Ulnar tunnel (Guyon Canal) Syndrome

By Dr Oscar Brumby‑Rendell – Adelaide Hand, Wrist & Upper Limb Surgeon Adelaide Shoulder & Upper Limb Clinic

Ulnar tunnel syndrome (Guyon’s canal syndrome) is a compressive neuropathy of the ulnar nerve at the wrist. It occurs in a narrow tunnel on the palm side (Guyon’s canal) and leads to numbness, tingling, or weakness in the ring and little fingers. This condition is relatively rare compared to other nerve compression syndromes.

It is most often caused by local pressure on the nerve, for example from a wrist cyst or repetitive hand use. Patients may notice gradual loss of grip strength and altered sensation.

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Ulnar tunnel (Guyon Canal) syndrome diagram

What is Guyon Canal Syndrome?

Cause

The most common cause is a ganglion cyst (a benign fluid-filled lump) pushing on the ulnar nerve. Other causes include benign tumors (like lipomas), narrow anatomy of the canal, or any mass in that area. Hand/wrist trauma such as a fracture of the hamate bone can also pinch the nerve.

Repetitive pressure or vibration on the palm – for example from using jackhammers or prolonged cycling (“handlebar palsy”) – can inflame or compress the nerve. In many cases, though, no clear cause is found (idiopathic).

Symptoms

Symptoms usually develop gradually. Typical complaints are numbness, tingling or burning in the little finger and half of the ring finger (ulnar nerve distribution). Patients often have weakness of hand muscles, causing poor pinch strength or a weak grip.

Over time, fingers may curl slightly (a “clawing” deformity) and fine finger coordination can worsen. Some also feel pain or aching on the palm or outer wrist side. Symptoms often worsen at night or when the wrist is bent or pressed.

Diagnosis

Diagnosis begins with a healthcare exam. Dr. Brumby-Rendell will check for hand sensation and strength and may do a Tinel’s test by tapping the inside of the wrist – a shock-like tingling in the little fingers suggests ulnar nerve irritation. They will also test grip and pinch strength. If needed, electrodiagnostic tests (nerve conduction studies/EMG) confirm reduced signal in the ulnar nerve.

Imaging may be used to find a cause: an X‑ray can identify bone spurs or fractures, while MRI or ultrasound can show cysts or other masses pressing on the nerve. These studies help rule out other problems.

Guyon Canal Treatment

Non-Surgical Treatment

Initial treatment is conservative. Patients are advised to modify activities – for example, avoid resting wrists on hard surfaces and reduce repetitive strain. Wrist splints or padded gloves can protect the nerve. Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen may relieve pain and swelling. Occupational or physical therapy can teach nerve-gliding exercises and ergonomics to keep the nerve moving freely.

Surgical Treatment

If a specific lesion (like a ganglion) is found or if symptoms are severe/persistent, surgery may be needed. In surgery, the underlying cause is removed (e.g. excising a cyst) and the roof of Guyon’s canal is released to relieve pressure. This is often done on an outpatient basis. After surgery, sensation and strength often gradually improve, but full recovery can take months.

Rehabilitation

Rehabilitation focuses on restoring motion and strength once symptoms are controlled. Whether treated conservatively or surgically, hand therapy exercises help maintain finger and wrist mobility and prevent stiffness. Therapists may teach nerve-gliding exercises (gentle wrist/finger moves that “floss” the nerve) to ease irritation. Gradual strengthening of the hand and fingers is added as pain allows.

For cyclists or others with repetitive activities, ergonomic training (like proper handlebar positioning or padded gloves) helps prevent recurrence. If surgery was performed, patients often wear a soft wrist splint for a short period and then work on gradual restoration of full grip and dexterity under a therapist’s guidance. (Note: recovery can take several months, and long-standing cases may not fully reverse if there was muscle wasting.)

Frequently Asked Questions

How is ulnar tunnel syndrome different from carpal tunnel syndrome?

Can ulnar tunnel syndrome get better without surgery?

What can I do at home to help my symptoms?

Simple changes can help. Avoid pressing on the palm side of your wrist (for example, don’t lean on your wrist or grip tools too tightly). If you work at a keyboard, adjusting wrist position or using padded support may reduce pressure. Cyclists should frequently shift hand position or use padded gloves.

Over-the-counter NSAID pain relievers and short-term use of a wrist splint can ease pain. Gentle nerve-gliding stretches (taught by a therapist) can also keep the nerve moving smoothly.

Who is most at risk for ulnar tunnel syndrome?

It can happen to anyone, but certain activities increase risk. People who put chronic pressure on their palms or wrists are more likely to develop this condition. This includes bicyclists (especially long-distance), people who use jackhammers or power tools, golf/tennis/baseball players, and even heavy computer users or smokers.

Men appear to get it more often than women. The risk is higher if an injury or cyst is already present in the wrist area.

Why Choose Dr Oscar Brumby-Rendell?

Qualifications and Experience: Dr Oscar Brumby-Rendell is an Adelaide orthopaedic surgeon with extensive training and experience in treating upper limb conditions.
Patient-Centred Approach: Dr Brumby-Rendell prioritises your needs with a compassionate, patient-centred approach, providing clear explanations and personalised treatment plans.
Values: Driven by commitment, passion, and integrity, Dr Brumby-Rendell is dedicated to achieving the best outcomes and maintaining the highest standards of care.