• OBJECTIVES
    • The extensor carpi ulnaris (ECU) tendon synergy test is a simple and unique diagnostic maneuver for evaluation of chronic dorsal ulnar-sided wrist pain, which applies isolated tension to the ECU without greatly stressing other structures. This study aimed to investigate the diagnostic performance of the ECU synergy test to detect ECU abnormalities on sonography.
  • METHODS
    • Forty affected wrists from 39 consecutive patients with chronic dorsal ulnar-sided wrist pain that continued for greater than 1 month were examined with the ECU synergy test and sonography. The sensitivity, specificity, positive predictive value, and negative predictive value of the ECU synergy test to detect ECU abnormalities were evaluated. We compared the results of the ECU synergy test between groups with and without ECU abnormalities and also compared the ages, sexes, and symptomatic durations of the patients between groups with positive and negative ECU synergy test results and between the groups with and without ECU abnormalities.
  • RESULTS
    • The sensitivity, specificity, positive predictive value, and negative predictive value were 73.7%, 85.7%, 82.4%, and 78.3%, respectively. There was significant difference in the ECU synergy test results between the groups with and without ECU abnormalities (P < .01). There was no significant difference in age, sex, or symptomatic duration between any of the groups.
  • CONCLUSIONS
    • The results of this prospective study support the hypothesis that the ECU synergy test could be a useful provocative maneuver to detect ECU abnormalities in patients with chronic dorsal ulnar-sided wrist pain.