Patellar subluxation is the following situation: the patella (kneecap) and the knee trochlea are partially disconnected, or partially disjointed, causing knee pain and instability.
The common symptoms include: intense pain, rapid swelling, skin bruising (abnormally red, blue or purple), knee instability, standing or walking difficulty, knee deformity. Patellar subluxation usually requires immediate medical attention.
The common causes include: direct trauma, wide pelvis, shallow trochlea groove, gait abnormality, osteoarthritis, tendonitis. The following methods can be used to treat patellar subluxation: physical therapy, knee bracing, knee taping, surgery.