68-year-old patient presenting with lateral elbow pain, possibly aggravated by gripping and wrist extension. Symptoms may mimic or overlap with nerve-related complaints.
Ultrasound examination of the lateral elbow demonstrates degenerative changes of the common extensor tendon at its origin on the lateral epicondyle.
There is evidence of tendinopathy with a moderate to large intratendinous type 3 (soft) calcification measuring approximately 7.75 × 3.02 mm. Additionally, an enthesophyte is present at the tendon origin, consistent with chronic traction-related changes.
A small joint effusion is noted in the humeroradial joint. There is also a minor cortical irregularity of the radial head, likely degenerative in nature, which may contribute to joint irritation.
The posterior interosseous nerve (PIN) appears mildly thickened at and around the level of the Arcade of Frohse. This raises suspicion for possible nerve entrapment. The degree of thickening is subtle but may be clinically relevant.
1. Final diagnosis
Degenerative lateral epicondylopathy with calcific tendinopathy and enthesophyte formation, with associated mild humeroradial joint effusion and suspected posterior interosseous nerve entrapment at the Arcade of Frohse.
2. Differential diagnosis
Consider isolated lateral epicondylitis versus radial tunnel syndrome (PIN entrapment). These conditions may coexist or mimic each other clinically.
3. Teaching points
Calcific deposits can occur in the common extensor tendon and may contribute to symptoms. The posterior interosseous nerve should be evaluated in patients with persistent lateral elbow pain, as nerve entrapment can mimic epicondylitis. Differentiating between tendinous and neural causes is essential for targeted treatment.
4. Injury/disease information
Lateral epicondylopathy is a degenerative condition often caused by repetitive overload. In some cases, additional factors such as calcification or nerve entrapment may contribute to persistent symptoms. The posterior interosseous nerve can become compressed at the Arcade of Frohse, leading to pain patterns similar to tennis elbow.
Marc is founder of, and trainer at, SonoSkills. SonoSkills is an organization dedicated to MSK ultrasound education. He's also an MSK Sonographer at EchoConsult in Roermond, the Netherlands.
More Cases from Marc Schmitz
