Current understanding of dynamic patellofemoral joint (PFJ) mechanics in literature is limited to static or very slow in vivo measurements. Two studies were performed across a wide range of functional movements to improve upon our understanding on how the PFJ moves dynamically. The first study aimed to provide foundational data of the PFJ and associated mechanisms such as medial patellofemoral ligament (MPFL) length, joint congruence, and engagement. The second study looked at the effects of a gait rehabilitation program had on the PFJ. The program altered hip mechanics to mitigate pain associated with patellofemoral pain. Both studies used biplanar videoradiography (BVR) motion capture techniques in conjunction with a computed tomography scan of the knee to quantify and evaluate PFJ motion.
Four functional movements - walking, lunging, sidestepping, and running - were investigated. We observed several linear correlations between MPFL length, lateral patellofemoral tilt, lateral patellofemoral displacement, orientation of the patella ridge within the trochlear groove, and patellofemoral volumetric congruence. In the pilot gait rehabilitation study, we found that targeting the hip had significant effects on PFJ kinematics, mechanics, and congruence. Whether these changes can be maintained or are beneficial is yet to be determined; however, they currently provide insights into mitigating PFP using non-surgical methods. These datasets can be used to provide the basis of our understanding of the PFJ and guide future studies.