Ulnar tunnel syndrome

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Ulnar tunnel syndrome
Other namesGuyon's canal syndrome
Depiction of classic ulnar sensory distribution, including ulnar-4th and 5th fingers. Note that this diagram does not portray hand muscles affected by ulnar neuropathy.
SpecialtyOrthopedic surgery Edit this on Wikidata

Ulnar tunnel syndrome, also known as Guyon's canal syndrome or Handlebar palsy, is

cubital tunnel syndrome
, although it can uncommonly be due to compression at the wrist.

Causes

Ulnar neuropathy at the wrist is often associated with a mass such as a ganglion cyst or thrombosis or aneurysm of the ulnar artery.[3] The role of activities and exposure is less certain.

Diagnosis

Classification

Three locations (zones) in which the ulnar nerve can be compressed within Guyon canal

Ulnar tunnel syndrome may be characterized by the location or zone within the Guyon's canal at which the ulnar nerve is compressed. The nerve divides into a superficial sensory branch and a deeper motor branch in this area. Thus, Guyon's canal can be separated into three zones based on which portion of the ulnar nerve are involved. The resulting syndrome results in either muscle weakness or impaired sensation in the ulnar distribution.[1]

Location Symptoms Associations
  Zone 1   Proximal (prior to ulnar nerve bifurcation) Mixed motor & sensory Ganglia & hook of hamate fractures
  Zone 2   Surrounding deep motor branch ulnar nerve Motor only Ganglia & hook of hamate fractures
  Zone 3   Surrounding superficial sensory branch of ulnar nerve Sensory only Ulnar artery pathology

Zone 2 type syndromes are most common, while Zone 3 are least common.

Treatment

The role of gloves which help protect the ulnar nerve from compression is unclear. Palsy of the ulnar motor nerve isolated to the wrist is treated with operative decompression, often with concomitant ganglion excision. The surgery is to divide the volar carpal ligament which forms the roof of Guyon's canal, thereby reducing compression on the ulnar nerve.[4][5]

See also

References

  1. ^ a b Hatch, Daniel (August 20, 2014). "Ulnar Tunnel Syndrome". Orthobullets. Retrieved Sep 7, 2014.
  2. PMID 16000656
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Further reading