Osteoarthritis (OA) is a complex "whole
joint" disease pursued by inflammatory mediators, rather than purely a process of "wear and tear". Besides cartilage degradation,
synovitis, subchondral bone remodeling, degeneration of ligaments and menisci, and
hypertrophy of the joint capsule take parts in the pathogenesis.
Pain is the hallmark symptom of OA, but the extent to which structural pathology in OA contributes to the
pain experience is still not well known. For the knee OA, intraarticular (IA) injection (
corticosteroids,
viscosupplements, blood-derived products) is preferred as the last nonoperative modality, if the other
conservative treatment modalities are ineffective. IA
corticosteroid injections provide short term reduction in OA
pain and can be considered as an adjunct to core treatment for the relief of moderate to severe
pain in people with OA. IA
hyaluronic acid (HA)
injections might have efficacy and might provide
pain reduction in mild OA of knee up to 24 wk. But for HA
injections, the cost-effectiveness is an important concern that patients must be informed about the efficacy of these preparations. Although more high-quality evidence is needed, recent studies indicate that IA platelet rich plasma
injections are promising for relieving
pain, improving knee function and quality of life, especially in younger patients, and in mild OA cases. The current literature and our experience indicate that IA
injections are safe and have positive effects for patient satisfaction. But, there is no data that any of the IA
injections will cause
osteophytes to regress or cartilage and meniscus to regenerate in patients with substantial and irreversible bone and cartilage damage.