In vivo assessments of patellofemoral kinematics and contact areas with applications to osteoarthritis

Mechanical-based treatment strategies for patellofemoral osteoarthritis (OA) have had limited success. This is likely because the magnitude of mechanical change required to improve clinical symptoms has not been quantified because, until recently, the tools required to do so were not available. The aim of this thesis was to develop and characterize MRI-based assessments of in vivo joint mechanics (three-dimensional patellar kinematics and contact areas) that can be used in studies of patellofemoral OA. Three studies of three-dimensional patellar kinematics were carried out. Study 1 examined the effect of load on kinematic measurements. The results showed that increased load caused patellae to flex, tilt medially and translate proximally and posteriorly (p<0.05). In Study 2, the need to carry out a full kinematic assessment through the range of knee flexion was assessed. The results showed that a single, widely used measure of patellar position and orientation was an inadequate surrogate marker and a full kinematic assessment was required. In Study 3, the effect of a patellofemoral brace on kinematics was examined in patients with patellofemoral OA. The brace caused the patellae to extend, spin externally, tilt medially and translate distally, medially and posteriorly (p