Prevalence of sesamoid bones in the hands: 3D-reconstructed CT study

Abstract

Introduction: The prevalence of sesamoid bone in hand is known to be variable among populations of various geographic origins. Since counting with radiographs might be inaccurate due to superimposition of adjacent digits, we tried to overcome this obstacle using 3D-reconstructed CT in Korean patients. The purpose was to provide an accurate incidence of sesamoid bones using 3D-CT. Methods: Sesamoid bones were examined in 427-CT images. 3D-CT images were analyzed by one observer and parts of hands (411-hands) were evaluated with radiograph to compare with CT results. Statistical analysis between the CT and radiograph results was performed. Results: Sesamoids of metacarpo-phalangeal (MP) joint of the thumb were always present on both radial and ulnar sides, except for 9-cases (2.1%) where they were not present on radial side and 6-cases (1.5%) where they were not present on ulnar side. MP joint of the little finger was the second most prevalent location (62.8%). The sesamoid of the index finger MP joint and thumb interphalangeal joint was observed in 44% and 42.4%, respectively. There was a rare incidence in the MP joints of middle and ring finger (0.7%). The incidence of sesamoid bone was statistically different between the two counting methods for the MP joints of index and little finger and thumb interphalangeal joint (P < 0.005). Discussion: We could observe five frequent sesamoid bones in the MP joints of the thumb, index, and little finger, and the interphalangeal joint of the thumb in Korean individuals. 3D-CT images revealed the accurate incidences of hand sesamoid bones. Copyright (C) 2014, Anatomical Society of India. Published by Reed Elsevier India Pvt. Ltd. All rights reserved.