until surgery, length of the leg should be maintained (Skeletal traction or joint spanning external fixation).

Plate location should allow for a raft of screws to be placed immediately below the elevated articular fragments. The plate length should travel distal to the exit point of the split fragment to reliably prevent caudal displacement of the medial epiphyseal (split) fragment. The plate location is typically anteromedial or straight medial.

The following complications should be checked for during surgery:

• Articular malreduction
• Alignment malreduction
• Intra-articular hardware
• Prominent fixation
• Vascular and nerve injury and compartment syndrome

The patient is placed in the Supine position.

• Supine position

A tourniquet is helpful in most cases. Whether a tourniquet is used depends on the amount of bleeding. Exsanguinate the limb by elevating it.

To allow for intraoperative radiographic control of reduction and fixation, the use of a radiolucent table is mandatory.

The vast majority of subarticular and metaphyseal bone defects are currently filled with morcellized cancellous allograft and/or bone graft substitutes. These should be available during the procedure. Autologous bone graft is rarely utilized.

A medial or anteromedial approach is used for the vast majority of cases.

• Medial/posteromedial approach

Contralateral imaging of the other knee will help determine the final height of the articular surface and frontal and sagittal plane alignment.

The injured knee should be examined under anesthesia, and a sense of frontal and sagittal plane instability should be identified.

Ligamentotaxis will not reduce depressed articular fracture fragments. Direct elevation, with the use of bone tamps and dental picks, is required.

The medial articular and cortical surfaces are exposed. Cleansing of the cancellous surface hematoma and clearing periosteum from the cortical surface of the split fracture fragment margins is performed. The medial cortex is reduced using cortical interdigitations as a guide for an accurate reduction. The split fracture is now stabilized with K-wires and clamps. Reduction of the depressed medial articular surface now requires careful joint visualization. Knee flexion is used, often with a medially-based femoral distractor is used and careful distraction is then applied. A sub-meniscal arthrotomy is performed anterior to the superficial medial collateral ligament once the joint has been distracted. At this point the medial meniscus should be identified and found to be attached to the peripheral capsule. It is not uncommon for the peripheral meniscus, however, to be partially or completely detached from the capsule anteriorly. Intrameniscal tears may also be identified.

A cortical window is then created through the reduced split fragment, and a bone tamp is used to elevate the depressed articular fragments. Accurate reduction is identified with direct visualization and radiographic confirmation.

Subchondral K-wires are used to maintain the reduction, and the bone defect is grafted

The split fragment and articular reductions may be compressed by adjusting the clamp. Anatomic articular reduction is prioritized over the cortical interdigitations. Accurate reduction is confirmed radiographically, and with direct visualization. At this point, confirm the frontal and sagittal plane alignment is restored.

The medial column is stabilized with traditional buttress plate fixation. Plate length should allow for adequate fixation distal to the exit point of the split fragment. Periarticular plates contoured to the proximal medial tibial plateau are the preferred implant. Fixation begins in the metadiaphyseal region immediately distal to the exit point of the split component. This traps the split component, resisting its distal displacement. Fixation then proceeds proximally, with the use of lag screws through the plate to compress the split fragment to the remaining proximal tibia. Conventional screw-plate devices will compress the plate to the medial or anteromedial cortex and create interfragmentary compression. A raft of screws from medial to lateral through the proximal portion of the plate will function to support the elevated medial articular surface. Care should be taken to ensure that the plate is placed proximally enough to allow the proximal screws to support the elevated articular surface. It is imperative to correct the frontal and sagittal plane alignment as this will be critical for maintaining knee stability.

Once osteosynthesis is completed, make a final check with the image intensifier. If all is well, remove the femoral distractor or external fixator. The knee should then be placed through a full range of motion to ensure fracture stability, and frontal and sagittal plane stability must be reexamined. At this point significant varus instability and/or hyperextension may be identified. Posterolateral corner repair/reconstruction, acute or staged, should be considered in these situations.

More information is provided here.

In situations with meniscal disruption from the capsule the meniscus can be repaired back to the capsule using absorbable mattress sutures. The submeniscal arthrotomy is then closed, ideally with a watertight closure. In situations where the capsule is deficient from the medial proximal tibia the capsulotomy can be repaired to the proximal portion of the medial plate.

In some situations, the fracture line is extremely lateral, with impaction of the lateral plateau articular surface. This may require a separate anterolateral approach and joint distraction with a femoral distractor, with elevation and provisional stabilization, before addressing the medial fragment.

The wound is closed in layers.

Close monitoring of the tibial compartments should be carried out, especially during the first 48 hours after injury and again after surgery to rule out compartment syndrome. More information is provided here:

• Compartment syndrome

The neurovascular status of the extremity must be carefully monitored. Impaired blood supply or developing neurological loss must be investigated as an emergency and dealt with expediently.

Oral or subcutaneous administration of DVT prophylaxis for six weeks should be strongly considered.

Optimal stability should be achieved at the time of surgery, in order to allow early range of motion exercises. Unless there are other injuries or complications, mobilization may be performed on post OP day 1. If available, continuous passive motion (CPM) splints can be very helpful in the early phase of rehabilitation. Static quadriceps exercises with passive range of motion of the knee should be encouraged. Afterwards special emphasis should be given to active knee and ankle movement.

The goal is to achieve as full range of motion as possible within the first 4–6 weeks.

Weight-of-leg weight bearing is initiated depending on patient comfort. Depending on the severity of the articular displacement, weight bearing can begin as early as 6 weeks postoperatively. In situations where articular displacement was significant weight bearing should be delayed for 10–12 weeks.

Wound healing should be assessed within the first two weeks. Subsequently, a 6- and 12-week follow-up with radiographic assessment is usually performed. If a delayed union is recognized, further surgical care may be necessary and should be carried out as soon as possible. Residual knee instability may require delayed reconstruction.

Implant removal is not mandatory and should be discussed with the patient.