Somatosensory processing is altered in people with hip osteoarthritis compared to controls: A cross-sectional study.

Background: With knee osteoarthritis (OA), measures of mechanical and thermal pain sensitivity relate to both pain severity and treatment outcomes, and lower limb left/right judgement is impaired. However, little is known about these somatosensory variables in people with hip OA. Objectives: Our cross-sectional study aimed to explore the differences in sensitivity to noxious mechanical and thermal stimuli, and lower limb left/right judgement, in people with hip OA compared to matched controls without hip OA. Methods: Demographic variables and self-reported hip-related disability were collected using an online survey, while physical function was assessed in person using standardised procedures. Quantitative sensory testing was conducted using mechanical (pressure) and thermal pain thresholds. Left/right judgement was assessed through a lower limb left/right judgement task on an online application. Generalised linear regressions were used to analyse differences between groups and explore associations between the demographic variables and the somatosensory measures. Results: 15 participants with hip osteoarthritis and 15 controls were included. Mean (SD) age was 62.1 (11.2) years, median (IQR) BMI 26.2 (4.4) kg/m Conclusions: Increased mechanical, but not thermal, pain sensitivity was found in people with hip OA compared to controls. Demographic variables are associated with somatosensory measures and require consideration in any analyses using these measures.