Ultrasound changes following controlled mechanical stress in synovial tissue in the hands of healthy individuals

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.