Overview of Wrist Arthrogram
Wrist arthrography, a technique first introduced in 1961 by Kesseler and Silberman, is an important tool used by doctors to look inside your wrist. This procedure works by injecting a contrast material, or a special dye, into your wrist. This helps make the inner structures of your wrist show up more clearly during imaging tests like X-rays, MRI (Magnetic Resonance Imaging), and CT (Computed Tomography) scans.
This procedure is especially handy when looking at the articular cartilage (a tough, flexible tissue that covers the ends of your bones), ligaments (tissues that connect bones to each other), tendons (tissues that connect muscles to bones), joint stability, and how your wrist functions when it moves. While newer imaging techniques like MRIs have become more popular, wrist arthrography is still very important for finding problems like wrist ligament tears, injuries to triangular fibrocartilage complex (a structure in the wrist that acts as a cushion and stabilizes the joint), and other issues inside your wrist.
Anatomy and Physiology of Wrist Arthrogram
The wrist is a joint that connects the end of the radius (one of the two bones in your forearm) with a row of small bones known as carpal bones. Think of it as a bridge between your hand and forearm. For a better understanding, the carpal bones make a bump-like shape that fits with the hollow end of the radius bone. However, the ulna bone (the other bone in your forearm) does not directly connect with the carpal bones, it instead connects with the radius.
Now, there are some very important ligaments, or strong pieces of tissue, that help hold the wrist joint together and allow it to move smoothly. There are four main ligaments in the wrist:
- The palmar radiocarpal ligament securely binds the radius with the carpal bones from the palm side. This ligament makes it possible for your hand and forearm to move in a coordinated manner when you twist your wrist, as in opening a door knob.
- The dorsal radiocarpal ligament also connects the radius to the carpal bones, but from the back side of your wrist. It plays a key role in stability and assists in coordinating hand and forearm movements when you twist your hand in the opposite direction.
- The ulnar collateral ligament stretches from ulna (small knobby bone on the pinky side of your wrist) to two specific carpal bones. This stops your hand from bending too much towards the radius.
- The radial collateral ligament links the radius (small knobby bone on the thumb side of your wrist) to two other specific carpal bones. This prevents your hand from bending too much towards the ulna.
Then, there’s something called the Triangular Fibrocartilage Complex (TFCC), which is a crucial part of the wrist that aids in stability. It is positioned between the ulna and two carpal bones, Imagine it as a triangle-shaped bridge providing stability between these bones. It has various components that help hold the various parts of your wrist together. Besides providing stability, the TFCC also acts as a cushion for the carpal bones on the side of the ulna, handles some of the pressure when you put your weight on your wrist, and plays a key role in controlling the position of the wrist bones on the side of the ulna.
Why do People Need Wrist Arthrogram
Doctors perform a wrist arthrogram, which is a type of X-ray imaging procedure that uses a special dye to see the inside of your wrist joint, for several reasons. Sometimes it may be used on its own, and other times it might be used with other types of imaging tests. Reasons for this imaging procedure include:
1. To check for wrist joint conditions that are caused by wear and tear or inflammation, such as osteoarthritis or rheumatoid arthritis. Osteoarthritis can happen as we age or after an injury, and rheumatoid arthritis is a disease where the body’s immune system mistakenly attacks the joints.
2. To identify trauma-related injuries. For instance, you could have had an injury to the ligaments in your wrist, such as the scapholunate ligament, lunotriquetral ligament, or the TFCC.
3. To check the wrist joint’s articular cartilage for osteochondral defects. The articular cartilage is the smooth, slippery substance that covers the ends of bones where they come together in a joint, while osteochondral defects are injuries or small fractures that can occur on both the cartilage and the underlying bone of the joint.
4. If you have long-lasting wrist pain that hasn’t been diagnosed, the doctor might ask for a wrist arthrogram to try and find the cause.
5. If a scaphoid fracture, a break in the small bone in your wrist, isn’t healing as expected.
6. To check for ulnar abutment, a painful condition where one of the bones in the forearm hits against one of the smaller bones in the wrist.
When a Person Should Avoid Wrist Arthrogram
A wrist arthrogram- a type of test which involves taking pictures of your wrist- is generally safe but there are certain cases where it might not be the best option for some people. Here are some conditions when doctors may advise against a wrist arthrogram:
Absolute Reasons:
- Allergy to contrast material: If you know that you’re allergic to the substance (usually contains iodine) used in the test, you should not do the procedure.
- Active infection: If you have an active infection around your wrist, the test can cause the infection to spread further. Hence, it’s not safe to have this procedure.
Relative Reasons:
- Kidney dysfunction: People with significant kidney problems might face complications from the contrast material used in the test. So, the amount of substance used needs to be adjusted for these individuals.
- Bleeding disorders: If you have a bleeding disorder or take medications that thin your blood, you may be at a higher risk of bleeding during or after the test. Your doctor might need to modify your medication before you can safely have this procedure.
- Uncontrolled diabetes: If your diabetes is not well controlled, you might face complications related to contrast material used in the test. So, you may need to manage your diabetes better before the test.
- Pregnancy: Being pregnant can also be a deciding factor. The risk of radiation exposure from X-ray pictures (made during this procedure) should be reduced as much as possible when you’re pregnant.
Before suggesting a wrist arthrogram, your healthcare team will thoroughly examine your medical history and current health status. They might also think about all possible complications based on your condition. If you face any of the above-mentioned conditions, your doctors could suggest other ways to diagnose or may change the procedure to ensure your safety.
Equipment used for Wrist Arthrogram
To carry out a wrist arthrogram, a procedure to examine the wrist, certain tools and substances are needed. These will be used to inject a numbing drug (local anesthesia) and a special liquid (contrast material) into the wrist joint. Here’s what’s needed:
* Clean, sterile sheets known as drapes
* Solutions to clean the area and kill germs (local antiseptic solutions)
* A wide, blunt needle to get the numbing drug and contrast solutions ready
* A sharp, fine needle to inject into the joint
* Small 3-milliliter syringes for injecting the contrast solution
* Bigger 10-milliliter syringe to prepare and inject the numbing drug
* The contrast agents, which could be gadolinium or iodine-based
A numbing drug called lidocaine, specifically 1% lidocaine, is typically used because it acts quickly. To lessen any irritation caused by the acidic nature of lidocaine, a sodium bicarbonate solution can be mixed in. Approximately 0.5 milliliters of sodium bicarbonate can be added to 10 milliliters of 1% lidocaine. It’s important to have an emergency resuscitation cart nearby. This is a cart of tools and medication used in case of a severe allergic reaction (anaphylactic reaction) to any materials injected.
How is Wrist Arthrogram performed
Before a wrist arthrography, an imaging test of the wrist, can be carried out, you must give your consent. The doctor will need to make sure that you are not allergic to the contrast dye used in the test and that you don’t have an infection. During the procedure, you will lie down on a special x-ray table, with your wrist in a relaxed, normal position.
The skin on your wrist will be carefully cleaned with an antiseptic to prevent infection. A sterile technique is used to inject the contrast dye, ideally on the side of the wrist that isn’t causing you discomfort. For example, if the pain is located on the inner side (ulnar side) of your wrist, the dye will be injected into the outer side (lateral side). This makes it easier to tell the difference between the dye that was purposely injected and any that may have leaked due to a tear in the joint capsule. The injection is normally done under image guidance, using a tool called an image intensifier, which helps the doctor see exactly where the dye is going.
The test may involve injecting dye into one, two, or three compartments of your wrist, the most common being three. To inject dye into the compartment in the middle of your wrist, the doctor targets the spaces between certain wrist bones. This causes the dye to flow into other areas within your wrist. However, if the natural ligaments in this area are intact, the contrast dye will not flow into the main wrist joint.
To inject dye into the primary wrist joint, the raidocarpal compartment, the doctor targets the area between the small bone at the base of your hand (pisiform) and another wrist bone (triquetrum) when injecting from the ulnar side. If the dye is to be injected from the lateral side, the space between a bony prominence on the forearm (styloid process) and the top part of the wrist bone (scaphoid) is targeted. To inject dye into the joint at the point where your forearm bones connect, the outer edge (radial margin) of the ulnar head is targeted.
Possible Complications of Wrist Arthrogram
When having a wrist arthrogram, which is an imaging test used to examine your wrist joint, some complications can happen. This might include:
Allergic reactions: Some people might be allergic to the special dye (called contrast material) used in the test. These reactions could be mild, like skin irritation, or severe, like a condition called anaphylaxis, which requires immediate medical care.
Septic Arthritis: There’s a chance of getting an infection in your wrist joint during the procedure, especially if the area isn’t cleaned properly. Signs of this can include swelling, redness, and pain in the area, as well as fever. If this infection is diagnosed, a quick surgical clean-up of the wrist joint is required to keep the joint healthy and prevent the spread of the infection.
Bleeding: There is a chance of bleeding at the place where the needle was inserted or within the joint, particularly in people with bleeding conditions or those taking blood-thinning medicines. Your healthcare provider might weigh up the pros and cons of you stopping your blood-thinning medication before this test.
False Positives: Sometimes gas can accidentally get into the injection site, causing the test to show something that might look like loose bodies in the joint, even if they’re not there. This mistake could lead to a misunderstanding of your test results.
Chemical Synovitis: The most common side effect of a wrist arthrogram is pain because of a condition called chemical synovitis. This happens when the contrast dye causes a non-infected inflammation of the joint lining, leading to pain, swelling, and discomfort. This condition often mimics infection, so healthcare professionals should closely watch and manage your symptoms to ensure the right treatment.
Nerve or Vascular Injury: Rarely, the needle used for the injection can damage nearby nerves or blood vessels accidentally, leading to complications involving those structures.
Joint Structure Injury: Occasionally, the injection could harm the structures of your joint, especially if there’s already something wrong with your joint.
Pain or Discomfort: Some people might feel temporary pain or discomfort at the site of the injection or within the joint, though this tends to be mild and fade quickly.
Radiation Exposure: If x-rays are used during the procedure, there is a potential for exposure to radiation. Although this is usually a small amount, it is still something to consider, particularly for pregnant patients. Therefore, healthcare providers should take precautions to minimize risks and follow safety rules.
What Else Should I Know About Wrist Arthrogram?
A wrist arthrogram is an important tool doctors use to evaluate possible issues like different kinds of injuries within the wrist. Here’s some reasons why you might get one:
TFCC Tears: The TFCC (Triangular fibrocartilage complex) helps keep the wrist stable. It’s often injured in activities that need strong wrist movements, such as tennis, baseball, or when you fall on an outstretched hand. An MRI alone has trouble telling the difference between an age-related and an injury-related tear in the TFCC. But, combining an MRI with arthrogram, a kind of test that uses a special dye to provide a more detailed picture, helps doctors more accurately identify the tear (about 97.1% sensitivity).
Scapholunate Ligament Injury: The scapholunate ligament is the wrist ligament that gets injured most often. Serious cases can lead to widening of the spacing between certain bones of the wrist, seen on X-rays. If a dye test (a single compartment arthrogram) is performed and the dye is seen in a certain part of the wrist, this suggests this ligament is damaged. The arthrogram combined with the MRI is more accurate in identifying where and how this ligament is injured.
Midcarpal Instability: This is a rare type of injury that happens when there is damage to the ligaments between some of the wrist bones while other ligaments are okay. Here too, combining the MRI with the arthrogram helps in identifying the exact location of the injury.
Distal Radioulnar Joint Abnormalities: The wrist arthrogram is also beneficial in evaluating any damage to the cartilage at a specific wrist joint (the distal radioulnar joint) and the surrounding tissue for any signs of tears or inflammation.
In all these cases, the arthrogram helps your doctor see your wrist in more detail, to make sure they find any injuries and treat them accurately.
