Evidence-based framework for a pathomechanical model of patellofemoral pain: 2017 patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester, UK: part 3.

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 clinical entity of PFP remains unclear (figure 1). The goal of this consensus document is to place known associated factors within the context of a pathomechanical model of PFP. An underlying assumption of the proposed pathomechanical model is that PFP is associated with abnormal loading of the patellofemoral joint (elevated joint stress). In this model, abnormal loading could affect the various patellofemoral structures that can contribute to nociception (ie, subchondral bone, infrapatellar fat pad, retinaculum and ligamentous structures); however, the specific tissue sources related to PFP are not known. The experience of PFP is not just nociception. Persons with persistent PFP exhibit abnormal nociceptive processing (ie, widespread mechanical hyperalgesia, impaired pain modulation), altered somatosensory processing (implying neuropathic pain), impaired sensorimotor function (ie, proprioception and balance) and certain psychological factors (ie, catastrophising and kinesiophobia). The amount and quality of research in the non-‘patho-mechanical’ pathways to PFP are evolving, and will be included in future consensus statements emanating from the International Patellofemoral Pain Research Retreats. Evidence-based framework for a pathomechanical model of patellofemoral pain: 2017 patellofemoral pain consensus statement from the 4th International Patellofemoral Pain Research Retreat, Manchester, UK: part 3 Christopher M Powers, Erik Witvrouw, Irene S Davis, Kay M Crossley consensus statement