OST viscoelastic solution 20 mg / 2 ml, 1 pre-filled syringe. medical device intra-articular.injection OST viscoelastic solution 20 mg / 2 ml, 1 pre-filled syringe intended for use in the case of pain and limited mobility of the knee and other synovial joints in the course of degenerative and post-traumatic changes. pain, warmth, redness and swelling.