Overview of Wrist Arthrocentesis
Arthrocentesis, or the process of extracting fluid from the wrist, is a medical procedure. It’s performed in a clean, controlled environment and involves the removal of a fluid called synovial fluid from your wrist. This procedure is used for two main purposes; it can either help to relieve symptoms or aid in diagnosis.
The process can be carried out in different places like an emergency department or even a regular doctor’s office, depending on the situation. However, it needs to be done by well-trained healthcare professionals who are familiar with the procedure to lower the chances of any complications.
Anatomy and Physiology of Wrist Arthrocentesis
When conducting a procedure related to your wrist, there are several parts of your anatomy to keep in mind. These include:
- The distal radius, which is the end part of one of the two big bones in your forearm close to the wrist.
- The anatomic snuffbox, which is a small, triangular, hollow space on the outer part of your wrist just below the thumb.
- The extensor carpi radialis brevis, and extensor pollicis longus, which are muscles that help in wrist and thumb movement.
The healthcare provider will feel for a particular space in your wrist, towards the hand from the bulging bone (distal radius) and towards the small finger from the anatomic snuffbox on the backside of the wrist. This is done to stay away from specific wrist muscles – the extensor carpi radialis brevis and extensor pollicis longus. An alternative way of reaching the same space can be from the side of the small finger (ulnar side). From this ulnar approach, space can be felt towards the hand (distally) from the other big bone in the forearm close to the wrist (distal ulna).
Why do People Need Wrist Arthrocentesis
Wrist arthrocentesis is a medical procedure that can help both in diagnosing and treating certain health issues. The procedure involves using a needle to take fluid from your wrist joint, which can tell the doctor a lot about your condition or how well your treatment is working. This procedure is usually recommended in the following situations:
Your doctor might suggest it if they think you have an infection in your wrist joint area, known as septic arthritis. It can also be used to measure the progress in your treatment for this kind of infection.
Another reason for wrist arthrocentesis is if you are dealing with acute monoarticular arthritis, which is a condition that causes inflammation and pain only in one joint.
If your wrist is painfully swollen due to fluid buildup, known as a joint effusion, the doctor might use this procedure to reduce the swelling by taking out some of the fluid.
Sometimes, the doctor may need to deliver medication directly into your wrist joint. In such cases, they can use the same needle procedure to administer the drugs.
If you have a large amount of painful fluid accumulation in your joint, your doctor might aspirate or drain it out using wrist arthrocentesis.
Yes, if draining out the fluid from your joint gives you relief from the pain and the fluid keeps building up again, the doctor might repeat the procedure multiple times.
When a Person Should Avoid Wrist Arthrocentesis
While there are no hard rules against performing wrist arthrocentesis (a procedure to remove fluid from the wrist joint), certain conditions could possibly make it less suitable. These could include:
– A skin infection (cellulitis) overlying the wrist
– An existing bloodstream infection (bacteremia)
– Skin problems or wounds on the wrist
– A wrist that has an artificial joint, which might require a cleaner method by surgeons
– A wrist joint that is not stable
– A recent break or crack in the wrist (acute fracture)
Additionally, if a patient has bleeding problems (like coagulopathy or thrombocytopenia), or is taking medication to prevent blood clotting (anticoagulants), these factors need to be considered before going through with the procedure. In such cases, the doctors might have to take certain precautions such as giving drugs that reverse the effect of the anticoagulants, or addressing the bleeding problems in a particular way.
Equipment used for Wrist Arthrocentesis
The usual supplies for this procedure include:
- An antiseptic solution like Betadine or chlorhexidine to clean your skin and prevent infection.
- Sterile gloves and a drape to maintain cleanliness.
- Sterile gauze for cleaning and dressing wounds.
- A skin marking pen used by the doctor to indicate the precise location for the procedure.
- Lidocaine, a local anesthetic used to numb your skin and lessen discomfort.
- A very fine 25-27 gauge needle for injecting the anesthetic.
- A slightly larger 20-21 gauge needle for removing fluid from the joint (aspiration).
- Small syringes (2-5 ml) to hold the fluids removed.
- Specimen tubes to send any samples to the lab for further examination.
Sometimes, doctors use a device called a reciprocating syringe instead of a regular one. This kind of syringe improves the ability of the doctor to perform the procedure, allowing them to work with one hand. It can also help to make the procedure quicker and less painful.
Another tool that is often used is an ultrasound machine. This machine helps the doctor see the area around the joint and any collections of fluid. Using ultrasound can increase the success of fluid removal and lower the chance of complications. This is especially useful for smaller joints.
Who is needed to perform Wrist Arthrocentesis?
A procedure called wrist arthrocentesis, which is used to take out fluid from the wrist, can be done by healthcare professionals in the emergency room or even in a clinic. Unlike some other procedures, it doesn’t need other medical staff to help out.
Preparing for Wrist Arthrocentesis
Before a doctor can perform a procedure, they need to get the patient’s permission. This is known as ‘informed consent’. Once permission is received, the patient is positioned lying down flat, with their wrist slightly bent towards the palm. This might be achieved by placing a rolled up sheet or towel under the wrist. The doctor will then identify and mark where the needle needs to go.
Afterwards, the doctor will clean the area, using either a special type of iodine solution called Betadine, or another cleaning agent known as chlorhexidine. To help with any pain or discomfort, a local anesthetic like Lidocaine 1% or 2% might be used. This helps numb the area where the procedure will be done. However, some doctors might choose to use a cold spray (ethyl chloride) instead, or even no local anesthesia at all, depending on the procedure and the patient’s comfort level.
How is Wrist Arthrocentesis performed
In simpler terms, the landmarks that should be palpated (lightly felt by a doctor) before sterilization of the skin refers to distinct areas on the body that is felt with the fingers to locate the joint space – this can be identified slightly below the distal radius (or the end of one of the forearm bones), towards the anatomic snuffbox (a small triangular hollow on the palm side of the wrist). It’s also important to steer clear of the associated extensor tendons (these facilitate finger movements). For the radial approach, the needle must be carefully inserted from above and directly perpendicular to the skin. If the needle hits the bone, it should be carefully withdrawn and redirected towards the thumb.
Interestingly, the ulnar approach uses the same technique. The joint space in this method is found by feeling distal to the distal ulna (the other bone of the forearm). The needle is then inserted from above towards the radial direction.
One way to confirm the needle has entered the joint space is a pop or give that can be felt. The synovial fluid (which lubricates the joints) can now be withdrawn. You might encounter some resistance depending on the needle size, the thickness of the fluid, amount of fluid, and presence of fibrin clots (which help stop bleeding). If resistance is experienced, slightly rotating the needle or pulling it out a little might be helpful. If any medication needs to be injected, the syringe is removed (while keeping the needle secure) and the medication is then given. Once completed, the needle is removed, and a slight pressure should be applied to the insertion site. The synovial fluid taken out should be sent for tests that include cell count, glucose, protein, LDH, lactate, crystals, and culture.
Another efficient tool to identify joint swelling/effusions and perform arthrocentesis (procedure to relieve joint inflammation) is the ultrasound. If an ultrasound is used, the patient is positioned in a similar manner with the palm facing downward. It’s crucial that the ultrasound probe has a sterile covering to maintain a sterile technique. The ultrasound probe is placed in a sagittal (or side) view over the distal radius until the joint space between either the radius and scaphoid (a small wrist bone), or radius and lunate (another small wrist bone) can be seen. If a swelling is present, a hypoechoic fluid collection (dark patches on the screen) above the carpal bone (bones in the wrist) will be visible. Using an in-plane method from distal (away from the centre of the body) to proximal (towards the centre of the body), the needle should be advanced while inhaling until the needle tip can be seen in the swelling. Inhalation will reduce the swelling size on the ultrasound.
Possible Complications of Wrist Arthrocentesis
There can be problems tied to the procedure itself or due to the compound injected into the body during the process.
Problems that might come from the procedure include harming nearby areas like causing a tendon to tear or injuring a nerve, getting an infection such as septic arthritis, experiencing pain, bleeding into the joint spaces, and the fluid in these spaces coming back after being drained. Septic arthritis, which is a severe infection in a joint, is a rare but serious problem. Using clean and sterile techniques lowers this risk. However, if the risk for infection is high, the doctor might give the patient preventive antibiotics for safety.
There might also be complications related to the use of corticosteroid injections. These can include allergic reactions, high blood sugar for people with diabetes, a reaction that causes inflammation and redness (steroid flare), weakening or thinning of the tendons, or the outside layer of the skin becoming thin.
What Else Should I Know About Wrist Arthrocentesis?
Arthrocentesis is a procedure that helps doctors identify the cause of joint swelling and pain. It involves using a needle to withdraw (or drain) fluid from a swollen joint. This process is used to provide relief from pain and to test the joint fluid for signs of disease.
While your symptoms and a physical examination can give doctors important clues, examining the fluid inside the joint provides the most accurate diagnosis. For example, to detect septic arthritis – a severe infection within a joint, doctors look for specific indicators in this fluid:
* High white blood cell count – White blood cells are part of your immune system, and their number increases when there’s an infection.
* Low glucose – Glucose is a type of sugar your body uses for energy. Lower levels in joint fluid could point to an infection.
* High protein – Protein levels can rise due to inflammation or infection in your joint.
* High lactate dehydrogenase level – This is an enzyme found throughout the body, and higher levels may indicate damage to cells in the joint.
The presence of a lot of white blood cells or a certain type of white blood cell called polymorphonuclear cells often points towards an infection in the joint, leading to treatment with antibiotics. Once this diagnosis is confirmed, typically by a positive test for bacteria in the joint fluid, your doctor will decide on the best antibiotic to treat the specific infection. Frequently, the bacteria causing the infection is Staphylococcus aureus, but sometimes, the tests don’t identify the bacteria.
In some cases, doctors find crystals in the joint fluid, which can be a sign of a condition called crystalline arthropathy that often affects wrists. It’s important to know that even with these crystals, an infection could still be present. The type of crystals can help doctors distinguish between different inflammatory joint diseases such as gout, which has negatively charged urate crystals, and pseudogout, which has positively charged calcium pyrophosphate crystals.
