Ulnar Drift in Rheumatoid Arthritis

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​Ulnar drift, also referred to as ulnar deviation, is a deformity of the hand. It is most commonly associated with rheumatoid arthritis (RA) as well as other inflammatory conditions such as lupus or psoriatic arthritis.

Ulnar drift occurs when your knuckles—called the metacarpophalangeal (MCP) joints—become swollen and cause your fingers to bend abnormally toward your little finger. (It’s called ulnar deviation because your fingers bend toward the ulna bone on the outermost edge of your forearm.)

The distortion caused by ulnar drift can be painful, unsightly, and, over time, may make daily tasks that require gripping—such as opening a jar, twisting a doorknob, or using a zipper—challenging.

Signs and Symptoms

Swelling of your 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

Causes

Ulnar drift is primarily associated with rheumatoid arthritis. Chronic inflammation of the MCP joints damages the joint capsule and surrounding structures. It may also occur with other inflammatory conditions or connective tissue diseases, such as lupus or psoriatic arthritis. One case study also revealed an association with an uncommon disorder known as pigmented villonodular synovitis (PVNS), a disease in which the tissue lining the joints and tendons in the body (synovium) grows abnormally.

Osteoarthritis—a form of arthritis not caused by autoimmune disease—can also result in ulnar drift. With this condition, joint cartilage wears away due to overuse or age. Eventually, your bones start to rub together, damaging the joints and potentially causing them to become bent and distorted.

Diagnosis

Your doctor may perform X-rays to look more closely at your joints and the surrounding tissue.

To assess the severity of ulnar drift, a device called a goniometer may be used. The stationary arm of the goniometer is placed over the metacarpal (the finger bone that connects the knuckle to the hand) while the moveable arm is placed parallel to the proximal phalange (the bone extending upward from the knuckle). After the degree of deformity is determined, the patient is usually asked to straighten their hand, if possible, to actively correct the alignment and a re-measurement is taken. Other hand function tests may also be used to evaluate the severity of the deformity.

If an underlying disease such as rheumatoid arthritis or lupus is suspected, blood tests may be used to confirm the diagnosis.

Treatment Options

There is no cure for ulnar drift, which tends to progress over time. 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, use of a transcutaneous electrical nerve stimulation unit, or TENS unit, and ultrasound. Hand exercises, which primarily involve stretching, are recommended to preserve range of motion as much as possible. Exercises that put pressure or stress on the hands, such as yoga or riding a bicycle—should be avoided.

Splinting is sometimes recommended to properly position the MCP joints. Generally, splints are worn at night or during rest periods in the daytime. Splints may help with pain, but have not been shown to prevent or stop the progression of ulnar deviation.

View Article Sources
  • Kelley's Textbook of Rheumatology. Ninth edition. Firestein et al. Elsevier Saunders. Clinical Features of Rheumatoid Arthritis. Chapter 70. Hands and Wrists. Page 1112.
  • Volar Subluxation of Metacarpophalangeal Joint
  • Best Practice Recommendations for Management of Ulnar Drift Deformity in Rheumatoid Arthritis. Vancouver Coastal Health. The Arthritis Society (Canada).