The authors have discovered an error in their figures and have provided replacement figures which have been corrected. Specifically, the positions of "Lateral" and "Medial" were reversed, and the positions of "Ischium" and "Sacrum" were reversed. Additionally, the solid lines at the boundaries of each muscle and bone have been removed, and only the nerves have been marked with dotted lines, which is a common notation in ultrasound images. The authors would also like to add the following Acknowledgment: The authors are grateful to Tadashi Kobayashi and Yoshihiko Shiraishi for advising us on the accurate anatomy of ultrasound images. Reference: Mihiro Kaga, Takeshi Ueda. Effectiveness of Hydro-Dissection of the Piriformis Muscle Plus Low-Dose Local Anesthetic Injection for Piriformis Syndrome: A Report of 2 Cases. Am J Case Rep, 2022; 23: e935346. DOI: 10.12659/AJCR.935346.