Cleft feet. Proposals for a new classification based on roentgenographic morphology.

The authors studied 45 cleft feet from among their patients and 128 from the literature with regard to their roentgenographic morphology. An increasing degree of malformation was found, from deepening of a central interdigital commissure to a monodactylous cleft foot. These observations resulted in a classification of six groups based on the number of metatarsal bones. Types I and II are cleft feet with minor deficiencies, both having five metatarsals. The metatarsals are all normal in Type I and partially hypoplastic in Type II. As the degree of malformation increases, only four metatarsals in Type III, three metatarsals in Type IV, and two metatarsals in Type V can be identified. Type VI represents the monodactylous cleft foot. Of the 173 feet studied, 166 could be assigned to one of these types. Two additional forms were also found: four cleft feet with central polydactyly are described as polydactylous type, and three monodactylous feet with lower-leg diastasis or tibial aplasia or both are described as diastatic type. According to the distribution of syndactylies, synostoses, and aplasias, it became evident that cleft formation begins at the second or third ray. It then proceeds in a longitudinal direction from distal to proximal as well as in a transverse direction from tibial to fibular, while the first ray remains intact. The first ray is only missing in the monodactylous cleft foot, which possesses only the fifth ray. The defects are always larger distally than proximally. Synostoses are found only at the margin of the cleft. Cross-bones are rare and usually occur in mild cases of the deformity. Another rare feature is polydactyly.(ABSTRACT TRUNCATED AT 250 WORDS)