Tibial plateau fractures constitute 1% of all fractures and 8% of fractures in the elderly.

Isolated injuries to the lateral plateau account for 55% to 70% of tibial plateau fractures, as compared with 10% to 25% isolated medial plateau fractures and 10% to 30% bicondylar lesions.

From 1% to 3% of these fractures are open injuries.

The tibial plateau is composed of the articular surfaces of the medial and lateral tibial plateaus, on which are the cartilaginous menisci. The medial plateau is larger and is concave in both the sagittal and coronal axes. The lateral plateau extends higher and is convex in both sagittal and coronal planes.

The normal tibial plateau has a 10-degree posteroinferior slope.

The two plateaus are separated from one another by the intercondylar eminence, which is nonarticular and serves as the tibial attachment of the cruciate ligaments. Three bony prominences exist 2 to 3 cm distal to the tibial plateau. Anteriorly is the tibial tubercle on which the patellar ligament inserts. Medially, the pes anserinus serves as attachment for the medial hamstrings. Laterally, the Gerdy tubercle is the insertion site of the iliotibial band.

The medial articular surface and its supporting medial condyle are stronger than their lateral counterparts. As a result, fractures of the lateral plateau are more common.

Medial plateau fractures are associated with higher energy injury and more commonly have associated soft tissue injuries, such as disruptions of the lateral collateral ligament complex, lesions of the peroneal nerve, and damage to the popliteal vessels.

Fractures of the tibial plateau occur in the setting of varus or valgus forces coupled with axial loading. Motor vehicle accidents account for the majority of these fractures in younger individuals, but elderly patients with osteopenic bone may experience these after a simple fall.

The direction and magnitude of the generated force, age of the patient, bone quality, and amount of knee flexion at the moment of impact determine fracture fragment size, location, and displacement.

Neurovascular examination is essential, especially with high-energy trauma. The trifurcation of the popliteal artery is tethered posteriorly between the adductor hiatus proximally and the soleus complex distally. The peroneal nerve is tethered laterally as it courses around the fibular neck.

Hemarthrosis frequently occurs in the setting of a markedly swollen, painful knee on which the patient is unable to bear weight. Knee aspiration may reveal marrow fat.

Direct trauma is usually evident on examination of the overlying soft tissues, and open injuries must be ruled out. Intra-articular instillation of more than 120 cc of saline may be necessary to evaluate possible communication with overlying lacerations.

Compartment syndrome must be ruled out, particularly with higher energy injuries and/or fracture-dislocations.

Assessment for ligament injury is essential.

Soft tissue injury is seen in approximately 90% of these fractures.

Meniscal tears occur in up to 50% of tibial plateau fractures. Medial meniscus tears are highly associated with medial plateau fractures and lateral meniscus tears are associated with lateral tibial plateau fractures.

Associated ligamentous injury to the cruciate or collateral ligaments occurs in up to 30% of tibial plateau fractures.

Young adults, whose strong subchondral bone resists depression, are at the highest risk of collateral or cruciate ligament rupture.

Fractures involving the medial tibial plateau may be associated with higher incidences of peroneal nerve or popliteal neurovascular lesions owing to higher energy mechanisms; it is postulated that many of these represent knee dislocations that spontaneously reduced.

Peroneal nerve injuries are caused by stretching (neurapraxia); these will usually resolve over time; however, these are rare.

Arterial injuries frequently represent traction-induced intimal injuries presenting as thrombosis; only rarely do they present as transection injuries secondary to laceration or avulsion.

Anteroposterior and lateral views supplemented by 40-degree internal (lateral plateau) and external rotation (medial plateau) oblique projections should be obtained.

A 5- to 10-degree caudally tilted plateau view can be used to assess articular step-off.

Avulsion of the fibular head, the Segond sign (lateral capsular avulsion) and Pellegrini-Stieda lesion (calcification along the insertion of the medial collateral ligament seen late) are all signs of associated ligamentous injury.

A physician-assisted traction view is often helpful in higher energy injuries with severe impaction and metadiaphyseal fragmentation to delineate the fracture pattern better and to determine the efficacy of ligamentotaxis for fracture reduction.

Stress views, preferably with the patient under sedation or anesthesia and with fluoroscopic image intensification, are occasionally useful for the detection of collateral ligament ruptures (Fig. 36.1).

Computed tomography with two-dimensional or three-dimensional reconstruction is useful for delineating the degree of fragmentation or depression of the articular surface, as well as for preoperative planning.

Magnetic resonance imaging is useful for evaluating injuries to the menisci, the cruciate and collateral ligaments, and the soft tissue envelope.