The Extensor Pollicis Brevis: A Review of Its Anatomy and Variations

INTRODUCTION The standard anatomical description of the extensor pollicis brevis tendon provided in textbooks of anatomy is at odds with that of published anatomical studies. It is crucial to the hand surgeon that he or she has a clear understanding of its anatomy, including its variations. The aim of this study was to provide a comprehensive review of the current literature on the anatomy and variants of the extensor pollicis brevis. It is hoped that this review will be indispensable to the hand surgeon in informing him or her about the anatomy and variants encountered when dealing with the extensor pollicis brevis. METHODS Inclusion and exclusion criteria were defined and a literature search was carried out on MEDLINE, PubMed, Embase, and Google Scholar from inception to March 2013 for studies on the topic of extensor pollicis brevis anatomy. The following key words were used: "extensor pollicis brevis," "anatomy," "anatomic variations," "cadaveric study," "clinical study," "case report," and "dissection". RESULTS The search retrieved a total of 52 studies following removal of duplicates. Forty-five studies were excluded following screening of the title and abstract. Three studies were excluded as they did not meet the eligibility criteria, leaving 4 cadaveric studies for inclusion in the review. CONCLUSION We recommend the use of ultrasound scanning to determine anatomy of the extensor pollicis brevis before reconstructive procedures involving the extensor pollicis brevis, as well as in traumatic injuries to the extensor pollicis brevis. There appears to be ethnicity-related variations in the anatomy of the extensor pollicis brevis, and further study into these variations may be indicated.