Is it really safe to evaluate symptomatic extensor carpi ulnaris tendon instability by magnetic resonance imaging (MRI)?

The extensor carpi ulnaris (ECU) tendon is in the sixth extensor compartment of the wrist and is isolated from other tendons by a different sheath. Extensor carpi ulnaris pathologies are characterized by pain locally localized to the wrist ulnar side. Outpatient records and wrist MRI (magnetic resonance imaging) tests were retrospectively scanned between January 2018 and July 2019. By examining the anamnesis and examination notes of the patients in the outpatient clinic records, patients with wrist ulnar side pain, pain or sensitivity on the ulnar styloid and provocation test (synergy) were assigned to the first study group (Group 1).The second study group was composed of patients who underwent wrist MR for the diagnosis or differential diagnosis of a synovial cyst around the wrist, without ulnar side pain (Group 2).While evaluating MR images in the axial plane, the depth and width of the ulnar groove, thickness of the ECU tendon were measured. The position of the ECU tendon relative to the ulnar groove and the forearm rotation during the shooting were recorded.105 cases evaluated, there were 41 cases in the symptomatic subgroup and 64 cases in the asymptomatic subgroup. Among all patients, the mean patient age was 38.05.In the evaluation according to whether cases were symptomatic or not, there was no significant relationship between being symptomatic and the degree of instability and MR withdrawal position. Our study suggests that ECU instability in MR is not a specific condition, and detection of MR in instability may not be associated with a patient's symptoms.