Radiographic appearance of sesamoid bones in the hands and feet of Malawian subjects

Our aim was to determine the prevalence of sesamoid bones in adult black Malawians from radiographs of the hands and feet. A total of 255 radiographs from 85 men and 45 women aged 16-66 years were used: 126 of the hands and 129 of the feet. All the hand films revealed one sesamoid bone at the interphalangeal joint and two at the metacarpophalangeal joint of the thumb. All the foot films showed two sesamoid bones at the metatarsophalangeal joint of the big toe. Occasional sesamoid bones were found at the metacarpophalangeal and metatarsophalangeal joints of the index finger and the small toe, respectively. Only 4.8% of the hands had sesamoid bones at the metacarpophalangeal joint of the index finger, compared with reported percentages of between 35% and 64.2% in Caucasians. The present study also records, probably for the first time in Africans, an incidence of 10.8% of sesamoid bones occurring at the metatarsophalangeal joint of the small toe, which again is at variance with the reported range of 5.5-10% in Caucasians. This study provides anatomical data that will help in the diagnosis and management of disorders of sesamoid bones which are often overlooked in Africans.