Anatomy and pathology of the sesamoid bones. The hand compared to the foot.

The sesamoid bones were studied in 100 hands and feet in 50 cadavers and in 1000 radiographs of the hands of South Sinai Bedouin children. The sesamoids of the metacarpophalangeal joint of the thumb and metatarsophalangeal joints of the hallux were always present in the dissections and radiographs. Other sesamoids were observed in the radiographs of the metacarpophalangeal joints of the index finger in 50% of the cases, the middle finger in 3%, the ring finger in 1% and the little finger in 70%. Sesamoids were also seen in 62% of the interphalangeal joints of the thumb. There are differences between the hand and the foot in relation to the occurrence of degenerative changes in the joints. In the thumb, the metacarpophalangeal joint is involved macroscopically in 75% of the cases, and only in 13% of the radiographs, with the pathological changes located in one or the other part of the joint. In the hallux, 40% of the cases are involved both macroscopically and in radiographs, but all the parts of the joint are affected.