FIGURE 42.7 Testing for meniscal injury with the Apley compression test With the patient prone and the knee flexed to 90 degrees, apply pressure to the heel while the tibia is rotated If this produces pain that resolves when the tibia is distracted from the femur, a meniscal injury should be suspected Posttraumatic Infection Although not considered injuries, acute infections may present after a vague history of trauma Physical findings of acute infection will be present The most common disorders are septic arthritis, osteomyelitis, cellulitis, and septic prepatellar bursitis (see Chapters 94 Infectious Disease Emergencies and 121 Musculoskeletal Emergencies ) Subacute Injuries Many subacute knee problems may present in the ED Osgood–Schlatter disease of the tibial tubercle may present with similar symptoms as a traumatic avulsion of the tubercle; however, the symptoms have likely been noted for days or weeks The symptoms of Osgood–Schlatter disease are exacerbated by squatting or jumping, but they not cause the same disability as an acute avulsion The disease is usually seen in patients between 11 and 15 years of age It may be caused by recurrent contractions of the patellar tendon during knee extension,