Ulnar Nerve Entrapment

Ulnar nerve entrapment occurs when something irritates or puts pressure on your ulnar nerve, which runs down your arm.

Nerve entrapment is a type of nerve compression syndrome. Compression (a pinched nerve) may lead to inflammation, causing nerve pain and damage.

Your ulnar nerve travels from your shoulder, down your arm and into your elbow. It then goes down the pinky side of your forearm and wrist into your hand. It can get pinched at any point along this tract. But it most often gets pinched in your elbow area, causing symptoms like pain and numbness.

Treatment ranges from medication and physical therapy to surgery.

Types of this condition

Ulnar nerve entrapment typically occurs at your elbow or wrist. Types include:

• Cubital tunnel syndrome: This involves pressure or stretching of your ulnar nerve in your elbow region. It’s the second-most common peripheral mononeuropathy that affects the upper limbs, after carpal tunnel syndrome.
• Guyon’s canal syndrome: This happens from pressure on your ulnar nerve in your wrist region and is very rare.

Symptoms of ulnar nerve entrapment

Symptoms can start somewhat suddenly or come on gradually. They may come and go or be fairly constant. They may get worse at night or when you do activities that stretch or put pressure on your elbow or wrist.

Symptoms of ulnar nerve entrapment and damage include:

• Numbness and tingling in your pinky and ring fingers (most common)
• Curving pinky and ring fingers, like a claw
• Elbow or wrist pain
• Difficulty spreading your fingers out
• Hand weakness that makes it hard to hold onto or pick up items or do tasks like writing or buttoning a shirt
• Muscle loss in your ring or pinky fingers (rare)

Ulnar nerve entrapment causes

Activities that stretch your ulnar nerve at your elbow, or put a lot of pressure on your elbow, can lead to cubital tunnel syndrome. Sleeping with your elbows bent for long periods can cause or worsen symptoms of ulnar nerve entrapment. Repetitive elbow bending can cause or worsen symptoms.

Ganglion cysts cause up to 2 in 5 cases of Guyon’s canal syndrome. They’re noncancerous fluid-filled sacs that form near your wrist joint. Sometimes, healthcare providers can’t find the cause of this syndrome (idiopathic). Less commonly, cysts can also cause pressure on the ulnar nerve within your elbow.

Other causes of ulnar nerve compression and damage include:

• Accidents and trauma
• Arthritis
• Broken bones and bone spurs
• Complications from surgeries to treat carpal tunnel or shoulder fractures
• Nerve damage from diabetes
• Dislocated elbow
• Pressure from casts, splints or using crutches
• Tumors or cysts

Risk factors

You’re at increased risk of ulnar nerve entrapment if you do jobs or activities that require a lot of elbow or wrist pressure or stretching. For example, it can develop in:

• Baseball players, golfers and tennis players
• Bicyclists
• Construction workers
• Typists, writers and others who use a keyboard frequently
• Weightlifters

Smoking also increases your risk.

Complications of this condition

Ulnar nerve compression that’s severe can cause muscle loss in your hand. This damage may be permanent in some cases. This is why it’s important to see your healthcare provider early about symptoms.

How doctors diagnose this condition

Your healthcare provider may do several tests during a physical exam to evaluate your symptoms. These tests may seem simple, but they help your provider assess finger and hand strength. Your provider may recommend other tests to confirm the diagnosis.

Physical tests

Physical tests that help diagnose ulnar nerve entrapment include:

• Froment’s test: Your provider watches how you hold a piece of paper between your thumb and index finger. Flexing at the joint at the tip of your thumb may point to a nerve problem.
• Tinel’s sign: Your provider gently taps your elbow’s funny bone (ulnar nerve). A shock-like sensation or tingling in your pinky or ring finger may suggest a nerve problem.
• Wartenberg’s sign: Your provider watches you spread your fingers apart and bring them back together. You do this while resting your hand on a flat surface. You may have a nerve problem if you can’t bring your pinky finger in to meet with the others.
• Neurological exam: Your provider may test the strength of individual muscles in your hand. They may use a pin to test sensation in your hand and fingers. Certain patterns of weakness or an inability to feel sharpness in your pinky and ring fingers may point to an ulnar nerve problem.

Other tests

These tests can confirm or rule out ulnar nerve entrapment:

• Electromyography (EMG) and nerve conduction studies: These measure how well signals travel through nerves to stimulate your muscles. It’s generally the most accurate test for diagnosing and assessing the severity of an ulnar nerve problem.
• MRI, neuromuscular ultrasound or X-rays: These imaging tests can show signs of nerve compression or inflammation. They can help rule out problems like arthritis, ligament injuries and fractures.

How is it treated?

Healthcare providers typically suggest nonsurgical treatments for ulnar nerve entrapment first. For example:

• Nonsteroidal anti-inflammatory drugs (NSAIDs) can help relieve nerve pain and swelling.
• Physical and occupational therapy helps improve your flexibility. You learn to do tasks in ways that are less likely to irritate your ulnar nerve. You may learn nerve-gliding exercises to help your ulnar nerve move more smoothly through ulnar tunnels.
• Splints or braces help support your arm joints.

If nonsurgical treatments don’t help, you may need surgery. Depending on the cause of the nerve entrapment, surgery can:

• “Release” your pinched ulnar nerve at the point of entrapment (cubital tunnel release surgery)
• Remove tumors or cysts
• Move your ulnar nerve to the front of your bony elbow joint (transposition surgery)

What can I expect if I have this condition?

About half of all people with ulnar nerve entrapment get symptom relief through nonsurgical means.

When needed, surgery may eliminate nerve pain and other symptoms. But symptoms may return if the procedure doesn’t fully treat the underlying cause. There’s also a risk of surgical damage to your median nerve, ulnar artery or ligaments in your elbow or wrist.

Can this be prevented?

These steps may lower your risk of developing ulnar nerve entrapment or ease symptoms:

• Extend and stretch your arms throughout the day if you do activities that involve bending your elbows for a long time.
• Don’t rest your elbows on an office chair or desk while typing or working on a computer.
• Secure a towel around your straightened arm at night to keep from sleeping on a bent elbow. Or you can wear an elbow brace backward on the elbow joint.