History
Patients with knee fractures may have a history of the following:
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Direct or indirect trauma with resultant pain and edema
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Patella fracture - Caused by a direct blow, such as a dashboard injury in a motor vehicle accident or a fall on a flexed knee, also caused by forceful quadriceps contraction while the knee is in the semiflexed position (eg, in a stumble or fall).
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Femoral condyle fractures due to axial loading with valgus or varus stress.
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Tibial eminence fracture [1] - Due to a direct blow to the proximal tibia with the knee flexed, such as falling off a bicycle; or due to hyperextension with varus or valgus stress, such as in motor vehicle collisions or athletic accidents, [7] (Tibial eminence avulsion fractures occur most often in children aged 8-14 years but can also occur in the skeletally mature patient. [1] )
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Tibial tubercle fracture - Usually occurs with jumping activities, such as basketball, diving, gymnastics, and football [7] ; more common in males than in females; more common in adolescents; infrequent in adults.
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Tibial plateau fracture - Caused by axial loading with valgus or varus forces, such as in a fall from a height or collision with the bumper of a car, due to the impaction of the femoral condyle into the tibial plateau. (In elderly persons and those with osteoporosis, tibial plateau fracture can occur with minor trauma. Patient is generally unable to bear weight. The lateral tibial plateau is fractured more frequently than the medial plateau.)
Physical
When examining a patient for a knee fracture, one should first examine the patient for edema, ecchymosis, and point tenderness. A careful neurovascular examination should be performed. Ask the patient to perform a straight-leg raise against gravity to check the integrity of the extensor mechanism, which commonly is disrupted with transverse patellar fractures caused by indirect forces. [2]
Patella fractures
Patients present with pain directly over the patella. [8, 9, 10, 11]
The patient may have pain with leg extension or may be unable to extend the knee with a severe fracture.
Femoral condyle fractures
Patient will present with pain over the distal femur and often will have a hemarthrosis.
Patients are often unable to bear weight.
Femoral condyle insufficiency fractures are frequently associated with overlying cartilage loss and ipsilateral meniscal injury. [12] The extent of cartilage loss and meniscal damage, in addition to loss of knee range of motion at the time of presentation, are significantly associated with clinical progression. [13]
Tibial eminence fractures
Patients may present with a knee effusion and pain. [1, 14]
Patients may represent with an avulsion of the tibial attachment of the anterior cruciate ligament.
Tibial tubercle fractures
Patients present with pain over the anterior tibia about 3 cm distal to the articular surface. [15]
In severe fractures, the patient may be unable to extend the knee.
Tibial plateau fractures
Often, patients present with a knee effusion, and tenderness will be present over the medial or lateral plateau.
Up to 30% of tibial plateau fractures are associated with knee ligamentous injuries (medial collateral or anterior cruciate ligaments with lateral plateau fractures; lateral collateral or posterior cruciate ligaments with medial plateau fractures).
Tibial plateau fractures are articular injuries that have a broad spectrum of clinical presentations and are frequently associated with long-term complications. The Schatzker classification system is widely accepted and divides these fractures into the following 6 types [16, 8, 17] :
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Type I: split wedge of the lateral tibial plateau.
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Type II: split wedge depression of the lateral tibial plateau.
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Type III: pure depression of the lateral tibial plateau.
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Type IV: split wedge of the medial tibial plateau.
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Type V: bicondylar tibial plateau fracture, where there is continuity between the epiphysis and the diaphysis.
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Type VI: bicondylar fracture with complete dissociation between the epiphysis and the diaphysis.
