Purpose: The purpose of this study is to demonstrate if the intra-articular injection of a new viscoelastic Hydrogel (Hymovis) is superior to Placebo (phosphate buffered saline [PBS] in subjects with symptomatic osteoarthritis of the knee.

Inclusion Criteria:

1. Male or female ambulant outpatients ≥ 40 years of age with an active lifestyle:
2. Has a medical history of OA symptoms confirmed at least 3 months prior to the screening visit with radiographic evidence of OA, Kellgren-Lawrence grade 2-3
3. Discontinuation of any analgesic/NSAID therapy prior to baseline with no intent to resume during study

Exclusion Criteria:

1. Clinically significant apparent large effusion of the target knee;
2. Clinically significant valgus/varus deformities, ligamentous laxity or meniscal instability as assessed by the Investigator;
3. Any musculoskeletal condition affecting the target knee that would impair assessment of the effectiveness in the target knee such as Paget's disease
4. Medical history of anaphylactic reactions
5. History of septic arthritis in any joint
6. Females who are pregnant or breast-feeding