Tibial plateau fractures are serious injuries involving the articular portion of the proximal tibia and the proximal tibial metaphysis. They account for 1% of all fractures and up to 8% of fractures found in the elderly. As is often the case, the occurrence of tibial plateau fractures follows a typical bimodal demographic distribution: there is a peak of high-energy injuries among young, active patients and a secondary peak of low-energy injuries seen in the elderly. Just as the surgical management of these injuries will change based on the nature of the injury and the amount of energy involved in the fracture, the rehabilitation protocol must also be tailored to the patient’s age and activity level.

The history of the injury itself can be helpful in determining surgical plans for repair and for determining the best plans for maximizing the patient’s postoperative functional recovery. Historically, these injuries can largely be grouped into three types. First, there are low-energy falls in patients with osteoporosis, which typically cause lateral tibial plateau fractures. Second, younger patients can incur these fractures from either sports or falls. These types of fractures also tend to involve isolated portions of the tibial plateau, either laterally or medially; the prognosis with these types of fractures for functional recovery is quite good. Third, high-energy mechanisms such as major motor vehicle accidents, serious falls, or injuries occurring at high speed will cause the most serious problems and have the poorest outcomes. Knee fracture-dislocations, such as from logging accidents or motorcycle injuries, can be devastating and cause permanent loss of mobility and function.

The classification system used by surgeons for many years to describe these injuries was first proposed by Schatzker et al in 1979. This classification system is important because many surgeons use it to guide their operative interventions. While the system describes six characteristic fracture patterns, it is useful to understand that the fractures occur in this fashion largely based on the osseous anatomy of the tibial plateau. The lateral portion of the tibia is higher than the medial; as such, the lateral plateau forms an angle of 3° varus in regards to the tibial shaft. Furthermore, the lateral plateau is smaller and convex compared to the medial plateau, which is larger and concave. The shape of the plateaus, then, favors the medial portion of the tibia, which, in turn, bears 60% of the physiologic load. This asymmetric distribution of weight results in the medial portion of the tibia forming stronger, denser bone. As such, it requires less energy to fracture the lateral plateau, which often fails before the medial side; thus, low-energy mechanisms predispose to lateral plateau fractures. Since older patients are more likely to have osteoporosis, lateral plateau fractures are more commonly found in that demographic. Involvement of the medial side is more common in younger patients, while involvement of both the medial and lateral plateau requires a far greater amount of energy. Statistically, the majority of plateau fractures occur in the lateral side. Between 10% to 23% of fractures are isolated medial plateau injuries, and only 10% to 30% are bicondylar fractures.

More specifically, the Shatzker system describes six general patterns of fractures (Figure 74.1). While there is clearly overlap among the pattern of injury that cause the bone to fracture into any one of these general categories, most injuries occur in a fairly characteristic manner. Specifically, low-energy falls in the elderly would generally result in a Shatzker type II or Shatzker type III injury. While many younger, active patients may sustain Shatzker type II fractures, the vast majority of Shatzker types I and IV injuries occur in young patients with good bone quality. Last, Shatzker types V and VI fractures are usually a result of high-energy injuries, with potentially dramatic disruption of both the bone and associated soft-tissue structures.

While injuries to ligaments and menisci also commonly occur in conjunction with tibial plateau fractures, treatment of the fracture generally takes precedence. The complications resulting from the fracture itself or poor recovery from such a fracture are often more significant impediments to the patient’s recovery than any concomitant ligament or soft-tissue injury. Ligamentous injuries can occur in almost 30% of tibial plateau fractures, and meniscal tears occur in as much as 50% of these injuries. As the energy level of the mechanism of injury increases or the bone quality decreases, there is a greater likelihood of bicondylar fractures or fractures involving the tibial spines and potentially the cruciate ligaments. When ligamentous injuries to the knee occur in isolation, much of the treatment is directed toward addressing the instability caused by their loss. When such injuries occur in conjunction with a plateau fracture, an entirely opposite set of problems arises. In plateau fractures, even those associated with anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) ruptures, stiffness or loss of motion is a far more serious and common problem; instability from the associated ligamentous injury is rarely encountered and is only dealt with in delayed fashion, after the fracture has been treated and is well healed. Compartment syndrome and injury to neurovascular structures—namely, the peroneal nerve—may also occur with higher-energy mechanisms. Regardless of the mechanism, a tibial plateau fracture portends other concomitant injuries, and as such, almost 40% are polytraumas.

Overall, tibial plateau fractures occur due to direct axial and/or indirect coronal compressive forces. The location, comminution, and displacement are directly related to the bone quality and the degree of knee flexion, as well as the direction, force, and location of the impact. Typically, varus stress and compression will yield a medial plateau fracture and a valgus stress with compression will yield a lateral plateau fracture.

All patients with pain or tenderness around the knee after an injury should be assessed for a tibial plateau fracture. Often, a hemarthrosis may be present, but with enough damage to the surrounding tissue, the capsule can be disrupted, leading to its decompression to the surrounding area. Any lacerations should be assessed to ascertain if it communicates with the joint. In all patients, but especially in high-energy traumas, neurovascular status should be assessed and the popliteal, posterior tibial, and dorsalis pedis pulses should be palpated or found on Doppler. Patients should also be assessed for compartment syndrome. Initial radiographic investigation should start with anteroposterior and lateral views of the knee, 15° caudal, and two oblique views. CT scan with axial, sagittal, and coronal reconstruction can aid in surgical planning to assess the degree of comminution, and MRI has increasingly been used to assess for associated soft-tissue injury. One study that compared CT versus MRI found that while CT could be used to diagnose bony ligament avulsion, MRI analysis was necessary to detect ligament and meniscal injury.

There are two predominant methods in classifying tibial plateau fractures: the Schatzker classification and the AO/ASIF classification. The Schatzker classification subdivides these injuries into six types. In type I, there is a split fracture of the lateral tibial plateau, which can be displaced laterally and distally. This has a large incidence of ligamentous disruption and trapping of meniscus at the fracture site. Type II is a split depression fracture of the lateral plateau, in which the femoral condyle splits and depresses the lateral tibial plateau. A type III is a pure depression of the lateral articular surface without a split of the bone. Type IV is a fracture of the medial tibial plateau, and carries a poor prognosis. This injury pattern is frequently associated with cruciate and lateral ligament tears and a possible traction lesion of the peroneal nerve and popliteal artery. It is considered to be equivalent to knee dislocation. A type V is a bicondylar fracture of the medial and lateral tibial plateau. A type VI is a tibial plateau fracture with associated proximal shaft fracture. Types V and VI fractures have the highest incidence of compartment syndrome.

The AO/ASIF Classification first subdivides the injury pattern into whether the fracture is nonarticular, partial articular, or complete articular. 41-A1 is a nonarticular fracture with ligamentous avulsion. 41-B fractures are partially articular and 41-C injuries are complete articular with increasing decrees of comminution.