Symphalangism (two phalanges) in the digits of the Japanese foot.
We report here an investigation into the number of phalanges of the 2nd to 5th toes in a Japanese population. The number of phalanges in each of these toes is normally three, distal, middle and proximal. However, occasionally only two phalanges are observed. In this condition, known as symphalangism, the middle and distal phalanges are fused (synarthrosis of the distal interphalangeal joint). The incidence of symphalangism in the 488 feet was found to be 72.5% in the 5th toe, 11.9% in the 4th toe, 0.8% in the 3rd toe, and 0.0% in the 2nd toe. No left-to-right or sex differences were observed. The reported overall incidence of symphalangism in the 5th toe of the foot in the Japanese population (74.7%) is significantly higher than that in the European population (40.2%). In the present sample, the incidence of symphalangism of the 4th toe (11.9%) was significantly higher than that in Japanese population samples previously studied (4.2%).
Nakashima
T
T
Department of Anatomy and Anthropology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu City, Japan.
Hojo
T
T
Suzuki
K
K
Ijichi
M
M
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001842:Bone and Bones / Q000002:abnormalities* / Q000000981:diagnostic imaging; D002648:Child; D005060:Europe / Q000453:epidemiology; D005260:Female; D005532:Foot Deformities, Congenital / Q000000981:diagnostic imaging / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012727:Sex Characteristics; D014034:Toes; D044465:White People