Ulnar Nerve Compression
(formerly “cubital nerve” at the elbow)
Definition
This condition involves compression of the ulnar nerve (formerly called the cubital nerve) within an anatomical groove located on the inner side of the elbow, between the humerus and the ulna.
What causes it?
In most cases, no specific cause is identified; the condition is then considered idiopathic.
In some cases, surrounding structures may contribute to nerve compression within the groove:
Elbow osteoarthritis with bone spurs (osteophytes), cysts, etc.
Occupational factors involving repeated elbow flexion and extension
Hormonal or metabolic conditions such as diabetes or hypothyroidism
An unstable nerve that moves out of its groove can also contribute to symptoms.
What are the symptoms?
This syndrome causes tingling in the last two fingers of the hand (ring finger and little finger) and along the outer edge of the hand.
In advanced stages, there may be muscle weakness affecting grip, due to involvement of the small hand muscles, with a characteristic “clawing” deformity of the last two fingers.
What tests may be required?
After a thorough physical examination to establish the diagnosis and severity, an electromyography (EMG) will be prescribed for diagnostic and prognostic purposes.
In some cases, an elbow X-ray and/or imaging of the nerve and surrounding tissues may be requested if an external compressive structure is suspected.
How is it treated?
Initial treatment is usually non-surgical, including splinting and avoidance of positions that trigger symptoms.
If this approach fails, in the presence of severe signs, or if compression is caused by surrounding structures, surgery may be proposed.
Two main surgical techniques exist:
Simple decompression (neurolysis)
Decompression with anterior transposition (the nerve is moved out of its groove and repositioned in front of the elbow)
The choice depends on severity, underlying cause, and whether the nerve is unstable.
In cases of anterior transposition, elbow immobilization for about 8 days is required.
What are the risks of surgery?
They are rare:
General surgical risks (<1%):
Complex regional pain syndrome (chronic pain with swelling, redness, and heat)
Soft tissue infection
Hematoma
Nerve injury is exceptional
Temporary or permanent burning sensations around the scar, due to irritation or injury of small skin nerves (particularly the posterior branch of the medial antebrachial cutaneous nerve). These nerves are carefully identified during surgery to minimize risk
Persistence of sensory or motor deficits in cases that were severe at the outset.