Synpolydactyly of the hand: a radiographic classification.

UNLABELLED: Synpolydactyly is an uncommon congenital anomaly characterized by polydactyly with syndactyly in the central hand. The purpose of this investigation was to develop and assess the reliability of a radiographic classification system for synpolydactyly. We identified 56 hands with central synpolydactyly and developed a radiographic classification system that categorizes by the location within the hand, the bony level of polydactyly, and the presence of a delta phalanx. Four paediatric hand surgeons independently reviewed each radiograph to establish reliability. There was exact agreement among raters in 40 cases (71%). The inter-rater reliability was 0.97 and intra-rater reliability was at least 0.87. Seven of 16 bilateral cases had symmetric deformity classification. The most common presentations were types 1A and 2A. We present a new, reliable radiographic classification system for synpolydactyly that will allow improved communication between clinicians and serve as a foundation for future investigations. LEVEL OF EVIDENCE: 2.

Treatment of congenital syndactyly of the fingers.

BACKGROUND: Syndactyly or webbed fingers is one of the most common congenital malformations of the upper extremities, but it comprises few new cases annually. The purpose of treatment is to enhance hand function. METHOD: The article is based on current text books and literature searches in PubMed as well as the authors' clinical experience within this field. RESULTS: The purpose of surgical treatment is to separate the fingers and reconstruct a webspace. It is difficult to indicate exact treatment results because of large variations in the extent of the deformity. For syndactyly involving only soft tissue (simple syndactyly), a good functional result is achieved with a less than 10% risk of complications. Syndactyly where also the bones have fused (complex syndactyly) or where there is additional bone formation between two digital rays (complicated syndactyly), gives a poorer functional outcome and a higher risk of complications. Gradual stretching of the tissue using a distraction device enables separation of fingers one was previously reluctant to separate. INTERPRETATION: It should be possible to expect safe separation with a good and independent function of the fingers with surgical treatment. The parents should be informed that the surgical treatment is a reconstructive procedure that may require secondary corrections.

Syndactyly: phenotypes, genetics and current classification.

Syndactyly is one of the most common hereditary limb malformations depicting the fusion of certain fingers and/or toes. It may occur as an isolated entity or a component of more than 300 syndromic anomalies. Syndactylies exhibit great inter- and intra-familial clinical variability. Even within a subject, phenotype can be unilateral or bilateral and symmetrical or asymmetrical. At least nine non-syndromic syndactylies with additional sub-types have been characterized. Most of the syndactyly types are inherited as autosomal dominant but two autosomal recessive and an X-linked recessive entity have also been described. Whereas the underlying genes/mutations for types II-1, III, IV, V, and VII have been worked out, the etiology and molecular basis of the other syndactyly types remain unknown. In this communication, based on an overview of well-characterized isolated syndactylies, their cardinal phenotypes, inheritance patterns, and clinical and genetic heterogeneities, a 'current classification scheme' is presented. Despite considerable progress in the understanding of syndactyly at clinical and molecular levels, fundamental questions regarding the disturbed developmental mechanisms leading to fused digits, remain to be answered.

Central ray deficiency with extensive syndactyly: a dilemma for classification.

Split Hand Foot Malformation (SHFM) (cleft hand/foot, central ray deficiency) is a complex, highly variable anomaly involving the hands and/or feet. A clinical epidemiologic study of split hand/foot (central ray deficiency) of the Manitoba population identified a subset of patients who did not present with either typical or atypical split hand. Clinically, some patients presented with "mitten hand" syndactyly; the deficiency was not recognized before imaging. In this paper, we identify additional similarly affected literature cases, review existing classifications of split hand and syndactyly and attempt to classify these patients. This group presents a challenge for classification and genetic counseling. General classifications permit inclusion of patients with diverse phenotypes; however, details are overlooked. Osseous fusions and disorganization of osseous components complicate classification. Many of these patients had findings that overlapped different subtypes within existing classifications. This cohort highlights the importance of imaging patients with distal limb anomalies. An effective classification scheme should include relevant clinical and radiographic findings in order to assist clinicians following these patients.

[Symbrachydactyly]. / Symbrachydactylie.

Symbrachydactyly is literally defined as a combination of short fingers with syndactyly. Blauth and Gekeler described four types of symbrachydactyly, ranging from simple shortness of middle phalanges to complete absence of digital rays. In type I (short finger) function is quite normal and syndactyly release is usually the only procedure needed. In type II (cleft hand), presence of a thumb and at least one ulnar finger allows pinch function. Surgical treatment, when needed, consists in separation of webbed fingers, resection of nonfunctional digital stumps, or finger translocation. In type III (monodactyly) all long fingers are absent. Pinch function can be created between the thumb and a toe transfer in ulnar location. Bone lengthening is an alternative procedure to create a pincer. Surgery is not always indicated in type IV (peromely) as function can only be restored if active motion is already present at wrist or carpometacarpal levels.

[Syndactyly]. / Syndactylies.

Syndactyly is one of the most common congenital anomalies of the hand. It can be isolated or associated with systemic syndromes. Surgical treatment is performed between the ages of six and 18 months depending on the type and extent of the malformation. Commissure construction is achieved using local flaps. Direct closure of the lateral sides of the digits is possible in many cases. In complex cases, and/or when adjacent web spaces are involved, full-thickness skin grafts remain useful. Functional and cosmetic results are usually excellent in simple cases. In complex cases, postoperative prognosis depends on the severity of bone, joint and tendons abnormalities.

[Results of surgical treatment in simple syndactily using a commissural dorsal flap. About 54 procedures]. / Résultats du traitement chirurgical des syndactylies simples par lambeau commissural dorsal. A propos de 54 commissuroplasties.

OBJECTIVE: The authors evaluate their results of congenital syndactyly correction using a classic commisural dorsal flap technique and full thickness skin grafts to cover the lateral and medial aspect of the fingers. MATERIAL AND METHOD: It is a retrospective study on a homogeneous series of 38 children (54 simple syndactylies) operated over a 10-year period. Twenty-two children were included with a mean follow-up of five years and 10 months. RESULTS: This technique is reliable, reproducible, with a low rate of complications (only four complications requiring reoperation). Long-term outcomes are satisfactory in 92% of cases. CONCLUSION: This is an effective technique, restoring the natural shape of the web space. Procedures without skin-graft are less time-consuming in terms of operational time and cosmetically acceptable, but still need to prove their worth.

Complex toe syndactyly with characteristic facial phenotype: a new syndrome?

Nonsyndromic syndactyly is a common, heterogeneous hereditary condition of webbed fingers and toes that can be cutaneous or bony, unilateral or bilateral. We describe a patient with complex toe syndactyly and oligodactyly, some interesting skeletal hand findings and atypical facial features without other case like this described before. Cenani-Lenz syndrome (CLS) is a rare disorder with total syndactyly and irregular synostosis of carpal, metacarpal and phalanges, it may involve ulna and radius and digital rays may be absent, some of these were described with atypical facial features and one patient had renal hypoplasia and vertebral anomalies but our patient does not have the oligodactyly or syndactyly of the hands that is consistently present in all patients with CLS. The atypical facial features of our patient resemble Kabuki syndrome but oligodactyly and complex syndactyly have not been described in Kabuki syndrome and this patient has normal intelligence, and extreme eyelid defect (resembling ablepharon). Therefore, for our patient, we suggested to treat in a new condition of limb anomalies and atypical face.

Synpolydactyly: clinical and molecular advances.

Synpolydactyly (SPD) is a rare limb deformity showing a distinctive combination of syndactyly and polydactyly. Of the nine non-syndromic syndactylies, it is clinically and genetically one of the most heterogeneous malformation. SPD families may show clinical features consistent with the Temtamy and McKusick criteria as well as additional phenotypic variants, which vary from case to case. In certain instances, these variants predominate in a given family, while the typical SPD features remain less explicit. We have reviewed all the clinical variants occurring in well-documented SPD families. We conclude that typical SPD features can be delineated from minor clinical variants. Then, we propose to lump all the phenotypic variants, manifesting themselves in SPD families into three categories: (i) typical SPD features, (ii) minor variants, and (iii) unusual phenotypes. Next, we discuss the likely reasons for the occurrence of minor variants and the obvious lack of penetrance in SPD families. Finally, we show that for the SPD phenotype associated with HOXD13 mutations, a straightforward genotype-phenotype correlation is weak. Our lumping and splitting scheme for SPD phenotypic variants could be useful for the understanding of this interesting malformation.

[Genetic background of isolated forms of congenital malformations of the hand]. / Genetyczne podloze izolowanych wrodzonych wad dloni.

Congenital hand malformations comprise a clinically and etiologically heterogeneous group of developmental anomalies. They may occur as an isolated trait or be a part of a syndrome. In recent years, enormous progress in revealing the molecular background of congenital hand anomalies has been made. It proved helpful for better understanding of function of the genes responsible for embroynic limb development in humans. This review presents a classification of hand malformations, which takes into account not only differences of anatomic and morphological origin, but also distinct genetic background. Since there is an abundance of syndromes with congenital hand anomalies, the paper is focused mainly on the non-syndromic hand malformations and their genetic etiology.

Expression of familial middle-ring-little finger syndactyly as either simple syndactyly or synpolydactyly.

A family with middle-ring-little finger syndactyly is reported to demonstrate that the responsible autosomal gene may be expressed as either simple syndactyly or synpolydactyly.

A simple method for characterising syndactyly in clinical practice.

Non-syndromic syndactyly is a heterogeneous group of limb malformations involving webbing of fingers and/or toes. There are at least nine non-syndromic types described in the literature. For the clinician and the genetic counsellor not having gathered experience with this malformation, it is rather tedious to identify the correct subtype for the patient's phenotype. We therefore present a protocol for clinical use, which visualises the malformation in a graphical way and thereby simplifies typing. In addition, this protocol provides a simple documentation system for reporting clinical data for new syndactyly families. It might encourage clinicians to report families that are still unclassifed and thus, helping to extend and improve the existing classification system.

Evidence for clinical and genetic heterogeneity of syndactyly type I: the phenotype of second and third toe syndactyly maps to chromosome 3p21.31.

There is good evidence from the medical literature that type I syndactyly, the most common form of the nonsyndromic syndactylies, is clinically heterogeneous. We therefore propose to group the condition into four subtypes, which are all autosomal dominantly inherited. Subtype 1, zygodactyly (cutaneous webbing of second and third toe without hand involvement) is the mildest and most common form. The phenotype varies from unilateral minor impression of webbing to bilateral complete webbing of second and third toe including a fusion of nails. Bony involvement is never observed. Subtype 2 is characterized by bilateral cutaneous and/or bony webbing of third and fourth finger, and second and third toe. The phenotype maps on chromosome 2q34-q36 and was designated as SD1 (ie syndactyly 1). The hallmark of subtype 3 is bilateral cutaneous or bony webbing of third and fourth finger, while subtype 4 shows bilateral cutaneous webbing of fourth and fifth toe. Both, subtype 3 and 4, are rare entities. Here, we present clinical and molecular data of a large Pakistani family with zygodactyly that was mapped to a new locus on chromosome 3p21.31 by genome-wide linkage analysis. The highest LOD score (Zmax=3.38) was obtained with microsatellite marker D3S2409. The disease interval is flanked by markers Chr3_4919 and Chr3_4940 encompassing about 0.20 Mb. Since the same phenotype appears not to be linked to this locus in a German family, we predict genetic heterogeneity in zygodactyly and propose to designate the 3p21.31 locus as ZD1 (i.e., zygodactyly 1).

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.

Simplicity and treatment of the typical cleft hand.

The typical cleft hand is now distinguished from symbrachydactyly. This review of the surgical treatment of 108 hands in 63 patients treated over a 28-year period concentrates upon the technical principles of surgical correction. The key to these reconstructions is a wide incision which extends from the ulnar side of the cleft around the malpositioned index finger to the thumb. This wide exposure provides clear identification of all anatomic structures within the palm. There are no tenuous flaps with narrow random pedicles. These difficult surgical corrections may often include index transposition, metacarpal and/or phalangeal osteotomies, joint releases, phalangeal ostectomies, preservation of the adductor pollicis muscle, first dorsal interosseous muscle release, syndactyly separation(s) and thumb duplication correction. Following reposition of all skeletal structures the dorsal and palmar full-thickness flaps are easily contoured to create a satisfactory first webspace. Outcomes data shows that although the pinch and grip remain weak, these hands are quite functional. It is important that the repositioned index ray not interfere with gripping and precision maneuvers between the mobile thumb and the ulnar two digits (ring and small) of the hand.