Hyaluronic acid injections for knee arthritis ineffective, surgery for meniscal tears noninferior to PT, studies find
A meta-analysis found no significant change in pain and more adverse events with viscosupplementation for osteoarthritis of the knee compared to placebo, while another study offered longer-term evidence that surgery was no better than physical therapy (PT) for degenerative meniscal tears.
Injections of hyaluronic acid to treat knee osteoarthritis make almost no difference in pain and might increase risk of adverse events, a meta-analysis concluded.
Researchers reviewed 169 trials involving 21,163 patients that compared viscosupplementation with placebo or no treatment for pain and function in patients with knee osteoarthritis. Results were published by The BMJ on July 6.
The main analysis included a subset of 24 large trials of higher methodological quality involving 8,997 patients. Viscosupplementation was associated with a small reduction in pain compared with placebo, but the difference was small, described by the reviewers as “clinically irrelevant” (standardized mean difference, −0.08; 95% CI, −0.15 to −0.02). The effect corresponds to a difference in pain scores of −2.0 mm (95% CI, −3.8 to −0.5 mm) on a 100-mm visual analogue scale, they noted. Based on 15 large, placebo-controlled trials with 6,462 randomized participants, viscosupplementation was associated with a statistically significant higher risk for serious adverse events than placebo (relative risk, 1.49; 95% CI, 1.12 to 1.98).
The authors noted some limitations, including that the study's summary estimates do not exclude the possibility that selected patient populations could benefit from viscosupplementation. Also, the study examined adverse events that emerged rather than adverse events that were directly and clearly related to treatment.
“Strong conclusive evidence indicates that, among patients with knee osteoarthritis, viscosupplementation is associated with a clinically irrelevant reduction in pain intensity and with an increased risk of serious adverse events compared with placebo,” the authors wrote. “Our findings do not support the broad use of viscosupplementation for the treatment of knee osteoarthritis.”
In other recent research on knee care, a study published by JAMA Network Open on July 8 reported follow-up results of a trial from nine hospitals in the Netherlands that compared the effectiveness of meniscectomy and physical therapy on patient-reported knee function and progression of knee osteoarthritis in patients with a degenerative meniscal tear.
Patients ages 45 to 70 years with a degenerative meniscal tear were randomized to arthroscopic partial meniscectomy or 16 sessions of exercise-based physical therapy. The primary outcome was patient-reported knee function as measured by the International Knee Documentation Committee Subjective Knee Form (range, 0 [worst] to 100 [best]) during five years of follow-up based on the intention-to-treat principle. The secondary outcome was progression in knee osteoarthritis shown on radiographic images.
Of 321 patients (mean age, 58 years; 50.2% women), 278 patients (87.1%) completed follow-up, with a mean follow-up time of 61.8 months (range, 58.8 to 69.5 months). The mean (SD) improvement was 29.6 (18.7) points in the surgery group and 25.1 (17.8) points in the physical therapy group. The crude between-group difference was 3.5 points (95% CI, 0.7 to 6.3 points; P<0.001 for noninferiority), which did not exceed the noninferiority threshold of 11 points. Comparable rates of progression of radiographic-demonstrated knee osteoarthritis were noted in both groups.
Based on these results, physical therapy should therefore be the preferred treatment over surgery for degenerative meniscal tears, according to the authors, who noted that their findings can be used to develop and update guideline recommendations about treatment for patients with a degenerative meniscal tear.
An editorial stated that the five-year results are important compared to the previously reported two-year results, since durability is relevant. “[T]he issue really is why we are comparing arthroscopy with physical therapy for this patient population when the inefficacy of arthroscopy has been shown,” the editorial said. “Multiple studies, including several with sham surgeries as a control have shown repeatedly over the previous 2 decades that surgery is not superior to physical therapy, yet the issue and use of surgery persist.”