INTRAARTICULAR HYALURONIC-ACID IN THE TREATMENT OF OSTEOARTHRITIS OF THE KNEE - CLINICAL AND MORPHOLOGICAL-STUDY

Objective To evaluate, in a pilot, open clinical trial on 40 patients with knee osteoarthritis, the structural changes in the synovial membr ane and cartilage following treatment with intra-articular hyaluronic acid (HA-Hyalgan(R)). Methods The structural effects of HA given as 5 weekly injections (20 mg/2 mi once a week for 5 weeks), were evaluated by microarthroscopy and morphological analysis of biopsy samples take n at baseline and after 6 months, under blind conditions. Clinical eff icacy was also evaluated using visual analogue scales for pain and fun ctional parameters. Results At 6 months, the microarthroscopic evaluat ion indicated that the majority of the patients (60%) showed no change s compared to baseline, while 32.5% of the patients showed improvement in the grading and/or extension of cartilage lesions and 7.5% showed a worsened condition. These changes were accompanied by a statisticall y significant reduction in the synovial inflammation (p = 0.001). The results were confirmed by morphological examination of the cartilage a nd synovial membrane. At 6 months compared to baseline, a statisticall y significant reconstitution of the superficial amorphous layer of the cartilage (p = 0.0039), an improvement in the chondrocyte density (p = 0.0023) and vitality (p = 0.05), and a statistically significant red uction in synovial inflammation (p = 0.0001) accompanied by a signific ant increase in the synovial repair process (p = 0.0001) were observed . Significant and long lasting improvement in pain and joint mobility were also seen after HA treatment. Joint effusion when present, was re duced. The treatment was well tolerated. Conclusion Hyalgan(R) represe nts a useful therapy for knee OA, with long-lasting symptomatic effica cy and potential positive effects on joint tissues. Other studies, in particular placebo-controlled studies, are warranted to confirm these promising results observed on joint tissues.