Overview
what it is and why it mattersGuyon's canal syndrome is a pinched nerve at the wrist on the pinky side — the ulnar nerve gets squeezed as it passes through a small tunnel called Guyon's canal. Symptoms include numbness and tingling in your ring and little fingers, weak grip, and trouble with fine pinch. It's much less common than carpal tunnel syndrome but often shows up alongside it.
The most common causes are a ganglion cyst pressing on the canal, a fracture of a small wrist bone (the hook of the hamate), repetitive pressure from cycling handlebars, or prolonged wrist work on hard surfaces.
Symptoms
what you may noticeThe hallmark is numbness and tingling on the pinky side of your hand — specifically the little finger and the pinky half of the ring finger. You may notice your grip getting weaker or have trouble with fine-motor tasks like turning a key or buttoning a shirt. Symptoms tend to come on gradually and may be worse with prolonged wrist pressure (resting on a desk edge, gripping handlebars).
In more advanced cases the small muscles between your fingers (the interossei) can waste away, leaving visible hollows on the back of your hand. If the compression is from a ganglion cyst or a hook-of-hamate fracture, you may also have a tender lump or pinpoint pain at the base of your palm on the pinky side. Some patients have both Guyon’s canal syndrome and carpal tunnel syndrome at the same time, so median-nerve symptoms (thumb-side numbness) may overlap.
Diagnosis
exam first, imaging secondYour surgeon will tap over Guyon's canal at the wrist (Tinel's sign) and check sensation in your ring and little fingers. Nerve conduction studies and EMG pinpoint where exactly the nerve is being compressed and rule out the more common version higher up at the elbow (cubital tunnel syndrome). X-rays or CT can show a hamate fracture; MRI reveals any soft-tissue mass like a cyst.
Treatment Path
how care progresses at OSI1
Activity modification
Padded cycling gloves, ergonomic adjustments to the wrist rest at your keyboard, and avoiding direct pressure on the pinky side of your wrist.
2
Wrist splinting
A wrist splint that keeps the wrist straight reduces tension on the nerve, especially overnight.
3
Corticosteroid injection
An corticosteroid injection can help when inflammation or a small cyst is the underlying cause.
Surgical Options at OSI
if non-operative care isn't enoughSurgery (Guyon's canal release) is recommended when a cyst or other mass is taking up space in the canal, when a hook-of-hamate fracture hasn't healed, or when symptoms persist despite a real trial of non-surgical care.
Providers Who Treat Guyon's Canal Syndrome
sports-medicine team
Further Reading
authoritative sourcesExternal patient-education references and related OSI pages for additional background: