“Snapping” of the extensor carpi ulnaris tendon in asymptomatic population

BACKGROUND: Extensor carpi ulnaris tendinopathy (ECU) can be one cause of ulnar side wrist pain and it is more prominent in pronation-supination movements against resistance. In supination, flexion, and ulnar deviation within the ulnar groove, the tendon is tense and becomes predisposed to subluxation or dislocation. Snapping occurs during this dislocation and relocation. As a result of this friction between the tendon sheath and ulnar groove, tendinopathy and pain occur. ECU tendon is an important structure that contributes to the dynamic stability of wrist therefore resulting degeneration contributes disruption of distal radioulnar joint and causes wrist instability. METHODS: Participants without active wrist complaints who presented to the outpatient clinic between 2019 and 2020 were included. Provocation test was performed and participants with snapping were evaluated with ultrasound to determine subluxation or dislocation. Participants asked to indicate approximately how much time they spent daily on the phone, computer and game console. The distribution of data was evaluated with the Kolmogorov-Smirnov test. Quantitative data that were not normally distributed were evaluated using the Mann-Whitney U test, and Student’s t-test was used for normally distributed data. The Chi-square test was used to compare categorical variables. For all tests, p < 0.05 was considered statistically significant. RESULTS: Four hundred and fifteen women and 340 men were included in the study. Fifty of the 755 participants (6.6 %) had snapping. 22 of the 755 participants (2.9 %) had dislocation or subluxation on ultrasound. Three (13.6 %) participants had dislocation and 19 (%86.4) participants had subluxation on ultrasound. All 50 of the participants with snapping had significant repetitive trauma and sports activities. It was determined that 21 of the 22 participants who were found to have subluxation or dislocation by ultrasound had more than two hours of hobby activity and significantly more participants had more than two hours of activity compared to the group without subluxation or dislocation. CONCLUSIONS: This study with a large number of participants will contribute to the literature in terms of evaluating the contribution of technological devices, such as computers, smartphones, and consoles to chronic wrist pain and the prevalence of ECU snapping in the asymptomatic population. TRIAL REGISTRATION: Date of Approval; 19.02.2019, Approval Number; 19-KAEK-045.