Cubital tunnel syndrome is compression of the ulnar nerve where it passes behind the inside of the elbow. It causes numbness and tingling in the ring and little fingers, often worse when the elbow is bent, and in more advanced cases weakness and clumsiness of the hand. It is the second most common nerve compression in the arm after carpal tunnel syndrome. Many cases settle by changing how the elbow is held, particularly overnight. Where the nerve is under sustained pressure, an operation releases it. It takes 30 to 45 minutes as a day procedure, and the sooner it is done in the course of the condition, the more complete the recovery.
What is cubital tunnel syndrome?
On the inside of the elbow the ulnar nerve runs through a tunnel made of bone and fibrous tissue, called the cubital tunnel. It is the nerve you hit when you knock your funny bone. After passing through the tunnel the ulnar nerve travels down the forearm towards the ring and little fingers.
The ulnar nerve is responsible for sensation in the ring and little fingers and parts of the back and inside of the hand. It also moves the fine, small muscles within the hand, the intrinsic muscles, which are what let you spread the fingers, pinch strongly and perform anything requiring dexterity.
In cubital tunnel syndrome the ulnar nerve does not have enough space in the tunnel at the elbow. Bending the elbow stretches the nerve and narrows the tunnel at the same time, which is why symptoms are worse when the elbow is held bent, and why they so often wake people at night.
The consequence of leaving it is different from carpal tunnel syndrome, and worse. Prolonged compression of the ulnar nerve causes wasting of the small muscles of the hand, and those muscles recover slowly and sometimes incompletely. Timing matters more here than almost anywhere else in the hand.
Symptoms
Symptoms fluctuate and vary. Most people describe:
- Tingling, numbness or pain in the ring and little fingers
- Symptoms that come on when the elbow is bent for a while, on the phone, driving, or asleep
- Waking at night with a numb hand, usually with the elbow curled up
- Pain on the inside of the elbow, sometimes travelling down the forearm
- Clumsiness, dropping things, and difficulty with fine tasks such as buttons, coins and typing
- Weakness of grip and pinch
- In advanced cases, visible hollowing of the muscle between the thumb and index finger on the back of the hand, and difficulty holding the fingers together
The distribution is the useful clue. The ulnar nerve supplies the little finger and half the ring finger, and the split runs down the middle of the ring finger. Numbness that includes the thumb and index finger is carpal tunnel syndrome, not this. Some people have both.
Visible wasting of the small hand muscles is a late sign and a reason to be seen promptly rather than to wait and see.
Causes and risk factors
- Prolonged or repeated elbow bending, at work, on the phone, or during sleep. Most people sleep with the elbow fully bent without knowing it.
- Leaning on the elbow, on a desk, an armrest or a car door, which presses directly on the nerve.
- Previous elbow fracture or dislocation, sometimes many years earlier, which can alter the shape of the tunnel.
- Arthritis of the elbow, where bone spurs narrow the tunnel.
- Diabetes, which both raises the risk and makes nerves more vulnerable to compression.
- A nerve that subluxes, meaning it slips forwards over the bony point of the elbow as you bend it, irritating itself repeatedly.
How it is diagnosed
Clinical examination
The distribution of the numbness, whether it wakes you, how long it has been present and whether it is progressing all matter. Examination includes sensory testing in the ulnar distribution, testing the strength of the small hand muscles, looking for wasting, tapping over the nerve at the elbow, holding the elbow bent to see whether it reproduces symptoms, and feeling whether the nerve slips forwards as the elbow bends.
Nerve conduction studies
In nearly all cases we confirm the diagnosis with a nerve conduction study before proceeding to surgery. It measures how well the ulnar nerve conducts across the elbow and localises where the compression actually is.
That last point is the important one. Ulnar symptoms can arise at the elbow, at the wrist, or from the neck, and the treatment for each is entirely different. The study distinguishes them, grades severity, and gives a documented baseline against which to judge recovery.
As with carpal tunnel syndrome, a normal study in someone with a clear clinical picture does not exclude the diagnosis.
Imaging
An X-ray of the elbow is worth having where there has been a previous fracture or where arthritis is likely. Ultrasound can show the nerve and demonstrate whether it subluxes, but it is not routine.
Non-surgical treatment
Mild and intermittent cases often respond well, and this is worth a genuine attempt first.
Night splinting
A splint that stops the elbow bending past about forty five degrees overnight is the single most effective non-surgical measure, for the same reason a wrist splint works in carpal tunnel syndrome: it removes the position that causes the compression during the hours you cannot control it. A folded towel wrapped around the elbow and taped works nearly as well and is better tolerated by some people.
Activity change
Stop leaning on the elbow, use a headset rather than holding a phone, and set up a desk so the elbows are not resting on a hard edge. This sounds minor and it is often what turns the condition around.
Hand therapy
Our therapists provide nerve gliding exercises, fit and adjust the night splint, and work through the ergonomics with you.
What does not work
Corticosteroid injection around the ulnar nerve at the elbow is not useful in the way it is for tendon conditions, and it carries risk to the nerve. It is not part of the standard treatment of this condition.
Surgery
Cubital tunnel release surgery involves release of the fibrous band that forms the roof of the cubital tunnel, through an incision in the overlying skin at the inside of the elbow. This releases pressure on the ulnar nerve.
In some cases the ulnar nerve needs to be moved outside the tunnel, which is called an anterior transposition, or a small part of the elbow bone needs to be shaved down, which is called a medial epicondylectomy. The nerve is moved where it slips forwards over the bony point as the elbow bends, or where releasing the tunnel alone would leave it irritated.
A simple release is what we do in most cases. The nerve is moved only where it slips forwards over the bony point of the elbow as you bend it, which is something we test for during the operation. That applies to roughly one in five people.
The procedure takes approximately 30 to 45 minutes and usually takes place as day surgery, using a general anaesthetic and a local anaesthetic for postoperative comfort. The incision is closed with dissolving skin sutures, and a tape bandage covers the wound under a soft elbow dressing.
What to expect from the result
Surgery reliably stops the condition progressing. Pain and the intermittent tingling usually improve first and often quickly. Numbness that has become constant, and wasted muscle, recover slowly and may not recover fully. In some cases symptoms do not improve, even after a year of recovery, and another operation may be required in the future.
That is the honest position and it is the whole argument for not leaving this one too long.
Recovery, week by week
Indicative, and it varies with whether the nerve was released alone or moved.
Timeframe
What to expect
Day of surgery
Some or all of your fingers may feel extra numb or tingly for one or more days because of the local anaesthetic, particularly the ring and little fingers. You can start to move and use your hand and fingers for light tasks before you leave hospital, but avoid bending the elbow more than 90 degrees.
Days 1 to 5
Keep the soft dressing clean and dry. You will be referred to a hand therapist on day 4 or 5. They take down the outer bandage, keep the tape dressing on the skin intact, and advise you on starting gentle elbow exercises.
Days 5 to 14
The tape bandage can get wet in the shower. Dab it dry afterwards. If it comes off, replace it with new tape. Use your hand and wrist as tolerated, but move the elbow only gently as directed by the hand therapist.
Two weeks
Your progress is reviewed. The skin sutures dissolve and do not need removing. If needed, a new tape bandage goes on for another three to five days.
Six weeks
A further follow up appointment to monitor progress. Elbow movement is normally well recovered by this stage.
Three to twelve months
Nerve recovery continues over this period. Pain and intermittent symptoms settle first. Numbness that was constant before surgery, and any muscle wasting, recover slowly and may be incomplete.
Driving and work
Driving and office work at about four to five days, once the elbow moves freely enough to steer comfortably. Light manual work at two to four weeks, and heavy work at six weeks.
The elbow is deliberately kept below 90 degrees at first and then progressed by the therapist. That restriction is the main practical difference between this recovery and a hand operation, and it is what makes driving and desk work worth planning around.
Hand therapy
Therapy starts on day 4 or 5, earlier than after most hand operations, because the elbow stiffens quickly and because the nerve needs to glide rather than scar in place. The therapist takes down the dressing, starts gentle elbow movement at the right pace, and progresses you as the wound allows.
Risks and complications
Cubital tunnel release is routine and safe, and complications are uncommon. When they occur they can include:
- Wound healing problems or infection.
- Bleeding or bruising. Usually minor and settles on its own.
- Numbness behind the elbow. Small sensory nerves cross the incision and a numb patch below and behind the scar is common. It usually improves, and it is not the same as the ulnar nerve itself being injured.
- Elbow stiffness, which is why therapy starts early.
- Ongoing tenderness around the scar or slower than expected recovery.
- Symptoms not improving. In some cases cubital tunnel syndrome symptoms do not improve, even after a year of recovery. Another surgery may be required in the future.
When to be seen sooner
Contact us, or see your GP, if you have:
- Constant rather than intermittent numbness in the ring and little fingers
- Visible hollowing of the muscles on the back of the hand, particularly between the thumb and index finger
- Difficulty holding the fingers together, or crossing your fingers
- Weakness of pinch, or dropping things
- Symptoms progressing over weeks rather than months
- Symptoms following an elbow injury
Muscle wasting is the sign that changes the urgency. It means the nerve has been under sustained pressure long enough to affect the muscles it supplies, and those recover slowly. If you have had surgery with us and have questions or concerns afterwards, phone the rooms during office hours on (08) 7127 0365.
Other nerve compression in the arm
The ulnar nerve can also be compressed at the wrist, in Guyon's canal, which causes similar finger symptoms without the elbow pain and without numbness on the back of the hand. The radial nerve can be compressed in the forearm, causing aching on the outside of the elbow that is often mistaken for tennis elbow. The median nerve can be compressed above the wrist as well as within the carpal tunnel.
These are less common, they are distinguished by examination and nerve conduction studies, and they are worth considering when a nerve problem does not fit the usual pattern.
Frequently asked questions
Why are only two of my fingers numb?
Because the ulnar nerve supplies only the little finger and half the ring finger. The split runs down the middle of the ring finger, which is a distribution no other condition produces, and it is what makes this diagnosis recognisable.
Is this the same as carpal tunnel syndrome?
No. Different nerve, different place, different fingers. Carpal tunnel syndrome is the median nerve at the wrist, affecting the thumb, index and middle fingers. Cubital tunnel syndrome is the ulnar nerve at the elbow, affecting the ring and little fingers. Some people have both, and each is treated on its own merits.
Why is it worse at night?
Because almost everyone sleeps with the elbow bent, and bending the elbow both stretches the ulnar nerve and narrows the tunnel it runs through. That is also why a splint that stops the elbow bending overnight is the most useful non-surgical treatment.
How long does the operation take, and will I be asleep?
Approximately 30 to 45 minutes, as day surgery under a general anaesthetic, with a local anaesthetic given at the same time for comfort afterwards. You go home the same day.
Will the numbness go away completely?
Pain and intermittent tingling usually improve first and often quickly. Numbness that had become constant before surgery, and any wasting of the small hand muscles, recover slowly over months and may not recover fully. Surgery reliably prevents further deterioration, which is the main reason not to leave it.
When can I drive and go back to work?
Driving and office work at about four to five days, once the elbow moves freely enough to steer and to perform an emergency stop. Light manual work at two to four weeks, and heavy work at six weeks. The elbow is deliberately kept below 90 degrees for the first few days, which is the practical limit early on. There is no legislation covering surgery and driving, so the test is whether you can control the car safely.
Do I need my stitches removed?
No. The skin is closed with dissolving sutures. You are still reviewed to check the wound and your progress.
Do I need a nerve conduction study first?
In nearly all cases, yes. Ulnar symptoms can come from the elbow, the wrist or the neck, and the study tells us which. It also grades severity and gives a baseline to measure recovery against.
What does the surgery cost?
You will receive written informed financial consent setting out the surgeon, anaesthetist and hospital fees, your Medicare rebate and your health fund's contribution before anything is booked. Phone the rooms on (08) 7127 0365 for an estimate.
Do I need a referral?
A referral from your GP or another specialist means you can claim a Medicare rebate on the consultation. We can see you without one, but the rebate will not apply.
Written and clinically reviewed by Dr Paul van Minnen, MD, PhD, EBOPRAS, FRACS (Plast)
Last reviewed 9 September 2026