Cubital Tunnel Syndrome and Other Ulnar Neuropathies



  • Compression of the ulnar nerve on the medial aspect of the elbow where it enters the cubital tunnel results in cubital tunnel syndrome (CuTS). Elbow pain, loss of grip strength, and paresthesias of the forearm, wrist, and 4th and 5th fingers are the most common symptoms.
  • Synonym(s): ulnar neuropathy
  • Compression of the ulnar nerve at the wrist results in ulnar tunnel syndrome (UTS).


  • Predominant sex: male > female (3 to 8 times more common)
  • Incidence is estimated at 30 new cases per 100,000 person-years and increases with patient age (1).
  • Elbow is the most common site of compression of ulnar nerve resulting in CuTS.
    • Less common sites of entrapment include the following:
      • Arcade of Struthers
      • Medial intermuscular septum
      • Medial epicondyle
      • Deep flexor pronator aponeurosis
  • CuTS is second to carpal tunnel syndrome as the most common nerve compression of upper extremity (2).

Etiology and Pathophysiology

  • The ulnar nerve is the terminal branch of the medial cord of the brachial plexus; it is composed of portions of the C8 and T1 nerve roots.
  • The ulnar nerve becomes more superficial as it enters the ulnar sulcus near the medial epicondyle. The nerve runs posteriorly to the medial epicondyle and medial to the olecranon to enter the cubital tunnel.
  • The cubital tunnel is a fibro-osseous canal bordered by the arcuate ligament of Osborne as the roof and the medial collateral ligament of the elbow, the joint capsule, and the olecranon as the floor.
  • The distance from medial epicondyle to olecranon increases 5 mm for every 45 degrees of elbow flexion.
  • Elbow flexion places stress on medial (ulnar) collateral ligament, overlying retinaculum, and ulnar nerve.
  • The cubital tunnel shape changes from circular to ovoid and loses 2.5 mm of height with elbow flexion.
  • Loss of height of cubital tunnel with elbow flexion decreases tunnel volume by 55%, doubling intraneural pressure on the ulnar nerve.
  • Maximal pressure on the ulnar nerve in cubital tunnel is created by shoulder abduction, elbow flexion, and wrist extension.
  • Elbow flexion decreases volume of cubital tunnel, causing compression of the ulnar nerve.
  • Compression of the ulnar nerve causes pain at the medial elbow and symptoms in the forearm and hand.
  • Compression prior to or within the Guyon canal produces intrinsic muscle weakness and dorsolateral sensation loss.
  • Etiologies include constricting fascial bands, subluxation of ulnar nerve over medial epicondyle, cubitus valgus, bony spurs, hypertrophied synovium, tumors, ganglia, or direct compression of ulnar nerve as it crosses the cubital tunnel.
  • Compression by ganglia, anomalous musculature, carpal bone fracture, or direct hypothenar pressure results in UTS.

Risk Factors

  • Patients who sleep with their elbows bent and arms overhead
  • Patients with occupations demanding prolonged flexion of the elbows
  • Athletes in throwing sports, racquet sports, weight lifting, skiing, and cycling
  • Preexisting polyneuropathy
  • Patients on hemodialysis
  • Patients in a prolonged dependent position (e.g., postsurgery, ICU) where the elbow rests against firm bedding

General Prevention

  • Avoid long periods of elbow flexion, pressure on elbows, or anterior ulnar aspect of the wrist.
  • Sleep with elbows straight; avoid sleeping with arms overhead.
  • Proper ergonomic posture

Commonly Associated Conditions

  • Ulnar nerve subluxation
  • Ulnar collateral ligament laxity
  • Osteoarthritis of elbow joint
  • Carpal tunnel syndrome

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