ORIF - Conventional plating

Split partial articular fractures of the medial plateau are uncommon. These injuries are often secondary to high-energy forces and represent a fracture-dislocation variant. 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 common with these injury patterns. Compartment syndrome, and vascular and nerve injuries (peroneal) have a significant association.

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), MRI may further elucidate the soft-tissue injury
3. Centro-medial impaction of the lateral plateau may be identified
4. Definitive stable fixation is performed with the buttress screw plate technique

Posterolateral corner repair and/or fibular head fixation may be considered. Primary repair of cruciate ligament avulsions may 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 (eg, external fixator, traction, etc).

Ideally the plate is applied to the apex of the split medial fragment along the medial or posteromedial aspect of the proximal tibia. 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. A stiff medial proximal tibial periarticular plate is preferred.

The following complications should be checked for during surgery:

• Articular malreduction
• Alignment malreduction
• Intraarticular hardware
• Prominent fixation
• Vascular and nerve injury and compartment syndrome

In the majority of cases the patient is placed in the Supine position.

In some instances, the apex of the split component is located posteriorly where the medial condyle fails as a posterior shear mechanism. In these situations, a Prone position may be preferred.

• Supine position
• Prone 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.

A medial or posteromedial 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 improve the reduction, but direct fragment visualization and direct reduction is often required to complete the reduction.

The intraarticular exit point of the fracture plane may occur through the medial articular surface, within the tibial eminence area, or most commonly, through the medial part of the lateral tibial plateau. 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 medial articular surface, if involved, may require joint visualization. Typically, pure split fragments can be radiographically assessed satisfactorily, without direct visualization.

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 if necessary, with direct visualization.

Subchondral K-wires are used to maintain the reduction. At this point, the articular surface should be reduced and the frontal and sagittal plane alignment 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 should be considered in these situations. Further information on this can be found in this treatment.

Despite being a medial-sided injury, significant lateral soft-tissue injury may occur, including to the lateral meniscus. This may be identified with the use of an MRI, or with a lateral joint arthrotomy.

In situations with lateral 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.

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.