Ulnar nerve entrapment is an extremely common injury to a nerve that runs through the arm into the fingers on the outside of the hand.
While ulnar nerve entrapment is usually not serious, it can have permanent consequences if not treated promptly, including paralysis and loss of feeling in the affected hand or arm.
However, with proper diagnosis and treatment, most people with ulnar nerve entrapment can make a full recovery.
The ulnar nerve is one of the arm's major nerves and is part of the brachial plexus nerve system. It gets its name from its location near the ulna bone, a bone in the forearm on the side of the pinkie finger.
The ulnar nerve starts in the neck and travels through the shoulder down the arm into the wrist and fingers.
It provides sensation to the forearm and the fourth and fifth finger. It also innervates (stimulates) the flexor muscles of the hand, allowing it to bend and move.
What is ulnar nerve entrapment?
As the ulnar nerve runs the entire length of the arm, there are several places along the nerve that can become compressed or irritated. This compression or irritation is known as ulnar nerve entrapment.
Ulnar nerve entrapment is the second most common entrapment nerve pain in the upper body.
Ulnar nerve entrapment happens most often at or near the elbow, particularly on the inner part of the elbow. This is known as cubital tunnel syndrome. Ulnar nerve entrapment can also happen less frequently at or near the wrist.
While these two areas are the most common sites of ulnar nerve entrapment, it can also happen anywhere between the wrist and elbow in the forearm or between the elbow and shoulder in the upper arm.
The ulnar nerve runs through several areas of the arm that bend and can cause pressure on the ulnar nerve.
The single most common cause of ulnar nerve entrapment is compression on the ulnar nerve. The compression may be a result of any of the following:
- leaning on the elbow for an extended period
- the ulnar nerve slipping out of place when the elbow is bent
- fluid buildup in the elbow
- current or previous injury to the inside of the elbow
- bone spurs in the elbow
- arthritis in the elbow or wrist
- swelling in the elbow or wrist joint
- an activity that causes a person to bend and straighten the elbow joint repeatedly
Some of the symptoms of ulnar nerve entrapment may occur in the elbow, particularly if that is where the problem originates. However, most of the symptoms of this condition occur in the hand and fingers. Many of the symptoms tend to occur when the elbow is bent.
Symptoms of ulnar nerve entrapment include the following:
- intermittent numbness and tingling in the ring and pinkie fingers
- a weak grip in the affected hand
- a feeling of the pinkie and ring fingers "falling asleep"
- difficulty controlling fingers for precise tasks, such as typing or playing an instrument
- sensitivity to cold temperatures
- pain or tenderness in the elbow joint, especially along the inner aspect
In severe and long-standing cases, muscle wasting of the hand may also occur.
Getting ulnar nerve entrapment diagnosed properly is key to avoiding long-term loss of function and sensation in the affected hand and fingers.
If a person has any of the symptoms of ulnar nerve entrapment for more than a few weeks, they should see a doctor. Likewise, a person with any symptoms of ulnar nerve entrapment that are severe should seek medical attention promptly.
During a checkup for ulnar nerve entrapment, a doctor will begin by asking questions, regarding the person's general health and medical history, including any medications they may be taking.
After the discussion regarding general health and medical history, the doctor will then examine the person's arm and hand.
During the exam, the doctor may bend the person's elbow or wrist to try to produce symptoms and see whether or not the ulnar nerve slides out of place upon bending the elbow.
The doctor will also check the strength in the hand and fingers and sensation in the hand.
Depending on their assessment, the doctor may send a person with ulnar nerve entrapment symptoms for other tests, including:
- X-rays to check the elbow for bone spurs, fractures, or any other issues that may cause compression.
- Nerve conduction studies, where small needles are inserted into the muscles surrounding the ulnar nerve, to check muscle function and see how well the ulnar nerve is functioning.
Treatment for ulnar nerve entrapment depends on how severe the entrapment is.
For less severe cases, a doctor will probably recommend nonsurgical treatment options first. These may include some combination of the following:
- use of anti-inflammatory medications to reduce swelling
- elbow braces or splints to keep the joint straight at night
- exercises and physical therapy to help the nerve slide through the arm correctly
There is a selection of elbow braces available for purchase online.
If the ulnar nerve entrapment is severe or nonsurgical approaches to treatment fail, a doctor may recommend surgery to fix ulnar nerve entrapment.
Surgical treatment options for ulnar nerve entrapment include:
- Cubital tunnel release: A procedure to increase the size of the cubital tunnel to give the nerve more room.
- Ulnar nerve anterior transposition: A procedure to move the nerve from behind the muscle to in front of it, so there is less tension on the nerve when the elbow is bent.
- Medial epicondylectomy: A procedure that removes part of the protruding medial bone to prevent the nerve from rubbing on this area.
These approaches will only be used, as the first line of treatment if the ulnar nerve entrapment is severe enough to cause muscle weakness and wasting.
Surgical recovery varies from person to person and depends largely on the procedure performed. Surgical outcomes for ulnar nerve entrapment are often good, and most people can expect to make a full or nearly full recovery.
Home remedies and prevention
There are lots of things a person who has ulnar nerve entrapment can do at home to promote healing and recovery. These same steps can also prevent ulnar nerve entrapment from recurring or happening in the first place.
A person can help treat or prevent ulnar entrapment at home by doing the following:
- avoiding any activity that causes the elbow to bend and straighten repeatedly
- making sure they are sitting at a proper height when using a computer to allow the arm to straighten
- keeping the elbow straight at night
- avoiding leaning on the elbow or putting pressure on the inner aspect of the elbow
With active prevention and home treatment, most people can avoid ulnar nerve entrapment.