Unilateral Anterior Knee Pain as a Sign of Knee Asymmetry

Abstract

Anterior knee pain is a common complaint in the orthopaedic community. It is nonspecific in nature and can be frustrating to treat. Symmetry between the knees is necessary for people to perform everyday activities comfortably and for athletes to function at a high level. Through observation and research on thousands of patients, we have found that unilateral anterior knee pain can largely be attributed to asymmetry between knees, in particular the loss of full knee extension. Loss of full knee extension can be caused by many factors. Regardless of the specific etiology, patients favor one knee by standing solely on the normal knee rather than using both legs equally. Patients subconsciously stop using the involved leg and a flexion contracture can develop when they avoid weight bearing on the leg and they keep the knee bent. As the leg becomes weaker, the patient favors it even more and the knee can become “deconditioned.” Even small degrees of extension loss can cause anterior knee pain. Our experience has shown that the most important objective to keep in mind when dealing with anterior knee pain is the restoration and maintenance of symmetry between knees. This is primarily accomplished by treating any deficits in knee range of motion first followed by improving leg strength with appropriate rehabilitative exercises and instructions for correct symmetrical use of the legs with daily activities.