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

Polydactyly a review and update of a common congenital hand difference

PURPOSE OF REVIEW

The purpose of this review is to describe various forms of hand polydactyly and their different treatment approaches. Hand polydactyly is commonly classified as ulnar (small finger) or radial (thumb). Polydactyly can be sporadic, genetic, and/or associated with syndromic conditions.

RECENT FINDINGS

Both ulnar and radial polydactyly can be surgically treated to optimize hand aesthetics and function. Timing of surgery is based on multiple factors, most notably including safety of anesthesia and socialization of the affected child. The pediatrician should be aware of potential associated conditions, such as chondroectodermal dysplasia or Ellis-van Creveld syndrome for ulnar polydactyly.

SUMMARY

Polydactyly is a common congenital hand difference and can be broadly be classified by radial or ulnar involvement. Polydactyly warrants hand surgical referral, as surgical treatment is often indicated. Pediatricians should be aware of treatment options, as well as of commonly associated anomalies and syndromes.

Postaxial polydactyly of the hand in Japanese patients: Case series reports

PURPOSE

The incidence of postaxial polydactyly of the hand is rare in Japan. This study aimed to compare the clinical presentation of postaxial polydactyly between a cohort of patients from Japan and those from other racial and ethnic backgrounds.

METHODS

In this retrospective study, we included 30 patients who were treated at our hospital during a 25-year study period (1990-2015). Based on the clinical records of these patients, we characterized the Japanese presentation of the condition. We searched for studies that included other racial and ethnic groups and characterized the clinical presentations. Then, we compared the clinical presentations between Japanese patients and other racial and ethnic groups.

RESULTS

A total of 19 male and 11 female patients were treated in our hospital, and bilateral and unilateral involvements (right side: 4 patients; left side: 4 patients) were observed in 22 and 8 patients, respectively. Moreover, 22 postaxial polydactylies were type A and 28 polydactylies were type B, which were classified using the Temtamy-McKusick classification system. In addition, 4 patients had a family history of hand postaxial polydactylies; 18, 6, 4, and 3 patients presented with polydactyly of the foot, syndactyly, systemic abnormalities, and related syndromes, respectively.

CONCLUSION

Japanese patients had two distinguishing characteristics: (1) when the condition was unilateral, left side and right side involvement was almost equal with regard to incidence and (2) associated polydactylies of the foot were more common (60%) than those in other cohorts (less than 31%). To better understand postaxial polydactyly of the hand, guidelines to record the clinical presentations in patients with such a condition must be developed.

Synpolydactyly of the hand: a radiographic classification

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.

Polydactyly: A Review

Polydactyly, also known as hyperdactyly, is a common congenital limb defect, which can present with various morphologic phenotypes. Apart from cosmetic and functional impairments, it can be the first indication of an underlying syndrome in the newborn. Usually, it follows an autosomal dominant pattern of inheritance with defects occurring in the anteroposterior patterning of limb development. Although many mutations have been discovered, teratogens have also been implicated in leading to this anomaly, thus making it of multifactorial origin. There are three polydactyly subtypes (radial, ulnar, and central), and treatment options depend on the underlying feature.

A classification system for ulnar polydactyly and clinical series

PURPOSE

To describe a modified classification that includes both complicated ulnar polydactyly and ulnar polydactyly with bifid or duplicated proximal phalanx and to apply it to a clinical series.

METHODS

A total of 42 patients with ulnar polydactyly were admitted to our outpatient clinic between January 2004 and January 2014 and were included in the study. Patients' clinical and radiological data were evaluated retrospectively and organized into 5 different subgroups.

RESULTS

There were 20 bilateral and 22 unilateral patients with polydactyly. These were composed of 32 supernumerary digits represented as type I, 7 as type II, 9 as type III, 12 as type IV, and 2 as type V. Nine patients had bifid or duplicated proximal phalanges (types IIIA and IIIB) and 2 were of the complicated type (type V). We identified 5 types based on morphology, level of duplication, and other complicating features.

CONCLUSIONS

Complicated ulnar polydactyly and ulnar polydactyly with bifid proximal phalanx are 2 important types of ulnar polydactyly with surgical implications, both separately included in the Pritsch classification system and Rayan and Al-Qattan classification systems. None of the current classification systems include both types. We believe our modified classification system will help to better define diagnosis and treatment plans for bifid proximal phalanx and complicated type ulnar polydactyly.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Ulnar polydactyly - an analysis of appearance and postoperative outcome

BACKGROUND/PURPOSE

Ulnar polydactylies present with a wide variation in the size and appearance of the affected finger, ranging from small cutaneous appendages to fully formed additional fingers. Since ulnar polydactyly is rarely associated with functional disabilities, psychological and cosmetic reasons are the main rationale for surgical treatment. The aim of this study was to present the appearance, treatment regimen, and outcome of a series of children treated with ulnar polydactylies.

METHODS

Data of all pediatric patients treated between 2000 and 2010 were included. For assessing long-term outcome, patients were contacted via mail and asked to complete a questionnaire concerning location and appearance of the scar as well as functional and cosmetic satisfaction (VAS 0-100).

RESULTS

In that period, 32 patients (20 male, 12 female) with 53 ulnar polydactylies were treated. In 20 patients the polydactyly occurred bilaterally (63%), in 10 patients on the left side (31%), and 2 patients presented with right-sided ulnar polydactyly (6%). The vast majority of ulnar polydactylies were floating cutaneous appendages. The mean age of the patients at operation was 8.6 months (range 0 to 10 years). 20 patients (63%) responded to the postal questionnaire. Follow-up time was 4.9 years (range 2.1 to 10 years). The majority of patients reported a flat scar (n=18, 90%). Mean overall satisfaction with the postoperative result using a VAS 0-100 score was 89.

CONCLUSION

We were able to report a good postoperative outcome of a series of patients suffering from ulnar polydactylies.