Ultrasound in Elbow Epicondylitis: Tendinosis, Common Extensor Tear, and Treatment Monitoring
Terminology and Pathogenesis
Changes in the area of the common flexor tendon at the medial epicondyle (golfer’s elbow) and the common extensor tendon at the lateral epicondyle (tennis elbow) are traditionally referred to as epicondylitis. The term is considered a misnomer since the tendon, not the epicondyle, is primarily involved; the underlying issue is degeneration—tendinosis, not inflammation (Jacobson, 2026).
Ultrasound Features of Tendinosis
According to Griffith (2025), tendinosis is identified in more than 90% of symptomatic patients and is characterized by:
- a thickened, hypoechoic tendon with surface bowing;
- disruption of the normal fibrillar pattern;
- thickening and increased signal in the common extensor/flexor tendon at the lateral/medial epicondyle, respectively.
Peritendinitis is considered a sign of moderate or severe tendinosis. The presence of a fluid cleft indicates a tear (Griffith, 2025).
Common Extensor Tendon Tear
A tendon tear on ultrasound is manifested by a fluid cleft within the tendon (Griffith, 2025). When an ill-defined enthesophyte with adjacent altered tendon and hyperemia is detected, inflammatory enthesopathy should be considered, such as in spondyloarthropathies like psoriatic arthritis (Jacobson, 2026).
Differential Diagnosis of Enthesopathy
Hyperemia on color Doppler helps differentiate synovial proliferation from echogenic synovial fluid, as the latter is not vascularized (Griffith, 2025). This approach is useful in assessing the active inflammatory component.
Ultrasound Monitoring and Treatment Navigation
According to EFSUMB recommendations (Naredo et al., 2022), ultrasound-guided procedures, such as platelet-rich plasma (PRP) injection in epicondylitis, may be considered (LoE 2b, SoR weak; broad consensus 91%). Specific ultrasound criteria for treatment efficacy and protocols for dynamic monitoring in epicondylitis are not detailed in the fragments [clarification needed].
Frequently asked questions
Why is the term 'epicondylitis' inaccurate?
The tendon (tendinosis/degeneration) is primarily affected, not the epicondyle; inflammation is not the basis of the process (Jacobson, 2026).
What is the main ultrasound feature of tendinosis?
A thickened hypoechoic tendon with surface bowing and disrupted fibrillar structure; identified in >90% of symptomatic patients (Griffith, 2025).
How does a tendon tear appear on ultrasound?
A tear is manifested by a fluid cleft within the tendon (Griffith, 2025).
When should inflammatory enthesopathy be suspected?
When an ill-defined enthesophyte with adjacent altered tendon and hyperemia is present—spondyloarthropathy, such as psoriatic arthritis, is possible (Jacobson, 2026).
Is ultrasound navigation indicated in the treatment of epicondylitis?
According to EFSUMB (2022), ultrasound-guided PRP injection in epicondylitis may be considered (LoE 2b, SoR weak; broad consensus 91%).