Extracorporeal Shock Wave Rebuilt Subchondral Bone In Vivo and Activated Wnt5a/Ca2+ Signaling In Vitro

Background This study aimed to identify the optimal extracorporeal shock wave (ESW) intensity and to investigate its effect on subchondral bone rebuilt in vivo and Wnt5a/Ca2+ signaling in vitro using an osteoarthritis (OA) rat model and bone marrow mesenchymal stem cells (BMMSCs), respectively. Methods OA rats treated with (OA + ESW group) or without (OA group) ESW (n = 12/group) were compared with healthy controls (control group, n = 12). Gait patterns and subchondral trabecular bone changes were measured. Western blot and quantitative real-time polymerase chain reaction detected protein expression and gene transcription, respectively. Results The gait disturbances of OA + ESW group were significantly improved compared with the OA group at 6th and 8th weeks. The micro-CT analysis indicated that the BMD, BSV/BV, BV/TV, Tr.S, and Tr.Th are significantly different between OA group and OA + ESW group. Expression of Wnt5a was increased rapidly after ESW treatment at 0.6 bar and peaked after 30 min. Conclusions ESW were positive for bone remodeling in joint tibial condyle subchondral bone of OA rat. ESW prevented histological changes in OA and prevented gait disturbance associated with OA progression. Optimal intensity of ESW induced changes in BMMSCs via activation of the Wnt5a/Ca2+ signaling pathway.