Corticosteroid Injections

Corticosteroids are powerful anti-inflammatory drugs. Injected close to the problem, they suppress local inflammation and reduce a swollen, painful synovium or bursa, which relieves pain and can improve movement. The commonly used agents are methylprednisolone acetate, triamcinolone acetonide and hydrocortisone acetate, and they are often mixed with a local anaesthetic such as lidocaine, which can give immediate analgesia and some information about the source of pain, although it does not prove accurate placement or the diagnosis. The relief they provide is typically short-term, so the injection is used to create a window for rehabilitation rather than as a treatment on its own.

The indications are broad. Corticosteroid injections are useful in adhesive capsulitis (frozen shoulder), subacromial-subdeltoid bursitis, de Quervain tenosynovitis, trigger finger, carpal tunnel syndrome, and bursitis such as greater trochanteric or olecranon bursitis, and they can settle a flare of inflammatory arthritis. In osteoarthritis (OA), including the knee, hip and base-of-thumb joint, they provide short-term relief: current UK osteoarthritis guidance suggests considering an intra-articular corticosteroid when other treatments are ineffective or unsuitable, or to support therapeutic exercise, and advises that the benefit is short-term, in the region of two to ten weeks. The key exception is the body of a tendon: corticosteroid is not injected into a tendon such as the Achilles or patellar tendon because of the risk of tendon rupture.

The risks of a corticosteroid injection are usually minor and self-limiting, but they are discussed in advance. The most common is a post-injection flare of pain in the first day or two, which settles with simple analgesia and an ice pack. Local skin effects can occur days to weeks later, including depigmentation of the overlying skin and atrophy of the fat beneath it at the injection site, and some people notice facial flushing. Blood glucose can rise temporarily after the injection, so a person with diabetes is advised to monitor their blood glucose more closely, particularly in the first one to three days, and for longer if readings remain high. Serious infection is rare but important, and tendon rupture is a specific risk if corticosteroid is injected into a tendon, which is why this is avoided. Rarely, there are systemic effects.

How often a joint can be injected is a common question, and there is no single universal rule. Decisions depend on the site, the diagnosis, how many injections have been given before, and how well previous injections worked. As a general principle, injections are spaced out and repeated cautiously rather than given frequently, and repeated injections into a weight-bearing joint are used with particular care, because of uncertainty about the effect of repeated corticosteroid on cartilage, and possible implications for any future joint surgery. A reasonable, individualised approach is to limit the number of injections into any one site and to reconsider the diagnosis and the wider management plan if a joint is needing repeated injections, rather than simply repeating the injection.

Anti-doping is a central consideration whenever a competing athlete is injected with a corticosteroid. Under the World Anti-Doping Agency (WADA) rules, injectable glucocorticoids are prohibited in-competition, so the timing of the injection matters. A washout period is left between the injection and competition, and the exact interval depends on the specific glucocorticoid, its dose and the route, since some preparations, particularly longer-acting ones, can remain detectable for longer. If a corticosteroid injection is clinically necessary, a therapeutic use exemption (TUE) is applied for prospectively where the rules require it, and a medical file with the diagnosis, imaging and clinical notes is kept; keeping a file does not by itself guarantee a retrospective exemption, which is allowed only under defined criteria and is not guaranteed.

Because anti-doping status and washout guidance change over time, the specific agent, route, dose and the athlete's competition schedule are always checked against the current Prohibited List and the agent-specific washout guidance before injecting, rather than relying on memory. Beyond anti-doping, the practical message is the same as for any injection: the corticosteroid injection is used to support rehabilitation and a wider management plan, the athlete is counselled on the expected short-term benefit and the risks, and the response guides whether and when any further injection is appropriate. Getting the timing and documentation right protects the athlete from an inadvertent anti-doping rule violation while still allowing appropriate treatment.

• •Corticosteroid injections suppress local inflammation and give short-term relief; they support rehabilitation rather than reliably promoting healing.
• •Common agents are methylprednisolone, triamcinolone and hydrocortisone, often mixed with lidocaine, which gives immediate analgesia and some information about the pain source but does not prove placement.
• •Indications include adhesive capsulitis, subacromial-subdeltoid bursitis, de Quervain tenosynovitis, trigger finger, carpal tunnel syndrome, bursitis and osteoarthritis; current UK osteoarthritis guidance suggests short-term relief of about two to ten weeks, used to support exercise.
• •Corticosteroid is not injected into the body of a tendon (such as the Achilles or patellar) because of rupture risk.
• •Risks include a post-injection flare, skin depigmentation and fat atrophy, facial flushing, a temporary rise in blood glucose (monitor more closely, especially in the first one to three days, in diabetes), rare infection and tendon rupture; there is no single universal frequency limit, so injections are spaced and repeated cautiously.
• •Injectable glucocorticoids are prohibited in-competition, so check the exact agent and washout against the current World Anti-Doping Agency Prohibited List and apply prospectively for a therapeutic use exemption where needed; a retrospective exemption is not guaranteed.