Ulnar Nerve Entrapment: Cubital Tunnel Syndrome

Ulnar nerve entrapment affects the ulnar nerve, which is a single nerve network that is called the peripheral nervous system. It carries information to and from the brain via the spinal cord, helping to deliver sensory information about touch, pain, and temperature. People can experience the ulnar nerve in the elbow as the “funny bone” sensation.

What is Ulnar Nerve Entrapment?

The ulnar nerve helps bend and straighten the pinky and ring fingers so a person can grasp items while also delivering sensory information to the brain. When the nerve becomes compressed ( a pinched nerve), it can lead to inflammation and cause nerve pain or damage (neuropathy).

Ulnar nerve entrapment is the most common type of ulnar nerve problem, which occurs when something places pressure on the ulnar nerve in the elbow or wrist. This condition is a type of nerve compression syndrome, as described by “nerve entrapment” and ulnar designating where the nerve compression is.

Types of Ulnar Nerve Entrapment

Ulnar nerve entrapment can occur at either the elbow or wrist, each location having a different designation:

Cubital tunnel syndrome: pressure or pulling and stretching of the ulnar nerve in the elbow. This is the second-most common type of peripheral neuropathy that affects the upper limbs, with carpal tunnel syndrome being the first.
Guyon’s canal syndrome: pressure on the ulnar nerve in the wrist. This is a rare occurrence.

Ulnar Nerve Entrapment Symptoms and Causes

Ulnar nerve entrapment is caused by activities that stretch the ulnar nerve at the elbow or place a lot of pressure on it. For example, sleeping with the elbows bent for long periods can cause nerve entrapment. Other causes include:

Arthritis
Broken bones
Bone spurs
Trauma
Complications from carpal tunnel or shoulder fracture surgeries
Diabetes
Dislocated elbow
Pressure from crutches, casts, or splints
Cysts or tumors

Symptoms of ulnar nerve entrapment can begin gradually, worsening and disappearing throughout the day or with certain activities. These symptoms include:

Pink and ring fingers curving like a claw
Elbow or wrist pain
Numbness and tingling in the pink and ring fingers
Hand weakness to the point where it is difficult to hold onto or pick up items, writing, or button shirts
Muscle loss in the ring or pinky fingers ( a rare symptom).

Ulnar Nerve Entrapment Treatment & Diagnosis

To diagnose ulnar nerve entrapment, a healthcare provider has several tests at their disposal alongside a physical exam to assess the symptoms:

Tinel’s test: the ulnar nerve in the elbow (the funny bone) is gently tapped. If there is an extreme shock-like sensation in the pink or ring finger, there is likely an issue with the nerve.
Froment’s test: the doctor observes the patient holding a piece of paper between their thumb and index finger. Flexing at the joint at the tip of the thumb can indicate a problem with the nerve.
Wartenberg’s sign: spreading the fingers apart and bringing them back together while the hand rests flat on a surface. If the doctor observes that the pinky finger cannot meet with the other, it can indicate a nerve problem.

There are imaging tests that can help a healthcare provider confirm suspicions of ulnar nerve entrapment as well:

An EMG to measure how well signals travel through nerves
MRI, Neuromuscular Ultrasound, or X-ray: these tests can show signs of nerve compression and help rule out other potential causes like ligament injuries, fractures, or arthritis.

To treat ulnar nerve entrapment, healthcare providers usually begin with conservative and nonsurgical treatments, such as:

Nonsteroidal anti-inflammatory drugs (NSAIDs) to help relieve nerve pain and swelling
Physical and occupational therapy to help improve flexibility and learn to perform tasks in new ways to lessen stress and irritation of the ulnar nerve
Splints or braces to help support the wrist or elbow

If nonsurgical treatments fail to provide relief, a doctor may recommend nerve surgery. The procedure chosen depends on the cause of the nerve entrapment:

releasing the pinched ulnar nerve at the point of entrapment
Removing tumors or cysts
Moving the ulnar nerve to the front of the bony elbow joint

Preventative Care Strategies

The risk of developing ulnar nerve entrapment can be reduced and the following strategies can also ease symptoms:

Not resting elbows on an office chair or desk while typing or working on a computer
Extending and stretching the arms throughout the day when activities keep the elbows bent for an extended period of time
Securing a towel around a straightened arm at night to keep from sleeping on a bent elbow
Wearing an elbow brace backward on the elbow joint

Make an Appointment with our Wrist Specialists

If you’ve suffered any of the symptoms listed above, we encourage you to make an appointment with our wrist specialists!

We at Proliance Pacific Rim Orthopedic Surgeons strive to help our patients achieve a return to normal activity through compassionate and exceptional care using evidence-based medicine in a patient-friendly environment. We are committed to bringing you a high standard of care that is patient-focused, with the goal of improving your quality of life.