A nonclassified preaxial polydactyly of the foot

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.     

Treatment of preaxial polydactyly.

Preaxial polydactyly is the result of aberrant bifurcation of the embryonic preaxial anlage. Effective reconstruction of thumb duplication requires careful evaluation of all components. Skin, nail, bone, ligament, and musculoskeletal elements must be combined to reconstruct an optimal digit.     

Preaxial polydactyly of the foot

Background and purpose — Preaxial polydactyly of the foot is a rare malformation and clinicians are often unfamiliar with the associated malformations and syndromes. In order to give guidelines for diagnostics and referral to a clinical geneticist, we provide an overview of the presentation using a literature review and our own patient population.

Patients and methods — The literature review was based on the Human Phenotype Ontology (HPO) project. From the HPO dataset, all phenotypes describing preaxial polydactyly were obtained and related diseases were identified and selected. An overview was generated in a heatmap, in which the phenotypic contribution of 12 anatomical groups to each disease is displayed. Clinical cases were obtained from our hospital database and were reviewed in terms of phenotype, genotype, heredity, and diagnosed syndromes.

Results — From the HPO dataset, 21 diseases were related to preaxial polydactyly of the foot. The anatomical groups with the highest phenotypic contribution were lower limb, upper limb, and craniofacial. From our clinical database, we included 76 patients with 9 different diseases, of which 27 had a GLI3 mutation. Lower limb malformations (n = 55), upper limb malformations (n = 59), and craniofacial malformations (n = 32) were most frequently observed. Malformations in other anatomical groups were observed in 27 patients.

Interpretation — Preaxial polydactyly of the foot often presents with other upper and lower limb malformations. In patients with isolated preaxial polydactyly of the foot, referral to a clinical geneticist is not mandatory. In patients with additional malformations, consultation with a clinical geneticist is recommended. When additional limb malformations are present, analysis of GLI3 is most feasible.     

Tibial hypo-/aplasia with preaxial syn- and polydactyly

Summary Tibial hypo-/aplasia with preaxial syn- and polydactyly is a rare autosomal dominant condition. Fewer than 20 cases have so far been described. One is presented here.     

Classification of postaxial polydactyly of the foot

BACKGROUND: The origins and shapes of accessory digits in postaxial polydactyly of the foot were analyzed morphologically and radiographically, and their characteristics were determined. A simple classification method was then devised to assist in determining the most appropriate treatment options. METHODS: We evaluated 113 feet of 95 patients who had surgery for the treatment of postaxial polydactyly between 1998 and 2002. Based on the morphologic, radiographic, and operative findings, the cases were classified according to the origin of the accessory digit: middle phalangeal, proximal phalangeal, floating, fifth metatarsal, or fourth metatarsal. The proximal phalangeal type was further divided into three subtypes: proximal phalangeal lateral type, proximal phalangeal medial, and proximal phalangeal head. RESULTS: Of the 113 feet, 36 were middle phalangeal type, 45 were proximal phalangeal type, 5 were floating type, 15 were fifth metatarsal type, and 12 were fourth metatarsal type. Of the proximal phalangeal types, 15 were laterally duplicated supernumerary sixth digits, and 17 were medially duplicated supernumerary fifth digits. The duplicated digits of the remaining 13 originated at the distal portion of the proximal phalanx. In the middle phalangeal, proximal phalangeal head, proximal phalangeal medial, and fourth metatarsal types, the medial accessory fifth digit was an abnormally duplicated digit, which was excised. In the proximal phalangeal lateral, floating, and fifth metatarsal types, the lat eral accessory sixth digit was excised. For the children in this study, we did not perform reconstruction of the deep transverse metatarsal ligament or collateral ligament. Also, we did not use longitudinal pin fixation. Skin necrosis occurred in 10 feet that resolved, and in five of the 15 feet of the 5th metatarsal medial deviation occurred. CONCLUSIONS: Based on the morphologic, radiographic, and operative findings, we suggest a classification method of postaxial polydactyly of the foot. We believe this is a straightforward and useful method for the treatment of postaxial polydactyly.     

Delta formation in foot polydactyly

Congenital triangular deformity of the foot bones may occur in phalanges and metatarsals. As it resembles the Greek letter delta it is called "delta phalanx" and "delta metatarsal". We report on 19 delta formations in ten patients with foot polydactyly. Our long-term follow-up of these patients indicates four stages in the ossification process: no ossification of the epiphysis; appearance of single or multiple ossification centers; unification of the ossification centers with nonosseous tissue between the diaphysis and the epiphysis; and, finally, complete ossification. Pathogenetically, the delta formation may represent an intermediate stage in the bifurcation process of a polydactylic ray. Splitting longitudinally in a direction from distal to proximal, it is the root of the bifurcated toe ray.     

Delta formation in foot polydactyly

Summary Congenital triangular deformity of the foot bones may occur in phalanges and metatarsals. As it resembles the Greek letter it is called delta phalanx and delta metatarsal. We report on 19 delta formations in ten patients with foot polydactyly. Our long-term follow-up of these patients indicates four stages in the ossification process: no ossification of the epiphysis; appearance of single or multiple ossification centers; unification of the ossification centers with nonosseous tissue between the diaphysis and the epiphysis; and, finally, complete ossification. Pathogenetically, the delta formation may represent an intermediate stage in the bifurcation process of a polydactylic ray. Splitting longitudinally in a direction from distal to proximal, it is the root of the bifurcated toe ray.

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Zusammenfassung In polydaktylen Füßen können Rohrenknochen als dreieckige Fehlbildungen auftreten. Da these Anomalien dem griechischen Buchstaben ähneln, werden she Deltaphalanx oder Deltametatarsale genannt. Wir berichten über neunzehn solche Deltaformationen bei zehn Patienten mit polydaktylen Füßen. Die Beobachtung dieser Patienten vom ersten Lebensjahr his ins Erwachsenenalter läßt vier Entwicklungsstadien erkennen: Verknöcherung der Diaphyse ohne Ossifikation der Epiphyse; einzelne oder mehrere Ossifikationskerne der Epiphyse; Fusion dieser Epiphysenkerne mit Erhalt der knorpeligen Wachstumsfuge; knöcherne Kontinuität von Epiphyse and Diaphyse. Nach pathogenetischen Gesichtspunkten kann die Deltaformation ein Intermediärstadium im Gabelungsprozeß des polydaktylen Strahles darstellen. Da er sich von distal nach proximal teilt, kann die Deltaformation als Verzweigungsstelle des gedoppelten Zehenstrahls verstanden werden. Bei unseren Patienten waren der erste Zehenstrahl 13mal and der fünße 3mal betroffen. Bei einem Patienten waren der 1. and V. Zehenstrahl beider Füße befallen. Die Polydaktylie wurde nach ihrer Längsspaltung von distal nach proximal in einen distalen, mittleren and proximalen Phalanxtyp sowie einen metatarsalen and tarsalen Typ eingeteilt [2]. Bei unseren Patienten mit Deltaformationen im Fufßskelett fanden sich folgende Polydaktylieformen: Der distale und mittlere Phalanxtyp in jeweils einem Zehenstrahl, der proximale Phalanxtyp in sechs, der metatarsale Typ in neun and der tarsale in einem Strahl. Abgesehen von der Polydaktylie wurden andere angeborenen Anomalien bei sieben Patienten gesehen. Ein Erbgang war bei vier Patienten offenkundig. Diese Einteilung der Polydaktylie and der Verknöcherungsstadien von Deltaformationen sollen zum besseren Verständnis der Entwicklung von polydaktylen Füßen beitragen.

     

Problems in polydactyly of the foot.

1. Polydactyly should be treated early. 2. Adequate bone and soft tissue should be removed. 3. One arm of the Y should be removed surgically in the incompletely duplicated Y metatarsal. 4. The incompletely duplicated Y metatarsal shaved to form a single shaft may at first be bowed, but will remodel to form normal or nearly normal bone. 5. The wide metatarsal head associated with a duplicated phalanx should be narrowed surgically to avoid the development of a painful bunion. 6. Short block-like metatarsals remain abnormal. 7. Polydactyly associated with a short first metatarsal and congenital hallux varus carriers a poorer treatment prognosis and may require continuing treatment. 8. Postoperative casting and taping should be utilized to prevent angular deformities and encourage normal forefoot contour.     

复拇合并三指节拇指畸形家系的基因分析研究

目的 研究先天性复拇合并三指节拇指畸形的一个家系的临床表现及致病原因.方法 在患者家系调查的基础上,应用聚合酶链反应(PCR)技术对极化活性区(zone of polarizing activity,ZPA)调控序列进行扩增和测序分析.结果 体检发现,患者存在单侧或双侧拇指的复拇合并三指节拇指畸形,部分患者还可合并轴前和轴后的多指畸形.病因研究提示,在所有患者ZPA调控序列的第105位碱基对上发现了C→G的点突变.结论 复拇合并三指节拇指畸形家系患者由ZPA调控序列的第105位碱基对上C→G的点突变所致.     

An unusual case of preaxial polydactyly of the hands and feet: a case report

An unusual case of polydactyly of the hands and feet is described. The ulnar 4 digits of both hands and the outer 4 digits of both feet appeared normal, and the extra digits were on the radial side of the hands and on the medial side of the feet. The pattern of polydactyly did not fit any of the well-known deformities associated with radial digital duplication such as thumb polydactyly, mirror hand, or duplicated (multiple) hands. The harmonious deformities of the hands and feet suggest a genetic alteration to the development of all 4 limb buds, but the case did not fit any of the known syndromes that have high-level preaxial digital duplication of the hands and feet.     

An unusual presentation of postaxial polydactyly of the foot

A 6‐month‐old Caucasian baby is described with a postaxial polydactyly of the letf foot. Radiographic examination revealed the accessory digit was composed of soft tissue, some with a tiny osseous element, originated from around the metatarsophalangeal joint, defined by floating type (FT). The parents had consistent difficulty putting shoes. We encountered an exceedingly rare presentation of FT, to our inspection, had neither been previously related in published studies. To the best of our knowledge, this represents the unusual case of congenital deformity lesion on the left foot to be reported in the medical literature.     

An unusual and nonclassified central polydactyly of the foot

Central-type, 8-toed polydactyly is a distinctly rare congenital foot anomaly. In this report, a new subtype of the metatarsal type of the central ray polydactyly of the foot is presented. This includes a triplication, one of which is Y-shaped of the second metatarsal and 8 toes. In the literature, polydactyly of the foot has been usually operated during childhood after walking age. We performed the surgery at 6 months of age. After ray amputation of the extra toes, we reapproximated the muscle pieces that remained on the original first and second metatarsals and repaired the transverse metatarsal ligament. Despite the early surgery, we did not encounter any problems intraoperatively and postoperatively.     

Isolated hexadactylia: A rare case of central polydactyly of the foot

BackgroundCentral polydactyly of foot is uncommon form of polydactyly but it usually causes intermetatarsal widening because of metatarsal bifurcation. Central polydactyly associated with T shaped bifurcation of metatarsal in vertical plane has not been reported yet.CaseWe present a 4 year male child with extra toe on the dorsal aspect of right foot with complains of difficulty in wearing footwear and poor cosmesis. The extra digit was fully developed with bifurcation of 2^nd metatarsal bone proximal to the head without any intermetatarsal widening. The angular deviation was 45° to the longitudinal axis of foot and in a plane vertical to the transverse arch of foot. The child was operated with excision of extra toe without any residual bony deformity.ConclusionThe central polydactyly is rare type of polydactyly of foot. Central polydactyly with metatarsal extension causing intermetatarsal widening has been well described entity. But the previous classifications need to be modified to include central polydactyly with vertical oriented T bifurcation of metatarsal bone without intermetatarsal widening.     

Central polydactyly of the foot: An experience of a treatment of 22 patients

BackgroundThe central polydactyly of the foot is a rare congenital disorder, and its characteristics are not well known. This study aims to investigate its disease concept.MethodsWe obtained the medical records of patients who were treated surgically for central polydactyly of the foot at our hospital during a 32-year period from 1990 to 2021 retrospectively. We compared our clinical data with other case series reports to investigate the characteristics of this disorder further.ResultsThere were 22 patients (13 males and 9 females) included in our case series. Unilateral and bilateral involvements were observed in 19 (right side: 6 patients; left side: 13 patients) and 3 patients, respectively. The second toe is the commonest duplicated toe (observed in 19 toes). 19 patients had distally duplicated toes (with normal metatarsal bone). Proximally duplicated toes were observed in only two patients.ConclusionsThe incidence of central polydactyly of the foot is almost equal among male and female, and bilateral involvements are few. As this abnormality is rarely reported, further investigations are needed to clarify the clinical presentation of central polydactyly of the foot.     

Complex polydactyly of the limbs: mirror foot. Report of two cases and review of literature

Polydactyly is the most common congenital limb anomaly occurring both as an isolated defect or as part of a syndrome. However mirror foot is an exceptional abnormality (14 cases reported). The authors describe two sporadic cases of mirror foot. The first case presents a mirror polydactyly of the left foot, an hexadactyly of the right foot and a central polysyndactyly of both hands. The second case presents a mirror polydactyly of both feet. Mirror foot is a very rare defect. Both sporadic and familiar cases have been reported. This malformation can affect one or both feet. Some cases are associated with other congenital anomalies. The definition of mirror foot is warying according to the authors and the review of literature shows an important variability in the patterns of mirror polydactyly. Mirror duplication of hands and feet result of aberrant positioning of the zone of polarizing activity in relation to the apical ectodermal ridge during limb bud development. Different genes encoding limb pattern have been described.