Ulnar Neuropathy (Cubital Tunnel Syndrome)

Compression at the Elbow (Cubital Tunnel Syndrome — most common)

• Habitual elbow flexion — prolonged elbow bending (working at a desk, sleeping with arm flexed) stretches the nerve over the medial epicondyle
• Direct compression — leaning on the elbow on hard surfaces
• Thickening of the cubital tunnel ligament (Osborne's ligament)
• Medial epicondyle osteophytes, cysts or prior fracture with altered elbow anatomy
• Ulnar nerve subluxation — snapping of the nerve over the medial epicondyle during elbow flexion
• Previous elbow trauma can cause ulnar neuropathy – known as the tardy ulnar palsy.  

‍

Compression at the Wrist (Guyon's Canal)

Less commonly, the ulnar nerve can also be compressed at the wrist in Guyon's canal — the passage between the hamate and pisiform bones — from prolonged pressure on the heel of the hand (e.g. cyclists), a ganglion cyst, or other mass.

Sensory Symptoms

Numbness, tingling, and altered sensation in the little finger and the ulnar (inner) half of the ring finger — the area supplied by the ulnar nerve. Symptoms are often worse with elbow flexion (talking on the phone, sleeping with arm bent) and at night.

Elbow Pain

Aching pain on the inner side of the elbow, sometimes radiating down the forearm to the hand.

Weakness and Muscle Wasting

In more advanced cases, weakness of the intrinsic hand muscles — responsible for fine finger movements, grip, and pinch — develops. Patients notice difficulty with tasks requiring fine motor control. Visible wasting of the muscles on the back of the hand between the fingers (interosseous muscles) and at the little finger base indicates significant nerve injury. A characteristic 'claw hand' deformity of the ring and little fingers may develop in severe cases. 

• Clinical examination — assessment of ulnar nerve sensation, intrinsic hand muscle strength and Tinel's sign over the cubital tunnel
• Nerve conduction studies (NCS) and EMG — confirm ulnar nerve compression, localise the level (elbow vs. wrist), and determine severity, essential before surgery.
• Elbow MRI — assesses for medial epicondyle osteophytes, prior fracture deformity, or other abnormalities contributing to compression
• Ultrasound of the ulnar nerve — can demonstrate nerve enlargement, dynamic subluxation, and structural compression at the elbow.

Non-Surgical Treatment

Mild ulnar neuropathy may improve with conservative management:

• Avoidance of prolonged elbow flexion — the simplest and most effective initial measure
• Night splinting in elbow extension — prevents prolonged flexion during sleep
• Activity modification — avoiding pressure on the elbow and repetitive elbow flexion
• Steroid injections can be considered in selected cases which are usually performed under ultrasound guidance.
• Anti-inflammatory medication and neuropathic pain medications can be trialled

Surgical Treatment — Ulnar Nerve Decompression and Transposition

Surgery is recommended when symptoms are severe and progressive, when there is motor weakness or muscle wasting of hand muscles, or when conservative treatment has failed.  Your surgeon may also recommend surgery if NCS/EMG demonstrate severe nerve compression or if imaging tests demonstrate neve injury.  

Two main surgical approaches are used:

Simple Decompression (In Situ Decompression)

The cubital tunnel retinaculum (Osborne's ligament) is divided to release pressure on the nerve. This is a simpler procedure with a smaller incision and faster recovery, suitable when the nerve does not sublux and the medial epicondyle anatomy is normal.

Ulnar Nerve Transposition

The ulnar nerve is moved (transposed) from behind the medial epicondyle to a new position in front of it (anterior transposition — either subcutaneous, intramuscular, or submuscular). This relieves stretch and compression, and is preferred when the nerve subluxes over the medial epicondyle, when bony anatomy is abnormal, or when simple decompression has failed. At One Brain and Spine, our neurosurgeons are experienced in both approaches and will recommend the most appropriate technique for your anatomy.

Recovery

• Day case under general anaesthesia
• Arm rested for 1–2 weeks
• Return to light activities in 2 weeks
• Return to manual work in 3–4 weeks
• Sensory symptoms typically improve within weeks; motor weakness recovers more slowly and may be incomplete in severe cases

More than 80% of patients achieve good to excellent outcomes. Results are best when surgery is performed before significant muscle wasting has occurred.