Objective: The physiological response of the synovium to acute mechanical stress has not been extensively studied. This response is interesting in terms of the morphological changes it can cause as any such changes should be taken into account during ultrasound examinations. The purpose of this study was to assess the extent of changes in ultrasound images of the synovial joint in the hands of healthy individuals after controlled mechanical stress. Method: We included 110 healthy volunteers on whom we carried out two ultrasound examinations of the non-dominant hand: one at baseline and the other after controlled handgrip exercise at 70% of the maximum voluntary contraction. Results: The synovitis scores at baseline and after exercise were 0.472±0.798 and 0.772±1.162 t(109)=-3.791, respectively; p < 0.001. We observed no tenosynovitis in 88.2% of the participants at baseline, while after exercise the percentage fell to 70.9%; x2 (1, N=110) =10.0851, p = 0.0014. Conclusion: We conclude that synovitis and tenosynovitis are inducible by physical exercise and are detectable on ultrasound. This should be taken into account during ultrasound examinations for suspicion or follow-up of inflammatory rheumatism.

Introduction: Hand osteoarthritis (HOA) is a prevalent rheumatic disease that may cause significant disability. The Functional index for HOA (FIHOA) is a validated questionnaire to evaluate loss of function in patients with HOA. Objective: To undertake a cross-cultural adaptation and validation of FIHOA into Portuguese. Patients and methods: First, the original French version of FIHOA had been forward-backward translated into Portuguese, according to the guidelines for cross-cultural adaptation. Secondly, patients with primary HOA were consecutively recruited in three Portuguese rheumatology outpatient clinics between May 2016 and April 2018. The final consensual Portuguese version of FIHOA was administered to 52 patients. A numerical rating scale (NRS – 0 to 100mm) for hand pain and for perceived hand dysfunction was also registered. Ten randomly selected patients were re-administered the same tools 5 to 15 days later. Internal consistency, test-retest reliability, internal construct validity and external validity related to dysfunction NRS were evaluated. Results: Fifty-two patients were evaluated: all right-handed, 96% women, mean age of 63 (10) years and 8 (6) years of disease duration. Mean (SD) pain and dysfunction were 47 (25) and 46 (25), respectively, with 68% patients being symptomatic. Mean (SD) FIHOA was 7 (5). Cronbach’s alpha for internal consistency was high and adequate (0.87) and corrected item-total correlation revealed adequate performance. For reliability, Spearman’s rho coefficient was 0.88 and total intraclass correlation coefficient (ICC) between test and retest was 0.87, showing good reliability. Factor analysis revealed three factors accounting for 71% of the variance of the score, with the first one (including questions 1, 2, 3 and 10) being responsible for 47% of the variance. Spearman’s rho between FIHOA and dysfunction NRS was 0.5, showing a moderate but significant correlation and moderate external validity. Conclusion: The Portuguese version of FIHOA is a consistent, reliable, and valid instrument to measure loss of function in HOA Portuguese patients.