The Os Peroneum and Accessory Navicular: An integrated radiographic and cadaveric study

Abstract

INTRODUCTIONSesamoids and accessory bones commonly exist throughout the human body, especially in the foot. Pain from the foot and ankle is a common symptom, of which the Os Peroneum (OP) and Accessory Navicular (AN) are associated with pathologies that present to clinicians. The objective of this study was to investigate the use of CT as a paradigm in undiagnosed foot and ankle pain and to advocate the teaching the OP and AN in anatomy courses.METHODSLiterature search was conducted on anatomical texts, atlases, websites, and journals regarding the OP and AN. Roentogram and CT scans were conducted on 15 embalmed cadaveric lower limbs, followed by palpation and deep dissection of the distal tibialis posterior and fibularis longus tendons.RESULTSLiterature search revealed a 14 – 26% prevalence of the OP and 5–21% of the AN. Roentograms revealed OP in 2/22 and AN in 5/23 cadavers. CT scans revealed OP in 9/28 and AN in 13/28. Dissection revealed an OP in 9/30 and an AN in 10/28.DISCUSSIONDespite the prevalence of the OP and AN in the literature, they are not addressed in anatomy courses. They are a known cause of pain and are associated with false negatives radiologically.CONCLUSIONThis study suggests that anatomy courses include the OP and AN as clinically relevant structures. CT scans should follow roentograms as part of a diagnostic paradigm when treating unknown foot and ankle pain.