Exploration of the current evidence base for the incidence and prevalence of patellofemoral pain syndrome

Objectives: No consensus has been reached regarding the incidence and prevalence of patellofemoral pain syndrome (PFPS). This literature review aims to explore and present research conducted on the incidence and prevalence data for PFPS to date. Methods: The literature search employed databases Ovid SP, AMED, Ovid Medline (R) and EMBASE, accessed via the University of Central Lancashire Library Online service, and search terms 'adolescen*' 'anterior knee pain', 'incidence', 'outcome measure', 'patellofemoral pain', 'patellofemoral pain syndrome', 'prevalence', 'questionnaire' and 'response rate'. All articles were filtered by hand to determine relevance, as were reference lists of applicable studies/reviews to identify key articles. Pertinent journals were included as recommended by a specialist in the field. Results: Ten studies were selected for review, spanning 22 years of study that apparently focused on incidence over prevalence. Despite a lack of United Kingdom based research, this topic is of international interest. The participant groups demonstrate a large age span, comprising mainly military recruits, along with students, healthcare patients and athletes. The selection and definition of terminology differed greatly, as did methodologies, specifically the data collection tools. Despite questionnaires being well suited to incidence and prevalence data collection, none were identified as being valid and reliable. Discussion: Two major research gaps were identified: investigation into PFPS prevalence (and incidence) within athletic adolescents, and the development of a questionnaire to collect incidence and or prevalence data. Such research could facilitate clinical practice and the development of health strategies