RESUMEN
Background: Corticosteroid injection is frequently used for chronic coccydynia management. Ultrasonography can be used to improve the accuracy of the injection. This study aims to assess the clinical outcome of ultrasound-guided compared to blind coccygeal injection in chronic coccydynia. Methods: Thirty patients with chronic coccydynia were randomized into two groups and received a coccygeal corticosteroid injection at maximum tenderness point: 15 patients with and 15 patients without ultrasound guidance. The patient'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 of life 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 blinded groups (P < .001), without any significant difference between the groups (P = .964). Similarly, the Dallas pain scale had a significant decrease at eight weeks after intervention in both groups (P < .001) with no significant difference between the groups (P = .972). Although there was a significant improvement in the patient's quality of life in each group eight weeks after the intervention, it was not significantly different between the two groups. Neither of the treatment groups had any adverse effects associated with the injection. Conclusion: There were no significant differences in the clinical outcome of coccygeal ultrasound-guided vs. blind steroid injection for chronic coccydynia.
