Researched just published this week shows that they don't help pain any more than saline injections (placebo) and worsen arthritis in the knees!
Read on (from link above)...
Intra-Articular Corticosteroids Show No Benefit in Knee Osteoarthritis
By Amy Orciari Herman
Edited by David G. Fairchild, MD, MPH, and Lorenzo Di Francesco, MD, FACP, FHM
Intra-articular triamcinolone does not help relieve knee pain in adults with osteoarthritis — and might even lead to harm — according to a placebo-controlled trial in JAMA.
Some 140 adults with symptomatic knee osteoarthritis and ultrasound evidence of synovitis were randomized to receive intra-articular injections of either the corticosteroid triamcinolone (40 mg) or saline every 12 weeks for 2 years. At the end of the study, magnetic resonance imaging showed significantly greater knee cartilage volume loss with triamcinolone than with placebo, with no difference in knee pain between the groups.
The authors note, "It is likely that the difference in cartilage loss rates between groups was due to an adverse effect of intra-articular corticosteroids on cartilage rather than a benefit from intra-articular saline." They conclude, "These findings do not support [triamcinolone] for patients with symptomatic knee osteoarthritis."