The eccentric strengthening already mentioned is the best way for quad tendon strengthening. However, you have increased fluid there and may need to stretch you quad tendon and have manual therapy to find the ideal position of the patella during activity. If that is successful then you can strengthen and retrain the muscles in the pain-free position. If the quad is tight it will pull on the patella ligament from the inferior patella pole to the area of the tibial tuberosity. The bone spur may be a problem. It is there and often forms with constant pull or contact as in the shoulder. If it is in an area of contact during movement there is a problem. A good therapist can try t position the patella and have you perform activities that produce your pain, such as deep squats or ascending/descending deep steps. If it abolishes your pain you have a good chance of rehabbing it.