The Patellofemoral Joint



We think of the knee as one joint. And while "the knee" primarily refers to the joint between the femur (thigh bone) and the tibia (shin bone), the knee is actually a complex of this joint and two others. There is the proximal tibiofibular joint (PTFJ), which is rarely a source of knee pain, and the patellofemoral joint (PFJ), which is a very common source of knee pain.


The patellofemoral joint is the joint in which the patella (knee cap) sits in a groove on the femur. The quadriceps attach into the patella. The most medial of the quadriceps, the VMO, pulls the patella slightly inwards, while the most lateral of the quadriceps, the vastus lateralis, pulls it slightly outwards. If all quadriceps are pulling equally, then the patella slides up and down in the middle of its groove. However, often the vastus lateralis will pull more than the VMO and so the patella will get pulled against the side of the groove.


This imbalance in the pull of different quadriceps is why the pain tends to be aggravated by activities such as stairs, squatting, running and jumping, which load up the quadriceps.



Your physiotherapist will perform a thorough assessment to determine whether your knee pain is coming from the PFJ, or from another condition with similar presentation, such as patellar tendinopathy, pes anserine bursitis, ITB friction syndrome, or Hoffa's fat pad impingement.


Treatment of PFJ pain involves correcting the muscle imbalance. This includes strengthening the VMO and loosening the vastus lateralis. It also involves strengthening the gluteus medius and retraining movement patterns of activities such as squatting, lunging and single-leg squats. Taping can also be used to help relieve pain by preventing the patella from being pulled against the side of its groove.



The good news is that PFJ pain is easily treatable, and, because it's from irritation rather than tissue damage, you can continue to push through some pain provided it's not too severe.


If you need some help recovering from knee pain, come see our physiotherapist in Aubin Grove today!