Study of Evaluating the Duration of Efficacy of One Intra Articular Injection of Sodium Hyaluronate 2.0% in Patients With Painful Osteoarthritis of the Knee

Inclusion criteria

• Patients of both genders between 40 and 70 years of age;
• Primary tibiofemoral osteoarthritis of the knee according to American College of Rheumatology criteria;
• Pain ≥ 4 on a 10 point scale for at least two out of five subscores of the WOMAC Section A at baseline;
• Radiologically ascertained grade II or III severity knee osteoarthritis on the Kellgren-Lawrence scale;
• Having given signed informed consent.

Exclusion criteria

• Secondary knee osteoarthritis, including:

• septic arthritis;
• inflammatory joint disease;
• gout;
• recurrent episodes of pseudogout;
• Paget's disease of bone;
• articular fracture;
• ochronosis;
• acromegaly;
• haemochromatosis;
• Wilson's disease;
• primary osteochondromatosis.
• Clinical signs of acute flare (pain, warm, erythema, effusion of signal knee) at baseline;
• Axial deviation > 15 degrees in valgus or varus on a standing X-ray;
• Clinically significant medio-lateral or antero-posterior instability;
• Rapid destructive arthritis, evolving arthritis requiring surgery within the coming year;
• Significant injury to the signal knee within 6 months prior to baseline;
• Complete loss of range of motion;
• Painful knee conditions other than osteoarthritis (e.g., Sudeck's atrophy, intra-articular neoplasm, villonodular synovitis);
• Necrosis of one of the femur condyles;
• History or evidence of gout, chondrocalcinosis;
• Peripheral neuropathy;
• Concomitant rheumatic disease:

• fibromyalgia;
• rheumatoid arthritis;
• collagen diseases;
• psoriatic arthritis and other seronegative spondylarthropathies (e.g., ankylosing spondylitis);
• metabolic and crystal-induced arthropathies;
• other osteopathies.
• Contraindications to intra-articular injection according to investigator's judgement (e.g., local infection at injection site, generalised infection with possible bacteraemia);
• Skin disease in the area of injection;
• Severe coagulopathy, ongoing anticoagulation therapy;
• Accompanying OA of the hip of sufficient severity to interfere with the assessment of the signal knee;
• Disease of spine, hip or other lower extremity joints of sufficient degree to affect assessment of the signal knee;
• Poor general health interfering with compliance or assessment;
• Concomitant disease/ailment other than knee OA requiring the regular use of the patient's normal analgesic medicine;
• Initiation of chronic treatment with antihistaminics, glucocorticoids, antidepressants or tranquilisers, within less than 3 months prior to baseline;
• Use of assistive devices other than a cane (walking stick);
• Surgery of the signal knee other than arthroscopy;
• Arthroscopy of the signal knee within one year prior to baseline;
• Treatment with symptomatic slow acting drug for OA (SYSADOA, i.e., chondroitin sulfate, diacerein, glucosamine, piascledine), unless the patient has been on a stable dose for at least 4 months prior to baseline;
• Intra-articular depocorticosteroid injection into the signal knee within 3 months prior to baseline;
• Intra-articular SH injection into the signal knee within 6 months prior to baseline;
• Ascertained hypersensitivity to any product used in the study (SH, paracetamol, diclofenac, omeprazole) or to similar compounds;
• Pregnant or lactating female;
• Female of childbearing potential without adequate contraceptive methods;
• Participation in a drug clinical trial within 3 months prior screening;
• Patients who, in the judgement of the investigator, will not comply with the protocol.