RETRACTED: A universal Echosupport can fix a technique of ultrasound-guided continuous femoral nerve block

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief for inappropriate authorship. The Editor-in-Chief decision was based on the investigation by the Japanese Society of Anesthesiologists which concluded that the corresponding author, Dr. Ueshima presented the names of the individuals not involved or only partially involved in research as lead authors, presented the names of the individuals not involved in research as co-authors and submitted papers without the agreement of the co-authors. The investigation report can be found here.