Lateral Epicondylitis

Diagnosis Definition

• Most common cause of elbow pain
• Overuse syndrome of the common extensor origin, predominantly affecting the extensor carpi radialis brevis tendon
• Known as ‘tennis elbow’ despite 95% of patients not being tennis players
• Degenerative process (tendinosis) resulting from repetitive microtrauma rather than an inflammatory process as implied by the name
• Complete rupture of the common extensor origin is rare

Imaging Findings

• Abnormal thickening and increased signal intensity at the common extensor origin and peritendinous edema
• MR shows focal T2 hyperintense fluid within partial thickness undersurface tendon tears
• Lateral epicondyle bone marrow edema may be seen
• May be associated with injury to the radial collateral ligament

KEY IMAGES

Pearls

• Although uncommon, the symptoms of radial nerve entrapment can closely mimic those in lateral epicondylitis and should be considered when there is a strong history with no associated MRI findings

References

1. Sonin AH, Fitzgerald SW, Hoff FL et al. MR imaging of the posterior cruciate ligament: normal, abnormal, and associated injury patterns. Radiographics 1995; 15(3):551-61
2. Fanelli GC, Edson CJ. Posterior cruciate ligament injuries in trauma patients: part II. Arthroscopy 1995; 11:526-529
3. Rodriguez W Jr, Vinson EN, Helms CA, Toth AP. MRI appearance of posterior cruciate ligament tears. AJR Am J Roentgenol 2008 191;4:155-159
4. Sonin AH, et al. Posterior cruciate ligament injury: MR imaging diagnosis and patterns of injury. Radiology 1994;190:455-458