Ulnar Nerve Release at the Elbow
What is ulnar nerve compression at the elbow ?
The ulnar nerve is one of the three major nerves of the upper limb. It passes behind the elbow through a fibrous tunnel, the cubital tunnel, before travelling down to the hand, where it supplies sensation to the little finger and the ring-finger side of the ring finger, and controls the intrinsic muscles of the hand.
Compression of this nerve at the elbow, known as cubital tunnel syndrome, is the second most common peripheral neuropathy after carpal tunnel syndrome. It causes tingling and numbness in the little and ring fingers, weakness and clumsiness of the hand. In severe or neglected cases, wasting of the intrinsic hand muscles can develop, leaving permanent deficits if not treated in time.
Compression may be aggravated by prolonged elbow flexion, a previous elbow injury, or instability of the nerve, which dislocates forward over the medial epicondyle during elbow flexion.
What is the treatment ?
For mild cases, conservative treatment may be offered first:
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a night splint keeping the elbow in extension to reduce nerve compression during sleep
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activity modification to limit prolonged elbow flexion and direct pressure over the nerve
Surgery is recommended when conservative measures fail, when there is motor involvement, when nerve conduction studies confirm severe compression, or when the nerve is unstable at the elbow.
How is the procedure performed ?
The procedure is performed under regional anaesthesia on a day-case basis (the patient goes home the same day).
Two techniques are used depending on the clinical situation:
Simple decompression involves opening the cubital tunnel and releasing the nerve from all compressive structures while leaving it in its original position. This is performed for moderate cases without nerve instability.
Anterior transposition is preferred when there is motor involvement, severe compression or nerve instability, when the nerve dislocates forward over the medial epicondyle during elbow flexion. The nerve is repositioned in front of the elbow and secured in its new position with a fatty tissue flap, which protects it and prevents it from returning to its original tunnel. This technique simultaneously addresses both compression and instability.
What is the recovery ?
The arm is worn in a sling for one month on a non-strict basis. Gentle elbow movement is encouraged from the early post-operative period to prevent stiffness and promote healing of the nerve in its new position.
Tingling and numbness improve progressively after surgery, sometimes over several months. Recovery from motor weakness takes longer and depends on how long and how severely the nerve was compressed before surgery, early treatment is therefore important when hand weakness is present.
What are the risks?
Risks include:
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injury to the ulnar nerve during dissection, potentially causing transient worsening of symptoms
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wound infection
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elbow stiffness if post-operative mobilisation is delayed
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for anterior transposition: instability or fibrosis around the nerve in its new position
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incomplete recovery of motor function in longstanding severe compression