Clinical Impact of Stage-Specific Central Sensitization-Related Symptoms in Hip Osteoarthritis

Purpose This study aimed to compare the characteristics of central sensitization (CS)-related symptoms between mild and severe hip osteoarthritis (OA) and to clarify their associations with hip pain. Methods A total of 116 patients with unilateral hip OA secondary to acetabular dysplasia or borderline dysplasia (center-edge angle ≤ 25°) were enrolled. Patients were classified into mild (Tönnis grade 0–1, n = 39) and severe (Tönnis grade 2–3, n = 77) OA groups. CS-related symptoms were assessed using the Central Sensitization Inventory (CSI), including domain-specific scores (Physical Symptoms, Emotional Distress, Headache/Jaw Symptoms, and Urological Symptoms). Hip pain intensity was evaluated with the Visual Analog Scale (VAS). Between-group comparisons were conducted, and multivariate regression analyses were performed to examine the associations between CSI domain scores and VAS. Results VAS scores were higher in the severe OA group than in the mild OA group. Total CSI scores did not differ significantly between groups. However, the Headache/Jaw Symptoms domain score was significantly higher in the mild OA group (p < 0.001) and was the only domain independently associated with hip pain intensity in this group (β = 0.59, p = 0.034). No significant associations were observed in the severe OA group. Conclusion CS-related symptoms, particularly headache and jaw complaints, play an important role in pain perception in mild hip OA. Evaluating and managing these symptoms may help optimize stage-specific pain treatment strategies for patients with hip OA.