Ulnar nerve compression at the elbow

By Dr Maxime Cievet-Bonfils, hand, wrist and elbow surgeon in Lyon, France · Updated 2026-10-16 · Version française

Ulnar nerve compression at the elbow, or cubital tunnel syndrome, is the second most common nerve compression in the upper limb after carpal tunnel syndrome. It causes tingling in the ring and little fingers, especially with the elbow bent, then a loss of strength and dexterity in the hand. Treatment starts with simple measures (avoiding keeping the elbow bent, a splint at night); if symptoms persist or the nerve is suffering, an operation releases the nerve.

What is ulnar nerve compression at the elbow?

The ulnar nerve runs down the arm and passes along the inner side of the elbow, in a bony groove behind the medial epicondyle (the bony bump on the inner side of the elbow), covered by a fibrous arch: this is the cubital tunnel. It is the spot that gives an electric shock in the last two fingers when you knock your elbow.

When the elbow is bent, the tunnel narrows and the nerve is stretched. Prolonged positions with the elbow bent (telephone, sleeping with the arm folded, leaning on the elbow), a nerve that slips forwards each time the elbow bends, elbow arthritis or the after-effects of a fracture all promote compression.

What are the symptoms?

• Tingling or numbness in the little finger and half of the ring finger, sometimes along the inner edge of the hand
• Symptoms triggered or made worse with the elbow bent: telephone, reading, at night
• Pain on the inner side of the elbow, spreading to the forearm
• Clumsiness, difficulty with fine movements (buttons, keys), loss of pinch strength
• At advanced stages: wasting of the hand muscles (hollow between the thumb and index finger), fingers curling into a claw, little finger drifting away from the others

Unlike carpal tunnel syndrome, muscle damage can set in without much tingling: weakness of the hand should prompt you to seek advice.

How is it diagnosed?

The examination looks for reduced feeling, weakness of the small muscles of the hand and pain when tapping on the nerve at the elbow; it also checks whether the nerve slips out of place when the elbow bends. An electromyogram (EMG, nerve conduction study) confirms the compression, shows its level (elbow or wrist) and its severity, and rules out a problem in the neck. Ultrasound is the most sensitive test: it allows the structure of the nerve to be checked and a local cause of compression to be looked for. An X-ray looks for a bony cause.

What are the non-surgical treatments?

In early forms, with no muscle involvement, non-surgical treatment is offered first:

• Avoid keeping the elbow bent for long periods: hands-free kit for the telephone, adapting your workstation
• Avoid leaning on the inner side of the elbow
• Night splint or cushion keeping the elbow only slightly bent during sleep
• Rehabilitation with nerve gliding exercises can complement these measures

These measures are continued for several weeks to a few months before judging whether they are working.

When is surgery needed?

The operation is offered when symptoms persist despite non-surgical treatment, or straight away when there is loss of strength, muscle wasting or severe damage on the EMG. Long-standing muscle damage recovers less well: it is best not to wait too long.

How is the operation performed?

The operation usually offered is in situ release of the nerve (neurolysis): through an incision on the inner side of the elbow, the surgeon opens the fibrous arch and the areas of compression, without moving the nerve. When the nerve is unstable and slips forwards as the elbow bends, or in certain situations (after-effects of a fracture, recurrence), it can be moved in front of the medial epicondyle: this is anterior transposition.

When the ulnar nerve is compressed by an enlarged triceps muscle, partial removal of the muscle can relieve the compression.

The operation is done as a day case, under regional anaesthesia of the arm.

After the operation

• The elbow is moved early to avoid adhesions around the nerve
• Tingling often improves within a few weeks; recovery of feeling and especially of strength is slow, over several months
• Hand rehabilitation may be prescribed if the muscles are affected
• The length of time off work depends on your job and on the procedure performed

Complications are rare: haematoma, infection, tender scar, numbness of a small area of skin near the scar, persistent symptoms. They are explained to you in consultation.

Frequently asked questions

What is the difference with carpal tunnel syndrome?

Carpal tunnel syndrome compresses the median nerve at the wrist and affects the thumb, index and middle fingers. Ulnar nerve compression at the elbow affects the ring and little fingers. The two can occur together.

Do I need an electromyogram before the consultation?

Ideally, yes. The EMG confirms the diagnosis, locates the compression and measures its severity, which directly guides treatment.

Will the hand muscles recover?

Tingling generally recovers better than strength. The longer-standing and more severe the muscle damage, the slower and less complete the recovery, which is why it is best not to wait.

Should I sleep with my arm straight?

Avoiding sleeping with the elbow very bent often relieves night-time symptoms. A splint or a towel wrapped around the elbow helps keep the arm almost straight at night.

This page provides general information. It does not replace a consultation: every situation is different.