Sesamoid bone of interphalangeal joint of thumb
Os sesamoideum articulationis interphalangealis pollicis
Definition
The sesamoid bone at the interphalangeal joint of the thumb is a small, oval or round ossicle located on the volar (palmar) aspect of the thumb's interphalangeal (IP) joint. It is embedded within the volar plate and the flexor pollicis longus tendon, acting as a fulcrum to enhance the mechanical advantage of the tendon during thumb flexion.
This sesamoid is most commonly found at the IP joint of the thumb, with a prevalence ranging from approximately 47% to 75% in adult populations, depending on imaging modality and population studied.
References
1.Prevalence of Sesamoid Bones in the Interphalangeal Joint of the Thumb and Fingers: A Radiographic Study.Seki Y, Hoshino Y, Kuroda H.Clinical Anatomy (New York, N.Y.). 2013;26(7):823-6. doi:10.1002/ca.22201.
2.Prevalence and Distribution of Sesamoid Bones in the Hand Determined Using Digital Tomosynthesis.Koo BS, Song Y, Sung YK, Lee S, Jun JB.Clinical Anatomy (New York, N.Y.). 2017;30(5):608-613. doi:10.1002/ca.22881.
3.The Prevalence of the Sesamoid Bones of the Hand: A Systematic Review and Meta-Analysis.Yammine K.Clinical Anatomy (New York, N.Y.). 2014;27(8):1291-303. doi:10.1002/ca.22378.
