Intra-articular treatment of osteoarthritis of the knee: An arthroscopic and clinical comparison between sodium hyaluronate (500-730 kDa) and methylprednisolone acetate

Corticosteroids have long represented the drugs of choice for intra-articular treatment of osteoarthritis (OA), but their use has drawbacks, indicating the need for alternatives devoid of these effects. This comparative study examined the clinical efficacy and the structural effects of intra-articular injections of sodium hyaluronate (HA) of molecular weight (MW) 500-730 kDa (one injection weekly for 5 weeks) versus methylprednisolone acetate (MP) (one injection weekly for 3 weeks) in the treatment knee OA. We studied 99 patients with knee OA, primary or secondary to a traumatic event, classified according to criteria of the American College of Rheumatology. Pain assessments by VAS and arthroscopic examinations of synovial membrane and cartilage were performed at baseline and 180 days after the start of the treatment. Arthroscopic features were evaluated under blind conditions. Initially, MP showed a more immediate beneficial clinical effect in reducing pain than HA, but after 180 days the symptomatic effect of HA was more long lasting than that of MP. Arthroscopic findings at day 180, in comparison with baseline conditions, showed that both drugs were decreased synovial membrane inflammation but HA was superior to MP in reducing the grade and extent of cartilage damage. HA of 500-730 kDa represents a valid alternative to corticosteroids in the intra-articular treatment of OA with a beneficial effect on the structural alterations. This study supports previous data on a potential structure-modifying activity of HA in OA of the knee.