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.
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 1. The snapping motion may be painful in itself, or may become symptomatic with dislocation of the adjacent ulnar nerve.
Ultrasound is the imaging modality of choice since it can dynamically image the triceps insertion and medial epicondyle during flexion and extension.
To evaluate 2:
- 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,
- 1. Snapping Triceps Syndrome: A Review of the Literature. Matthias K.D. Vanhees, Ghislain F.A.E. Geurts and Roger P. van Riet. Shoulder & Elbow 2010 2:30. DOI: 10.1111/j.1758-5740.2009.00033.x
- 2. Jacobson JA. Fundamentals of Musculoskeletal Ultrasound: Expert Consult-Online and Print, 2e (Fundamentals of Radiology). Saunders. ISBN:1455738182. Read it at Google Books - Find it at Amazon
- 3. Watts AC, McEachan J, Reid J et-al. The snapping elbow: a diagnostic pitfall. J Shoulder Elbow Surg. 2009;18 (1): e9-10. doi:10.1016/j.jse.2008.03.010 - Pubmed citation