Ulnar Deviation in Rheumatoid Arthritis and Other Diseases

​Ulnar deviation is a deformity of the hand that affects people with rheumatoid arthritis (RA) and other inflammatory diseases.

Also known as ulnar drift, it occurs when your knuckles—called the metacarpophalangeal (MCP) joints—become swollen and cause your fingers to bend abnormally toward the ulna bone on the outermost side of your forearm.

Ulnar distortion can be painful and aesthetically undesirable. Over time, it can make it difficult to perform daily tasks that require gripping, like opening a jar, twisting a doorknob, or using a zipper.

This article discusses ulnar deviation. It explains the common symptoms and causes of ulnar drift, how it is diagnosed, and different treatments.

Symptoms of Ulnar Drift

Swelling of the knuckles is the main symptom of ulnar deviation. Other signs and symptoms include:

• Loss of ability for the thumb to oppose the index finger
• Warmth in your wrist, hand, and finger joints
• Pain or tenderness in the hand
• Inability to fully flex your fingers or make a fist
• Tightness and stiffness in the hand

You may also experience body-wide symptoms, such as fatigue or weight loss, and pain and stiffness in similar joints, like your toes. This can occur when ulnar deviation is due to an underlying autoimmune disease.

What Causes Ulnar Deviation?

Ulnar deviation is most commonly associated with rheumatoid arthritis, but it can occur with other conditions as well.

Rheumatoid Arthritis

With rheumatoid arthritis, chronic inflammation of the MCP joints damages the joint capsule and surrounding structures, which can result in ulnar drift. This causes joint erosion that can be seen on X-rays.

Osteoarthritis

Osteoarthritis can also result in ulnar deviation. With this condition, joint cartilage wears away due to overuse or age rather than being damaged by autoimmune disease.

Eventually, your bones start to rub together, damaging the joints and potentially causing them to become bent and distorted.

Lupus

Ulnar deviation can also occur with the autoimmune disease lupus and other diffuse connective tissue disorders (DCTDs), such as scleroderma, polymyositis, and Sjogren’s syndrome.

The deformity is caused by chronic inflammation of connective tissue (tendons, ligaments, and cartilage) that supports the MCP joints. However, unlike with RA, the inflammation does not cause joint erosion.

Psoriatic Arthritis

Ulnar deviation is sometimes seen in psoriatic arthritis (PsA), but it is not very common. When it does, it typically occurs in reverse and is related to psoriatic nail disease.

In PsA, the deformity starts in the distal interphalangeal (DIP) joint at the top of the finger. Over time, it can move to the proximal interphalangeal (PIP) joint in the middle of the finger and then travel to the other joints in the hand and wrist.

Brachial Plexus Palsy

Ulnar deviation is also seen in people with brachial plexus palsy (BPP), a type of paralysis caused by injury to nerves in the shoulder. The brachial plexus nerves carry signals from the upper parts of the spinal cord to your shoulder, arm, and hand.

Brachial plexus palsy in babies can be caused by shoulder dystocia (a birth injury). It can also occur as a result of sports injuries, trauma, inflammation, pressure, or tumors.

Pigmented Villonodular Synovitis (PVNS)

Research has also revealed an association with an uncommon disorder known as pigmented villonodular synovitis (PVNS), a disease in which the tissue lining your joints and tendons (synovium) grows abnormally.

Genetics

Genetics may play a factor in ulnar deviation as well. According to researchers at Texas Tech University, a type of ulnar deviation commonly referred to as windblown hand may run in families. 

In windblown hand, the fingers tilt outward in an almost uniform fashion and cannot be corrected without pain. It may be present at birth but commonly develops in early adulthood.

It may start with pain at the base of the thumb, followed by a slow drifting of fingers. It is not always painful and may or may not impact dexterity. 

Smoking

Smoking cigarettes increases your risk of autoimmune diseases, like RA and lupus, which are associated with ulnar drift. In addition, smoking worsens joint pain and inflammation and lowers the effectiveness of disease-modifying antirheumatic drugs (DMARDs) like methotrexate.

Diagnosing Ulnar Deviation

Ulnar deviation is usually evident from an examination of your hand. Your medical history will also be considered.

To assess the severity of ulnar drift, healthcare providers measure the joint angle using a goniometer, a combination of a protractor and ruler with two moveable arms.

One arm of the goniometer is placed over the metacarpal (the finger bone that connects the knuckle to the hand). The other arm is moved so it is parallel to the proximal phalanx (the bone extending upward from the knuckle).

After the healthcare provider gets a measurement, they'll usually ask you to straighten your hand as much as possible to actively correct the alignment and then take a second measurement.

Your healthcare provider may also use other hand-function tests and X-rays to get more information about bone and tissue damage as well as deformity.

If an underlying disease such as rheumatoid arthritis or lupus is suspected, but not yet diagnosed, blood tests may be used to investigate further.

Ulnar Deviation Treatment

There is no cure for ulnar drift, which tends to progress over time. Lifestyle changes, exercises, therapies, and interventions can help ease discomfort and potentially slow progression.

Lifestyle Changes

The following lifestyle changes can help you avoid too much strain on your joints, which can worsen symptoms of ulnar drift:

• Use both hands to lift and hold heavy objects.
• Avoid using the handles on objects such as pots or coffee mugs (use oven mitts for hot objects).
• Try to avoid doing too many activities that move your fingers in the ulnar direction, such as opening jars or using doorknobs (keep internal doors cracked, for example).

Talk to your healthcare provider if you're finding it hard or painful to complete routine manual tasks. They may be able to recommend assistive devices to make things easier.

Hand Exercises

Hand exercises, which primarily involve stretching, are recommended to preserve range of motion as much as possible. Physical activities that put undue pressure or stress on the hands, such as planks or riding a bicycle (which requires gripping the handlebars) should be avoided.

Splinting

Splinting is sometimes recommended to properly position the MCP joints, relieve pain, and possibly slow disease progression. Generally, splints are worn at night or during rest periods in the daytime.

These types of splints may help slow disease progression:

• MCP joint splints, which you can wear during the day to support your fingers and help you grip objects with less pain
• Hand-resting splints, which are usually worn at night on your wrist and fingers to relax your MCP joint and reduce inflammation and pain
• Exercise splints, which support your MCP joint when you extend or flex your fingers to help reduce joint tightness or inflammation

Medications and Therapies

Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen and naproxen can relieve pain.

Other options for treating hand swelling and pain include:

• Ice
• Moist heat
• Paraffin wax baths
• Transcutaneous electrical nerve stimulation unit, or TENS unit
• Ultrasound therapy

Immunosuppressant medications are often necessary if hand pain and swelling are caused by an autoimmune disease such as RA.

Surgery

Metacarpophalangeal (MCP) arthroplasty is a surgical method of improving pain, alignment, and function in people with ulnar drift. The procedure involves replacing painful knuckle joints with artificial knuckle joints.

For eight to 12 weeks after the surgery, patients wear hand splints and perform exercises to maintain and increase motion in the healing hand. This is known as post-operative therapy.

Summary

Ulnar deviation is a hand deformity where fingers lean toward the outer side of the hand. Symptoms include swollen knuckles, pain and stiffness in the hand, and difficulty bending your fingers. 

Also called ulnar drift, it is more common in people with inflammatory autoimmune diseases like rheumatoid arthritis, psoriatic arthritis, and lupus. Osteoarthritis, a nerve injury, or genetics can also cause it. 

Ulnar deviation treatment aims to maintain hand function, relieve pain, and manage underlying autoimmune disease. Though not always painful, when it is, anti-inflammatory medications, ice packs, or moist heat can help. 

Physical therapy, finger exercises, and wearing a splint or brace to realign fingers may help to relieve ulnar deviation. Surgery may sometimes be needed to fix the deformity, relieve pain, and improve functioning.