Pain directly in the front of the knee is most commonly referred to as patellofemoral syndrome or anterior knee pain. The development of patellofemoral syndrome can be a result of an injury, overuse phenomenon, imbalance of leg musculature or weight gain.
Typical symptoms that one will complain of include: pain in the front of the knee with activity which often even worsens while walking up or down an incline or stairs. Sitting for prolonged periods of time may also trigger pain and one or both knees may be affected by it at any given time. An acute injury that causes swelling to the knee joint can contribute to the presence of anterior knee pain as it results in shutdown of the quad musculature which lends itself to atrophy of the quad muscle.
The patella, aka kneecap, rides in the front of the knee and articulates with the groove at the end of the femur ( thigh bone). This groove is also referred to as the trochlea. There are many different forces that act upon the patella to not only provide proper stability but also tracking of the kneecap in the trochlear groove. The kneecap not only moves up and down but also tilts and rotates slightly in position. These movements of the kneecap cause for various different contact points between the undersurface of the patella and the trochlear groove. Repetitive contact at any of these points along with maltracking of the kneecap tends to be the most likely reason people will develop patellofemoral syndrome or pain.
Weight gain has also been noted to be a common reason why individuals will develop anterior knee pain. Because such movements like bending of the knee increases pressure behind the patella and the multiple different contact points with the trochlear groove, patellofemoral pain is commonly classified as an “overload phenomenon”. For every pound of over ideal body weight that is carried, it increases load to the front of the knee by seven times with movements such as stairs and going from a sit to a stand position. Reduction in ones’ body weight has been known to substantially help in the elimination of anterior knee pain.
Diagnosis of patellofemoral syndrome is obtained through both a physical examination and symptoms reported by the patient. There is typically no need for any advanced imaging to be performed in the initial diagnosis of anterior knee pain or patellofemoral syndrome.
Treatment for complaints such as those described above may include such things as: physical therapy, home exercise regimen and a weight loss program, if indicated. Specific physical therapy exercises will include closed chain quad strengthening, hip, core, glute and balance or stability exercises can all help to aid in the reduction of pain.
In the presence of persistent anterior knee pain which has shown no signs of improvement with conservative means, further investigation and intervention may become necessary. An MRI scan may be performed at that time to further assess for any additional cartilage abnormalities present in the patellofemoral compartment however this is not typical first line treatment for patellofemoral syndrome.
Presented by Midwest Orthopaedics at Rush