Ultrasound-Guided vs. Blind Coccygeal Corticosteroid Injections for Chronic Coccydynia: A Randomized, Clinical Trial

Background: Corticosteroid injection is frequently used for chronic coccydynia management. Ultrasonography canbe used to improve the accuracy of the injection. This study aims to assess the clinical outcome of ultrasound-guidedcompared to blind coccygeal injection in chronic coccydynia.Methods: Thirty patients with chronic coccydynia were randomized into two groups and received a coccygealcorticosteroid injection at maximum tenderness point: 15 patients with and 15 patients without ultrasound guidance. Thepatient’s pain was evaluated with the visual analog scale (VAS) at 1-, 4-, 8-, and 24-week postinjection. Furthermore,the Dallas Pain Questionnaire was assessed before injection; also, four and eight weeks after treatment. The quality oflife of patients was evaluated before an assessment and four weeks after the intervention by the SF-36 questionnaire.Results: The VAS score decreased significantly 24-week after the intervention in both ultrasound-guided and blindedgroups (P .001), without any significant difference between the groups (P = .964). Similarly, the Dallas pain scale hada significant decrease at eight weeks after intervention in both groups (P .001) with no significant difference betweenthe groups (P = .972). Although there was a significant improvement in the patient’s quality of life in each group eightweeks after the intervention, it was not significantly different between the two groups. Neither of the treatment groupshad any adverse effects associated with the injection.Conclusion: There were no significant differences in the clinical outcome of coccygeal ultrasound-guided vs. blindsteroid injection for chronic coccydynia.Level of evidence: I