Patellofemoral pain subgroups: a systematic scoping review of the evidence and clinical potential

Introduction: Patellofemoral Pain (PFP) remains challenging to manage, with high rates of symptom recurrence. Subgrouping has been suggested as a strategy to enhance treatment effectiveness. Objectives: This scoping review aimed to map the emerging literature on PFP subgroups and their evolution over time. Specifically, it explored study designs, stratification methods, subgroup classifications, and discussed their methodological rigor and clinical applicability. Methods: Searches were conducted in seven databases. The review followed the PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. Critical appraisal was performed using JBI checklists. Results: Forty-six studies were included. While efforts to stratify individuals with PFP date back to the 1990s, 90% of the studies were published after 2010. Most were observational cross-sectional designs (52.17%), and 17.39% were interventional. Twenty research groups proposed novel subgrouping approaches, but only four were replicated in subsequent studies. Many methods relied on imaging and biomechanical assessments, potentially limiting clinical use. Conclusion: Subgrouping in PFP research has increased notably since 2010. Despite growing interest, few models have been tested in intervention studies, and their dependence on specialized assessments may hinder routine clinical implementation. Importantly, the most cited approach uses simple, low-cost clinical tests to classify individuals into three subgroups.