The Diagnosis and Initial Treatment of Patellofemoral Disorders

Our purpose is to provide simple guidelines for the diagnosis and early care of patellofemoral disorders. Any clinician who treats knee problems, including family practitioners, rheumatologists, orthopedic surgeons, or physical therapists, must know how to make the correct diagnosis, or at least a presumptive diagnosis, at the initial visit. This can avoid unneeded and costly tests, ineffective treatment, and even damaging exercises and unnecessary surgery. The diagnosis of patellofemoral disorders is confusing because they can have many causes. That is, the etiology of patellofemoral disorders is multifactorial. To dispel this confusion and simplify the process, we use a clinical classification based on etiology. Within that framework are 7 key abnormalities or factors that can cause both patellofemoral pain and instability: vastus medialis obliquus deficiency, medial patellofemoral ligament laxity, lateral retinaculum tightness, increased quadriceps angle, hip abductor weakness, patella alta, and trochlear dysplasia. At the initial evaluation, the clinician can assess for these abnormalities through history-taking, physical examination, and standard radiography. Any abnormalities identified, along with their severity, can be used to arrive at a diagnosis, or a presumptive diagnosis, and begin early nonoperative treatment. The clinician does not need magnetic resonance imaging at this point, unless a presumptive diagnosis cannot be made or a more complex problem is suggested.