Cubital tunnel syndrome

What is Cubital tunnel syndrome?

Ulnar nerve or funny bone nerve is a long nerve that runs from a shoulder to hand, supplying sensation to little finger and half of ring finger and also powers around 20 small muscles of the hand. Cubital tunnel syndrome is a condition in which the ulnar nerve is compressed or entrapped or pinched around the elbow (commonly in a tunnel behind funny elbow bone). This condition is also called ulnar nerve entrapment or peripheral nerve compression neuropathy. The nerve is usually swollen, inflamed and is due to compression or irritation or injury.

It is second most common ailment of nerves of upper extremity after carpal tunnel syndrome. In most patients’ ulnar nerve compression occurs without any obvious reason, however its reported in some after prior fractures, arthritis, swelling of the elbow joint, cysts near the joint, direct injury to the tunnel and prolonged repetitive bending of the elbow. It can also be caused by repetitive leaning of the elbow on a hard surface. It can be associated with other conditions like cubitus varus, medial epicondylitis or burns.


What are the symptoms of Cubital tunnel syndrome?

Its common symptoms are numbness and tingling in the little finger and ring finger which is felt most while driving or using a phone. Pain usually radiates from the elbow to the little and ring fingers. It is felt most in night when you sleep, keeping your elbow bent. You may feel weakness in the grip, clumsiness and difficulties in finger coordination especially during typing or playing an instrument. In severe cases, you might have muscle wasting and could permanently lose the sensation.


How is it diagnosed?

Your orthopaedic surgeon will take your medical history, handedness, your job and medications you are taking. He will perform physical exam by checking the nerve in your elbow, wrist and neck. He will examine the sensation in your hand and your muscle power. He may ask you for nerve conduction test and in some X-ray/MRI scan/CT scan to identify other causes of nerve entrapment and to plan the management. Nerve conduction study and clinical assessment is essential to rule out compression of nerve elsewhere (wrist- Guyon’s canal and neck-cervical spine)


What happens if nothing is done?

If it is left untreated, the condition could lead to progressive damage to the ulnar nerve. This may result in permanent tingling and numbness in the hand. You will have deformity in the hand (clawing) and also muscle wasting, clumsiness and inability to use your hand for activities of daily living.


How is it treated?

Both Conservative and surgical treatment are effective in cubital tunnel syndrome. Conservative treatment is selected when the compression is mild and there is no muscle wasting. It includes non steroidal anti-inflammatory medicines, splint, activity modification and nerve gliding exercises.

Surgery is indicated

  • Failure of conservative treatment
  • Severe symptoms
  • Nerve compression secondary to tumour, bone spur or bony projections, heterotypic (new) bone, fracture, arthritis etc
  • Throwing athlete
  • Painful subluxation of nerve with elbow movement


What are the non-operative treatments?

Non-operative treatment includes the following-

  • Activity modification- you should avoid all the activities that can trigger pain or render pressure to the elbow. Your surgeon can give you elbow pads to wear at work. Frequent bending of the elbow should be restricted.
  • Splinting or bracing- your surgeon may give a splint or brace to apply at night. This will help in keeping the elbow in straight position while sleeping. You can also use a towel to wrap that arm and tape it to hold it in place.
  • Medications- non- steroidal anti-inflammatory medicines like aspirin or ibuprofen are prescribed to reduce pain and swelling. Steroid injections could be of benefit in some patients, however the effect might be temporary.
  • Physical therapy- nerve gliding exercises could help with the symptoms in early stages. Besides the hand therapists also teach you strengthening exercises for the ulnar nerve innervated muscles.


What does the operation involve?

The primary goal of surgery is to release pressure on the ulnar nerve and to prevent further damage to the nerve. Most patients respond well and restore function and strength following surgery. The operation involves ulnar nerve release and/or proceed to anterior transposition.

  • The operation is performed as day case procedure, skin is cut over the affected area to approach the nerve. The roof of the cubital tunnel is divided and other potential sites of compression of nerve are also released. In some patients if the nerve is subluxing after release and if it appears stretched in the groove, its moved to the front of elbow (anterior transposition).
  • The skin is stitched with dissolvable sutures. The whole operation ends in 1-2 hours and most patients are discharged on the same day.


What happens after surgery?

  • The local anaesthetic wears off in 4 to 12 hours after surgery. Patients are given painkillers before the pain starts i.e. on return to home. It is continued for at least 48 hours after the first dose. Thus, most of our patients report little or any pain.
  • You will have a bulky bandage when you wake up, that usually needs to be reduced in 24-48 hrs. You will have spare dressings to take home and have to keep the wound dry and clean for 2 weeks
  • You have to keep your arm elevated in a sling and keep moving your fingers, elbow (gently) and shoulder to maintain the flexibility and prevent stiffness of its joints.
  • You are reviewed again after the period of two weeks to check the wound and hand therapy is advised for rehabilitation.
  • The wound should be massaged (typically after 2 weeks) using moisturising cream by the patient 3 times a day for 3 months once the wound is well healed. This reduces the scar sensitivity and scar-related complications (tenderness; helps scar to mature).
  • Physical therapy of hand and elbow is needed to restore the range of motion, normal function and strength of the hand. This will be guided by your surgeon and physiotherapists.


Are there any risks?

  • Infection
  • Elbow stiffness
  • Ulnar nerve injury
  • Recurrence
  • Persistent pain
  • Scar tenderness
  • Formation of neuroma
  • Injury to medial antebrachial cutaneous nerve
  • Vascular injury (uncommon, brachial artery)
  • Anaesthetic complications
  • Chronic Regional Pain Syndrome “CRPS”.
  • Any surgery can end up with rare complications and leave a patient worse than before surgery and is rare in this surgery


What are the results of the operation?

The outcome of the surgery is good with minimal complications (<1%). In patients with mild or moderate symptoms without muscle wasting, the symptoms get better and resolve >95% in around 6 months. However in patients with severe compression, the primary aim of the surgery is to prevent further worsening, however the improvement in numbness and muscle power is slow and incomplete.


When can I return to driving and work?

You can get back to work in few days- 2 weeks if you have a desk job, however might take 4-6 weeks if your job involves physical work. You should be able to resume driving in 2-4 weeks. The above time line could vary based on the severity of problem and the treatment modality.  Your surgeon can give you the correct estimation for this.


Cubital Tunnel Syndrome – Pain/tingling radiates from inside of elbow joint to little and ring finger (Yellow arrow), Numbness and tingling in little and part of ring finger (red arrow)


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