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Condition/Disorder Synonyms

  • Cubital tunnel syndrome

  • Ulnar tunnel syndrome (UTS)

  • Tardy ulnar nerve palsy

  • Medial neuritis syndrome

  • Ulnar nerve entrapment

ICD-9-CM Codes

  • 354.2 Lesion of ulnar nerve

  • 354.5 Mononeuritis multiplex

  • 955.2 Injury ulnar nerve

ICD-10-CM Code

  • G56.20 Lesion of ulnar nerve, unspecified upper limb

Key Features


  • Motor and/or sensory changes in the ulnar nerve distribution due to pressure from 3 possible ways.

    • Compression

    • Stretch

    • Friction

  • Potential entrapment sites

    • Medial humeral groove

    • Arcade of Struthers

    • Medial intermuscular septum

    • Flexor digitorum profundus

    • Flexor carpi ulnaris

    • Just proximal to or within Guyon's canal

    • Sensory and motor involvement between the abductor digiti minimi and flexor digiti minimi

    • Near hook of hamate, involves motor only

    • Distal end of Guyon's canal, involves sensory only

Essentials of Diagnosis

  • Night pain

  • Sensory changes on volar aspect of digit V and ulnar aspect of digit IV

  • Hand clumsiness and/or weakness

  • Symptom changes with elbow position and/or pressure over the cubital tunnel

  • Reproduction of symptoms during clinical examination

General Considerations

  • Need to differentiate from more proximal and distal ulnar nerve compression, thoracic outlet syndrome (TOS), ulnar tunnel, and cervical radiculopathy.

  • Postoperative therapy depends on surgical procedure performed: endoscopic release, in situ decompression, medial epicondylectomy, and anterior transposition.

  • Second-most common nerve compression syndrome in the upper extremity (UE)


  • Those who work for sustained periods with power tools or on computers

Clinical Findings

Signs and Symptoms

  • Acute or chronic paresthesia in ulnar nerve distribution (digits IV ulnar half and V) dorsally and volarly.

  • Sensory changes, hypo- or hypersensitivity of hand

  • Night pain especially with elbow flexion and wrist extension

  • Inability to separate fingers

  • Hand clumsiness

  • Hand weakness and loss of grip power and dexterity

  • Clawing of the hand (less pronounced than with ulnar tunnel syndrome)1

  • Intrinsic muscle atrophy and possible guttering

  • Wartenberg sign

  • Froment sign

  • Bishops deformity

  • Positive elbow flexion test

  • Resting abduction of digit V

Functional Implications

  • Night pain/poor sleep habits

  • Difficulty with hand function during ADLs/IADLs due to hand clumsiness and possible loss of strength.

Possible Contributing Causes

  • Prolonged pressure on cubital tunnel, particularly with elbow flexion such as working at a computer2

  • Laxity of soft tissue structures that hold ulnar nerve in cubital tunnel

  • Bony abnormality of the humuerus

  • Shallow ulnar groove

  • Small medial condyle

  • Tightness of the flexor carpi ulnaris (FCU) with distal FCU inflammation

  • Viral infection

  • Ganglion/space occupying lesion

  • Ulnar artery thrombosis

  • Ulnar-sided wrist fractures or dislocations

  • Anomalous muscles

  • Repetitive trauma

  • Sustained pressure over Guyon's canal such as resting hypothenar eminence on handlebars while long distance cycling.

Differential Diagnosis


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