Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Cubital Tunnel Syndrome

Basics
Description
  • Cubital tunnel syndrome consists of pain and paresthesias over the medial border of the forearm and hand, as well as weakness in an ulnar nerve distribution from compression of the ulnar nerve as it passes through the cubital tunnel at the elbow.
  • It affects the elbow, forearm, and hand in the ulnar nerve distribution and is most commonly seen in adults.
  • Synonym: Ulnar tunnel syndrome
Epidemiology
Incidence
  • The 2nd most common entrapment neuropathy (after CTS) in the upper extremity
  • Males and females are affected equally.
Risk Factors
Diabetes
 
Etiology
  • The ulnar nerve is compressed as it passes through the cubital tunnel at the medial side of the elbow, which may compress the blood vessels that feed the nerve and create symptoms.
  • Possible causes of the compression include:
    • Enlarged medial head of the triceps muscle
    • Trauma
    • Recurrent dislocation of the nerve from the tunnel
    • Arthritis (bony spurs)
    • Ganglia
    • Abnormal muscles (anconeus epitrochlearis)
Associated Conditions
TOS
 
Diagnosis
The diagnosis is made clinically, with aid from nerve conduction studies.
 
Signs and Symptoms
  • Vague, aching pain
  • Paresthesias
  • Numbness over the medial forearm, hand, and (occasionally) upper arm
Physical Exam
  • Note decreased sensation in the ulnar nerve distribution.
  • Check for intrinsic weakness by placing a sheet of paper between the patient’s thumb and 1st finger and attempting to pull the paper away as the patient resists.
  • Look for intrinsic muscle wasting, especially of the 1st dorsal interosseous muscle.
  • Percussion test (Tinel sign): Tapping over the ulnar nerve at the elbow causes a reproduction of symptoms .
  • Elbow flexion test: Keeping the elbow fully flexed (and the wrist in neutral or extension to avoid carpal tunnel symptoms) for 1 minute causes a reproduction of the symptoms.
  • Order nerve conduction studies (nerve conduction is slowed across the elbow).
Tests
Imaging
AP radiography of the elbow may be indicated.
 
Pathological Findings
  • At decompression, specific sites of nerve compression usually can be found.
  • Inspect the arcade of Struthers, intermuscular septum, cubital tunnel, and Osborne fascia (between 2 heads of flexor carpi ulnaris).
Differential Diagnosis
  • Thoracic outlet syndrome
  • C8-T1 cervical root compression
  • Compression of the ulnar nerve at the wrist (Guyon canal)
  • CTS
  • Guillain-Barre syndrome
  • Amyotrophic lateral sclerosis
Treatment
General Measures
  • Nonoperative treatment involves splinting the elbow in extension to relieve acute symptoms.
  • Patients wear the splint when sleeping.
  • Nighttime elbow extension splints with the forearm held in neutral or supination
  • Avoid prolonged elbow flexion.

Surgery

  • Consider surgery if symptoms continue after 3 months of nonoperative therapy.
  • Many procedures have been described:
    • Procedures usually consist of some form of decompression of the nerve in the canal.
    • Operations often involve transposition of the nerve out of the canal in an anterior direction.
Follow-up
Prognosis
  • Nonoperative therapy: 50% excellent results
  • Surgical therapy: Good to excellent results in nearly all patients
Complications
  • Reflex sympathetic dystrophy and nerve irritation may occur after surgery.
    • If left untreated, severe ulnar neuropathy can lead to clawing of the small finger and ring finger, atrophy of intrinsic muscles, and positive Froment and/or Wartenberg signs.
Patient Monitoring
Motor and sensory examinations are performed at follow-up visits.
 
Miscellaneous
Codes
ICD9-CM
354.2 Cubital tunnel syndrome
 
Patient Teaching
Patients are counseled to avoid activities that exacerbate their symptoms.
 
Prevention
  • Avoid:
    • Repetitive work activities if they cause symptoms
    • Prolonged elbow flexion
FAQ
Q: Is there a nonoperative treatment for cubital tunnel syndrome?
A: Mild or mild/moderate cubital tunnel syndrome can be treated with a nighttime elbow extension splint to minimize elbow flexion during sleep.
Patients also are advised to avoid prolonged activity with the elbow flexed. Nerve glides (active exercises that help to prevent scarring around the nerve) may be of some benefit.
 
Q: Once a patient has intrinsic wasting, what can be done to restore intrinsic strength?
A: Once intrinsic atrophy occurs, nothing can be done specifically to restore the intrinsic motor loss. Ulnar nerve decompression and transposition can halt additional progression of motor loss and, if the patient has a functional deficit, tendon transfers could be considered.
 
Q: What are the symptoms of cubital tunnel?
A: Patients typically present with complaints of numbness and tingling in their small and ring fingers. Symptoms frequently are worse during extended periods of elbow flexion, for example, talking on the phone or blow-drying hair.

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