Chronic knee pain in the young athlete may be caused by inadequate rehabilitation of a previous injury or repetitive activity. Chronic knee pain can also be caused by conditions unrelated to sports activity (eg, bone tumors, infection, arthritis, slipped capital femoral epiphysis, Legg-Calvé-Perthes disease) and these conditions must be considered in the differential diagnosis and evaluation . (See appropriate topic reviews).
The approach to chronic knee pain is similar to that for acute pain. The same physical examination techniques are used to evaluate individual structures, although the patient usually is in less pain. Additional techniques and maneuvers are used to detect problems that only occur chronically (eg, the Ober test for iliotibial band syndrome, the Thomas test for quadriceps flexibility).
The approach to the young athlete with chronic knee pain will be reviewed here. The causes and treatment of knee pain, and the approach to acute knee pain in the young athlete, are discussed separately. (See "Traumatic causes of acute knee pain and injury in the young athlete" and "Treatment of knee injuries in the young athlete" and "Approach to the young athlete with acute knee pain or injury".)
In the evaluation of a young athlete with knee pain or injury, it is important to determine [2,3]:
- Whether the complaint is acute or chronic. The evaluation of acute complaints is discussed separately. (See "Approach to the young athlete with acute knee pain or injury".)
- The mechanism of injury. For example, was it triggered by a specific event, or did it arise after repetitive activity? If a specific event was involved, are there videotapes of it, or eyewitnesses who can describe what happened? If repetitive activity was involved, what was the activity? What are the training demands of the activity? Was the patient using the appropriate equipment and sports technique?
- The location of the pain.
- Whether there are mechanical symptoms (eg, locking, popping, or catching).
- Whether the patient has a sense of instability (ie, "giving way") or functional limitation.
- Any history of previous knee injury. If so, how was it evaluated and treated?