Osteoarthritis (OA) knee is the most common debilitating degenerative disorder beyond age 60 seeking medical attention for disabling pain and progressive reduction of joint movements and functional limitation. Conservative and rehabilitative measures remain the mainstay for early stages. In the recent years, intra articular injections particularly steroids and viscosupplementation are increasingly used for early stage management and have raised concerns about their efficacy. Various studies have claimed that intra-articular viscosupplementation with Hyaluronic acid (HA), specially hylan G-F 20 appeared to be safe, effective in pain relief and improved functional outcomes. Having this hypothesis, we wanted to analyze in detail by using various outcome scores (VAS, WOMAC, SF-36) and compare it with the steroids (methyl prednisolone acetate).
Materials and methods: After the institutional review board clearance, this study was conducted as a randomized, prospective study between July 2012 and April 2015. Patients of both sexes beyond age 40 with symptomatic knee OA demonstrating radiological evidence of arthritis [Kellgren-Lawrence (K-L) grade of less than III were randomized into two groups. Patients in the steroid group (group 1, MPG) were subjected to two sittings of intra-articular 6-Methylprednisolone acetate 40mg each (day 0 and day 7). Patients in viscosupplementation group (group 2, HG) were given a single intra-articular injection of hylan G-F 20. Both groups were given standard physiotherapy regimen post-injection. We used the following parameters to measure outcome, 1) 100 mm visual analog pain scale (VAS), 2) Western Ontario and McMaster Universities Osteoarthritis index (WOMAC), 3) SF-36 health survey and 4) Range of motion (ROM) to document the baseline characteristics and subsequent follow ups at 2nd, 4th, 12th, 24th and 52nd week.
Results: Among the 68 enrolled patients, no statistically significant differences were found regarding demographic patterns and the baseline outcome scores of patients between two groups. The mean age, grade and duration at presentation among the two groups were 56.57 /59.83 years, grade 2 and 3.4 / 3.8 years respectively. At 54 weeks, HG group had a mean ROM of 126.93o compared to 120.83oin the MPG group (p=0.001). Regarding VAS, better pain relief (24.80) was noted in the MPG during early period (<3 weeks) as against the HG (67.10). However, reversal of results was noted in the later period (>3 months) with the VAS scores doing significantly better in the HG group (18.67) as against MPG (61.18). In the HG group, WOMAC scores revealed a delayed (>4 weeks) onset of improvement, with plateau formation at 6th month (28.43). Early improved WOMAC scores in the MPG showed a decreasing trend reaching pre-injection baseline level (55.93) within 3 months. Post-treatment SF-36 health survey at final follow-up revealed that, patients in hylan group showed greater improvement of mean score from baseline in all 8 functional categories compared to corticosteroid group (p value < 0.001).
Conclusion: With regard to the intra articular injections in the management of early osteoarthritis, Hylan-G-F-20 has shown a sequential improvement in quality of life beyond 3 weeks post-injection lasting for more than six months. Methylprednisolone acetate gave improved early (<3 weeks) response with effect not sustained for more than 3 months.