Congenital anomalies of the hand. The Asian perspective

Epidemiology of congenital upper limb anomalies in 562 children born in 1997 to 2007: a total population study from stockholm, sweden

PURPOSE

There are few true epidemiological studies of congenital anomalies of the upper limb (CULA) on total populations in the literature, and most incidence studies are hospital based. The purposes of this study were to describe the epidemiology and classify all CULA in a region of Sweden during an 11-year period.

METHODS

Between 1997 and 2007, there were 261,914 live births in the Stockholm region. A total of 562 children born during this period were found to have CULA. From medical records and available radiographs, all cases were analyzed regarding the type of congenital anomaly, gender, laterality, occurrence among relatives, associated non-hand anomalies, and syndromes. All 585 main anomalies were classified according to the International Federation of Societies for Surgery of the Hand classification. Individuals with right- and left-side main anomalies belonging to different categories were counted as having 2 anomalies.

RESULTS

The recorded incidence of CULA was 21.5 per 10,000 live births. Of the 562 children, 304 were boys. The anomalies affected the right side only in 169 children, the left side only in 186, and both sides in 207. Non-hand anomalies were recorded in 129 children, most commonly in the lower limbs. In 99 children, there was a known occurrence among relatives. Failure of differentiation was the most common category (276 of 585) followed by duplication (155 of 585), failure of formation (103 of 585), undergrowth (18 of 585), generalized abnormalities and syndromes (14 of 585), overgrowth (10 of 585), and constriction ring syndrome (9 of 585).

CONCLUSIONS

The incidence of CULA in our region was similar to the only previously comparable total population study from Western Australia. The minor differences in incidences between the categories according to the International Federation of Surgical Societies of the Hand may be due to variations in classification strategy. The results of the present study can be used as a reference of CULA in a total population.

[Central ray deficiency of the hand]

Cleft hand is an uncommon congenital malformation, which is defined as a deficiency of the central part of the hand. It results from the absence or alteration of development of the central rays. Although the function of the hand is often excellent, the cosmetic appearance drives parents to seek consultation. The goal of this article is to define the different factors that dictate the classification of this anomaly and to facilitate choosing among many surgical procedures. Treatment improves aesthetic aspect of the hand and maintains excellent function. A retrospective review of 33 operated cases is presented.

Occurrence of central polydactyly, syndactyly, and cleft hand in a single family: report of five hands in three cases

Central polydactyly, syndactyly, and cleft hand are categorized separately in the International Federation of Societies for Surgery of the Hand classification. However, some investigators have proposed that these malformations should be classified into a single category: abnormal induction of finger rays. In this article, we report 5 hands with central polydactyly, syndactyly, and cleft hand in 3 patients from the same family and discuss the phenotypes in each hand.

Embryology of the upper limb

An increased understanding of embryogenesis has advanced our fundamental knowledge of limb anomalies. Animal models with similar limb patterning have been used to dissect and manipulate crucial signaling centers that affect limb development and orientation. Experimental embryologists can produce limb anomalies that are similar to the human phenotype encountered in clinical practice. The evaluating physician must possess a basic comprehension of embryogenesis and limb formation to comprehend congenital limb anomalies and to communicate relevant knowledge to the family. This Current Concepts article is intended to provide an update of limb development that is germane to the clinical scenario.

Two rare cases of association of thumb hypoplasia and polydactyly of the homolateral foot

This paper presents two cases of radial deficiency and thumb aplasia associated with polydactyly of the homolateral foot and a supernumerary toe resembling a thumb. To our knowledge, this association of malformations has not been described previously.

[Cleft hand: a review of 33 cases and new ideas about classification]

Cleft hand is an uncommon congenital malformation, which is defined as a deficiency of the central part of the hand. It is the result of the absence or altered development of the central rays. The aim of treatment is to optimise the function of the hand at a young age and to improve its aesthetics. A retrospective review of 33 cases is presented and, with reference to their treatment, ideas about the classifications of cleft hand are discussed. The various anomalies seen and the management for each type of cleft hand are presented.

Early morphological changes leading to central polydactyly, syndactyly, and central deficiencies: an experimental study in rats

PURPOSE

Various combinations of central polydactyly, syndactyly, and cleft hand have been frequently observed in the individual hands and feet in the same patients. Little is known, however, about the early changes of abnormal induction of digital rays during limb development. To determine the early changes and process of formation of central polydactyly, syndactyly, and cleft hand, we experimentally induced these anomalies in the hind limbs of rat embryos and discussed the relationship among these abnormalities.

METHODS

Inbred WKAH/Hkm rats were used for this study. Pregnant females were treated with busulfan at embryonic day (E) 11. The embryos were removed at E12 to E21 and stained with alcian blue and alizarin red S. The abnormal changes in the treated embryos' hind limbs were observed with a microscope.

RESULTS

The edges of the footplates were irregular, and their growth was reduced at E14. By E15, abnormal clefts in the distal edge were present that disrupted the central digits (2 to 4) of the footplates. Because of these abnormal clefts, the digital rays were bent or branched, and the neighboring interdigital spaces were narrowed. These changes led to central polydactyly, syndactyly, and central deficiencies.

CONCLUSIONS

These findings show that central polydactyly, syndactyly, and central deficiencies have the same early morphological changes: abnormal clefts in the central part of the footplate.

Busulfan‐induced central polydactyly, syndactyly and cleft hand or foot: A common mechanism of disruption leads to divergent phenotypes

The prevalence of clinical phenotypes that exhibit combinations of central polydactyly, syndactyly, or cleft hand or foot is higher than would be expected for random independent mutations. We have previously demonstrated that maternal ingestion of a chemotherapeutic agent, busulfan, at embryonic day 11 (E11) induces these defects in various combinations in rat embryo limbs. In an effort to determine the mechanism by which busulfan disrupts digital development, we examined cell death by Nile Blue staining and TdT-mediated dUTP nick end labeling (TUNEL) assays; we also carried out whole mount in situ hybridization for fibroblast growth factor-8 (Fgf8), bone morphogenetic protein-4 (Bmp4), and sonic hedgehog (Shh) to examine developmental pathways linked to these defects. In busulfan-treated embryos, diffuse cell death was evident in both ectoderm and mesoderm, peaking at E13. The increased cell death leads to regression of Fgf8 in the apical ectodermal ridge (AER) and Bmp4 and Shh in the underlying mesoderm. The subsequent pattern of interdigital apoptosis and cartilage condensation was variably disrupted. These results suggest that busulfan manifests its teratogenic effects by inducing cell death of both ectoderm and mesoderm, with an associated reduction in tissue and a disruption in the generation of patterning molecules during critical periods of digit specification.

Reconstruction of the first web space in symbrachydactyly using the reverse radial forearm flap

PURPOSE

To present a new approach for the reconstruction of severe first web contractures using a distally based reverse radial forearm flap in symbrachydactyly patients.

METHODS

This study included 6 hands in 5 patients. Subjective evaluation included appearance, parent satisfaction (and patient satisfaction when appropriate), and ability to perform daily activities such as thumb-index grasp and pinch at follow-up evaluations. We measured the angle between the first and second rays using a goniometer at maximum radial abduction, and pinch and grasp strengths were evaluated as an objective assessment.

RESULTS

The average follow-up period was 2 years. All parents and patients were happy with the aesthetic appearance. They were completely satisfied in their daily living activities. The average first web angle measurement was 56 degrees . An average of 39 degrees of improvement of web measurement was achieved. For the unilateral 4 patients, the average pinch strength measurement was 80% of the normal contralateral hand and the grip strength was 75% of the normal contralateral hand.

CONCLUSIONS

The reverse radial forearm flap was found to be a safe and simple method in the reconstruction of severe first web contractures in symbrachydactyly patients. This method provided good coverage of appropriate thickness and skin quality, and supple soft tissue that filled the first web space.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Thumb polydactyly with radius hypoplasia--a case report

Triplication of the thumb is a rare condition described only in several case reports. Radial longitudinal deficiency is a relatively more common entity. These 2 congenital abnormalities generally do not occur within the same extremity. We present a patient with a combination of 3 thumbs (triplication of the thumb) and hypoplastic radius in the same limb.

Developmental abnormalities in rat embryos leading to tibial ray deficiencies induced by busulfan

BACKGROUND

Little is known about the developmental changes associated with tibial ray deficiencies. The aim of this study was to detect cell death, proliferation, and gene expression that result in tibial ray deficiencies.

METHODS

We induced tibial ray deficiencies in rat embryos using a teratogenic agent (busulfan) and observed the developmental changes in 1126 hindlimbs. We performed Nile blue staining, whole mount in situ hybridization for fibroblast growth factor 8 (Fgf8), bone morphogenetic protein 4 (Bmp4) and Sonic hedgehog (Shh), terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) and assessment of cell proliferation by 5-bromo-2'-deoxy-uridine (BrdU)/anti-BrdU immunohistochemistry.

RESULTS

In situ hybridization showed reductions in Fgf8 and Bmp4 expression. Histological examination showed a delay of mesenchymal condensation, increased mesenchymal cell death, decreased mesenchymal cell proliferation, and a reduction in the number of mesenchymal cells. These abnormalities may cause hypoplasia of the limb. Bmp4 expression was markedly reduced in the anterior mesenchyme. Shh was expressed in the posterior mesenchyme. We suggest that the posterior skeletal elements may be fully formed owing to Shh expression, but the anterior skeletal elements may be underdeveloped owing to an intense reduction of Bmp4 expression in the anterior mesenchyme, causing hypoplasia of the tibial ray.

CONCLUSIONS

The combined effects of increased cell death, decreased cell proliferation, reduction of Fgf8 expression, and intense reduction of Bmp4 expression in the anterior mesenchyme may play an important role in the development of tibial ray deficiency induced by busulfan.

A variant of Cenani-Lenz syndactyly (CLS): review of the literature and attempt of classification

An oligodactylous variant of Cenani-Lenz syndactyly and its surgical treatment is presented. The deformity is believed to be of autosomal recessive inheritance and caused by a disordered axial and longitudinal differentiation of the upper and lower extremities. The classical form is mainly characterised by a complete syndactyly of the hands. Malformations may also affect the bones of the forearm and, to a lesser extent, the lower limbs. We analysed clinical features and compared them with those previously described. According to our research of literature and our clinical findings there seem to exist two grossly different clinical phenotypes: spoon hand type and oligodactyly type. Typical constant clinical features such as carpal, metacarpal and digital synostoses, disorganisation of carpal bones, reduction of digital rays and syndactyly of toes are found in the reported cases. Inconstant features such as radio-ulnar synostosis, brachymesomelia, metatarsal synostoses and reduction of metatarsal rays may be present. In our case, successful bilateral digital ray individualisation and tendon transfers were performed to construct a grip function of the grossly deformed hands.

A morpho-etiological description of congenital limb anomalies

BACKGROUND

Limb anomalies rank behind congenital heart disease as the most common birth defects observed in infants. More than 50 classifications for limb anomalies based on morphology and osseous anatomy have been drafted over the past 150 years. The present work aims to provide a concise summary of the most common congenital limb anomalies on a morpho-etiological basis.

PATIENTS AND METHODS

In a retrospective study, 70 newborns with anomalies of the upper and/or lower limbs were ascertained through clinical examination, chromosomal analysis, skeletal surveys and other relevant investigations.

RESULTS

Fetal causes of limb anomalies represented 55.8% of the cases in the form of 9 cases (12.9%) with chromosomal aberrations (trisomy 13, 18 and 21, duplication 13q and deletion 22q) and 30 cases (42.9%) with single gene disorders. An environmental etiology for limb anomalies was diagnosed in 11 cases (15.7%) as amniotic band disruption, monozygotic twin with abnormal circulation, vascular disruption (Poland sequence, sirenomelia and general vascular disruption) and an infant with a diabetic mother. Twenty cases (28.5%) had limb anomalies as part of sporadic syndromes of unknown etiology.

CONCLUSIONS

The morpho-etiological work-up of limb anomalies adopted in the present study is valuable for detecting the cause of the anomaly and is crucial for its prevention. Prevention can be achieved by proper genetic counseling, which includes recurrence risk estimation and prenatal diagnosis.

Cleft hands with six metacarpals

PURPOSE

The purpose of this study was to identify children with cleft hands whose radiographs showed metacarpal polydactyly with 6 metacarpals to support the hypothesis that cleft hand develops not as a result of a longitudinal failure of formation but through a process of central polydactyly and osseous syndactyly.

METHODS

We screened the hand radiographs of all children with a transverse or longitudinal deficiency of the upper limb and identified 8 children with cleft hands containing 6 metacarpals.

RESULTS

Six cleft hands had a missing middle finger and consisted of a thumb and index finger separated from the ring and small fingers by a V-shaped central cleft. Two children had a more severe form of cleft hand with absence of both the index and middle fingers but presence of 6 metacarpals.

CONCLUSIONS

These 8 cleft hands containing 6 metacarpals showed progression of polydactyly of the middle finger and osseous syndactyly between the 2 middle finger metacarpals and the adjacent index and ring finger metacarpals. This contradicts a longitudinal failure of formation mechanism and supports the alternative hypothesis that cleft hand, polydactyly, and syndactyly develop through a similar teratogenic mechanism. The 2 cleft hands that had more severe suppression of the index and middle fingers yet had 6 metacarpal polydactyly provided confirmatory evidence that both typical cleft hands and the more severe manifestations of cleft hand with absence of multiple digits develop through a similar failure of induction mechanism.