Injection Therapy

Injection therapy delivers medication, most commonly a corticosteroid, directly into an inflamed joint, tendon sheath, or area of nerve compression to relieve symptoms.

A targeted injection delivers medication — most often a corticosteroid combined with local anaesthetic — directly into the tendon sheath, joint or compartment that is generating symptoms. Its purpose is to reduce local inflammation so that pain settles and function returns, and in several conditions it is definitive rather than temporary. An injection is offered where the diagnosis is clear and the target is specific. It is not a general painkiller for an undiagnosed hand, and it is not used to postpone an operation that is already clearly indicated. Where the expected benefit is short-lived, that is said before the injection, not after it.

Patients with a confirmed diagnosis in which local inflammation is the main driver of symptoms: trigger finger, De Quervain's tenosynovitis, thumb base and small joint arthritis, and some cases of carpal tunnel syndrome where symptoms are mild to moderate and there is no muscle wasting. Injection is also useful diagnostically, where the response to a precisely placed injection helps confirm which structure is responsible. It is avoided where there is active infection, skin breakdown at the site, a complete tendon rupture, or established nerve or muscle damage that needs decompression rather than anti-inflammatory treatment. Diabetes is not a barrier, but it is discussed in advance because blood glucose usually rises for several days afterwards.

The injection is given in clinic and takes a few minutes. The site is identified by surface anatomy, and ultrasound guidance is used where accuracy materially changes the result, such as small joints, the first extensor compartment or around a nerve. The skin is cleaned, local anaesthetic is included in the injection itself, and the medication is placed into the sheath or joint rather than into the tendon substance — injecting tendon tissue directly risks weakening it. You will usually feel immediate numbness from the local anaesthetic, which wears off after a few hours before the steroid effect begins. No sedation or fasting is needed and you can drive home unless a regional block was used.

The local anaesthetic gives relief for a few hours. It is common for symptoms to return, and sometimes to be briefly worse, over the following one to three days before the steroid takes effect — this post-injection flare is expected and is managed with simple analgesia and ice. Benefit is usually apparent within one to two weeks. In trigger finger, a single injection resolves symptoms permanently in a majority of patients; in De Quervain's the response is similarly good. In arthritis the effect is symptomatic rather than structural and typically lasts several months. Normal activity is resumed immediately, though heavy loading of the injected structure is best avoided for about two weeks.

Post-injection flare is the commonest complication. Skin thinning and loss of pigment at the injection site occur in a minority and are usually permanent though cosmetic only, and are more visible in darker skin. Fat atrophy can leave a small dimple. Blood glucose rises for several days in patients with diabetes. Infection is rare but serious and is the reason any increasing pain, redness and swelling after 48 hours needs same-day assessment. Repeated injections into the same site carry a cumulative risk of tendon weakening and rupture, which is why they are limited in number and why a condition that keeps returning after injection is usually better treated surgically.