Guyon's canal release is an operation to decompress the ulnar nerve at the wrist, where it passes through a narrow tunnel (Guyon's canal). Compression here causes numbness in the ring and little fingers and weakness of the hand muscles.
A small incision is made on the inner (ulnar) side of the wrist/palm. The roof of Guyon's canal is divided, releasing pressure on the ulnar nerve. Any ganglion, anomalous muscle, or other cause of compression is identified and addressed. The operation takes 20–30 minutes and is usually a day case.
Surgery is recommended when ulnar nerve compression at the wrist causes persistent numbness, tingling in the ring and little fingers, or weakness of the small hand muscles, and has not responded to activity modification or splinting.
Activity modification (avoiding sustained pressure on the palm), wrist splinting, and ergonomic adjustments. If symptoms are caused by a ganglion, aspiration may be tried.
Nerve conduction studies to confirm the site of compression. Ultrasound or MRI to identify space-occupying lesions. Day-case procedure.
Relief of numbness and tingling. Recovery of hand muscle strength depends on the duration and severity of compression — early surgery gives the best results.
Tenderness at the incision site.
If nerve damage was advanced before surgery, some weakness may persist.
Damage during decompression.
The artery runs alongside the nerve in Guyon's canal.
Wound infection.
Symptoms may recur if compression is not fully addressed.
Local, regional, or general anaesthesia.
Light dressing for one to two weeks. Stitches removed at 10–14 days. Gentle hand use immediately. Full recovery of strength takes weeks to months depending on pre-operative nerve damage.
Wound check at two weeks. Review at six weeks.
No. Carpal tunnel affects the median nerve, causing numbness in the thumb, index, and middle fingers. Guyon's canal affects the ulnar nerve, causing numbness in the ring and little fingers.