The Ulnar Nerve is one of the hand nerves starting at the neck, passing through the arm to the forearm by crossing the elbow, and from there to the palm.
The Ulnar Nerve Entrapment Syndrome is a condition in which pressure is exerted at the ulnar nerve in the elbow. This syndrome is the second most common in the upper body after the carpal tunnel syndrome.
The cause of the Ulnar Nerve Entrapment Syndrome
When passing through the elbow joint, the nerve might be pressed by muscles in the area as well as by ligaments and bone spikes due to a fracture or local ossification.
Characteristics of the syndrome
The ulnar nerve entrapment syndrome is characterized by paresthesia of the little finger and the middle finger as well as on the outer back side of the palm. Signs of paresthesia may appear at night during sleep (especially when sleeping on one's belly with a bent elbow), long conversations using a mobile phone or athletic activities with repeated movement of the elbow.
A reduction of muscle strength of the palm in grabbing motion and distancing between the fingers.
A reduction of touch sensitivity on the little and middle fingers.
Diagnosing the Ulnar Nerve Entrapment Syndrome
Exploring occupational and athletic causes for the disease's creation.
On observation – checking the elbow's carrying angle, straightening the middle and little fingers.
In touch – checking sensitive spots or a "jump" of the nerve in its duct in the elbow – when moving from a bent position to a straight position and back to a bend position, testing the sensitivity of the palm to touch.
In a clinical examination the patient is checked for muscle reduction in the palm as well as for the elbow's movement ranges.
Imaging tests – neural conduction tests (EMG/NCS) – the electrical conduction speed of the ulnar nerve is tested in the elbow pass. A speed lower than 50m/sec is considered as positive with regard to pressure on the nerve.
Treating the Ulnar Nerve Entrapment Syndrome
Conservative treatment -
Changing activities suspected to cause pressure on the nerve.
Referral to fitting a night splint to prevent the elbow's bending.
Pharmaceutical treatment -
Surgical treatment -
The purpose of the surgery is to reduce the pressure on the ulnar nerve where it passes the elbow. In mild cases, it is possible to free the ligament stabilizing the nerve where it passes the elbow duct and thus reduce the pressure on the nerve.
In more severe cases, it is possible to move the ulnar nerve forward to the medial part of the humerus at the elbow and keep it above the muscles, inside a duct in the bending muscles or below the bending muscles.
Possible complications following surgery -
Neuroma - due to damage to a sense branch of the nerve during surgery.
A return of symptoms - due to insufficient release or secondary to scarring around the nerve.