Abstract: A system for the therapeutic treatment of joints comprising a composite material comprising a biodegradable polymer matrix and a plurality of piezoelectric particles adapted to generate local electric charges in response to an external stimulation made by means of ultrasound, said plurality of piezoelectric particles being dispersed in the matrix. The composite material also comprises a plurality of stamina cells dispersed in the biodegradable polymer matrix and a plurality of carbon-based particles. The system also comprises a releasing device, arranged to deposit the composite material in a joint cavity at predetermined areas of the cartilage, and a stimulator device arranged to emit ultrasound at a predetermined frequency, a predetermined intensity and for a predetermined time of application, in such a way that, when the device is located near a joint wherein the composite material has been deposited, said ultrasound stimulate the plurality of piezoelectric particles.