Elastosonographic features of the metacarpophalangeal joint capsule in horses

Abstract

Background Capsulitis leads to the release of inflammatory mediators in the joint, causing capsular fibrosis and osteoarthritis (OA). Strain elastosonography (SE) measures the elasticity of tissue by evaluating its strain in operator-dependent deformation. The aims of the study were to assess the feasibility, repeatability, and reproducibility of SE for imaging the distal attachment of the joint capsule (DJC) of metacarpophalangeal joints in sound horses (Group S) and in horses with metacarpophalangeal OA (Group P) and to evaluate differences in the elastosonographic patterns of these horses. After a whole lameness examination, fore fetlock DJCs were assigned to Group S and Group P and were thereafter examined by two operators using SE. Qualitative (i.e., colour grading score) and semi-quantitative (i.e., elasticity index (EI) and strain ratio (SR)) methods were used to evaluate the elastograms. The inter-rater reliability (IRR), intraclass correlation coefficient (intra-CC) and interclass correlation coefficient (inter-CC) were used to compare colour grading scores and the repeatability and reproducibility of EI and SR outcomes. The same parameters were compared between groups. P < 0.05 indicated a significant finding. Results Forty-one horses were included: 11 were in Group S and 30 were in Group P (16 with bilateral OA, 8 with left OA and 6 with right OA). IRR outcomes ranged from good to excellent. For transverse and longitudinal ultrasound scans, the colour grading score of Group S was significantly higher than the metacarpophalangeal DJCs of Group P. Both Inter-CC and intra-CC were higher in Group S than in Group P, with values always > 0.8. Significative differences in EI and SR were detected between groups and between Group S and the affected limb of Group P; values were lower in Group S than in Group P. Conclusions SE can be a useful technique for evaluating DJCs, with good repeatability and reproducibility. DJCs appear softer in sound horses.

Extracorporeal shockwave therapy in an immobilized knee model in rats prevents progression of joint contracture

“…35 Fibrosis and inflammation alter joint capsule elasticity. 29,37 For instance, posterior-capsule elasticity increased following joint immobilization, in the same rat model as the present study. 29 In our study, at 6 weeks, posterior joint-capsule sound speed was significantly lower in the ESWT group than in the control, indicating that ESWT suppressed immobilization-induced changes in joint-capsule elasticity.…”

“…ESWT improves tissue elasticity, 35,36 for instance, by improving plantar fascia shear wave elastosonographic velocity 35 . Fibrosis and inflammation alter joint capsule elasticity 29,37 . For instance, posterior‐capsule elasticity increased following joint immobilization, in the same rat model as the present study 29 .…”

Osteoarthritis: a common disease that should be avoided in the athletic horse’s life

“…The power Doppler tool can provide further information on increases in vascularization of the joint synovium and capsule, reflecting the inflammation of such tissues ( Yamada et al, 2020 ). Strain elastosonography has recently been reported as an additional tool for ultrasonographic imaging, aiming to detect reduced elasticity (increase in stiffness) in the joint capsule ( Straticò et al, 2021 ).…”