Patellofemoral pain syndrome (PFPS) is the most common cause of knee pain in the outpatient setting. It is caused by
imbalances in the forces controlling patellar tracking during knee flexion and extension, particularly with overloading of
the joint. Risk factors include overuse, trauma, muscle dysfunction, tight lateral restraints, patellar hypermobility, and
poor quadriceps flexibility. Typical symptoms include pain behind or around the patella that is increased with running and
activities that involve knee flexion. Findings in patients with PFPS range
from limited patellar mobility to a hypermobile patella. To confirm
the diagnosis, an examination of the knee focusing on the patella and
surrounding structures is essential. For many patients with the clinical
diagnosis of PFPS, imaging studies are not necessary before beginning
treatment. Radiography is recommended in patients with a history of
trauma or surgery, those with an effusion, those older than 50 years (to
rule out osteoarthritis), and those whose pain does not improve with
treatment. Recent research has shown that physical therapy is effective
in treating PFPS. There is little evidence to support the routine use of
knee braces or nonsteroidal anti-inflammatory drugs. Surgery should
be considered only after failure of a comprehensive rehabilitation program.
Educating patients about modification of risk factors is important
in preventing recurrence.