What is Ulnocarpal Impaction Syndrome

Ulnocarpal impaction syndrome is a condition in which the bones, cartilage, and ligament tissue in the wrist become increasingly damaged over time (degenerative condition). This happens when the end of the forearm bone on the little finger side of the hand (ulna) is longer than the other bone (radius) in the forearm (ulnar variance). As a result, the ulnar bone puts excess pressure on the bones, cartilage, and ligaments of the wrist.

Normally, the radius bears most of the stress in the wrist. If the stress is on the ulna instead, the end of the ulna begins to wear down the bones and tissues in the wrist. One of the wrist bones (carpal bones) called the lunate bone is commonly affected. Over time, this causes pain and limits movement in the wrist.

What are the causes?

This condition is usually caused by ulnar variance. You may be born with a long ulna (congenital ulnar variance). You may also develop ulnar variance from overuse or from a previous wrist injury or wrist surgery.

What increases the risk?

The following factors may make you more likely to develop this condition:

• Playing sports or doing work that involves repetitive or forceful motions of the arm, wrist, and hand.
• Having had a previous wrist injury or wrist surgery.
• Being born with an ulna that is longer than normal.

What are the signs or symptoms?

Symptoms of this condition start slowly and get worse gradually. Symptoms may include:

• Pain around the ulnar side of the wrist. Pain may get worse when:
  • Your wrist is bent toward the little finger side.
  • You do intense physical activity involving your hand and arm, such as push-ups.
  • You grip or grasp objects.
• Swelling of the wrist.
• Pain when pressing on the ulnar side of the wrist (tenderness).
• Limited ability to move the wrist.

How is this diagnosed?

This condition may be diagnosed based on a physical exam and your medical history. During the exam, your health care provider will check your wrist for tenderness and for limited or painful motion. You may also have X-rays of your wrist to confirm the diagnosis.

How is this treated?

Treatment varies depending on the severity of your condition. Treatment may include:

• Wearing a splint on your hand and wrist to prevent movement during healing.
• Medicines to reduce pain and inflammation, such as nonsteroidal anti-inflammatory drugs (NSAIDs).
• Avoiding activities that cause pain.
• Doing exercises to strengthen and stretch your arm, wrist, and hand (physical therapy). You may be referred to a physical therapist.
• Steroid injections in your wrist.
• Surgery. This may be needed if you have severe degeneration in your wrist or if your condition does not improve with nonsurgical treatments.

Follow these instructions at home:

If you have a splint:

• Wear the splint as told by your health care provider. Remove it only as told by your health care provider.
• Do not put pressure on any part of the splint until it is fully hardened. This may take several hours.
• Loosen the splint if your fingers tingle, become numb, or turn cold and blue.
• Do not let your splint get wet if it is not waterproof.
• Keep the splint clean.

Bathing

• Do not take baths, swim, or use a hot tub until your health care provider approves. Ask your health care provider if you can take showers. You may only be allowed to take sponge baths for bathing.
• If your splint is not waterproof, cover it with a watertight covering when you take a bath or a shower.

Managing pain, stiffness, and swelling

• Move your fingers often to avoid stiffness and to lessen swelling.
• Raise (elevate) the injured area above the level of your heart while you are sitting or lying down.

Driving

• Do not drive or operate heavy machinery while taking prescription pain medicine.
• Do not drive while wearing a splint on a hand that you use for driving.

Activity

• Return to your normal activities as told by your health care provider. Ask your health care provider what activities are safe for you.
• Do range-of-motion exercises only as told by your health care provider.

General instructions

• Do not use any tobacco products, such as cigarettes, chewing tobacco, and e-cigarettes. Tobacco can delay bone healing. If you need help quitting, ask your health care provider.
• Take over-the-counter and prescription medicines only as told by your health care provider.
• Keep all follow-up visits as told by your health care provider. This is important.

Contact a health care provider if:

• Your symptoms get worse or do not improve after treatment.
• You have pain, numbness, or coldness in your hand.
• Your fingernails turn a dark color, such as blue or gray.
• You develop new symptoms.