Inflammatory, angiogenic and neurogenic serum biomarkers in patients with patellofemoral pain compared to healthy controls.

Purpose: The inflammatory, angiogenic and neurogenic pathways of osteoarthritis (OA) might already be present in patients with patellofemoral pain (PFP), a supposed precursor of OA. In this study, differences in serum levels of biomarkers of inflammation, angiogenesis and neurogenesis were compared between PFP patients and healthy controls. Furthermore, we aimed to determine the associations between serum marker levels and both clinical and MRI based inflammatory features. Methods: In a post hoc analysis of data from a prospective case-control study, a wide range of serum levels of markers of inflammation, angiogenesis and neurogenesis were measured in 44 PFP patients and 50 healthy controls aged 18-40 years. Clinical measures included the NRS for knee pain intensity, duration of complaints and pressure pain thresholds. Morphologic and dynamic contrast enhanced MRI of the knee were performed to assess inflammatory features and quantitative perfusion parameters. Differences in biomarker levels between patients and controls were assessed and additional analyses in the patient group were performed to study associations between serum biomarkers and inflammatory MR features and clinical parameters. Results: There were no significant differences between patients and controls in serum biomarker levels. Additional analyses in the patient group revealed no associations between serum markers and inflammatory MR features and clinical parameters. Conclusion: Our results were unable to confirm the hypothesis that inflammation, angiogenesis or neurogenesis plays a role in PFP pathophysiology.