Ultrasound nets a qualified win in tennis-elbow contest

Pitting ultrasound against MRI at detecting and grading tears of the common extensor tendon in patients with chronic lateral epicondylitis—aka “tennis elbow”—researchers in Poland have found the former is fine at screening for high-grade tears. However, when any tear is clear on ultrasound, MRI should be considered to precisely assess the extent of the injury, they conclude.

Artur Bachta, MD, and colleagues at the Military Institute of Medicine in Warsaw published their findings online July 27 in in the open-access journal PLoS One.

The researchers used both modalities to look for common extensor tendon tears in 58 patients with chronic tennis elbow. They classified results as no tear, suspected tear (possible but not evident), low-grade tear (<50 percent thickness) and high-grade tear (≥50 percent thickness).

The ultrasound had moderate agreement with the MRI in detecting and grading tears (κ = 0.49), the authors report.

Their key findings:

  • Sensitivity, specificity and accuracy in tear detecting by ultrasound were 64.5 percent, 85.2 percent and 72.7 percent, respectively.
  • Ultrasound had a positive predictive value of 83.3 percent and a negative predictive value of 67.7 percent.
  • No patient with an unconfirmed tear on ultrasound had a high-grade tear on MRI.

Commenting on that last finding, Bachta et al. state that, despite the moderate agreement between ultrasound and MRI in grading common extensor tendon tear, “high-grade tear in ultrasound can be considered as a reliable equivalent of confirmed tear. On the other hand, lack of evident tear in ultrasound virtually excludes the presence of high-grade common extensor tendon tear.”

To read the full study, click here.