What is Cubital Tunnel Syndrome?
Cubital tunnel syndrome is a pinched nerve at the elbow that occurs when your “funny-bone nerve,” known as the ulnar nerve, is compressed on the medial (inside) portion of the elbow. This is the second most common peripheral nerve entrapment syndrome.
Similar in concept to carpal tunnel syndrome, cubital tunnel syndrome is typically caused by chronic pressure or stretch on the nerve. This can be positional--leaning on the inside of the elbow or bending the elbow for long periods such as when on the phone. Therefore, people who must bend their elbows for extended periods or who have other conditions like golfer’s elbow or carpal tunnel syndrome are more likely to get cubital tunnel syndrome.
The ulnar nerve goes along the arm, traveling from the neck to the hand. It can become compressed along the cubital tunnel, which runs from just above the bony bump inside the elbow to just below it. Osborne’s fascia (the ligament that is the roof of the carpal tunnel) and the flexor carpi ulnairs (opening between two heads of the muscle) are the two most frequent spots of compressions.
Causes of Cubital Tunnel Syndrome
All causes of cubital tunnel syndrome include compression of the ulnar nerve:
Sliding or stretching the nerve
Bending the elbow for long periods of time causes the ulnar nerve to shift out of place or snap over the medial epicondyle (the bony part inside the elbow). This grating can irritate the nerve.
Leaning on the elbow frequently can increase pressure directly to the nerve and aggravate it.
Hitting the elbow
Hitting the elbow directly causes a shock-like sensation (hitting your “funny bone”), which is usually temporary. Repeated trauma to the elbow, however, can cause damage to the ulnar nerve.
Symptoms of Cubital Tunnel Syndrome
Symptoms of cubital tunnel syndrome range in severity, but generally include the following:
Numbness can occur in the ring or pinkie finger. This numbness can be fleeting and generally occurs when the elbow is bent in the same position for some time.
Pins and needles
When the elbow is bent, there may be a tingling or pins and needles feeling. This is caused by the pinched ulnar nerve.
Depending on cubital tunnel syndrome severity, your hand may become weaker and it will be difficult to perform tasks that require hand strength.
How is Cubital Tunnel Syndrome Diagnosed?
Cubital tunnel syndrome is diagnosed using the following:
- A thorough examination of the arm
- A detailed history, that includes symptoms, medical conditions, activities and prior injuries
- X-rays to check for deformities about the elbow. In some cases, electrodiagnostic studies (nerve conduction tests) are performed to confirm the diagnosis.
How is Cubital Tunnel Syndrome Treated?
Initial treatments are conservative and involve decreasing the pressure and stretching of the nerve.
Activity Modification. Avoid leaning on elbow when sitting at desk or in chairs with armrest. An elbow pad can be helpful with this. Avoid prolonged flexion of elbow, such as using an earpiece for phone.
Towel or pillow wrapping. When wrapped around the elbow, a soft bath towel will pad the elbow, and prevent it from full flexion. This can be especially helpful at night during sleep.
Bracing. Wearing a brace during the day and/or at night takes pressure off the nerve by keeping the elbow straight.
Hand therapy. Stretching and strengthening the muscles of the forearm, wrist, and hand may help decrease pain.
Anti-inflammatory medications. Over-the-counter and prescription medications are used to decrease inflammation and pain.
When symptoms do not respond to conservative treatment options, surgical intervention may be required. There are several ways to surgically remove the pressure from the nerve.
Open In Situ cubital tunnel release. The tunnel is expanded with an incision, which allows the surgeon to release the tissues on top of the ulnar nerve causing compression. This procedure is for mild/moderate cubital tunnel cases.
Endoscopic cubital tunnel release. A minimally invasive procedure performed using an endoscope. The surgeon looks through an endoscope and making a small incision, expands the tunnel.
Ulnar nerve anterior transposition. The ulnar nerve is released and moved to the front of the elbow so it doesn’t stretch over the bony ridge
Medial epicondylectomy. The surgeon takes out part of the medial epicondyle and releases pressure on the nerve.
Like carpal tunnel syndrome, the numbness and tingling may improve quickly or slowly. It may take many months for recovery after surgery.