How to perform a wrist joint injection: Radiocarpal joint technique
Source
Surgeon:
Joonas Rautavaara (rheumatologist)
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Clinician Summary
Focus: Safe access to the wrist joint (radiocarpal joint) for synovial fluid sampling and local treatment.
Key elements: Patient positioning, needle and medication examples, dorsal radiocarpal landmarks, injection technique, synovial fluid analysis, aftercare, pitfalls, and complications.
Indications and Clinical Context
General
Medical expert: Joonas Rautavaara, rheumatologist
Name of Procedure: Wrist joint injection (radiocarpal joint), wrist joint puncture, wrist arthrocentesis, wrist corticosteroid injection
Goal
Safe access to the wrist joint (radiocarpal joint) for synovial fluid sampling and local treatment.
Problem
Unspecific wrist joint effusion or the need for local treatment of an inflammatory joint condition, gout, or osteoarthritis.
Diagnosis
M13.9 Arthritis, unspecified
M05.8 Other rheumatoid arthritis with rheumatoid factor
M19.8 Other specified arthrosis
Short Pathophysiological Description
The wrist joints consist of the radiocarpal, midcarpal, and distal radioulnar joints. The radiocarpal joint, which is the primary focus here, is the most frequently inflamed and symptomatic of the wrist joints.
The radiocarpal joint is commonly inflamed in conditions such as rheumatoid arthritis, gout, and psoriatic arthritis. Inflammatory conditions can lead to synovial hypertrophy and increased production of synovial fluid in the joint.
Significant osteoarthritis of the wrist joint may develop, particularly after trauma.
Key Anatomical Structures
Radiocarpal joint
Radius
Extensor digitorum tendon
How to perform a wrist joint injection: Radiocarpal joint technique
Step-by-Step Technique
Preparations and Patient Positioning
The patient can sit with the affected hand face-down on their lap, supported by a cushion. Alternatively, they can lie back with the hand in the same position.
For example, an orange needle 25 G (0.5 × 16 mm) or a blue needle 23 G (0.6 × 30 mm) can be used.
For anti-inflammatory treatment and for alleviating symptoms of osteoarthritis, 0.5–1 ml methylprednisolone 40 mg/ml can be used.
Landmarks and Injection Site
The aim is to find a safe injection site into the radiocarpal joint. This ensures that arthrocentesis or treatments are done accurately into the joint, while also lessening the chance of injuring nearby tendons or neurovascular structures.
Palpate the distal end of the radius on the dorsal side.
By having the patient lift their index finger, the extensor digitorum tendon is traced to the radius’s distal end.
The injection site is identified slightly radially to the tendon at the radius’s distal end.
There are no significant neurovascular structures in this area, which makes it an ideal spot for injecting.
Mark the entry site.
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Injection
Clean the skin area and let it dry.
Insert the needle perpendicularly to the skin or slightly ulnarly, underneath the extensor digitorum tendon. The depth of insertion is about 1.5–2 cm from the skin surface.
Inject the medicinal agent appropriate to the situation. There is typically very low resistance in the joint space.
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Synovial Fluid Analysis, if a Sample Is Taken
The turbidity and color of the synovial fluid can be assessed visually. Fairly clear synovial fluid with visible measurement markings on the syringe is a sign of no pronounced infection. Cloudy synovial fluid is caused by a large number of white blood cells making the measurement markings invisible.
If the cause of joint effusion is unclear, take a sample if possible.
Cell count + crystal analysis and bacterial culture.
If antibiotic treatment has already been initiated and septic arthritis is strongly suspected, request a bacterial nucleic acid analysis.
If Lyme disease-related joint condition is suspected, request a Borrelia nucleic acid analysis.
If only a drop of synovial fluid is available, it is possible to take a bacterial swab sample.
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Piftalls and Complications
Pitfalls
Wrong Injection Site
If the injection is given too far on the radial side, there is a risk of hitting the radial artery and the radial nerve in the anatomical snuffbox.
The extensor tendons of the wrist and the digits should be avoided, as injecting through these is extremely painful.
The superficial veins should also be avoided when giving the injection in order to avoid local hematoma.
Challenges with Sample Aspiration
If the joint capsule is thickened, synovial debris may block the needle when aspirating. The risk increases with the aspiration force and syringe volume. Try changing to a smaller syringe. You can also try to unblock the needle tip by injecting a small amount of fluid into the joint and then reaspirating.
If sample aspiration is unsuccessful when acute gout is suspected, try saline irrigation. After injecting 1 ml of fluid, try aspirating again. This will also yield a sample for bacterial analysis.
Storage of a Synovial Fluid Sample
A synovial fluid sample should be analyzed promptly after taking the sample. Synovial fluid containing blood will rapidly coagulate. There may be cell degradation in the sample after just an hour. Crystals, on the other hand, are inorganic salts and are better preserved, and so their analysis can be made the next day.
Injecting Too Frequently
In case of acute inflammation involving a small joint, like the radiocarpal joint, intra-articular injections can be given at 1-month intervals for the first 3 months. Afterwards, if needed, 6 weeks apart.
There is no strong evidence of adverse effects of glucocorticoids on the joint, although frequent injections may cause unwanted systemic effects.
Complications
Infection
Intra-articular infection after a joint injection is very rare, the incidence being 1:2000–1:100,000, most commonly 1:10,000. Nevertheless, maintain aseptic technique while doing the procedure.
Joint Pain
Joint pain for 24 hours post-injection is an adverse effect occurring in up to 10% of cases, particularly with glucocorticoid injections. It may result from a local tissue injury caused by the needle alone but is usually due to an irritation reaction to the crystalline glucocorticoid or hyaluronate. The joint may be painful, perhaps even feel warm, for about 24 hours, but these symptoms ease spontaneously. The symptoms can be alleviated by analgesics or cold treatment.
Hemarthrosis
Intra-articular hemorrhage is a very rare complication of a joint injection. Antithrombotic treatment or anticoagulant medication is not a contraindication for intra-articular injection, as the risk is very small, about 0–2%, even in patients using these medicines. In patients on anticoagulants, however, the smallest possible needle is recommended for joint injection.
Local Skin Atrophy or Hypopigmentation
Local skin atrophy occurs in about 1% of the patients after intra-articular injection of glucocorticoids. Typically, atrophy at the injection area develops at 1–4 months post-injection. In addition to atrophy, there may be hypopigmentation around the injection area. Atrophy and hypopigmentation are caused by subcutaneous glucocorticoid accumulation, potentially due to extracapsular injection or extracapsular seepage of the glucocorticoid via the puncture canal.
Tendon Tear
Tendon tears during intra-articular injections are very rare and are often due to unintentional injection of glucocorticoid into the adjacent tendon rather than the joint itself. To avoid tendon injuries, glucocorticoids should always be injected against low resistance.
Pericapsular Calcium Deposit
Pericapsular calcification, or calcium deposits around the joint capsule of the target joint, is very common, occurring after intra-articular injections in up to 10% of cases. Pericapsular calcium deposits are usually asymptomatic and harmless. In most cases, calcium is spontaneously absorbed from the synovial capsule, but in some patients X-ray images may show even permanent calcifications, particularly in small joints such as the PIP and the DIP joints of the fingers.
Compromise of Diabetes Management
Following intra-articular injections, some of the glucocorticoid dose will be absorbed into the systemic bloodstream and in diabetic patients, for example, blood sugar level might be elevated for a few days post-injection. The risk is highest for short-acting agents or when multiple injections are given together. Patients with diabetes should be advised to step up their blood sugar monitoring post-injection and, if necessary, to adjust their diabetes medication doses temporarily.
Aftercare
General Guidelines
Cover the injection site with an adhesive bandage and keep it dry and clean for 24 hours to minimize the risk of infection.
For a better therapeutic effect, avoid stress of the injected joint for 24–48 hours and avoid heavy strain for one week.
Glucocorticoids are absorbed more into the bloodstream, particularly from large weight-bearing joints, if the joint is stressed.
FAQ
What is the goal of radiocarpal wrist joint injection?
The goal is safe access to the wrist joint, specifically the radiocarpal joint, for synovial fluid sampling and local treatment.
Where is the injection site identified?
The injection site is identified slightly radially to the extensor digitorum tendon at the distal end of the radius.
What sample tests are listed for synovial fluid analysis?
The listed tests are cell count, crystal analysis, and bacterial culture.
What aftercare is recommended after the injection?
The injection site should be covered with an adhesive bandage and kept dry and clean for 24 hours. The injected joint should be rested for 24–48 hours, and heavy strain should be avoided for one week.
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