Referred knee pain in a young athlete: a case study.

Parapatellar pain is a common complaint in the active adolescent patient population. Patello-femoral pain syndrome, Osgood-Schlatter disease, Sinding-Larsen-Johansson syndrome, patellar tendinitis, and other stress failure conditions are the primary causes of these parapatellar symptoms. Not all cases of knee discomfort are related to knee pathology. This case study discusses hip pathology as a source of referred knee pain in an 8-year-old male athlete. Care must be taken to evaluate all possible sources of both primary and referred pain in all cases.