Definition of phlegm for English Language Learners. : 1  a thick, yellowish liquid that is produced in the nose and throat especially when a person has a cold. : 2  calmness in a difficult or unpleasant situation.
Kneecap (Patellar) Subluxation. A subluxing patella (kneecap) is a temporary, partial dislocation of the kneecap from its normal position in the groove in the end of the thigh bone (femur). This groove is located between two bumps at the end of the thigh bone called the femoral condyles.
Causes of Patellar Subluxation. There are dozens of factors implicated in the cause of patellar subluxation. The bottom line is that it is probably the contribution of several factors that lead to instability of the kneecap.