What is cubital tunnel syndrome?
Cubital tunnel syndrome is a clinical condition due to compression or irritation of the ulnar nerve at the elbow.
Cubital tunnel syndrome is commoner in men than women and is the second commonest compression neuropathy after carpal tunnel syndrome.
What causes it?
There are known anatomical structures or reasons in the elbow region which could cause constriction or irritation of the ulnar nerve:
- Arcade of Struthers
- Medial intermuscular septum
- Osborne's ligament
- Anconeus epitrochlearis
- Medial epicondyle
- Subluxing medial head of triceps
- FCU aponeurosis
- Ganglions, osteophytes
- Elbow trauma causing cubital valgus (tardy ulnar nerve palsy) or cubital varus deformities
- Elbow flexion contracture
- Instability of the ulnar nerve ('flicking' ulnar nerve)
Symptoms & Signs
- Pins & needles, tingling sensation affecting the little and ulnar (inner) half of ring fingers and ulnar dorsal hand
- The symptoms are often nocturnal with night waking (due to sleeping with the elbow flexed)
- The hand appears clumsy and less dextrous (due to impaired joint proprioception)
- In severe cases, the small muscles of the hand and the inner forearm muscles could be wasted, leading to weakened grasp and pinch grip
- Clawing of the little and ring fingers
- Neurophysiology (NCS/EMG) are useful in suspected cubital tunnel syndrome for diagnosis and prognosis.
- Xray of the elbow is indicated in the situation of trauma or deformities. This is aided by CT/MRI if there is concern with a space-occupying lesion.
- MRI of the neck is sometimes required if the symptoms are felt to be arising from the neck instead.
- Pain killers
- Activity modification
- Nighttime elbow extension splinting (this may be a little cumbersome but it is worthwhile trying for a minimum of 3 months, particularly in those with predominantly night symptoms or if the symptoms are mild/intermittent)
- In-situ cubital tunnel release/decompression involves releasing any potential constricting structures of the ulnar nerve at the elbow.
- Ulnar nerve decompression plus anterior transposition is indicated in:
- Revision decompression
- Unstable ulnar nerve (subluxing on elbow flexion/extension)
- Space occupying lesion at the cubital tunnel
- Certain traumatic situations
- The ulnar may be transposed into a local fat flap, subcutaneously (beneath a fat layer), subfascially (beneath a fascia), or submuscularly (beneath a muscular layer).
- Surgery is generally performed under a general anaesthesia.
What should I expect when undergoing a cubital tunnel release?
- It is performed as a day-case procedure, under general anaesthesia.
- At the end of the procedure, a bulky dressing is applied over the elbow.
- The dressing is reduced within 3-5 days and generally absorbable sutures are used.
- Early mobilisation of the elbow is encouraged but heavy physical activity is best avoided in the first 4-6 weeks.
- Tingling often resolves first but the altered sensation/numbness, if present preoperatively, may take a while to resolve and the recovery of normal sensation may not be complete in some patients.
- If there was preoperative muscle wasting, the recovery of muscle is less predictable.
What are the risks?
There are recognised risks of wound infection, nerve injury, pain syndrome, incomplete recovery and recurrence. These are fortunately uncommon.