Abstract
Background Posttraumatic extensor carpi ulnaris (ECU) instability is an increasingly recognized cause of ulnar-sided wrist pain that occurs when the ECU subsheath is disrupted. Purpose The purpose of this systematic review was to assess outcomes of operatively treated posttraumatic ECU instability. Methods A systematic search of Medline, Embase, Web of Science, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases was performed using "extensor carpi ulnaris" as the keyword. Studies were systematically screened and data extracted independently by two reviewers. Results Eight retrospective studies met the inclusion criteria with a total of 97 wrists. The mean age was 32 years (13-61). Patients underwent either primary repair (40%) using sutures and anchors, or reconstruction (60%) using extensor retinaculum flaps. One study performed deepening of the osseous ulnar groove. Two studies compared preoperative and postoperative values. They both reported a significant improvement in pain scores, functional scoring instruments, satisfaction, and grip strength. The rest of the studies reported similarly favorable outcomes across the same outcomes. Concomitant pathologies were identified in 66% of the study population. Complications occurred in 9% of the sample size, including ECU tendinitis, ulnar sensory nerve irritation, and reintervention for concomitant pathology. None of the studies reported recurrence or reruptures. However, five patients (6.7%) did not return to their previous activity level. Conclusion Patients can expect favorable outcomes with a potentially low complication rate. Nevertheless, the heterogeneity of the sample population, operative techniques, and outcome measures warrant further standardized studies. Level of Evidence IV.