Ossa Sesamoidea — prevalence of sesamoid bones in human hands

Abstract

Background: This study describes the morphology of sesamoid bones in the human hand. Ultrasound imaging was used to record the presence and measurements of sesamoids in 120 hands of 60 healthy, young adults of Caucasian ethnicity. Materials and methods: The mean number of sesamoid bones was 4.16 in the left hand and 4.03 in the right hand. 21.6% of cases showed asymmetry between the right hand and the left. There was a significant difference in the prevalence of sesamoid bones between right and left hand in males in this study. Females show a higher incidence of sesamoid bones overall, but do not demonstrate a significant difference between the sides. Results: Prevalence findings: Two in the 1 st Metacarpophalangeal joint (MCPJ) in 99.2% of cases, with one case of a single bone. One in the 2 nd MCPJ in 43.3% of cases. One in the 5 th MCPJ in 84.2% of cases. One in the 1 st Interphalangeal joint (IPJ) in 83.4%of cases. Aside from that there was one case of sesamoid in the 3 rd MCPJ and separate case of sesamoid in the 3 rd proximal IPJ. Conclusions: Moreover, this study discusses discrepancies of opinion regarding sesamoid bones in morphological research.

Morphology of sesamoid bones in keyboard musicians

“…Considering that both groups consisted of people in similar age (mean: 23.7 years for the study group and 22.8 years for the control group), and similar built (mean height: 172.8 cm for the study group and 174.3 cm for the control group, mean weight: 67.3 kg for the study group and 69.2 kg for the control group) with very small differences that could only possibly favour the control group (statistically bigger body mass should translate for the bigger mass of the skeletal structures), and that the sexual make-up of the control group was proven not to influence the outcome (no significant sexual dimorphism in the control group), it could be speculated that the main reason for the differences in the mean sum of the volume of the sesamoid bones was the musical training during the age of sesamoids' ossification. It would agree with the assumption that the sesamoid bones function as a pulley for the muscular tendons, therefore making the movement faster, stronger and safer for the joint underneath [2,3,8,9,12,22,25]. It could be speculated that the time when the hand undergoes most significant morphological adaptation to the task of playing the keyboard instrument, and therefore possibly most important time for regular musical training is the time of sesamoids' ossification which starts during early stages of puberty.…”

“…There also seems to be a noticeable tendency regarding sexual dimorphism. Despite general tendency for women to have more sesamoid bones than men [3,9,20,25], the men in the musicians' group proved to have statistically significantly (p-value = 0.003094) bigger sum of the volume of the sesamoid bones in one hand than women. Such dimorphism did not occur in the group of non-musicians was no proof that such "Bactrian" sesamoid occurred due to damage, or conjunction of two smaller bones, moreover similar sesamoid bones were observed by Jones [7] in smaller mammals, such as rabbits.…”

“…Both Sang-Hie [15,16] and Sakai [14] bring up Wagner's analysis -that hands of the male pianists are on average bigger but less mobile than female, both when it comes to active and passive range of motion, and that left hand has statistically greater hand's span than the right one. Interestingly enough there is research suggesting that more sesamoid bones occur both in females than males and in the left hand compared to the right hand [3,[14][15][16]20].…”

Prevalence of metacarpophalangeal sesamoid bones of the hand in Turkish population

“…The presence of at least one sesamoid at the MCP I in different ethnicities has been reported by many authors. [3][4][5][6][7][8][9] In a meta-analysis, Yammine [1] reported a prevalence of sesamoid bone on radial, ulnar and both side of MCP I of 99.93%, 99.81%, and 99.93%, respectively. [1] This slight difference may be caused by physiological agenesis of one sesamoid bone in some subjects, as three patients having one sesamoid bone in our study.…”

“…[2] The main hypotheses proposed for functions of sesamoids are as follows: (i) reduction of tendon friction, (ii) protection of tendon, (iii) reduction of pressure, and (iv) maintaining the position of flexor pollicis longus. [2,3] Plain radiographs, postmortem studies, ultrasound (US) and digital tomosynthesis (DTS) were used Objectives: This study aims to investigate the prevalence and location of the metacarpophalangeal (MCP) sesamoid bones using computed tomography (CT) images. Patients and methods: A total of 767 hands of 735 patients (503 males, 232 females; mean age: 36.9±17.0 years; range, 18 to 105 years) obtained from picture archiving and communication system were retrospectively analyzed between January 2016 and December 2019.…”