Classification of polydactyly of the hands and feet

Classification of radial polydactyly based on physical characteristics

BACKGROUND

Previous classifications in polydactyly of the thumb were by the level of duplication on radiography. This study aimed to develop a practical algorithm based on physical characteristics for treatment guidelines.

METHODS

The polydactylies were stratified using four physical characteristics: floating, symmetry, dominant side, and joint angulation/nail size. The algorithm identified the hypoplastic type and then stratified the polydactylies as symmetric and asymmetric. The asymmetric type was divided into ulnar dominant and radial dominant. The symmetric type was divided into adequate type and inadequate type. The prediction of treatments was studied retrospectively by the distribution of surgical procedures in 500 patients with 545 affected thumbs, by the new classification and the Wassel-Flatt classification.

RESULTS

Of the 545 polydactylies, 78 (14.5%) were categorized as the hypoplastic type, 369 (67.5%) as the ulnar-dominant type, 8 (1.5%) as the radial-dominant type, 70 (12.8%) as the symmetric adequate nail type, and 20 (3.7%) as the symmetric inadequate type. Treatments were excision and reconstruction in 403 polydactylies (73.9%), simple excision in 135 polydactylies (24.8%), and the Bilhaut-Cloquet procedure, ray amputation, and on-top plasty procedures were only performed in 7 polydactylies (1.3%). The distribution of surgical procedures was distinct among the new classification types and was similar among the Wassel-Flatt types.

CONCLUSIONS

The new classification stratified polydactylies by physical findings in a stepwise manner. Though surgical technical details are not included, this simple classification is useful for paediatricians and parents to understand how a surgical decision is made.

LEVEL OF EVIDENCE

Diagnostic Level IV.

Morphologic Changes in Postaxial Polydactyly of the Foot: A Standardized Quantitative Analysis Using the Watanabe-Fujita Classification

BACKGROUND

Postaxial polydactyly of the foot is one of the most common congenital abnormalities. A wide forefoot, short toe, and lateral joint deviation are associated with aesthetic and functional outcomes. This study used the Watanabe-Fujita classification to characterize the preoperative and postoperative skeletal morphology of postaxial polydactyly of the foot.

METHODS

This retrospective study included 42 patients (51 feet) with postaxial polydactyly treated at age 1 year. Radiographs taken at ages 0 and 3 to 4 years were used for morphologic analysis. The length of the reconstructed toe, the distance between the fourth and fifth metatarsals, and joint deviation angles were measured. The length measures were standardized using the length of the third metatarsal. Morphologic characteristics were compared based on the Watanabe-Fujita classification at ages 0 and 3 to 4 years. Long-term outcomes were also evaluated in patients followed up for longer than 6 years.

RESULTS

The fifth-ray proximal phalangeal subtype had the shortest toe length both at ages 0 and 3 to 4 years. Proximal phalangeal joint lateral deviation improved postoperatively in 78% of patients with the fifth-ray middle phalangeal subtype, regardless of reconstruction type. There was no significant change in proximal phalangeal joint deviation between ages 3 to 4 years and 7 years or older. A residual metatarsal was associated with lateral metatarsophalangeal joint deviation and a wide intermetatarsal distance, and required revision surgery.

CONCLUSIONS

Morphologic changes of postaxial polydactyly of the foot were successfully characterized using the Watanabe-Fujita classification. This classification could be useful for planning surgical strategies and anticipating morphologic outcomes.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Wassel VI Thumb Duplication With Triphalangeal Radial and Ulnar Thumbs: Anatomy and Surgical Reconstruction

A 6-year-old otherwise healthy girl presented with a Wassel VI duplication of the left thumb metacarpal and triphalangeal radial and ulnar thumbs. The patient underwent successful thumb reconstruction by transposition of the distal ulnar thumb onto the radial thumb metacarpal. To the best of our knowledge, this case report represents the first published anatomical dissection and surgical reconstruction of a Wassel VI duplication with triphalangeal radial and ulnar thumbs.

A Rare Combination of Heptadactyl and Hexadactyl Polydactyly in a Neonate

Heptadactyly and hexadactyly are rare congenital disorders from the polydactyly family. This type of polydactyly is usually classified into three major groups: preaxial (medial ray), postaxial (lateral ray), and central polydactyly. The most common presentation is both preaxial and postaxial polydactyly. The occurrence of heptadactyly and hexadactyly has been reported but the presence of both in the same infant has not been reported yet. We report the presence of both these abnormalities in the same infant.

An unusual manifestation of asymmetric polydactyly of both feet and symmetrical polydactyly of both hands

In the routine treatment at the hospital, it was observed that a 31-year-old Asian woman developed foot pain after work, with clinical manifestations including local tenderness, abrasion, and a rare case of polydactyly with bilateral foot asymmetry. In addition, we also found that the patient had two-handed symmetric polydactyly. According to our observations, there seem to be few similar cases reported in the past of a two-handed symmetric polydactyly combined with a feet asymmetry polydactyly in the same person, so this is a relatively rare reported case of polydactyly. This paper aims to present detailed case report and discuss related diseases in a morphological and clinical study.

Genetic overview of postaxial polydactyly: Updated classification

Polydactyly or polydactylism, also known as a hyperdactyly, is a congenital limb defect with various morphologic phenotypes. Apart from physical and functional impairments, the presence of polydactyly is an indication of an underlying syndrome in the newborn. Usually, it follows as an autosomal dominant/recessive inheritance pattern with defects in the limb development's anteroposterior patterning. Although mutations in several genes have been associated with polydactyly; however, the exact underlying cause, pathways, and disease mechanisms are still unexplored, thus making it of multi-factorial origin. Polydactyly is divided into three subtypes; radial, ulnar, and central polydactyly. So far, 11 loci (PAPA1-PAPA11) and seven human genes have been reported to cause non-syndromic postaxial polydactyly in humans, including the ZNF141, GLI3, IQCE, GLI1, FAM92A1, KIAA0825, and DACH1. In this review, we discuss emerging evidences of clinical and molecular characterization of polydactyly types in term of the involvement of newly associated genes and loci for non-syndromic postaxial polydactyly, and how these might impact our understanding of the genetic mechanisms and molecular etiology involved in the cause of polydactyly.

New Notations for Better Morphological Distinction of Postaxial Polydactyly of the Foot

There have been many reports on the classification and treatment of postaxial polydactyly of the foot. However, despite its being a common congenital anomaly, there is no universal notation about its morphology.

Examination of Postoperative Outcomes Using Morphological and X-Ray Classifications and Selection of the Toe to Be Excised in Postaxial Polydactyly of the Foot

The treatment of postaxial polydactyly requires excision of the medial fifth or lateral sixth toe, and separation of the adjacent fourth/fifth toes if the adjacent toes exhibit skin syndactyly. Morphological changes in the retained toes and reoperation are common problems after such surgery. This study examined the effects of preoperative classifications and selecting the medial fifth or lateral sixth toe for excision on the postoperative outcomes of surgery for postaxial polydactyly. From April 2006 to March 2019, surgery for postaxial polydactyly was performed on 55 feet in 49 patients. The patients' mean age at surgery was 28.8 months. Postoperative esthetic and bone alignment scores, the reoperation rate, and postoperative dysfunction were examined. The postoperative esthetic and bone alignment evaluations were performed by examining postoperative photograph and X-ray images using original scoring systems. The surgical procedure was chosen by the surgeon-in-charge during a preoperative conference after considering the toe growth and bone alignment. In the postoperative esthetic evaluation, excising the lateral sixth toe produced significantly better outcomes than excising the medial fifth toe. The morphological classification also indicated that excising the lateral sixth toe produced better outcomes, as it resulted in the bifurcated toes being clearly independent. Interestingly, the postoperative X-ray-based bone alignment score was not correlated with the esthetic score. The reoperation rate tended to be high after medial fifth toe excision. There were no postoperative functional complications. Lateral sixth toe excision for postaxial polydactyly of the foot produces good postoperative esthetic outcomes.

Complex Hand Polydactyly: A Case Report and Literature Review

Polydactyly is a common congenital malformation in which extra digits are present in at least one extremity. It has various presentations, and it can be an isolated anomaly or part of other diseases. Most isolated polydactyly cases are sporadic and unilateral, but there is an increased incidence in some populations. Polydactyly is multifactorial and can occur in different forms. Its main line of treatment is surgery to improve cosmesis and functioning. In this report, we present a rare case of bilateral complex hand polydactyly in a one-year-seven-months old girl of African descent. She is otherwise healthy with no family history of malformations. The pattern is not consistent with any syndromic disease. She subsequently underwent surgical resection of the extra digits.

Two Cases of Preaxial Polydactyly of the Foot: Important Implications for Plastic Surgeons

Although polydactyly is quite common in general, preaxial polydactyly of the foot is rare (0.4 per 10,000 patients) and specifically associated with certain congenital abnormalities and syndromes, which can include craniosynostosis, corpus callosum agenesis, and renal malformations. We present 2 recent cases of preaxial polydactyly of the foot that highlight the importance of maintaining a high level of suspicion for associated abnormalities in these patients. The first patient, who presented with supernumerary preaxial digits on both feet, pre- and postaxial polydactyly of the hands, was also macrocephalic and hyperteloric; this presentation strongly suggested a diagnosis of Greig cephalopolysyndactyly, a GLI3-variant syndrome. The second patient, who had 2 preaxial digits on one foot, was found to also have a horseshoe kidney, a malformation that has been associated with limb defects as part of an acrorenal syndrome. These cases emphasize the importance of a thorough clinical approach to patients with preaxial polydactyly of the foot. Although many patients with this anomaly may be well known to geneticists, a child may be referred to a plastic surgeon for reconstruction of what is thought to be an isolated cosmetic or local functional issue. Plastic surgeons should be aware of the complex nature of preaxial polydactyly of the foot and potential syndromic presentation.

Mid-term foot function and pedobarographic analysis of 52 feet after polydactyly resection in childhood

AIMS

The aims of this study is to report the clinical and radiological outcomes after pre-, central-, and postaxial polydactyly resection in children from a tertiary referral centre.

METHODS

All children who underwent resection of a supernumerary toe between 2001 and 2013 were prospectively enrolled and invited for a single re-assessment. Clinical parameters and several dedicated outcome scores (visual analogue scale (VAS), Paediatric Outcomes Data Collection Instrument (PODCI), Activities Scale for Kids (ASK), and American Orthopaedic Foot and Ankle Society Score (AOFAS)) were obtained, as were radiographs of the operated and non-operated feet along with pedobarographs.

RESULTS

In all, 39 children (52 feet) with a mean follow-up of 7.2 years (3.1 to 13.0) were included in the study. Resection of a duplicated great toe was performed in ten children, central polydactyly in four, and postaxial polydactyly in 26. The mean postoperative VAS (0.7; 0 to 7), ASK (93.7; 64.2 to 100), and AOFAS range (85.9 to 89.0) indicated excellent outcomes among this cohort and the PODCI global functioning scale (95.7; 75.5 to 100) was satisfactory. No significant differences were found regarding outcomes of pre- versus postaxial patients, nor radiological toe alignment between the operated and non-operated sides. Minor complications were observed in six children (15%). There were seven surgical revisions (18%), six of whom were in preaxial patients. In both groups, below the operation area, a reduced mean and maximum force was observed. Changes in the hindfoot region were detected based on the prolonged contact time and reduced force in the preaxial group.

CONCLUSION

Excellent mid-term results can be expected after foot polydactyly resection in childhood. However, parents and those who care for these children need to be counselled regarding the higher risk of subsequent revision surgery in the preaxial patients. Also, within the study period, the plantar pressure distribution below the operated part of the foot did not return to completely normal. Cite this article: Bone Joint J 2021;103-B(2):415-420.

Extreme bilateral polydactyly in a wild-caught western grey kangaroo

Polydactyly is a congenital malformation resulting from an autosomal dominant mutation manifesting as supernumerary digits of the hands or feet. It is most commonly reported in humans and domestic mammals, though there have also been isolated examples across a range of wild vertebrate species. Here we report a case of extremely unusual bilateral preaxial polydactyly on the pectoral limbs of a male western grey kangaroo (Macropus fuliginosus) from the South West region of Western Australia, in which two supernumerary digits were present on each manus. A supernumerary digit I on each manus was rudimentary in morphology without extrinsic muscular connections. However, supernumerary digit II present on each manus had fully developed extrinsic and intrinsic muscular connections, suggesting that these digits possessed normal function in flexion and extension. An alternative hypothesis is that the two supernumerary digits are both representatives of the most radial digit I, though this would then require the true digit I to have taken on the appearance of digit II by acquiring an additional phalanx and modified muscular attachments. The carpal bones exhibited a number of subtle differences in morphology when compared to normal pentadactyl individuals. The presence of a distal, rather than proximal, epiphysis on the first metacarpal was unexpected but further investigation suggested that this characteristic is perhaps more variable (in this species at least) than has been previously recognized. This case provides an unusual example to be considered within the broader context of limb development.

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

BACKGROUND

Central 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.

CASE

We 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.

CONCLUSION

The 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.

Isolated postaxial polydactyly: Epidemiologic characteristics from a multicenter birth defects study

Isolated postaxial polydactyly (I-PAP), as a single defect, is a frequent malformation, characterized by an extra digit placed on the ulnar or fibular side of the limbs. Worldwide prevalence varies from as high as 225/10,000 in Nigerians to so low as 6.08/10,000 in Argentinians. Genetic-ethnic background significantly affects worldwide prevalence and type of I-PAP. Herein we describe the epidemiological characteristics of I-PAP in 697 newborns, 383 males and 314 females identified in 1,178,993 examined live births from a multicenter case-control hospital-based population study, the Mexican program of Registry and Epidemiological Surveillance of Congenital Malformations (RYVEMCE). The main characteristics analyzed included total I-PAP, stratified in Types A and B, defined as complete or incomplete extra-digit formation, respectively, sex prevalence, affected limb, laterality, parity, prematurity, delivery-type, twinning, consanguinity, and parental age. Males (6.35/10,000) are significantly more frequently affected than females (5.45/10,000), hands more than feet, left more than right limbs, and Type B (74.50%) more than A (25.50%). Prematurity and forceps use were significantly more frequent in cases than controls. An evident decreasing time-trend prevalence was present. Similar findings with other studies were males, upper and left limbs more frequently affected. Findings that were not previously reported include prematurity, forceps use, a significant decreasing time trend and an inverse ethnic prevalence for Types A (75%) and B (25%) in the Mayan population in contrast to other worldwide ethnic groups.

Clinical Genetics of Polydactyly: An Updated Review

Polydactyly, also known as hyperdactyly or hexadactyly is the most common hereditary limb anomaly characterized by extra fingers or toes, with various associated morphologic phenotypes as part of a syndrome (syndromic polydactyly) or may occur as a separate event (non-syndromic polydactyly). Broadly, the non-syndromic polydactyly has been classified into three types, i.e.; preaxial polydactyly (radial), central polydactyly (axial), and postaxial polydactyly (ulnar). Mostly inherited as an autosomal dominant entity with variable penetrance and caused by defects that occur in the anterior-posterior patterning of limb development. In humans, to-date at least 10 loci and six genes causing non-syndromic polydactyly have been identified, including the ZNF141, GLI3, MIPOL1, IQCE, PITX1, and the GLI1. In the present review, clinical, genetic and molecular characterization of the polydactyly types has been presented including the recent genes and loci identified for non-syndromic polydactyly. This review provides an overview of the complex genetic mechanism underlie polydactyly and might help in genetic counseling and quick molecular diagnosis.

Does timing of surgery influence the long-term results of foot polydactyly treatment?

BACKGROUND

There is an evident lack of research on timing of polydactyly surgery and its effects on treatment results.

METHODS

Retrospective comparative study on foot polydactyly patients treated at our department from 1995 to 2009. Patients were divided into 2 groups, group A - under the age of 5 at surgery, and group B - 5 years and older.

RESULTS

There were 24 patients (8 male, 16 female), 30 feet. Median age at surgery was 1 year (range, 9 months-4.5 years) for group A, and 8.5 years (range, 6-37 years) for group B. Median follow-up was 16.2 years (range, 7-21 years). There were 16 postaxial and 8 preaxial cases. At the last follow-up 12 patients' feet were "excellent" and 12 "good". No significant differences were identified between the two groups at final follow-up.

CONCLUSIONS

Timing of surgery for foot polydactyly is not crucial for final results.

Mutational screening of GLI3, SHH, preZRS, and ZRS in 102 Chinese children with nonsyndromic polydactyly

BACKGROUND

Polydactyly is a group of congenital limb malformations that show high degree of phenotypic variability and genetic heterogeneity.

RESULTS

In the present study, four genomic regions (exons of GLI3, SHH, and noncoding sequences of preZRS and ZRS) involved in hedgehog (Hh) signaling pathway were sequenced for 102 unrelated Chinese children with nonsyndromic polydactyly. Two GLI3 variants (c.2844 G > G/A; c.1486C > C/T) and four preZRS variants (chr7:156585336 A>G; chr7:156585421 C>A; chr7: 156585247 G>C; chr7:156585420 A > C) were observed in 2(2.0%) and 6(5.9%) patients, respectively. These variants are not over-represented in the Chinese healthy population. All the 8 cases showed preaxial polydactyly in hands. Additionally, no specific patterns of malformation predicted mutations in other candidate genes or sequences.

CONCLUSIONS

This is the first report of the assessment of the frequency of GLI3/SHH/preZRS/ZRS in Chinese patients to show any higher possibility of mutations or variants for the 4 genes or sequences in China. Developmental Dynamics 246:392-402, 2017. © 2017 Wiley Periodicals, Inc.

Polidactilias del pulgar. Tratamiento quirúrgico

Las polidactilias del pulgar, especialmente sus duplicaciones, constituyen una anomalía de frecuente presentación. Sus variantes son múltiples, lo que nos obliga a conocer cuáles son las diferencias anatómicas más relevantes en cada tipo en particular. Han sido muchas sus clasificaciones, pero la propuesta por Wassel, basada en los hallazgos radiológicos, continúa siendo tan simple como práctica. Excepto en los casos más simples, su cirugía reconstructiva es difícil, y debe ser encomendada a cirujanos con experiencia. Aun así, en los casos complejos el resultado dista de ser la obtención de un pulgar «normal», incluso con la técnica de «resección y reconstrucción» que utilizamos y que describimos en el presente artículo. Con frecuencia el tratamiento de las polidactilias se considera como algo simple y banal, y su dificultad real solamente se hace patente con el resultado desastroso de la cirugía. Las complicaciones que pueden presentarse son diversas y, en un significativo número de casos, van a requerir posteriormente una nueva cirugía reconstructiva para mejorar el resultado funcional y/o estético.

The Rotterdam Foot Classification: A Classification System for Medial Polydactyly of the Foot

BACKGROUND

Polydactyly at the medial side of the foot ("medial polydactyly" of the foot) is a rare and diverse congenital anomaly. In order to plan and evaluate surgical treatment, the classification of medial polydactyly is useful. The aim of our study was to develop a reliable and valid classification system for medial polydactyly of the foot that is more useful than previous systems for preoperative evaluation and surgical planning.

METHODS

A review of the literature and the clinical experience of a single experienced surgeon were used to determine classification categories. We identified all patients with medial polydactyly who had preoperative radiographs and clinical photographs and were treated at our hospital between 1993 and 2014. All affected feet were assessed according to our proposed classification system, the Rotterdam foot classification. The intrarater and interrater reliability among 5 observers who evaluated 30 feet were assessed with use of the Cohen kappa (κ) statistic.

RESULTS

We developed a classification system that describes duplication type, syndactyly, the presence of a hypoplastic ray, and deviation of the hallux. Seventy-three feet were classified according to the system. Seven duplication types were distinguished. Complete metatarsal duplication was most frequently seen (in 29%). Twelve feet showed a broad hallux without external expression of duplication. Syndactyly between medial and lateral (duplicate) halluces was present in 30 feet; between the lateral hallux and second toe, in 13 feet; and between both duplicated halluces and the lateral hallux and second toe, in 21 feet. A hypoplastic ray was seen in 75% of the feet. Intrarater agreement for duplication, hypoplastic rays, syndactyly, and deviation were, respectively, κ = 0.79, 0.75, 0.59, and 0.78. Interrater agreement for duplication, hypoplastic rays, syndactyly, and deviation were, respectively, κ = 0.72, 0.54, 0.48, and 0.64.

CONCLUSIONS

The proposed classification system contains 4 categories of anatomic features of the foot. Classification of all categories shows moderate to good reliability. Use of the Rotterdam classification in evaluating medial polydactyly improves type-specific description, which may, in the future, enhance the evaluation of surgical treatment.

CLINICAL RELEVANCE

The Rotterdam foot classification system is a reliable and easy-to-use system that we believe will improve communication between clinicians and researchers and facilitate the evaluation of treatment results in medial polydactyly of the foot.

A Postaxial Polydactyly with a Partial Duplication of the Fifth Metatarsal Without a Supernumerary Digit. Is Excision of the Duplicated Metatarsal Necessary?

Postaxial polydactyly of the foot is one of the most common congenital malformations. Only a few cases of postaxial polydactyly with a partial duplication of the fifth metatarsal without a supernumerary digit have been reported, and both metatarsal heads were united to form a common joint with the proximal phalanx in all of those cases. We present a rare case of postaxial polydactyly with a partial duplication of the fifth metatarsal characterized by dual metatarsal heads and an extra proximal phalanx bud, without a supernumerary digit.

A multicenter comparative study of two classification systems for radial polydactyly

BACKGROUND

The aim of this study was to compare type occurrence and reliability of the Wassel and Rotterdam classifications for radial polydactyly.

METHODS

The authors classified a large population of radial polydactyly patients from two European clinics using both classification systems, and compared the incidences of the different types to a population derived from a systematic literature review. The authors further assessed intraobserver and interobserver reliability of both classification systems in a test-retest design with seven observers, using kappa statistics.

RESULTS

Forty percent of the 520 cases with available radiographs could not be classified using the Wassel classification, whereas all cases could be classified using the Rotterdam classification. All unclassifiable cases had aberrant components; the majority were of the triphalangeal (63 percent), deviating (43 percent), or hypoplastic (39 percent) kind. Types III, IV, and VI occurred more often when using the Rotterdam classification. Intraobserver and interobserver reliability was comparable for both classification systems (κ=0.87 versus κ=0.83, and κ=0.65 versus κ=0.70). Types II and IV had the lowest reliability in both the Wassel and Rotterdam classifications (κ=0.30 to 0.59). Aberrant components indicating deviation and hypoplasia had the lowest reliability in the Rotterdam classification (κ=0.19 to 0.45).

CONCLUSIONS

The Rotterdam classification has broader classification possibilities and similar intraobserver and interobserver reliability compared with the Wassel classification. Although it is more complex and the aberrant components should be more strictly defined to increase its clinical relevance, we recommend using the Rotterdam classification.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, I.

Clubfoot associated with preaxial polydactyly

We report on three children with bilateral, congenital clubfoot. Four of the six clubfeet were associated with preaxial polydactyly. Five of the six clubfeet were treated without extensive surgery. A plantigrade foot was achieved, even in the three clubfeet with polydactyly, using serial casting and percutaneous Achilles tenotomy. Casting was adapted according to the existing polydactyly. One case with tibial hemimelia and a complex clubfoot deformity with preaxial tarsal polydactyly required more comprehensive surgery. A foot with good weight-bearing function was also achieved in this case following resection of the accessory medial ray, including resection of the accessory tarsal bones and posterior release. Remaining limitations in mobility were ascribed to hindfoot pathologies.

Ulnar polydactyly: long-term outcomes and cost-effectiveness of surgical clip application in the newborn

BACKGROUND

Postaxial polydactyly type B (PAPD-B) refers to the nonfunctional, floppy extra digit on the ulnar border of the hand. Suture ligation is applied in the newborn unit if the base is narrow or pedunculated. However, wart-like scars, residual bumps, or neuromas are frequent complications. Wider-based extra digits are treated at a later age by surgical excision under general anesthesia. Surgical clip application expands the indications for PAPD treatment in the newborn unit or outpatient setting with lesser incidences of complications.

DESIGN

A retrospective review identified 231 hands with PAPD-B in 132 newborns treated with surgical clips between January 1, 1996, and November 30, 2010, having a minimum of 2 years of follow-up. Medical records were queried for complications, revision procedures, and parent satisfaction. A relative cost survey compares the costs of surgical clips to surgery.

CONCLUSIONS

In all, 16 extremities in 9 patients (7%) required surgical scar revision. No wound complications were noted.

Rare presentation of foot postaxial polydactyly

Polydactyly is a prevalent birth anomaly observed in the foot, and a number of classification systems have been suggested for this condition. Postaxial (fifth or little toe) polydactyly is the most common type. We encountered an exceedingly rare presentation of foot postaxial polydactyly that, to our inspection, had neither been previously classified nor described in published studies. In the present report, we have described an otherwise healthy 2-year-old female who had presented to our clinic with an isolated, extra little toe on her left foot. Foot radiographs revealed the presence of all 5 metatarsals; however, the fifth metatarsal was blocked and did not give rise to the fifth toe. Instead, the fifth (medial normal) and sixth (lateral extra) toes had originated from a single, separate accessory bud from the fourth metatarsal, and the main fourth metatarsal had given rise to the normal fourth toe. The lateral sixth toe was excised, and a periosteal sleeve of the excised extra toe was used for reconstruction of the lateral collateral ligament. We propose that this heretofore unmentioned presentation of postaxial polydactyly be added to the existing systems of classification of pedal polydactyly. A review of the published data pertaining to pedal polydactyly has also been presented.

Polydactyly: phenotypes, genetics and classification

Polydactyly is one of the most common hereditary limb malformations featuring additional digits in hands and/or feet. It constituted the highest proportion among the congenital limb defects in various epidemiological surveys. Polydactyly, primarily presenting as an additional pre-axial or post-axial digit of autopod, is a highly heterogeneous condition and depicts broad inter- and intra-familial clinical variability. There is a plethora of polydactyly classification methods reported in the medical literature which approach the heterogeneity in polydactyly in various ways. In this communication, well-characterized, non-syndromic polydactylies in humans are reviewed. The cardinal features, phenotypic variability and molecular advances of each type have been presented. Polydactyly at cellular and developmental levels is mainly a failure in the control of digit number. Interestingly, GLI3 and SHH (ZRS/SHH enhancer), two antagonistic factors known to modulate digit number and identity during development, have also been implicated in polydactyly. Mutations in GLI3 and ZRS/SHH cause overlapping polydactyly phenotypes highlighting shared molecular cascades in the etiology of additional digits, and thus suggesting the lumping of at least six distinct polydactyly entities. However, owing to the extreme phenotypic and clinical heterogeneity witnessed in polydactyly a substantial genetic heterogeneity is expected across different populations and ethnic groups.

New classification of polydactyly of the foot on the basis of syndactylism, axis deviation, and metatarsal extent of extra digit

Background

Polydactyly of the foot is one of the most frequent anomalies of the limbs. However, most classification systems are based solely on morphology and tend to be inaccurate and less relevant to surgical methods and results. The purpose of this study is to present our new classification of polydactyly of the foot, which can serve as a predictor of treatment and prognosis.

Methods

To find a correlation between the various morphologic traits of polydactyly of the foot and the treatment plan and outcomes, we reviewed 532 cases of polydactyly of the foot in 431 patients treated in our hospital, expanding on our previous study that described polydactyly based on the importance of metatarsal bone status and varus deformity. The records of patients were evaluated and compared with previous studies at other centers.

Results

Unsatisfactory results were seen in 36 cases, which included 5 cases of incomplete separation due to syndactylism, 23 cases of axis deviation, and 8 cases of remnants of extra-digit metatarsal bones. The locus of the polydactyly, or the digit which was involved, did not seem to affect the final postoperative outcomes in our study. Three factors-syndactylism, axis deviation, and metatarsal extension-are the major factors related to treatment strategy and prognosis. Therefore, we developed a new classification system using three characters (S, A, M) followed by three groups (0, 1, 2), to describe the complexity of polydactyly of the foot, such as S₁A₂M₂.

Conclusions

Our new classification could provide a communicable description to help determine the surgical plan and predict outcomes.

Type A ulnar polydactyly of the hand: a classification system and clinical series

PURPOSE

To propose a classification system for type A ulnar polydactyly based on radiographic findings and characterize the demographic features of patients with these deformities.

METHODS

We identified 49 patients with type A ulnar polydactyly of the hand who were seen in our institution over 20 years. Patients' medical records and radiographs were retrospectively reviewed and used to distinguish morphological subtypes.

RESULTS

Ninety-six percent of the deformities (64/67) were allocated to 1 of the 5 subgroups of our suggested classification, and the type that originated from the metacarpophalangeal joint was the most common. Sixty-nine percent of patients in our series (34/49) had either bilateral type A or a contralateral type B ulnar polydactyly, and 63% (31/49) had ulnar polydactyly of one or both feet. Twenty-four percent of patients (12/49) had associated syndromes or congenital anomalies involving areas other than the hand or foot. The most common syndrome associated with type A ulnar polydactyly was chondroectodermal dysplasia (n = 3). Sixty-five percent of the patients (32/49) were Caucasian, 20% were Hispanic (10/49), 12% were African American (6/49), and one was Asian. The percentage of African Americans in our series was similar to that in the general patient population seen in our institution.

CONCLUSIONS

The majority of type A ulnar polydactyly can be classified into 1 of 5 morphological subtypes that have potential clinical relevance regarding surgical treatment. In patients with type A ulnar polydactyly, contralateral hand and foot polydactyly is frequent. Associated congenital anomalies and syndromes can also be present.

Correction of postaxial metatarsal polydactyly of the foot by percutaneous ray amputation and osteotomy

Polydactyly of the foot is a congenital anomaly characterized by the appearance of all or part of 1 or more additional rays. The patient with this condition might complain of an abnormal cosmetic appearance or difficulty with footwear. A minimally invasive technique for correction of postaxial metatarsal polydactyly of the foot is presented in this techniques report.

Supporting the collateral ligament complex in radial polydactyly type Wassel IV

Despite anatomical metacarpophalangeal joint (MCPJ) reconstruction in radial polydactyly (RP) Wassel IV, the prevention of long-term deformity and instability is still an issue. We report on clinical results following our modified surgical procedure with additional support of the hypoplastic radial collateral ligament complex (RCLC) after musculoligamentous MCPJ reconstruction. Fourteen patients (male: 10, female: 4) with radial resection of isolated RP Wassel IV (1987-2006), average age at surgery 1.7 years (0.6-8.6) were included. Distribution to group A and B depended on the procedure for MCPJ reconstruction. In group A (N = 7), RCLC reinsertion + reinforcement using autologous tendon grafts was performed (follow-up: 4.6 years (1.4-6.9)). Group B (RCLC reinsertion without support) consisted of N = 7 patients; follow-up: 9.6 years (8.2-20.2). The healthy contralateral hand (control A/control B) served as a control. Results were evaluated using our modified Tada-score considering: range of motion (ROM), interphalangeal joint (IPJ) and MCPJ stability on stress examination, palmar abduction and grip strength. Better score results (maximum 10) were seen in A: 7.3 (6-9) compared to B: 6.6 (4-10). Subscore 'stability' A: 1.1 (0-2); B: 0.9 (0-2) and 'alignment' A: 0.86 (0-2); B: 0.57 (0-2) showed greatest influence on the score result. Ulnar angulation at MCPJ level compared to healthy thumbs (control A + B) was greater (p < 0.05), with 11.4° (10-20) in group A and 14.3° (-5 to 30) in group B compared to 0° in control A and 5.7° (0-17) in control B. MCPJ ulnar deviation in A + B: 25° (0-35) compared to healthy thumbs control A + B was higher (p < 0.05). Ulnar deviation was higher in B 45° (30-60) compared to 34° (20-50) in A. In B, instability was evident in four, in A, only in one patient. In B, one patient required two re-operations due to MCPJ instability. Equivalent results were recorded regarding pinch grip and palmar abduction. Anatomical MCPJ reconstruction in combination with autologous support of the hypoplastic RCLC to enhance long-term stability is recommended.

An unusual case of fibular (postaxial) polydactyly: extrametatarsal head with fused duplication of the proximal phalanx

Polydactyly of the foot is a congenital anomaly characterized by the appearance of all or part of 1 or more additional rays. A number of morphologically and anatomically based classifications exist. We present an unusual case of fibular (postaxial) polydactyly characterized by an extrametatarsal head with fused duplication of the proximal phalanx. We describe the method of surgical correction and emphasize the need for careful preoperative planning to achieve a good functional and cosmetic outcome.

Sporadic familial ulnar hexadactyly of all four limbs

BACKGROUND

Polydactyly belongs to skeletal anomalies and may be a symptom of more complex genetic syndromes.

MAIN OBSERVATION

We observed an index case of ulnar hexadactyly of all four limbs in a 20-year-old man from India with three more brothers affected in his family. No additional anomalies were observed. The diagnosis of a sporadic (ulnar) postaxial hexadactyly was made.

CONCLUSION

Sporadic postaxial hexadactyly is one of the most common polydactylies in humans. In contrast, in the dermatologic literature the condition has only rarely been described.

CONCLUSION

Presence of supernummary digits or toes, i.e. polydactyly, is seen occasionally in the dermatologic practise. The present case is extraordinary since all limbs were involved and the same was true for three of his brothers. If treatment is asked, hand surgery would be necessary.

The distribution of the types of thumb polydactyly in a Middle Eastern population: a study of 228 hands

Several series have reported the distribution of the types of thumb polydactyly in the Caucasian and Far Eastern populations. No data are available for the Middle East. A total of 196 Saudi patients (228 hands) with thumb polydactyly were reviewed. The most common type was Wassel type IV (33.8%) and the least common was Wassel type I (0.4%). A total of 26 hands (11.4%) did not fit into the classic Wassel types including 18 cases of rudimentary duplications, two cases of thumb triplication, and five cases of thumb duplication with symphalangism. Concurrent ipsilateral little finger triplication (one case) and contralateral thumb aplasia/hypoplasia (two cases) were seen and the developmental biology of these cases are discussed. After reviewing our results and other series in the literature, we concluded that Wassel types IV and I remain to be the most and least common types respectively in almost all races. However, the genetic pools of various races greatly affect the distribution of other non-classic duplications (unclassifiable by Wassel classification) such as rudimentary duplication in the Far East, triplication in the Southwestern region of the Netherlands, and symphalangism in Asia.

A classification system of radial polydactyly: inclusion of triphalangeal thumb and triplication

PURPOSE

Radial polydactyly is a congenital anomaly with a wide range of manifestations. Current classifications do not have the capacity to classify all different types of radial polydactyly when combined with triphalangeal components. The objective of this study was to test an adjusted classification and nomenclature that allows classification of triphalangeal components and triplication in radial polydactyly.

METHODS

Patients from 1993 to 2006 with radial polydactyly (N = 104), a total of 121 affected hands, were identified from the hospital database. All x-rays were carefully examined and classified according to the existing classifications for radial polydactyly and a modified classification. In the modified nomenclature, Wassel's level of duplication is preserved. Type VII and VIII are assigned for partial or complete duplication of the carpal bones according to Buck-Gramcko. Triplication and triphalangeal components can be assigned to each type of radial polydactyly by suffixes. Symphalangism, deviation, and hypoplasia can also be classified. Triplication on different levels of the thumb is classified by determining and including the different types of the original Wassel classification.

RESULTS

Eighteen thumbs could not be classified according to existing classifications for radial polydactyly with triphalangeal components or triplication. Using the proposed classification, all patients could be classified.

CONCLUSIONS

We propose a modified classification that is a practical and utilitarian scheme for nomenclature of radial polydactyly and that may assist comparison of treatment outcomes and individual cases.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Triplicated thumbs: a rarity?

SUMMARY

Triplication of the thumb is supposed to be a rare condition and a complex form of radial polydactyly. However, we encountered an unusually high number of triplicated thumbs at our unit. Is triplication of the thumb indeed a rare condition? In our study, 121 patients with radial polydactyly were recorded between 1933 and 2005. In nine patients of this group, triplicated thumbs, either unilateral or bilateral, were identified. This complex type of radial polydactyly occurs in various forms. A total of 11 triplicated thumbs were found, and all cases were combined with triphalangeal components. Only one of these 11 triplicated thumbs could be classified according to currently used classifications. In all cases, aberrant rays were excised, thumb length and alignment restored by osteotomies, joints were stabilised, tendons reinserted and nails and nail walls corrected if necessary. Also, in all cases, a correction of triphalangeal components was carried out. Triplications are a rarity, and have only been presented in single case reports. We found that triplicated thumbs are not so rare. The likely explanation for this is the identification of a genetic isolate (a deformity located at chromosome 7q36) with radial polydactyly and triphalangeal thumbs in the southwest region of the Netherlands. Treatment for the presented triplicated thumbs was based on the same general principles as for less complex forms of radial polydactyly (i.e. to assemble useful elements of the separate [partial] thumbs to reconstruct one functioning, stable thumb).

Hypoplastic thumb in Gorlin's syndrome

Gorlin's syndrome or naevoid basal cell carcinoma syndrome (NBCCS) is an autosomal dominant disorder that predisposes to basal cell carcinomas of the skin, ovarian fibromas, and medulloblastomas. This condition is due to mutations in the Patched (PTCH) gene which maps to chromosome 9q22 and acts as a tumour suppressor gene. Gorlin's syndrome is characterized by the development of multiple jaw keratocysts and/or basal carcinomas. There is a distinctive coarse facial appearance with macrocephaly, frontal bossing and prognathism. Most individuals have skeletal anomalies such as bifid ribs or wedge-shaped vertebrae. We present a case in which the patient presented with bilateral thumb hypoplasia. Various hand deformities have been reported in patients with Gorlin's syndrome including short metacarpals, cutaneous syndactyly of the second and third fingers, and pre- or post-axial polydactyly, but hypoplasia of the thumb has not been reported previously. These features of Gorlin's syndrome may be helpful diagnostically. The thumbs should be examined carefully in Gorlin's syndrome patients as minor degrees of hypoplasia are easy to miss. However, they still needs a specialist input to give the patient an optimum function of the thumb and the hand.

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.

The developing limb and the control of the number of digits

Congenital malformations of the limbs are among the most frequent congenital anomalies found in humans, and they preferentially affect the distal part--the hand or foot. The presence of extra digits, a condition called polydactyly, is the most common limb deformity of the human hand and is the consequence of disturbances in the normal program of limb development. However, despite the extensive use of the developing limb as a classical developmental model, the cellular and genetic mechanisms that control the number and identity of the digits are not completely understood. The aim of this review is to introduce the reader to the current state of knowledge in limb development and to provide the necessary background for an understanding of how deviations from the normal developmental program may lead to polydactyly.

Polydactyly of the feet in children: suggestions for surgical management

Polydactyly is the commonest congenital deformity of the foot, presenting as a range of defects from minor soft tissue duplications to major bony abnormalities. There is a relative paucity of information on the management of this condition in the literature compared to that concerning polydactyly of the hand. We present a consecutive series of 34 cases of polydactyly of the foot in 25 patients treated surgically at our unit and these are classified according to the protocol described by Blauth and Olason. We emphasise the importance of preoperative classification using radiographs and an individualised surgical approach giving consideration to aesthetic and functional outcome. In the literature a number of authors have expressed the view that in polydactyly of the fifth ray of the foot the most lateral digit should always be excised irrespective of whether this is the more fully formed digit. We believe this should not always be the case and we describe two cases of polysyndactyly where the more medial element of a fifth-ray polydactyly was excised to allow for better maintenance of the contour of the foot. This involved more complex surgery than excision of the lateral element but gave a superior cosmetic and functional result.