The predictive value of diagnostic sonography for the effectiveness of conservative treatment of tennis elbow

Abstract

Objective: Tennis elbow is a common complaint. Several treatment strategies have been described, but an optimal strategy has not been identified. Sonographic imaging as a predictive factor has never been studied. The aim of our study was to determine the value of sonographic findings in predicting response to conservative therapy for tennis elbow. This was done in a randomized controlled trial in which the effectiveness of a brace only, physical therapy only, and a combination of both were compared.

Subjects and methods: Patients with tennis elbow complaints were randomized. Sonography was performed before randomization in 57 patients. Outcome measures at 6 weeks' follow-up were success rate and decrease in pain (scale, 0-100). Data were analyzed using an intention-to-treat analysis.

Results: In only 75% of the imaged patients, sonographic abnormalities were identified and the clinical diagnosis could thus be confirmed. The following entities were identified: hypo- and hyperechogenicity, swelling, calcification, bursitis, enthesopathy, and tendinosis. The positive predictive value of sonography for the different entities varied between 0.78 and 0.82, and the negative predictive value ranged between 0.23 and 0.71. Predictive value was studied by subgroups of sonographic findings: hypoechoic, swelling present, enthesopathy, any entity present, and no entity present. We found no significant differences among the subgroups for either success rate (range, 40-54%) or mean decrease in pain (range, 16-28 percentage points).

Conclusion: No predictive value of sonography for the detection of abnormalities was identified in this study. Its diagnostic capability showed limited value. However, limitations in this study necessitate drawing definitive conclusions with care.