Ulnar Nerve Entrapment Surgery
Compression of the ulnar nerve at the inner elbow causes numbness in the little and ring fingers and hand weakness. In advanced cases the nerve is released surgically.
The ulnar nerve is the nerve behind the inner side of the elbow, the “funny bone”. It provides feeling to the little finger and half of the ring finger and powers many of the muscles that control fine hand movements. It is most often compressed in the cubital tunnel at the elbow, and less often at the wrist (Guyon’s canal).
Causes
- Keeping the elbow bent for long periods (phone use, sleeping with the arm bent)
- Leaning on the elbow often
- Old elbow fractures and elbow arthritis
- The nerve slipping out of place as the elbow moves
- Cysts or masses pressing on the nerve
Symptoms
- Numbness and tingling in the little and ring fingers
- Symptoms that worsen after keeping the elbow bent
- Pain on the inner side of the elbow
- Weakness in the hand, reduced grip and pinch strength
- Difficulty with fine tasks (writing, buttons)
- In later stages, wasting of muscles on the back of the hand and between the thumb and index finger, and the little finger drifting outwards
Diagnosis
Sensation and muscle strength are assessed, and symptoms are checked on tapping the inner elbow or holding it bent. EMG shows where the compression is and how severe it is. Nerve compression from the neck is ruled out. Ultrasound or MRI is used when needed.
Non-surgical treatment
For mild cases:
- Avoiding keeping the elbow bent for long periods
- A splint or pillow that keeps the elbow slightly straight at night
- Not leaning on the elbow
- Nerve gliding exercises
Surgery
Surgery is recommended if symptoms continue despite non-surgical care, EMG shows moderate or severe compression, or weakness and wasting have started. Timing matters, because delayed treatment can leave permanent nerve damage.
- In situ decompression: The tissues pressing on the nerve are released.
- Anterior transposition: The nerve is moved to the front of the elbow, where it is under less tension. It may be preferred when the nerve slips or the elbow has a bony deformity.
Recovery
Numbness usually starts to improve within weeks. Muscle strength can take months to return, and in severe, long-standing compression full recovery may not occur. Hand exercises and, when needed, hand therapy follow surgery.
Compression at Guyon’s canal
The ulnar nerve passes through an area on the little-finger side of the wrist called Guyon’s canal. Long periods leaning on bicycle handlebars, wrist fractures, ganglion cysts and repeated pressure on this area can compress the nerve there. Unlike compression at the elbow, sensation on the little-finger side of the back of the hand is usually preserved. EMG helps tell whether the compression is at the elbow or the wrist.
How does a nerve recover?
Releasing a compressed nerve removes the pressure and creates the right conditions for recovery. In mild compression, sensation and strength can improve quickly. In long-standing compression, the nerve fibres need to repair themselves. Nerves heal slowly; muscles in particular can take months to regain strength. If muscle wasting is advanced, full recovery may not occur, which is why treatment should not be delayed once weakness begins.
Protecting the nerve in daily life
Using headphones for phone calls, not leaning on the elbow at a desk, not sleeping with the arm bent for long and working at a computer without bending the elbow too much reduce the strain on the nerve at the elbow. For night-time numbness, a towel wrapped around the elbow or a special pillow can stop the elbow bending too far during sleep.
After surgery
The elbow is protected with a dressing or splint for a short time. Finger and wrist movement starts immediately, and elbow movement starts in the first days or after a few weeks, depending on the technique. Stitches are usually removed within two weeks. Hand exercises and, if needed, hand therapy help regain muscle strength.
Ulnar nerve after elbow fractures
Elbow fractures in childhood or adulthood can change the shape of the elbow and, years later, stretch and compress the ulnar nerve. In these patients, symptoms develop slowly and are sometimes noticed years later.
Frequently asked questions
When should I have surgery?
If weakness or muscle wasting has started, surgery should not be delayed. In mild cases, non-surgical treatment is tried first.
Will feeling come back completely after surgery?
Many patients improve considerably. The longer and more severe the compression, the lower the chance of full recovery.
Is it the same as carpal tunnel syndrome?
No. In carpal tunnel syndrome the median nerve is compressed at the wrist and the thumb side is affected; in cubital tunnel syndrome the ulnar nerve is compressed at the elbow and the little finger side is affected.
Is general anaesthesia needed?
The operation can be done under regional anaesthesia (numbing the arm) or general anaesthesia, depending on the technique and the patient's preference.
When can I return to work?
Desk work can usually be resumed within a few weeks. Jobs that use the arm heavily take longer.
Does moving the nerve affect my movement?
No. Moving the nerve to the front of the elbow does not limit elbow movement; it reduces the stretch on the nerve during movement.
Can ulnar nerve compression be confused with a neck problem?
Yes. Nerve root compression in the neck can also cause numbness on the little-finger side. Examination and EMG help identify where the compression is.
How long should a night splint be used?
In mild cases, a night splint is used for a few weeks to a few months, and treatment is reviewed according to how symptoms develop.
Will I lose feeling around the elbow after surgery?
There may be numbness around the scar for a while. This usually eases over time.
The information on this page is general and does not replace an examination. An examination is needed to decide which treatment suits you.