Guyon's Canal Syndrome

What is Guyon’s Canal Syndrome?

Guyon’s canal syndrome refers to compression of the ulnar nerve while it passes from the wrist into the hand through a space called the ulnar tunnel or Guyon’s canal. 

Guyon’s canal syndrome is also called ulnar tunnel syndrome or handlebar palsy.

Anatomy and Function of the Ulnar Nerve

The ulnar nerve is one of the 3 major nerves of your hand that travels down from the neck through the medial epicondyle (a bony protuberance on the inner aspect of the elbow). It passes under the muscles of the forearm and into the hand on the side of the palm, towards the little finger. The ulnar nerve controls movement and provides sensation to specific areas of the hand.

Symptoms 

A compressed ulnar nerve affects your hand, wrist and little finger. The symptoms include:

• Pain
• Weakness
• Tingling
• Numbness
• Problem grasping objects

Causes or Risk Factors

The common risk factors or causes may include:

• Working with vibrating tools
• Joint arthritis
• Ganglionic cysts
• Acute or repetitive trauma
• Tumours
• Blood clots
• Broken hamate bone (one of a cluster of hand bones near the wrist)
• Synovitis (inflammation of the synovial membrane)

Diagnosis

Your doctor will assess your symptoms, take your medical history and perform a physical exam. Imaging tests such as X-ray, MRI or CT-scans may be ordered. Specific tests such as doppler ultrasound may be ordered to evaluate blood flow in the ulnar artery.

Diagnosis is confirmed through evidence of a nerve conduction velocity test, a specialised test that checks how quickly electrical signals move through a nerve.

Treatment

Your doctor first recommends non-surgical options to treat Guyon’s canal syndrome including:

• Home remedies
• Using padded tools
• Applying ice packs
• Avoiding activities that aggravate pain
• Immobilisation with a brace or splint
• Prescription pain medications
• Massage therapy
• Physiotherapy
• Steroid injections

Surgery is recommended if conservative options fail to relieve pressure on the ulnar nerve.

Ulnar Nerve Decompression

This surgery involves the following steps:

• An IV sedation is given to make you feel comfortable. Local anaesthesia of the wrist may be needed.
• A small incision is made along the ulnar nerve in your palm region.
• Your surgeon may remove a ganglionic cyst or repair a fracture. Certain ligaments may be cut to relieve pressure on the ulnar nerve.
• The incision is closed and dressed.

Recovery after Surgery

A combination of non-steroidal anti-inflammatory drugs (NSAIDs) and opioids may be used to manage pain. Your wrist is supported with a splint or cast. You are instructed to keep your arm raised above the level of your heart to decrease swelling. Physiotherapy instructions will be given to teach exercises for flexibility and range of motion.