The diarthrodial, knee joint is a remarkably efficient bearing system; articulating cartilage surfaces provide nearly frictionless performance with minimal wear. The low friction properties of the cartilage surfaces are due in part to the boundary lubricant, superficial zone protein (SZP); also known as lubricin or proteoglycan 4 (PRG4). In previous work, SZP localization and cartilage friction...

INTRODUCTION Patellofemoral joint osteoarthritis (OA) is common and leads to pain and disability. However, current classification criteria do not distinguish between patellofemoral and tibiofemoral joint OA. The objective of this study was to provide empirical evidence of the clinical features of patellofemoral joint OA (PFJOA) and to explore the potential for making a confident clinical diagno...

Patellofemoral osteotomies can provide excellent symptomatic relief for selected patients with isolated patellofemoral osteoarthritis (PFOA). Isolated PFOA is a relatively common disorder, seen in 24% of women and 11% of men over the age of 55 years. In up to 89% of these patients, PFOA occurs at the lateral facet of the patella, and is especially amenable to surgical treatment. Particularly in...

INTRODUCTION It has been suggested that abnormal lower extremity kinematics during running are related to patellofemoral pain (PFP). Specifically, during the first half of stance when the knee is loaded, excessive internal rotation of the femur may result in lateral patellae maltracking [1,2]. Similarly, the patellofemoral joint may also be influenced by excessive knee valgus, which may be part...

The purpose of this study was to determine if persons with patellofemoral pain (PFP) exhibit differences in patellofemoral joint reaction forces (PFJRFs) during functional activities. Forty females (20 PFP, 20 controls) underwent two phases of data collection: (1) magnetic resonance imaging (MRI) and (2) biomechanical analysis during walking, running, stair ascent, and stair descent. A previous...

Powers CM, et al. Br J Sports Med 2017;51:1713–1723. doi:10.1136/bjsports-2017-098717 IntroductIon The aetiology of patellofemoral pain (PFP) is a complex interplay among various anatomical, biomechanical, psychological, social and behavioural influences. Numerous factors associated with PFP have been reported in the literature, but the interaction between these proposed risk factors and the cl...

The development of radiographic systems for the grading of osteoarthritis requires knowledge of the reproducibility of their individual component features. This paper reports the reproducibility, both within and between observers, for five commonly used radiographic features of osteoarthritis in the tibiofemoral and patellofemoral compartments of the knee joint. The results suggest that assessm...

Patellofemoral disorders represent 20–40% of all knee problems and can be one of the most common complaints in sports related injuries. These disorders are a major cause of disability, particularly in females, and in extreme cases may contribute to termination of athlete’s career and could lead to degenerative arthritic changes of the knee joint. For these reasons, disorders and in particular p...

Patellofemoral pain is the most common chronic pathology in recreational runners. Female runners are at greater risk of developing patellofemoral pain, although the exact mechanism behind this is not fully understood. This study aimed to determine whether female recreational runners exhibit distinct knee loading compared to males. Fifteen males and 15 females recreational runners underwent 3D r...

BACKGROUND Patellofemoral chondral lesions are frequently identified incidentally during the arthroscopic treatment of other knee pathologies. A role has been described for arthroscopic debridement when symptoms are known to originate from pathology of the patellofemoral joint. However, it remains unclear how to manage lesions which are found incidentally whilst tackling other pathologies. The ...