Synvisc-One for Younger, Active Patients With Osteoarthritis

Inclusion Criteria: * Male or female patients aged 30-50 years * History of symptomatic unilateral primary or secondary knee OA for more than 6 months * Signed written informed consent * Radiographic evidence of Kellgren-Lawrence Grade I or II OA of the target knee * Body Mass Index (BMI) \< 30 kg/m2 * Activity criteria (Tegner score \> 3) * Continued target knee OA pain despite conservative treatment ≥ 3 months (e.g., weight reduction, physical therapy, analgesics) * Willing to withhold intake of NSAIDs (including COX-2 inhibitors) and analgesics, for a washout period of minimum 3 days up to 21 days prior to baseline visit (depending on medication) * Willing to discontinue prohibited treatments and medications throughout study period Baseline inclusion criteria * Completed OA medication washout period * Target knee pain 4-8 (0-10 NRS) during most painful knee movement (Worst Knee Pain) * If female, must have had a negative urine pregnancy test and used a medically acceptable form of contraception for at least 1 month prior to baseline and agree to continued use of contraception for the duration of the study. Otherwise, females must be surgically sterile, or postmenopausal (as documented in medical history) for at least 1 year. The fetal safety profile for G-F 20 is unknown. Pregnancy will affect the individual's regular activity levels. Females who become pregnant during the study will be excluded from the study. Subjects who become pregnant will be followed up by telephone every 3 months to check for any adverse effects. They will also be recommended to follow routine obstetric visits. Males should be able to father children as it has no expected effects on activity levels. Exclusion Criteria: * Known allergy to hylan G-F 20 or any of its components, or to avian proteins, eggs, feathers, down, or poultry * Clinically apparent tense effusion or other acute inflammation of the target knee at baseline * History of target knee viscosupplementation treatment * History of major surgery for OA in target knee including arthroplasty or tibial osteotomy * Arthroscopic surgery or intraarticular steroid injection in target knee within six months of baseline visit * Significant (as judged by the Investigator) alignment deformity of target knee * Ipsilateral symptomatic OA of hip or ankle; contralateral symptomatic OA of hip, knee, or ankle History of: * Septic OA of any joint * Inflammatory arthropathy such as RA, gout, pseudogout, lupus, crystalline inflammatory arthropathy * Active infection of lower extremity * Known significant acute and/or concurrent medical disease including, but not limited to current malignancy, history of transplant surgery, congestive heart failure, significant unstable cardiovascular disease, renal hepatic pulmonary, endocrine, metabolic, or GI condition * Any known contraindication to acetaminophen * Venous or lymphatic stasis in either leg * Peripheral vascular disease * Patient has been prescribed chronic opioid analgesics at time of baseline visit * Concurrent multi-system or multi-limb trauma * Patient plans to become pregnant during study period * Patient plans to move significantly out of area, have surgery, or initiate or cease other OA treatments * Knee pain improves during washout period * Workman's Comp patient