A nonclassified preaxial polydactyly of the foot S. Akin, M. Ozcan Department of Plastic and Reconstructive Surgery, Medical Faculty of Uluda~ University, G6rtikle, Bursa, Turkey
Abstract. Polydactyly of the foot has been classified according to anatomic differences in bony structures, external appearance of involved digits and associated anomalies. A new subtype of the metatarsal type of the medial ray (preaxial) polydactyly of the foot is presented. This includes triplication of the first metatarsal triplication of the tendons and three separate big toes. In addition, associated anomalies were present: short tibia and pes varus.
Case report A 14-month-old boy was admitted with polydactyly of his left foot. On examination, there were seven toes on his left foot. Of the seven toes, three were big toes (Figs. 1, 2). X-ray showed three metatarsals, proximal and distal phalanges with triplication of tendons (Fig. 3). The other toes were normal. There was also a short tibia and pes varus (Fig. 4). No familial occurrence, hand and other anomalies were noted. At surgery, an incision was made between second and third big toes. The first and second big toes were excised from metatarsals on the medial side. The third big toe together with the tendons was left on the lateral side (Figs. 5-7). The function of the foot and big toe was virtually normal.
Discussion Polydactyly of the foot is usually classified into three major groups: medial ray (preaxial), central ray, and lateral ray (postaxial) polydactyly . Oka et al. recommended a classification based on the level of duplication from analysis of their series of 97 patients . Venn-Watson described a morphologic classification of the metatarsal . Phelps and Grogan classified the duplications morphologically in 125 patients . A further classification was developed by Masada et al. In 1992, Watanabe et al. classified the precise morphologic patterns of polydactyly in 265 patients, giving type of ray involvement and level of duplication. In addition, they also reported associated anomalies and familial occurrence . This is the first description of medial ray polydactyly with metatarsal triplication.
Correspondence to: S. Akin, Uluda~ Oniversitesi Tip Fakiiltesi, Plastik ve Rekonstrtiktif Cerrahi, Anabilim Dali 16059, GOrfikle, Bursa, Turkey
In medial ray (preaxial) polydactyly, the most common levels of duplication are metatarsal and proximal phalangeal . Venn-Watson, Phelps, Baluth, Fallined, and Masada have classified medial ray polydactyly mainly on the basis of anatomic configuration of the metatarsal or whether the duplication involves the metatarsal or not [1, 3-7]. According to Watanabe, medial ray polydactyly is classified into four major types, i.e. tarsal type, metatarsal type, proximal phalangeal type, and distal phalangeal type . The metatarsal type of medial ray polydactyly is further divided into three subtypes, i.e. hypoplastic lateral member, highly deformed both metatarsals and hypoplastic medial member. A new subtype of the metatarsal type is presented (Fig. 8), a triplication of the first metatarsal with three separate big toes. The triplicated metatarsals were hypoplastic without syndactyly of the neighboring toes. The three big toes had complete proximal and distal phalanges. A short tibia and hand anomalies are associated with unilateral medial ray polydactyly of the foot . In our patient, there was a short tibia.
8 l~igs. 1, 2. Preoperative views of triplet big toes
Figs. 5-7. Postoperative views of his left foot
Fig. 3. This new subtype includes a triplication of the first metatarsal. The big toes had completely proximal and distal phalanges
Fig. 8. Anatomic pattern of a new subtype of the metatarsal type of the medial ray (preaxial) polydactyly of the foot
Fig. 4. There was a short tibia in the patient
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