Cubital tunnel syndrome occurs when the ulna nerve is pinched or irritated at the elbow.
This causes inner elbow pain that radiates down to the hand, as well as tingling and numbness in the ring and little finger.
Also known as Ulnar Nerve Entrapment or Ulnar Neuritis, cubital tunnel syndrome is one of the most common types of nerve injury in the upper limb, second only to carpel tunnel syndrome.
The symptoms of cubital tunnel syndrome feel very like when you hit you “funny bone” – shooting pain down your forearm and pins and needles in your hand. This is because the “funny bone” isn’t a bone at all, it is actually the ulna nerve!
Here we will look at what cubital tunnel syndrome is, the common causes and symptoms, how it is diagnosed and the different surgical and non-surgical treatment options for ulnar nerve entrapment.
Cubital tunnel syndrome occurs when the ulnar nerve is injured, irritated or compressed at the elbow.
The ulnar nerve travels all the way from the neck, down the upper arm, round the inner side of the elbow and down into the hand.
There are a few places where the ulnar nerve may become trapped, but the most common is at the elbow where it travels through the cubital tunnel.
The cubital tunnel is found on the inner side of the elbow formed by:
The cubital tunnel is a small oval-shaped space that is very narrow so it is easy for the ulna nerve to get pinched as it travels through here. This leads to irritation and inflammation of the ulnar nerve, known as cubital tunnel syndrome or ulnar nerve entrapment at the elbow.
Cubital Tunnel Syndrome is caused by irritation and/or inflammation of the ulna nerve from:
Let’s find out a little bit more about these causes of ulnar nerve entrapment.
Pressure on the ulnar nerve is the most common cause of cubital tunnel syndrome. This may be from a one-off injury or repetitive pinching of the nerve:
Increased tension on the ulnar nerve can result in cubital tunnel syndrome, particularly if it happens frequently.
This tends to occur when you hold the elbow in a bent position for long periods e.g. talking on the phone or sleeping with your elbows bent all the way up, which stretches the ulna nerve.
As you bend you elbow, the ulna nerve has to stretch around the medial epicondyle and this places tension through the nerve and irritates it.
Common causes of cubital tunnel narrowing include arthritis, as bone spurs encroach and narrow the tunnel, and previous elbow injuries e.g. elbow fracture or dislocation.
In some cases, it comes down to anatomy – some people have a naturally narrow cubital. And for some people, when they bend their elbow, the ulna nerve slides out from its position behind the medial epicondyle and “flicks over” the bone , which over time, can irritate the nerve
Some medical conditions increase the risk of developing ulna nerve entrapment, the most common being diabetes, hypothyroidism and obesity.
Cubital tunnel syndrome symptoms will vary from person to person but may include:
The ulna nerve supplies the ring and little finger so ulna nerve entrapment will only cause symptoms in that part of the hand. If there is tingling or numbness elsewhere in the hand, then one of the other nerves is affect - find out more in the nerve pain section.
Cubital tunnel syndrome can usually be diagnosed by your primary care physician (GP). They will start by taking a full history, asking questions about your signs and symptoms, how and when they started, aggravating and easing factors and past medical history.
They will then carry out a physical examination which may involve:
You doctor may then send you for various diagnostic tests such as:
The cubital tunnel syndrome icd 10 code is G56.20
Cubital Tunnel Syndrome may present similar to medial epicondylitis aka Golfers Elbow, which causes pain and tenderness on the inner elbow that may radiate down the forearm to the hand. Golfers elbow may cause weakness in the hand but there won’t be the tell-tale tingling or numbness in the ring or little fingers that there is with ulnar nerve entrapment. There are also other conditions that can cause inner elbow pain.
Most cases of ulnar nerve entrapment can be treated without the need for surgery although it may take a number of months for cubital tunnel syndrome symptoms to settle completely.
Cubital tunnel syndrome treatment usually involves:
It is really important to avoid any aggravating activities with ulna nerve entrapment otherwise the nerve will become increasingly irritated and symptoms will likely get worse. The main things to avoid are repetitive or sustained elbow flexion and leaning on your elbow, particularly on hard surfaces.
Wearing a padded cubital tunnel syndrome brace or splint at night holds your elbow in extension and stops it from bending. This helps reduce the tension through the ulna nerve allowing time for the irritation to settle.
An alternative is to wrap a towel around your elbow each night to prevent it from bending. You may need to wear a cubital tunnel syndrome brace at night for 3-4 months before your symptoms fully settle
If you can’t avoid leaning on your elbow e.g. because of your job, wear an elbow pad to keep the pressure off the nerve. It really does make a big difference.
Some people find that non-steroidal anti-inflammatories e.g. ibuprofen/naproxen help to reduce cubital tunnel syndrome symptoms. Always check with your doctor or pharmacist before taking any new medications.
Some doctors recommend cortisone injections as part of cubital tunnel syndrome treatment. Cortisone is injected above and below the site of the ulna nerve compression rather than into the nerve itself to prevent nerve damage.
Ideally, steroid injections should be carried out under ultrasound guidance to effectively target the exact location of compression otherwise there may be little improvement in symptoms.
Your physical therapist may teach you some ulnar nerve gliding exercises to help the nerve to slide through the cubital tunnel more smoothly and reduce tension on the nerve.
You can decrease the stretch by tilting your head towards your shoulder (same side as you are stretching) or increase the stretch by tilting your head towards the opposite shoulder
You can reduce the stretch by not fully straightening your elbow each time.
The movement may feel strange at first but image your hand is a mask! You can reduce the stretch by just gently making contacting with your face rather than bringing your thumb and fingers all the way up.
Most cases of ulnar nerve entrapment will settle down with non-surgical treatment but in more persistent or severe cases, surgery may be necessary.
Cubital tunnel surgery is indicated if there is:
There are a few different options with cubital tunnel surgery and your doctor will be able advise which one is best suited to you.
With cubital tunnel release surgery, aka decompression, the ligament that runs over the top of cubital tunnel is cut and divided. This helps to increase the diameter of the tunnel which in turn reduces the pressure on the ulna nerve.
Cubital tunnel release surgery works best in mild to moderate cases of ulnar nerve entrapment but is not the best option if the nerve is prone to slipping in and out of place behind the medial epicondyle.
With anterior ulnar nerve transposition surgery, the ulna nerve is moved and repositioned from running behind the medial epicondyle to running in front of it. This helps to ensure the nerve doesn’t get caught behind the bony lump and stretched each time you bend your elbow, and it shortens the course of the nerve around the elbow, reducing the tension on it.
The third option with cubital tunnel surgery is a medial epicondylectomy, where part of the medial epicondyle is removed. This allows more space for the nerve to move and is particularly useful if the nerve is getting pinched in more than one place or if you have ongoing symptoms despite previous cubital tunnel surgery.
In some cases, combination surgery may be performed, where a cubital tunnel release is combined with either anterior transposition or medial epicondylectomy.
Most cases of cubital tunnel surgery are performed as day cases so you can usually go home the same day. They may be performed under general or local anaesthetic with an incision made on the inner aspect of the elbow. Surgery usually takes 30-60 minutes, depending on which method is being used.
Following your cubital tunnel surgery, you will be given a sling to wear for the first few days. You may also be advised to wear a splint for a few weeks to keep the elbow in a bent position and allow the area time to heal. You will usually need to wear the splint for 2-6 weeks, depending on the type of cubital tunnel surgery you underwent. You will also need to restrict certain activities such as heavy lifting and sports for around 1 month.
Applying ice and keeping the elbow elevated for the first few days can help to reduce pain, stiffness and swelling.
You will be given a rehab program to work through by your physical therapist consisting of graded range of motion and strengthening exercises for your shoulder, elbow, wrist and hand to help restore full mobility and strength in the arm.
Full recovery from cubital tunnel surgery usually takes between 3-6 months but some people do notice improvements for up to 18 months post-surgery.
There are pros and cons of each type of cubital tunnel surgery but your surgeon should be able to recommend which is best for you.
Cubital Tunnel Release is the least invasive and quickest to perform, but doesn’t shorten the course of the nerve. It may also result in the formation of scar tissue and tethering which can actually reduce the neural glide and increase the tension on the nerve.
Anterior ulnar nerve transposition and medial epicondylectomy work better than cubital tunnel release if the ulnar nerve is getting trapped behind the medial epicondyle or “flicking” over it when the elbow bends. Ulnar Nerve Transposition is less invasive as there is no trauma to the bone but is 5x more likely to require further surgery due to ongoing symptoms.
Medial epicondylectomy creates the most space but is also the most invasive.
A systematic review published in the Journal of the American Medical Association (JAMA) comparing the different types of cubital tunnel surgery concluded that cubital tunnel release had the lowest risk of complications and the addition of an epicondylectomy increased the probability of symptomatic cure without increasing the risk of complications.
Page Last Updated: 11/29/2022
Next Review Due: 11/29/2024