Combining two hyaluronic acids in osteoarthritis of the knee


Background

Synovial fluid in patients may differ in molecular weight depending on the presence and degree of osteoarthritis. Treatment is not directed at this relationship. Patients with osteoarthritis of the knee with resting visual analogue scale (VAS) pain of >45 mm were included in a randomized, prospective, double-blind cohort followed for 16 weeks.

Method

Patients were randomized at baseline to receive a three intra-articular injection series with one of: dual molecular weight (DMW; 580–780 kDa+1.2 to 2.0 million Da); low molecular weight (LMW; 500–730 kDa); high molecular weight (HMW; 6 million Da); or saline placebo over 3 weeks. Patients completed baseline assessment of rest and walking VAS pain (primary efficacy variable), collection of a 5-point categorical global satisfaction score, and record of adverse events. Two-hundred and twenty-five patients (age 68±8 y) were screened and 200 were randomized to one of the four groups. There were no differences at baseline between groups.

Results

At 4, 12 and 16 weeks, respectively, walking VAS pain was significantly improved in all treatment groups vs. placebo: DMW (79.6%, p<0.001; 85.6, p<0.001; 89.3%, p<0.001); LMW (73.6%, p<0.001; 76.4, p<0.001; 81.3%, p<0.001) and HMW (69.1%, p<0.001; 81.0, p<0.001; 79.1%, p< 0.001). Patients in the DMW group had significantly greater improvement (p<0.007) in VAS walking pain by 3 weeks (following the second injection) compared to all groups. This difference was persistent at 16 weeks. Greater improvement in patients who received the DMW product was achieved by the second injection persistent at16 weeks.

Conclusion

Hyaluronic acid injections were highly satisfactory to patients with each HA series and included a very low rate of local adverse events. This supports previous reports that HA treatment of osteoarthritis of the knee is a safe, effective therapeutic option. Our findings suggest that alteration of MW range may further improve outcomes in these patients.

Long term efficacy and safety of a combined low and high molecular weight hyaluronic acid in the treatment of osteoarthritis of the knee


Abstract

Similar differences were observed for walking VAS 39, 41 and 43 (DMW, LMW, HMW) received repeat injections.

At 104 weeks, these differences were similar. DMW and LMW had no reported adverse events; HMW had 2 local reactions at 52 weeks and 1 at 104 weeks. There were no serious adverse events. Non- serious adverse events included pain and local swelling at the injection site (21%), erythema at the injection site (12%) and stiffness in the index knee (7%). Intra-articular hyaluronic acid injections using any of low, high or combined MW were highly effective in improving resting and moreso, walking pain in patients with osteoarthritis of the knee.

Greater improvement in both rest and activity outcomes in patients who received the DMW product, with concomitantly greater patient satisfaction and fewer use of concomitant therapeutic modalities at 16, 52 and 104 weeks suggest that combining a range of MW hyaluronic acid may be advantageous long term, particularly among active osteoarthriris patients.

Method

The primary objective of this study was to determine the efficacy and safety of intraarticular combined molecular weight hyaluronic acid in knee osteoarthritis as evaluated through the self-paced 40-m walking pain visual analog scale (VAS) at week 16, 52 and 104.

The secondary endpoints included: pain at rest. A 10 cm VAS, patient global satisfaction using a 5-point numerical scale, consumption of concomitant medications, number of patients with <45 mm pain at followup 52 and 104 weeks, and safety through the number of recorded adverse events. Patients received intra-articular injection once weekly for three weeks. Patients were followed up at week 16, 52 and 104.

Results

Greater improvement in patients who received the DMW product was achieved by the second injection and was persistent to 16 weeks.

At 52 weeks, 8 patients in DMW had VAS <45 mm and were not given repeat injections. At 104 weeks, 9 patients had VAS pain <45 mm in the DMW while all in the LMW or HMW groups was >45 mm.

DMW walking pain reduction was significantly greater than either of the LMW or HMW groups.

Again, those who received DMW had significantly greater walking pain reduction compared to the other 2 groups.

At 52 weeks, 8 patients in DMW group had resting VAS <45 mm. DMW had lower (62 mm, P<0.001) compared to LMW (76 mm) and HMW (88 mm) VAS at rest.

Global satisfaction was significantly higher for the DMW group compared to the other groups at 16, 52 and 104 weeks (P<0.005).

Patients in the DMW group had significantly greater improvement at 16, 52 and 104 weeks (P<0.001) compared to the other active treatment groups which did not differ from each other.

Further, fewer concomitant treatments (ie PT, acupuncture) were utilized by those who received DMW compared to the other treatments at all followup periods.

Similar trends in secondary outcomes were also observed at all time points. Combination of HA of lower and higher ranges of MW with low and high concentrations, may provide patients with a more physiologically dynamic HA viscosupplementation and hence a more responsive synovial rheology that improves pain and function in their osteoarthritic knee.

Conclusion

Greater improvement in patients who received the DMW product was achieved by the second injection persistent to 104 weeks.

Combination of Sodium Hyaluronate of lower and higher ranges of molecular weight with low and high concentrations, may provide patients with a more physiologically dynamic HA viscosupplementation and hence a more responsive synovial rheology that improves pain and function in their osteoarthritic knee.

The full clinical study can be found here.

Long-Term Efficacy And Safety Of A Combined Hyaluronic Acid In Osteoarthritis Of The Knee - POSTER PRESENTED AT EULAR 2010


The poster form of RenehaVis™ long term study was presented at EULAR 2010 in Rome. Please click on the document below to see a copy of this poster.