ASK DIS: Corticosteroid Intra-Articular Injection: Osteoarthritis

associated with a breakdown of cartilage of the joints, such as the knee.
When the joint loses cartilage, the body responds by growing bone abnormally, which can result in the bone becoming misshapen and the joint painful and unstable
Although osteoarthritis is generally thought to be of degenerative rather than inflammatory origin, an inflammatory component may be present at times.
Intra-articular corticosteroids are potent anti-inflammatory agents injected inside the knee joint.

Indication

Rationale for Use

Intra-articular corticosteroids reduce synovial blood flow, lower the local leukocyte and inflammatory modulator response, and alter local collagen synthesis.
These effects combine to reduce pain and inflammation
For short-term treatment of osteoarthritis of the knee, intra-articular steroid injection improves function and reduces swelling and pain.
onset of action is rapid (typically within 24 hours) and clinical effects last four to eight weeks.
Repeated steroid injections for osteoarthritis of the knee are safe and do not accelerate disease progression.
Although steroid injections are effective for osteoarthritis of the hip, technical challenges with this procedure preclude its routine use

Opposing Findings

Whether there are clinically important benefits of intra-articular corticosteroids after one to six weeks remains unclear in view of the overall quality of the evidence, considerable heterogeneity between trials, and evidence of small-study effects.
A single trial included in this review described adequate measures to minimise biases and did not find any benefit of intra-articular corticosteroids.
most of the identified trials that compared intra-articular corticosteroids with sham or non-intervention control small and hampered by low methodological quality.
An analysis of multiple time points suggested that effects decrease over time

Selection of Agents

little systematic evidence to guide corticosteroid selection for therapeutic injections.
Most recommendations are based on a combination of clinical experience and personal preference
Hydrocortisone esters are more effective in producing these effects than their parent compounds. Branched esterification further reduces solubility, allowing steroids to remain at the injection site longer.
Clinically, insoluble steroids have a longer duration of action and a higher incidence of cutaneous side effects.
Triamcinolone hexacetonide (Aristospan) is the least soluble of the commonly used injectable steroids, followed by triamcinolone acetonide (Kenalog)
methylprednisolone acetate (Depo-Medrol) is the most commonly used intra-articular steroid, followed by triamcinolone hexacetonide and triamcinolone acetonide in US
Many physicians empirically use triamcinolone hexacetonide (low solubility, longer duration of action) for intra-articular injection, and betamethasone (high solubility, shorter duration of action, fewer cutaneous side effects) for soft tissue injections
A recent review by the National Health Service of the United Kingdom recommends triamcinolone and methylprednisolone as preferred agents for injection of large joints (e.g., knee).
For smaller joints (e.g., finger), either hydrocortisone or methylprednisolone is recommended.

Local Anaesthetic

often combined with corticosteroids for intra-articular injection.
Local anesthetics relieve pain and can be used diagnostically to differentiate between local and referred pain.
They also add volume to the injectate and help to distribute corticosteroid within the joint space.

References:

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