Patellar tendonitis is an inflammation of the tendon just below the kneecap. Most patients report pain and swelling with this problem. It's often caused by overuse of the tendon from jumping or other repeated activities like walking or running.
Sometimes people have this kind of tendonitis as a result of alignment problems from the hips down to the feet. This could be from wide hips, knock-knees, fallen arches, or other abnormal posture.
If the problem is coming from the foot or ankle, a shoe insert to correct the alignment might help. If the problem is caused by a muscle imbalance, then a specific exercise program may be advised. In the case of overuse, rest and ice are used most successfully. Surgery is only considered when all forms of conservative care have been tried without success.
Studies show that patellar tendonitis can last from weeks to months to years. This is especially true for athletes who practice and train hours each day. Treatment will be guided by your physician, and will depend on the cause of your tendonitis and your particular circumstances.