This is probably one of the most common presenting symptoms in a clinical sports medicine along with the non athletic individual. The two most common causes of patellar femoral syndrome is patellar tendonitis and simple OA changes in the older adults.
Examination requires functional testing to reproduce the patient’s pain and careful palpation to determine the site of maximal tenderness, localised swelling of the patellar tendon maybe present with patellar tendonitis. Effusion (swelling) located underneath the kneecap of the fat pad can cause impingement. Effusion inside the knee joint usually indicates a partial tear of the meniscus (cartilage), which gives rise to locking of the knee. Finally, symptoms of the knee giving way usually indicates anterior cruciate ligament instability.

Ultrasound or MRI examination may be used to image the patellar tendon. This along with the standardised objective tests and the observation help to confirm diagnosis. These findings combined with the clinical picture help to determine the treatment regimen.
In my experience 98 percent of patellar femoral pain and dysfunction is associated with significant focal thickening and muscle tightness around the quadriceps, hamstrings, calf and IT band structures.

Treatment:
In most cases muscle tightness and trigger points in the above mentioned structures respond very well to and integrated approach consisting of ice, ultrasound and or interferential therapy to reduce acute pain and inflammation. Taping to correct abnormal positioning of the patella, VMO strengthening, bracing, correction of abnormal biomechanics.

However, I primarily use dry needling IMS (intramuscular stimulation) to release trigger point formation and deep tissue frictions with longitudal and lateral release techniques to help realign and off load excessive pressure off the patellae. This intervention along with a comprehensive stretch programme tends to bring miraculous results in achieving the restoration of normal knee function.