Do hyaluronic acid injections relieve OA knee pain?
Two RCTs show no difference in efficacy among HA products
The Cochrane review determined that not enough evidence existed to evaluate HA products against each other. Two subsequent RCTs compared HA products and found no differences in efficacy. One study compared Synvisc, Orthovisc, and Ostenil therapy in 660 patients over 6 months.4 The other compared Synvisc with Euflexxa in 321 patients over 3 months.5 Notably, 8% of patients in this study who used Synvisc developed an effusion, compared with 0.6% of patients who used Euflexxa (P=.0015).
Recommendations
,A 2007 report from the Agency for Healthcare Research and Quality (AHRQ) states that “viscosupplementation trials generally report positive effects on pain and function scores compared with placebo, but the evidence on clinical benefit is uncertain.”6
The 2007 guidelines of the Institute for Clinical Systems Improvement note that synthetic hyaluronates “may be effective” in selected patients with mild to moderate degenerative joint disease (based on evidence of middle quality on a 3-tier grading system).7
The American Academy of Orthopaedic Surgeons 2008 guideline on osteoarthritis of the knee indicates that, based on the AHRQ report,6 it cannot recommend for or against the use of intra-articular hyaluronic acid for mild to moderate symptomatic OA of the knee.8
TABLE 2
How HA products affect pain measures
| AT 1-4 WEKS | AT 5-13 WEKS | |||||
|---|---|---|---|---|---|---|
| PRODUCT | COMPARATOR | OUTCOME | N | PERCENT CHANGE VS COMPARATOR* (95% CI) | N | PERCENT CHANGE VS COMPARATOR* (95% CI) |
| HA/hyalin | Placebo | Pain on weight bearing | 2542 | -8 (-11 to -4) | 2090 | -13 (-18 to -8) |
| Hyalgan | Placebo | Pain on weight bearing | 1398 | -6 (-11 to -1) | 1095 | -9 (-14 to -4) |
| Synvisc | Placebo | Pain on weight bearing | 481 | -13 (-20 to -5) | 155 | -10 (-14 to -5) |
| Suplasyn | Placebo | WOMAC pain | 53 | NS | (Data not available) | |
| Durolane | Placebo | WOMAC pain | 346 | 4 (0 to 7) | 436 | NS |
| Orthovisc | Placebo | WOMAC pain | 110 | -12 (-13 to -10) | 69 | -5 (-7 to -4) |
| HA/hyalin | NSAID | Pain after walking | 333 | NS | (Data not available) | |
| Hyalgan | NSAID | Pain after 50-foot walk | 279 | NS | 140 | NS |
| Synvisc | NSAID | Pain at rest | (Data not available) | 57 | NS | |
| Suplasyn | NSAID | Pain after walking | 54 | NS | (Data not available) | |
| Hyalgan | Methylprednisolone | Spontaneous pain | 170 | NS | 170 | -8 (-13 to -3) |
| Synvisc | Triamcinolone | WOMAC pain, walking | (Data not available) | 215 | -10 (-17 to -3) | |
| Orthovisc | Methylprednisolone | Pain, walking | 55 | NS | 55 | -18 (-29 to -8) |
| Us medications Supartz and Euflexxa were not included in the Cochrane review. | ||||||
| CI, confidence interval; HA, hyaluronic acid; NS, not statistically significant; NSAID, nonsteroidal anti-inflammatory drug; WOMAC, Western Ontario and MacMaster universities Osteoarthritis Index. | ||||||
| *Negative values favor HA products. | ||||||
| Source: Bellamy n, et al. Cochrane Database Syst. Rev. 2006.3 | ||||||
