ACAN and Arthritis: LIPUS can stimulate the primary cilia of chondrocytes, activate the TRPV4 pathway, regulate the intracellular Ca2 + concentration, inhibit the endoplasmic reticulum stress, reduce the apoptosis of chondrocytes, increase the expression of COLII and ACAN, regulate the metabolism of the cartilage matrix, change the force of the chondrocytes in the matrix, and regulate the size and morphology of the chondrocytes, so as to form the new dynamic equilibrium between the chondrocytes and cartilage matrix, and ultimately slow down the development of arthritis.