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

Abstract

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.

Radially Based Extensor Retinacular Sling Reconstruction for Extensor Carpi Ulnaris Subsheath Injuries

“…Although ECU instability can be asymptomatic, frank physical examination findings or subluxation/dislocation on imaging is rare in asymptomatic patients. 15 Also, 66.7% of patients in our cohort had frank snapping or apprehension with a provocation on the examination with MRI findings of subsheath insufficiency and disruption. In contrast, the remaining 33.3% had subacute or chronic subsheath tears with clear findings of ECU tenderness in combination with MRI evidence.…”

Wrist Motion Assessment in Tennis Players using Three-Dimensional Motion Capture and Dynamic Electromyography

“…Excessive supination and ulnar deviation places the ECU tendon in a vulnerable position for injury. 12 Another potentially relevant finding was observed in the EMG data: during both backhand and forehand strokes, Player 2 minimally fired his dominant ECU during the backswing phase but rapidly and forcefully contracted his ECU around the time of ball strike. This contrasts with Player 1, who was firing his dominant ECU throughout most of each stroke phase.…”

Understanding the biomechanics of the forearm during the dart thrower’s motion

“…The ECU tendon runs in its own fibro-osseous sub-sheath in the groove at the distal ulna, deep to the extensor retinaculum (Chambers et al., 2020; Ghatan et al., 2016; Huang and Hanel, 2012). Contraction of the ECU stabilizes the DRUJ and the ulnocarpal joint by elevating the ulnar carpus dorsally while depressing the ulnar head palmarly (Erpala and Ozturk, 2021; Huang and Hanel, 2012). In cadaver studies, tensioning of the ECU tendon resulted in stability at the DRUJ and the ulnocarpal joint in supination and neutral forearm rotation when all the ligaments of the triangular fibrocartilage complex (TFCC) were sectioned (Iida et al., 2012).…”