What is interventional pain therapy?
Interventional pain therapy comprises medical procedures in which medication is delivered directly to the presumed site of pain – for example to nerve roots, joints or particular muscle areas. In contrast to the standard intake of tablets, the substance acts locally, often at a lower dose and with fewer systemic side effects.
A pain injection (infiltration) is one of the most common measures within this area of therapy. It is generally considered when other treatment steps – such as physiotherapy, exercise therapy or basic drug treatment – have not contributed sufficiently to relief.
How does a pain injection work?
During an injection, a thin needle is used to deliver a medication to a precisely defined location in the body. The substances most commonly used are:
- local anaesthetics, which temporarily "quieten" nerve fibres
- anti-inflammatory substances such as corticosteroid preparations
- in certain cases also hyaluronic acid–based solutions or other active substances
The aim is to interrupt the pain cycle, calm an inflammatory irritation and thereby improve mobility. The injection is often combined with active therapy such as physiotherapy in order to support more lasting effects.
Possible areas of application
Spinal injections
Injections in the area of the spine are among the best-known procedures in interventional pain therapy. They may be used, for example, for:
- disc-related complaints with radiation into the arm or leg
- irritation of individual nerve roots (e.g. with a herniated disc)
- wear-related changes of the small vertebral joints (facet joints)
- narrowing of the spinal canal (spinal stenosis)
- pain in the area of the sacroiliac joint
Depending on the clinical picture, different techniques may be considered – for instance periradicular injections at the nerve root, facet joint injections or epidural injections. Which variant is suitable is decided by the treating doctor following a thorough examination and imaging.
Joint injections
Outside the spine, too, injections are an established procedure. Frequently treated areas include:
- shoulder (e.g. with bursitis or impingement syndromes)
- knee (e.g. with activated osteoarthritis)
- hip
- ankle
- small joints of the hand and foot
Muscle and tendon attachments
For chronic irritation of tendon attachments – for example at the elbow ("tennis elbow") or the Achilles tendon – a targeted injection can contribute to relief. So-called myofascial trigger points, i.e. painful areas of tension in the musculature, can also be treated in this way.
Nerve blocks
In certain situations, individual nerves are temporarily blocked, for example in headaches originating from the neck (e.g. occipital nerve block) or in nerve compression syndromes. Such blocks serve both therapeutic purposes and the diagnostic narrowing down of the cause of pain.
How an injection is carried out in practice
Although the precise procedure depends on the individual technique, an injection generally follows a similar pattern.
1. History-taking and examination
Every treatment begins with a detailed consultation. Complaints, previous illnesses, current medications (in particular blood thinners) and allergies are recorded. A physical examination and – if not already available – appropriate imaging (e.g. MRI, X-ray) complete the diagnostic work-up.
2. Information and consent
Patients are informed about the aim, the procedure, possible risks and alternatives. Realistic expectations of the outcome are also discussed: an injection can relieve symptoms but is rarely a standalone solution and is usually used as part of an overall concept.
3. Preparation
The skin is carefully disinfected and the area covered with sterile drapes. For procedures on the spine or on deeper-lying structures, the puncture is often performed under image guidance – for example by ultrasound or fluoroscopy – in order to position the needle precisely.
4. Performing the injection
The injection itself usually takes only a few minutes. Many patients describe the puncture as a short, well-tolerated pressure. During the procedure a dull pulling sensation or a brief radiation may occur, which is usually an indication that the needle is correctly placed.
5. Observation afterwards
A short rest period after the injection is customary in order to check the effect and the patient's well-being. Depending on the procedure, it is recommended to avoid physical exertion on the day of treatment. After a spinal procedure, it is advisable not to drive home oneself.
Effects and possible risks
The effect can set in at different speeds: local anaesthetics often act within a few minutes, while anti-inflammatory components usually take several days. In some cases, several sessions are useful to achieve a more stable effect.
Like any medical measure, an injection is associated with certain risks. These include, among others:
- temporary increase in pain at the puncture site
- small bruises
- rarely infections
- allergic reactions to the substances used
- in procedures close to the spine, very rarely nerve irritation
Careful indication, sterile conditions and – where required – the use of imaging guidance help to keep the risk low.
When is an injection not suitable?
A pain injection is not appropriate in every situation. Possible reasons against treatment may include:
- acute infections, in particular in the area of the planned puncture site
- certain coagulation disorders or the use of blood-thinning medications that cannot be paused
- known intolerances to the substances used
- unclear causes of complaints that should first be investigated further
These questions are discussed individually beforehand.
Embedded in an overall concept
Injections unfold their benefit above all when they are understood as part of a comprehensive therapy concept. Exercise, physiotherapy, an adapted way of life and – where needed – supplementary drug therapy are important pillars. Interventional pain therapy can create a window of time in which active measures become more feasible.
Anyone with longer-lasting or recurring pain should have the symptoms clarified by a doctor. Together, it can then be decided whether an injection is a sensible option or whether other approaches would be more effective.
This article does not replace medical advice.