Central Sensitization and Pain Phenotypes in Symptomatic Pes Planus: A Multicenter Cross-Sectional Study.

Abstract

Background: Pes planus (PP) is a common foot disorder often associated with persistent pain despite treatment. Central sensitization (CS) and nociplastic pain (NcP) are potential contributors but remain underexplored in PP.

Purpose: To investigate the prevalence of CS and nociplastic-like features in patients with symptomatic PP and examine their associations with pain, disability, psychological distress, and quality of life.

Study design: Multicenter cross-sectional study.

Methods: A total of 107 patients with diagnosed PP and 107 age- and sex-matched healthy controls were enrolled. Participants completed Turkish versions of Visual Analog Scale (VAS), Foot Function Index (FFI), Pain-DETECT, Central Sensitization Inventory (CSI), Hospital Anxiety and Depression Scale (HADS), and Short Form-12 (SF-12). Group comparisons, correlation analyses, and regression models were performed to identify predictors of nociplastic-like features and CS.

Results: Compared with controls, PP patients reported greater pain (VAS mean difference 3.9, 95% CI 3.1-4.7) and disability (FFI mean difference 45.8, 95% CI 41.2-50.4). Probable nociplastic-like features were identified in 48.6% of PP versus 3.7% of controls, and CSI ≥40 in 61.7% versus 43.9%. Anxiety and depression scores were higher in PP, while SF-12 physical and mental scores were lower. In regression models, pain duration, intensity, disability, and CS predicted nociplastic-like features, while CS was predicted by pain severity, disability, nociplastic-like features, and psychological distress.

Conclusion: Symptomatic PP is not solely a structural condition but involves central and psychosocial mechanisms. Recognition of CS and nociplastic processes supports multidisciplinary management strategies that address biomechanical, central, and psychological contributors to persistent pain.

Level of evidence: Level III, Cross-sectional study.