Case Report: Ulnar nerve dislocation vs. Snapping triceps syndrome…or both??

This 19 year-old high-level golfer presented to me yesterday with acute onset pain and snapping in the medial elbow following the performance of a modified push-up performed during a conditioning session.  As can be noted in the video, during mid-range flexion/extension a visible and palpable ‘snapping’ occurs with accompanying pain and discomfort.  A differential diagnosis of Ulnar nerve dislocation vs. Snapping Triceps Syndrome (or both) was given with an immediate referral for dynamic sonography.

Ulnar nerve dislocation represents abnormal movement of the nerve out of the cubital tunnel and over the medial epicondyle during elbow flexion.  Snapping Triceps Syndrome represents dislocation of the medial head of the triceps muscle that moves over the medial epicondyle also during elbow flexion.  Both of these conditions are associated with transient snapping sensation in the elbow…and each can occur on its own or in combination making diagnosis difficult, as they may be clinically indistinguishable.  Differentiation of this condition is of utmost importance as ulnar nerve transposition surgery for ulnar nerve dislocation without appropriate treatment for unrecognized snapping triceps syndrome will result in persistent symptoms.

Given the dynamic nature of this condition, MR imaging has its limitations and thus dynamic sonography is the better choice.

I will try to update everyone on this case soon.