In patients with symptomatic knee osteoarthritis (OA), tenderness around the knee was linked to better short-term outcomes with intra-articular steroid injections, according to study results published in The Journal of Rheumatology.
However, the results indicated that clinical factors did not predict longer-term response to intra-articular steroid injections. In addition, patients with chronic widespread pain and depressive symptoms had a reduced likelihood of achieving longer-term benefits.
The study included participants age ≥40 with painful OA who participated in an open label trial of intra-articular steroid injections (n=199). Participants completed questionnaires and underwent clinical examination. The researchers used OMERACT-OARSI criteria to assess short-term response to therapy (within 2 weeks).
In participants who initially responded, patients whose pain had not returned to within 20% of their baseline Knee Injury and Osteoarthritis Outcome Score (KOOS)-pain score at 6 months were considered longer-term responders. The researchers used log binomial regression to determine factors associated with outcome.
Of 199 participants, 73.4% (n=146) were short-term responders and 20.1% (n=40) were longer-term responders.
Compared with short-term nonresponders, participants with medial joint-line tenderness (relative risk [RR], 1.42; 95% CI, 1.10-1.82), medial and lateral joint-line tenderness (RR, 1.38; 95% CI, 1.03-1.84), patellofemoral tenderness (RR, 1.27; 95% CI, 1.04-1.55), anserine tenderness (RR, 1.27; 95% CI, 1.06-1.52), and the belief that treatment would be effective (RR per unit increase, 1.05; 95% CI, 1.01-1.09) were more likely to be short-term responders.
The results indicated that aspiration of joint fluid (RR, 0.79; 95% CI, 0.66-0.95) and previous ligament or meniscus injury (RR, 0.63; 95% CI, 0.44-0.91) were associated with a reduced risk of being a short-term responder.
The researchers found that participants with a higher number of pain sites (RR per unit increase, 0.83; 95% CI, 0.72-0.97), chronic widespread pain (RR, 0.32; 95% CI, 0.10-0.98), perceived chronicity of disease (RR per unit increase, 0.86; 95% CI, 0.78-0.94) and a higher depression score(RR per unit increase, 0.89; 95% CI, 0.81-0.99) were less likely to be longer-term responders compared with initial non-responders and patients whose pain recurred within 6 months.
“Our data suggest there may be a limited role for clinical phenotyping in relation to targeting [intra-articular steroid injections] therapy in patients with joint disease though due to the exploratory nature of our study, other studies are required to confirm our findings,” the researchers wrote.
Maricar N, Parkes MJ, Callaghan M, et al. Do clinical correlates of knee osteoarthritis predict outcome to intra-articular steroid injections? [published online April 1, 2019]. J Rheumatol. doi:10.3899/jrheum.180233