Central sensitization and pain phenotypes in symptomatic pes planus: A multicenter cross-sectional study.

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.