Tibial plateau fractures were originally termed a bumper fracture or fender fracture but only 25% of tibial plateau fractures result from impact with automobile bumpers.

Pathology

The most common mechanism of injury involves axial loading, e.g. fall from a significant height. In younger patients, the most common pattern of fracture is splitting, while in older, more osteoporotic patients, depression fractures typically are sustained.

Soft tissue injuries (e.g. to cruciate and collateral ligaments) occur in approximately 10% of patients.

Fractures of the lateral plateau are much more common than the medial plateau. To injure the medial plateau, a large amount of force is required; fractures of the medial plateau are usually seen in conjunction with fractures of the lateral plateau and other bones around the knee joint.

The fracture pattern will depend on the mechanism of injury. The Schatzker classification is a useful classification to categorize the mechanism of injury ¹:

• Schatzker I: wedge-shaped lateral plateau fracture

  • valgus force with axial loading (femoral condyle rams the tibial plateau)

• Schatzker II: wedge-shaped lateral plateau fracture with compression fracture of ipsilateral plateau

  • valgus force (moderate association with medial collateral ligament and medial meniscus injury)

• Schatzker III: compression fracture of the lateral plateau

  • axial force

• Schatzker IV: medial plateau fracture with a split or compressed portion

  • varus force with axial load

• Schatzker V: wedge fracture of both plateaus 

  • complex high energy mechanism involving varus OR valgus forces with significant axial loading

• Schatzker VI: transverse tibial metadiaphyseal fracture, along with any type of tibial plateau fracture

  • complex high energy mechanism involving varus OR valgus forces with significant axial loading

Radiographic features

Tibial plateau fractures are complex injuries that require adequate imaging to assess prior to fixation. 

Plain radiograph

Plain radiography often underestimates the severity of the injury. Lipohemarthrosis should be present. 

CT

CT is very helpful in accurately defining the extent of the bony injury and facilitates orthopedic intervention.

MRI

MRI is very helpful in the assessment of soft tissue injury around the joint.

Treatment and prognosis

The goal of therapy is to reduce the fracture and begin early mobilization. If the patient is immobilized for a lengthy period (>3 weeks), the joint will not return to the full range of movement.

Depression of a tibial plateau that is inadequately corrected results in a varus or valgus deformity and accelerated osteoarthritis.

Unappreciated ligamentous injury causes greater than normal stress on the remaining support structures of the joint, malalignment, and the development of premature osteoarthritis.