Cubital Tunnel Syndrome
Pressure or stretching of the ulnar nerve at the elbow, causing symptoms in the ring and small fingers and weakness in the hand.
The ulnar nerve passes behind the inside of the elbow through a narrow space often called the funny-bone area. Bending the elbow can stretch the nerve and reduce the room around it.
Symptoms may be intermittent at first, particularly at night or with the elbow bent. Persistent compression can affect grip and the small muscles that coordinate the fingers.
Loading anatomy
Common symptoms
- Numbness or tingling in the ring and small fingers
- Symptoms that worsen when the elbow is bent or during sleep
- Weak grip or difficulty with buttons, keys and fine hand movements
- Pain or aching on the inside of the elbow
- In advanced cases, wasting of the small muscles of the hand
Causes and contributing factors
- Repeated or prolonged elbow bending
- Pressure on the nerve from leaning on the elbow
- Nerve instability that allows it to move over the elbow bone
- Arthritis, an old elbow injury or narrowing of the nerve tunnel
- Compression at another level in the arm can produce similar symptoms
How it is evaluated
The examination follows the ulnar nerve from the neck and shoulder through the elbow and forearm to the hand. The pattern of sensory change and weakness helps identify where the nerve is affected.
- Mapping sensation in the small and ring fingers
- Testing the small hand muscles, grip and finger coordination
- Checking the nerve for tenderness or movement at the elbow
- Nerve-conduction studies and electromyography when the diagnosis or severity is uncertain
- Imaging when arthritis, an old fracture or a mass is suspected
Nonsurgical treatment
Early treatment aims to reduce pressure and prolonged bending so the nerve has a chance to settle. The plan depends on how severe and persistent the symptoms are.
- Avoiding prolonged elbow flexion and direct pressure on the nerve
- A night splint or towel wrap to limit deep elbow bending during sleep
- Activity modification and ergonomic changes
- Hand therapy for nerve-protection strategies and maintained motion
- Treatment of contributing medical or neck conditions when present
Surgical treatment
Surgery may be considered when symptoms persist despite nonsurgical care, when nerve testing shows significant compression, or when weakness or muscle wasting is developing.
- In-situ decompression of the ulnar nerve at the elbow
- Anterior transposition when the nerve is unstable or the anatomy makes simple release unsuitable
- Treatment of a structural cause such as a bone prominence or scar
- Revision decompression when symptoms persist after prior surgery
Clinical detail
The choice between decompression and transposition depends on the nerve’s stability, the shape of the tunnel, prior treatment and the pattern of compression. The nerve is assessed along its whole course rather than at the elbow alone.
Recovery
Nerve recovery is slow and depends on how long and how severely the nerve was compressed. The incision and elbow movement usually improve sooner than numbness or intrinsic muscle weakness.
- Early elbow and hand movement as directed
- Temporary limits on pressure and heavy lifting
- Hand therapy for weakness, stiffness or altered hand use
- Ongoing assessment when sensation or strength changes slowly
When to seek urgent care
Seek immediate medical attention - an emergency department - if you experience:
- Sudden or rapidly worsening weakness in the hand
- New loss of sensation that does not settle after the elbow is straightened
- Severe elbow injury with a cold, pale or newly numb hand
This list is not exhaustive. If something about your hand worries you, have it looked at.
Frequently asked questions
Why does bending the elbow make symptoms worse?
Bending the elbow can stretch the ulnar nerve and reduce the space around it. Leaning on the elbow can add pressure at the same time.
Will numbness go away immediately after surgery?
Not necessarily. The operation removes or reduces the compression, but a nerve that has been irritated or injured may recover over weeks or months, and long-standing changes may not fully reverse.
Related conditions
Peripheral Nerve Injuries
Damage to the nerves that carry signals between the brain and the hand, causing numbness, weakness or pain in the territory that nerve supplies.
Wrist Fractures
Breaks involving the end of the forearm bones or the small bones of the wrist, most often after a fall onto an outstretched hand.
Complex Hand Trauma
Severe injuries that damage more than one tissue system at once - bone, tendon, nerve, blood vessel and skin together.
Discuss cubital tunnel with Dr. Champagne
A consultation begins with understanding your symptoms, how they affect what you do, and what has already been tried.