Snapping triceps syndrome

Snapping triceps syndrome is an uncommon cause of medial elbow pain. It occurs if the triceps insertion subluxates over the medial epicondyle during flexion and extension of the elbow, and two palpable "snaps" may be heard or felt during this motion. It may coexist with ulnar nerve dislocation.

Pathology

As the elbow is flexed, the triceps broadens because it is compressed against the distal humerus, thus making it possible for the triceps to dislocate over the epicondyle . The snapping motion may be painful in itself, or may become symptomatic with dislocation of the adjacent ulnar nerve.

Radiographic features

Ultrasound

Ultrasound is the imaging modality of choice since it can dynamically image the triceps insertion and medial epicondyle during flexion and extension.

To evaluate :

• the transducer is placed transversely over the medial epicondyle 
• the patient flexes the elbow
  • if there is translation of the triceps tendon and/or the ulnar nerve over the medial epicondyle, the diagnosis is made
  • a snap may be heard or felt with the movement
• evaluation of the ulnar nerve distal to the neuropathy may reveal a swollen and hypoechoic nerve, characteristic ultrasound findings in ulnar neuropathy, 

Differential diagnosis

• medial epicondylitis
• ulnar nerve dislocation
• cubital tunnel syndrome

Siehe auch:

• Nervus ulnaris
• Nervenkompressionssyndrom
• Kompressionssyndrom Nervus ulnaris
• Neuropathie Nervus ulnaris
• Dislokation Nervus ulnaris