A review published in RMD Open discussed the literature currently available regarding intra-articular therapies (IAT) for autoimmune and rheumatic diseases.
“As around the world life expectancy, obesity, and sedentary lifestyle increase, the burden of disease imposed by chronic arthropathies and their comorbidities also increases, thus providing the right scenario for local treatments such as IAT, while the search for disease-modifying osteoarthritic drugs continues,” the researchers explained. “Based on all this, a task force was assembled by the EULAR to produce recommendations for IAT in arthropathies. The objective of the present work was to inform the task force about the current state of the evidence.”
They reviewed systematic reviews (SRs) including randomized, controlled trials of IAT in adult patients through July 2020. The main efficacy and safety outcomes, respectively, were pain, function, and frequency of adverse events (AEs).
A total of 184 references were identified, of which 16 were eligible for inclusion; a search of the references of these items yielded 16 additional SRs, and after a full quality assessment, the final analysis comprised 29 SRs. The SRs focused on osteoarthritis (OA) of the knee (n=18), OA of the hip (n=6), shoulder capsulitis (SC; n=3) and rheumatoid arthritis (n=3).
IAT: Outcomes Vary by Condition, More Research Needed
Hyaluronic acid had a small effect on pain and function in knee OA, but this was not observed in hip OA or SC. Intra-articular glucocorticoids too had a small effect on pain and function in knee OA, as well as function in hip OA and SC. Platelet-rich plasma also impacted both pain and function in knee OA, but not hip OA. Data were similar for mesenchymal stem cells.
Regarding RA, one study found that hyaluronic acid was superior to placebo for pain, global inflammation, and self-reported effectiveness. Another study observed no differences in the number of flares, ROM, morning stiffness, grip strength, Ritchie articular index, or thermography index among methylprednisolone acetate, triamcinolone acetonide, or triamcinolone hexacetonide.
The quality of SR results tended to be moderate, the researchers noted, adding that “RCTs included often presented a high risk of bias, mainly due to inadequate blinding and heterogeneous results.” Safety signals did not largely differ among the data.
“In summary, the evidence shows that IAT in the most frequent arthropathies is well tolerated, with a very low frequency of AEs, but only marginally efficacious in the short-to-medium-term when compared with placebo. Nonetheless, it should be noted that the limited data found regarding the efficacy and safety of IAT in inflammatory arthropathies prevented us from drawing firm conclusions,” the researchers wrote in their conclusion.
A limitation of the study is that it only included SRs of RCTs, possibly leaving out other data. Additionally, different studies evaluated different outcomes: most studies evaluated pain and function, which are common outcomes, but far fewer assessed joint space narrowing or cartilage volume loss.