The acutely injured knee.

Acute knee pain is a common complaint among patients presenting to outpatient clinics. Although most injuries are minor and resolve without surgical intervention, some injuries, such as extensor mechanism injuries, tibial plateau fractures, and multi-ligament knee injuries, require prompt evaluation by an orthopedic surgeon. A thorough history and physical examination combined with radiographs are usually sufficient to diagnose these more urgent injuries. If the diagnosis remains uncertain, magnetic resonance imaging is the imaging modality of choice in diagnosing ligamentous, tendinous, meniscal, and chondral injuries.