Thumb polydactyly: clinical outcome after reconstruction

Secondary complications in Wassel II & IV thumb duplication: a comprehensive review of preventive measures

OBJECTIVES

Thumb duplication is one of the most challenging pediatric reconstructive hand surgeries. Wassel types II and IV are the most frequent, but also the most complex reconstructions as the duplication arises at the joint level. Ablation and reconstruction, the most widely used technique, aims at achieving a stable, well-aligned, mobile and esthetically acceptable thumb. The paucity of reliable surgical guidelines leads to high rates of suboptimal surgical outcomes. This review evaluated the various reconstruction techniques detailed in the literature and highlighted useful methods to prevent common secondary complications.

METHODS

A comprehensive PubMed and Embase literature search was made. Inclusion criteria were Wassel type II and/or IV, pediatric patients, and primary or secondary surgeries. Exclusion criteria were Bilhaut-Cloquet reconstruction and its modifications. Techniques were screened, collected and analyzed for the following secondary complications: instability, axial deformity, and contour deformity.

RESULTS

Thirty-two articles met the inclusion criteria and were reviewed. Postoperative instability was prevented by tightening the joint capsule by plication, advancement of the volar plate, or reconstruction of the collateral ligaments using a periosteal flap or the double-breasting technique. Axial deformity was prevented by arthroplasty, shaving a triangular portion of the metacarpal head, centralization of eccentric tendons, pulley reconstruction using flexor pollicis longus, or corrective osteotomies of the phalangeal or metacarpal bones using the wedge or oblique techniques. Limited range of motion was prevented by first webspace Z-plasty, and soft-tissue contouring was addressed by planned skin incisions and soft-tissue augmentation. Preoperative, perioperative and postoperative considerations, including splinting, imaging and immobilization, were also described.

CONCLUSION

Despite the ongoing advances and abundant knowledge in reconstructive strategies for thumb duplication, there are few studies that reviewed and analyzed the various reported options. This review provides physicians and trainees with guidance in surgical planning to prevent common secondary complications. Further research should focus on the development of standardized assessment tools, enabling reliable prospective comparative studies on thumb duplication reconstruction.

LEVEL OF EVIDENCE

IV.

Epidemiology of congenital polydactyly and syndactyly in Hunan Province, China

OBJECTIVE

To describe the prevalence and epidemiology of congenital polydactyly and syndactyly in Hunan Province, China, 2016-2020.

METHODS

Data were obtained from the Birth Defects Surveillance System in Hunan Province, China, 2016-2020. Prevalence of birth defects (polydactyly or syndactyly) is the number of cases per 1000 births (unit: ‰). Prevalence and 95% confidence intervals (CI) were calculated by the log-binomial method. Chi-square trend tests (χ2trend) were used to determine trends in prevalence by year. Crude odds ratios (ORs) were calculated to examine the association of each demographic characteristic with polydactyly and syndactyly.

RESULTS

Our study included 847,755 births, and 14,459 birth defects were identified, including 1,888 polydactyly and 626 syndactyly cases, accounting for 13.06% and 4.33% of birth defects, respectively. The prevalences of total birth defects, polydactyly, and syndactyly were 17.06‰ (95%CI: 16.78-17.33), 2.23‰ (95%CI: 2.13-2.33), and 0.74‰ (95%CI: 0.68-0.80), respectively. Most polydactyly (96.77%) and syndactyly (95.69%) were diagnosed postnatally (within 7 days). From 2016 to 2020, the prevalences of polydactyly were 1.94‰, 2.07‰, 2.20‰, 2.54‰, and 2.48‰, respectively, showing an upward trend (χ2trend = 19.48, P < 0.01); The prevalences of syndactyly were 0.62‰, 0.66‰, 0.77‰, 0.81‰, and 0.89‰, respectively, showing an upward trend (χ2trend = 10.81, P = 0.03). Hand polydactyly (2.26‰ vs. 1.33‰, OR = 1.69, 95%CI: 1.52-1.87) and hand syndactyly (0.43‰ vs. 0.28‰, OR = 1.42, 95%CI: 1.14-1.76) were more common in males than females. Polydactyly (2.67‰ vs. 1.93‰, OR = 1.38, 95%CI: 1.26-1.51) and syndactyly (0.91‰ vs. 0.62‰, OR = 1.47, 95%CI: 1.26-1.72) were more common in urban areas than in rural areas. Compared to maternal age 25-29, hand polydactyly was more common in maternal age < 20 (2.48‰ vs. 1.74‰, OR = 1.43, 95%CI: 1.01-2.02) or ≥ 35 (2.25‰ vs. 1.74‰, OR = 1.30, 95%CI: 1.12-1.50).

CONCLUSION

In summary, we have described the prevalence and epidemiology of polydactyly and syndactyly from hospital-based surveillance in Hunan Province, China, 2016-2020. Our findings make some original contributions to the field, which may be valuable for future research.

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.

Modified Radiographic Classification System for Congenital Thumb Duplication: An Analysis of 2,300 Thumbs in 2,108 Children

PURPOSE

The objectives of this study were to (1) evaluate the radiographic characteristics of children with congenital thumb duplication (CTD) seen in our institution between August 2015 and April 2021; (2) introduce a modified radiographic classification system (MCS) capable of including all cases of CTD based on their radiographic pathoanatomy; and (3) evaluate the inter- and intrarater reliability of the new classification system.

METHODS

We retrospectively reviewed 2,108 patients with 2,300 CTDs. The MCS is based on the Wassel-Flatt and Chung et al classification systems and includes specific subtypes from the Rotterdam and modified Wassel-Flatt classifications. The MCS is characterized by 4 groups according to the anatomical morphology of the duplication: A (joint), B (epiphysis), C (bone), and D (soft tissues). Each group includes 4 subtypes according to the location of the CTD, with subtypes 1-3 extending from the distal phalanx to the metacarpal or interphalangeal joints, then to the carpometacarpal joint, and with subtype 4 only including the triphalangia of the main thumb.

RESULTS

Among the 2,300 fingers, 360 (15.7%), 2 (0.1%), and 3 (0.1%) CTDs could not be classified according to the Wassel-Flatt, Chung et al, and Rotterdam classifications, respectively. According to the MCS, the 2 most common forms of CTD were A2 (680/2,300; 29.6%) and D2 (308/2,300; 13.4%). All cases could be classified according to this classification system. The MCS showed excellent intrarater (0.875) and interrater (0.851) reliability relative to the Wassel-Flatt (0.863 and 0.820, respectively), Chung et al (0.793 and 0.822, respectively), and Rotterdam (0.873 and 0.836, respectively) systems.

CONCLUSIONS

The MCS is a potential radiographic classification for CTD that enables the classification of all patients and has excellent inter- and intrarater reliability.

CLINICAL RELEVANCE

Existing classification systems do not allow classification of the full spectrum of CTD and are not always related to surgery, and some existing systems are complex, with many categories that are rarely encountered, or are difficult to use widely in clinical practice.

Complications after radial polydactyly surgery: analysis, prevention and management

Long-term follow-up after surgical correction of patients with radial polydactyly might reveal unexpected or undesired outcomes that are accentuated by growth. It should be stressed that assessment of outcomes differs considerably by the system used. Preoperative examination can elucidate the underlying pathological anatomy of these anomalies and consequently, these anatomical differences should be corrected as much as possible during the first operation to prevent worse outcomes at long-term follow-up. In various long-term studies, the reoperation rate was in the range of 7%-28%, with the most common reasons being deviation, instability, nail deformity and suboptimal appearance. Most unfavourable results occur during growth and are frequently revealed only at longer-term follow-up. Concentration of care to a few centres is advised since these malformations occur in small numbers and experienced surgeons tend to have better results. Consensus on the used assessment system and multicentred studies are essential in future to better understand how we can prevent reoperations.

Radiographic features of congenital thumb duplication type C2 of Wu et al. classification: new subtypes and surgical strategies

Objective

This study aimed (i) to evaluate the radiographic characteristics of patients with congenital thumb duplication (CTD) type C2 according to the classification of Wu et al., (ii) to describe the various subtypes of type C2 CTD, and (iii) to propose a classification system that allows the identification of different surgical strategies based on the radiographic anatomy of this specific subtype of duplication.

Methods

We retrospectively reviewed 92 patients (92 thumbs) with type C2 CTD according to the Wu et al. classification in our institution between August 2015 and April 2021. All CTDs were classified according to the interphalangeal joint alignment of the main thumb at the posteroanterior radiograph of the thumb before operation: type I (no deviation), type II (ulnar deviation), and type III (radial deviation).

Results

All CTDs (n = 92) could be classified according to the proposed classification system: 76 (82.6%) were type I, 10 (10.9%) were type II, and six were type III (6.5%). According to the Kim system of subtype classification, there were 55 (59.8%) type 1, 24 (26.1%) type 2, and 13 (14.1%) type 3 cases.

Conclusions

The suggested classification completes the Wu et al. system and has the potential to guide surgical treatment in children with type C2 CTD.

Level of evidence

III.

Factors affecting hand cosmesis and the aesthetic impact of surgery on congenital hand differences in Finland

We assessed the appearance and cosmetic impact of surgery in congenitally different hands in Finland. A questionnaire was sent to 1165 respondents (786 female) with a mean age of 33 years (range 3-84). Participants were shown nine image pairs and seven pairs of pre- and postoperative images twice in a random order and asked to choose the more cosmetically pleasing one. We found that the appearance and number of fingers had an important aesthetic role, with higher number and more normal appearing digits consistently scoring higher than its counterpart (range 59-99%). Postoperative appearances were perceived as better than preoperative ones in syndactyly (98%), thumb duplication (92%), cleft hand (93%) and radial dysplasia (99%). Toe transfer and pollicization had little impact on cosmesis. This study demonstrated that surgery could improve cosmesis in congenitally different hands and overall, most respondents prefer an appearance that is as close as possible to normality. Level of evidence: IV.

Radial Polydactyly

» Radial polydactyly is one of the most common congenital anomalies of the hand, with an incidence of 0.08 to 1.40 per 1,000 live births; it requires surgical treatment early in life.» Polydactyly occurs during weeks 5, 6, 7, and 8 of embryogenesis, principally due to misregulation of the sonic hedgehog protein within the developing limb bud.» The Flatt classification system of preaxial polydactyly (types I to VII), as published by Wassel, categorizes preaxial polydactyly based on osseous abnormalities, but it has substantial limitations.» For improved function and appearance, preaxial polydactyly ideally requires surgical intervention at an early age (between 1 and 2 years of age) before the development of fine motor skills.

A modified Bilhaut-Cloquet procedure for thumb duplication: Reconstruction of functionality and appearance

BACKGROUND

The Bilhaut-Cloquet technique is the preferred surgical method for thumb polydactyly with symmetrical caliber and osseous components. However, the traditional Bilhaut-Cloquet technique has many esthetic and functional complications. In this study, we aimed to investigate an effective modified Bilhaut-Cloquet procedure for Wassel type IV thumb duplication.

METHODS

The dorsal scar of the thumb was hidden on the ulnar side of the thumb through the flap design. The nail bed was sutured flat by combining the phalangeal bone and nail bed on different planes. The sensory function of the thumb was restored by keeping the ulnar skin of the thumb intact.

RESULTS

Our modified Bilhaut-Cloquet procedure did not reduce the mobility of the joints. All patients had relatively rounded fingernails, and no seagull deformity was present. The ulnar side of the palm skin of the thumb remained intact with no scars, maximizing the preservation of the sensory function of the thumb. All the operated children and their parents were satisfied with the esthetic result.

CONCLUSIONS

We hid the surgical scar by improving the surgical method and reducing the thumb seagull nail deformity, and the influencing of the finger sensation caused by the scar on the finger abdomen. The procedure improved not only the appearance of the reconstructed thumbs but also the sensory function of the thumbs.

Epidemiological characteristics and distribution of congenital thumb duplication in south China: An analysis of 2,300 thumbs in 2,108 children

OBJECTIVE

The objective of this study was to evaluate epidemiological and anatomical characteristics of children with congenital thumb duplication (CTD).

METHODS

We retrospectively reviewed 2108 children with CTD. Data regarding sex, age at the surgery, laterality, uni- or bilateral involvement, and dominant side were retrieved from the medical charts. Plain radiographs were used to classify all CTD according to Wassel-Flatt, Rotterdam and Chung classification systems and to evaluate the patho-anatomy of the duplication as well as the presence of associated anomaly.

RESULTS

A total of 796 girls and 1,312 boys with CTD (n = 2,300 thumbs) met the inclusion criteria. The male to female and unilateral to bilateral ratio were 1.6:1 and 10:1, respectively. Associated anomaly was found in 238/2108 patients (11.3%), and the middle phalanx deformity of the 5th finger was the most common one. A dominant thumb, larger and more developed, was on the ulnar side in 2270/2,300 cases (98.7%).According to the Wassel-Flatt classification, type IV (40.2%) was the most common deformity and the extra thumb was connected to the main thumb by a joint in most cases (437/780); overall, 15.7% of thumbs (n = 360) did not fit the Wassel-Flatt classification.According to the Rotterdam classification, type IV (51.3%) was the most common form; in most cases (363/1180) the thumb was hypoplastic or floating. Overall, 3/2,300 thumbs (0.1%) could not be classified according to Rotterdam classification.According to the Chung classification, type A was the most common subtype (44.1%); in most cases (716/1015) the duplication was at the level of the metacarpal bone. Overall, 2/2,300 thumbs (0.1%) did not fit the Chung classification.

CONCLUSIONS

In patients from southern China, CTD shows male and right-sided predominance with ulnar-dominant thumb. Abnormalities of the middle phalanx of the 5th finger are more frequent in patients with associated anomaly. The development of a simple and comprehensive classification system is needed to guide treatment and to adequately assess the epidemiological characteristics of patients with CTD in order to facilitate comparison between different patients' populations.

LEVEL OF EVIDENCE

III.

When Is Primary Metacarpal Corrective Osteotomy Recommended in Patients with Flatt Type IV Radial Polydactyly?

BACKGROUND

The aim of this study was to determine when primary metacarpal corrective osteotomy is recommended in patients with Flatt type IV radial polydactyly.

METHODS

A total of 78 patients with Flatt type IV radial polydactyly were included. The authors performed metacarpal osteotomy if the angulation of the metacarpophalangeal joint was not correctable by the intraoperative radial stress test. The authors measured the metacarpal deviation angle of the thumb in simple posteroanterior radiographs. The clinical outcomes were assessed using Japanese Society for Surgery of the Hand evaluation total score and the metacarpal deviation angle correction angle. These outcomes were compared between the patients who underwent metacarpal osteotomy and those who did not. Of the patients who did not undergo metacarpal osteotomy, the relationships between preoperative metacarpal deviation angle and the metacarpal deviation angle correction angle were formulated using segmented linear regression analysis.

RESULTS

There were no significant differences in the demographic features and the value of preoperative metacarpal deviation angle between the two groups. However, the metacarpal deviation angle correction angle and Japanese Society for Surgery of the Hand evaluation total score were significantly higher in the patients who underwent metacarpal osteotomy. The segmented linear regression analysis demonstrated a breakpoint, indicating that the soft-tissue procedure alone does not sufficiently correct the metacarpal deviation angle. For the postoperative metacarpal deviation angle to be 5 degrees, the preoperative metacarpal deviation angle was calculated as 10.8 degrees.

CONCLUSION

If the preoperative metacarpal deviation angle is greater than 10.8 degrees, metacarpal osteotomy can be considered even in patients with correctable metacarpophalangeal joint by intraoperative radial stress test.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Clinical Characteristics and Distribution of Thumb Polydactyly in South China: A Retrospective Analysis of 483 Hands

PURPOSE

This study was intended to characterize the epidemiological features of thumb polydactyly (TP) in South China.

METHODS

Clinical records were retrieved from 1 central hospital in South China to identify the patients with a definite diagnosis of TP from January 2004 to January 2017. The cases were classified by their x-ray appearance. The data collected included sex, age at first operation, reoperation, family history, unilateral/bilateral polydactyly, right/left hand involvement in unilateral cases, classification of polydactyly, and the presence of associated congenital anomalies.

RESULTS

A total of 428 patients with a definite diagnosis of TP were identified (278 males and 150 females) involving 483 cases, 373 unilateral and 55 bilateral. A syndrome or associated congenital anomaly was found in 26 (18 unilateral and 8 bilateral cases). A dominant thumb, larger and more developed, was observed in 448 hands (93%), and was the ulnar thumb in 433. Owing to postoperative complications, 31 thumbs (6.4%) underwent reoperation. The average interval from initial surgery to reoperation was 4.8 years.

CONCLUSIONS

Thumb polydactyly had a male predominance in this Chinese cohort, mostly occurring on the right hand with an ulnar dominant thumb. Bilateral cases had a higher incidence of associated anomaly and positive family history than unilateral cases. The need for additional surgery for TP might occur as late as 4.8 years after primary surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Correction of Thumb Duplication: A Systematic Review of Surgical Techniques

Surgical intervention for thumb duplication can be divided into three categories: simple excision of the accessory thumb, excision of the accessory thumb with reconstruction from available "spare parts," and combining the two thumbs into one, as described by Bilhaut. This prospectively PROSPERO registered systematic review evaluates the overall, aesthetic and functional outcomes for the latter two options (reconstruction from spare parts vs. combining two thumbs into one), aiming to facilitate evidence-based decision making when addressing thumb duplication and direct future research. The review was performed in accordance with the Cochrane Handbook of Systematic Reviews and PRISMA statement. Embase, PubMed, Medline, and Cochrane databases were systematically searched. Studies offering comparisons of techniques were included. Risk of bias was assessed using the Risk of Bias In Non-randomized Studies-of Intervention tool. The quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation. Ten retrospective observational studies were included. Data did not consistently allow analysis by procedure type. Four studies reported similar overall outcomes between techniques, while two specifically reported poor overall outcomes for the Bilhaut procedure. Two studies reported comparatively worse aesthetic outcomes for the Bilhaut procedure with four studies reporting comparatively improved functional outcomes for this procedure. Overall, interpretation of outcomes was challenging with no patient-reported outcome measures used. The quality of the evidence was universally "very low" due to all studies being at risk of methodological bias. Based on the available evidence, surgical techniques for thumb duplication correction appear comparable regarding overall outcome. There is limited evidence suggesting reconstruction with spare parts offers superior aesthetic outcomes at the expense of stability. The level of evidence is III.

Reconstruction of Wassel IV-D radial polydactyly with a boot-shaped neurovascular island flap: A Consecutive series of 91 thumbs

INTRODUCTION

Reconstruction of Wassel IV-D radial polydactyly is challenging and requires a custom strategy dependent on the relative size and shape of the radial and ulnar duplicates. Herein, we describe a technique using a boot-shaped neurovascular island flap and review our outcomes.

METHODS

Ninety-one consecutive patients had reconstruction with a boot-shaped neurovascular island flap. The flap was dissected out from the thumb to be removed. Specific flap modifications were inclusion of the lateral nail fold, Bruner incisions dorsally and volarly to reduce scarring at the interphalangeal (IP) joint and also complete mobilization of the island flap on its pedicle to allow easier inset. A flexor pollicis longus and extensor tendon rebalancing technique was used to correct the deviation of the reconstructed thumb IP joint.

RESULTS

All boot-shaped neurovascular island flaps survived with good contour, shape, and symmetry. The average follow-up period was 25 months (range 6-60 months). Using the Japanese Society for Surgery of the Hand (JSSH) score for classification of outcomes, seven cases were classified as excellent and 84 cases as good. The median JSSH score was 18. The median Kapandji score for opposition was 9 (range 8-10).

CONCLUSION

Using a boot-shaped neurovascular island flap completely mobilized on its pedicle with a custom strategy for each radial duplicate, good outcomes can be achieved in reconstruction of Wassel IV-D radial polydactyly.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Preoperative percutaneous arthrography provides detailed information for treatment of Wassel type IV thumb duplication

PURPOSE

We aimed to detect whether percutaneous arthrography can provide detailed information for surgery for Wassel type IV thumb duplication prior to skin incision.

METHODS

Percutaneous arthrography of the metacarpophalangeal (MP) joints was performed in eight infants. Of these, three patients had interphalangeal (IP) joints, in which thumb duplication at the MP joint (Wassel type IV) was detected on radiography. Based on the arthrographic findings, we designed the skin incision and determined whether and where osteotomies were required to correct the angular deformities before surgery.

RESULTS

Arthrography revealed the cartilaginous position and shape, shown as a black area on radiographs. Two patients demonstrated fibrous attachment between the proximal phalanx of the radial thumb and the capsule of the ulnar thumb. One patient had two completely separated MP joints. Cartilaginous connection between the two proximal phalanges was present in another two cases. The remaining three patients demonstrated a common joint between the duplicated proximal phalanges, sharing a common articular space with the MP joint, with the metacarpal head's surface forming two facets separated by a crease in the middle. IP joint arthrography was performed in three patients who presented with angular deformity.

CONCLUSIONS

Percutaneous arthrography can provide detailed information prior to skin incision. Furthermore, our arthrographic findings coincided with the practical situations we observed intraoperatively. Our experience indicates that preoperative percutaneous arthrography should be performed routinely in more cases and classified based on articular configuration to aid in the selection of surgical treatment.

POSTOPERATIVE RETROSPECTIVE ANALYSIS OF THE TREATMENT OF DUPLICATED THUMB

OBJECTIVE

To evaluate postoperative epidemiological and functional factors in patients operated to treat duplicate thumb.

METHODS

This retrospective case series evaluated 20 patients (23 thumbs) treated from January 2012 to December 2016 at our service. Epidemiological and clinical factors were studied, including Tada score.

RESULTS

Of the 34 children who were treated surgically, only 20 appeared for the functional evaluation and were included in the study. Of the operated cases, 60% were Wassel type 4. All evaluated cases had good functional results (Tada score ≥5, mean score: 6.65). The most frequently used surgical technique was resection of the radial thumb with reconstruction of the radial collateral ligament (47.8% of cases).

CONCLUSION

Surgical correction of duplicated thumb yields good results, as long as attention is paid to abnormalities in bones, ligaments, and tendons. Level of Evidence IV; Case series.

Defining postoperative stability in children with radial polydactyly

There is little fundamental data on paediatric metacarpophalangeal joint instability in radial polydactyly following surgical reconstruction. We evaluated 27 thumbs in a healthy paediatric population (Group A: eight girls and 19 boys with a mean age of 9.7 years (range 2.7-14.2)) and 12 thumbs following Wassel-IV reconstruction (Group B: eight girls and four boys with a mean age at follow-up of 10.6 years (range 2.7-13.2)). Metacarpophalangeal joint radial deviation, ulnar deviation on stress testing, interphalangeal joint and metacarpophalangeal joint alignment on posterior-anterior radiographs were measured and scored according to parameters defining joint instability. The aim of our study was to provide fundamental data on thumb metacarpophalangeal joint mobility patterns and alignment for further postoperative evaluations in children. The average ulnar deviation and radial deviation on stress testing of the healthy (Group A) metacarpophalangeal joints was 25° (10°-45°) and 30° (10°-55°), respectively. In the operated (Group B) thumbs, the ulnar deviation and radial deviation was greater at 35° (10°-55°) and 30° (10°-70°). Ulnar deviation (UD) of the proximal phalanx at the metacarpophalangeal joint on posterior-anterior radiographs was a mean of 10° (range -10°-30°) in Group B; this was significantly greater than in Group A at a mean of 5° (range -5-20°) (p = 0.029). The mean radial alignment of the interphalangeal joint (distal phalanx relative to the proximal phalanx) was significantly higher in Group B (15°) than Group A (0°) (p = 0.221). In the literature on radial polydactyly, cut off values defining metacarpophalangeal joint instability in children range from 5° to 20°. According to our results, high but physiological metacarpophalangeal joint mobility of the thumb needs to be taken into consideration when evaluating children following reconstruction. Ulnar or radial deviation greater than 30°, in combination with the lack of a definite end point on metacarpophalangeal joint stress testing, may be regarded as unstable. Based on our study on healthy paediatric and reconstructed thumbs, comparison of joint stability with the healthy contralateral hand is recommended in order to define pathological instability.

LEVEL OF EVIDENCE

II.

A clinically weighted approach to outcome assessment in radial polydactyly

Currently available outcome assessment systems for radial polydactyly are mainly based on expert opinion. The aim of this study was to develop an outcome assessment system based on clinical data. We performed linear regression analysis on data from a multicentre study of 121 patients with radial polydactyly types II, IV and VII to develop a clinically weighted outcome assessment system. Items were weighted according to their influence on overall functional and aesthetic outcome in the regression analysis. Active flexion, scar appearance and prominence at amputation site were the main items influencing overall functional and aesthetic outcome (β = 0.393, β = 0.326 and β = 0.288, respectively). Palmar abduction, metacarpophalangeal joint deviation and nail appearance influenced overall functional and aesthetic outcome the least (β = -0.002, β = -0.104 and β = 0.070, respectively). Our proposed assessment system for radial polydactyly reflects the way clinicians value individual aspects of outcome as determinants of overall outcome and helps guide future treatment and evaluation of outcome.

LEVEL OF EVIDENCE

III.

Congenital Anomalies of the Hand--Principles of Management

Physicians who specialize in pediatric orthopedics and hand surgery frequently encounter congenital hand abnormalities, despite their relative rarity. The treating physician should be aware of the associated syndromes and malformations that may, in some cases, be fatal if not recognized and treated appropriately. Although these congenital disorders have a wide variability, their treatment principles are similar in that the physician should promote functional use and cosmesis for the hand. This article discusses syndactyly, preaxial polydactyly and post-axial polydactyly, and the hypoplastic thumb.

Do Patient- and Parent-reported Outcomes Measures for Children With Congenital Hand Differences Capture WHO-ICF Domains?

BACKGROUND

Patient- and parent-reported outcome measures (PROMs) are increasingly used to evaluate the effectiveness of surgery for congenital hand differences (CHDs). Knowledge of an existing outcome measure's ability to assess self-reported health, including psychosocial aspects, can inform the future development and application of PROMs for CHD. However, the extent to which measures used among children with CHD align with common, accepted metrics of self-reported disability remains unexplored.

QUESTIONS/PURPOSES

We reviewed studies that used PROMs to evaluate surgery for CHD to determine (1) the number of World Health Organization-International Classification of Functioning, Disability and Health (WHO-ICF) domains covered by existing PROMs; (2) the proportion of studies that used PROMs specifically validated among children with CHD; and (3) the proportion of PROMs that targets patients and/or parents.

METHODS

We performed a comprehensive review of the literature through a bibliographic search of MEDLINE®, PubMed, and EMBASE from January 1966 to December 2014 to identify articles related to patient outcomes and surgery for CHD. We evaluated the 42 studies that used PROMs to identify the number and type of WHO-ICF domains captured by existing PROMs for CHD and the proportion of studies that use PROMs validated for use among children with CHD. The most common instruments used to measure patient- and parent-reported outcomes after reconstruction for CHD included the Prosthetic Upper Extremity Functional Index (PUFI), Disabilities of the Arm, Shoulder, and Hand questionnaire, Childhood Experience Questionnaire, and Pediatric Quality of Life Inventory.

RESULTS

Current PROMs that have been used for CHD covered a mean of 1.3 WHO-ICF domains (SD ± 1.3). Only the Child Behavior Checklist and the Piers-Harris Children's Self-Concept Scale captured all ICF domains (body functions and structures, activity, participation, and environmental factors). The PUFI, the only PROM validated specifically for children with congenital longitudinal and transverse deficiency, was used in only four of 42 studies. Only 13 of the 42 studies assessed patient-reported outcomes, whereas five assessed both patient- and parent-reported outcomes.

CONCLUSIONS

The PROMs used to assess patients after CHD surgery do not evaluate all WHO-ICF domains (ie, body structure, body function, environmental factors, and activity and participation) and generally are not validated for children with CHD. Given the psychological and sociological aspects of CHD illness, a PROM that encompasses all components of the biopsychosocial model of illness and validated in children with CHD is desirable.

LEVEL OF EVIDENCE

Level III, therapeutic study.

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.

Factors affecting surgical results of Wassel type IV thumb duplications

The aim of this study is to review the outcomes of Wassel type IV thumb duplications with a minimum of one year follow-up, and to identify any factors that may compromise the quality of results. Forty one patients (42 thumbs) returned for assessment of thumb alignment, metacarpophalangeal joint and interphalangeal joint stability and motion; carpometacarpal joint motion; pinch and grip strengths; and thumb size. The subjective assessment considered thumb shape and contour, scarring, nail deformity and examiner and patient/parent satisfaction. The mean age at surgery was 16 months and the mean follow-up time was 79 months. Metacarpophalangeal joint and interphalangeal joint mal-alignment was present in 56% and 38% of cases, respectively. Interphalangeal ulnar collateral ligament laxity was significant. Metacarpophalangeal joint and interphalangeal joint motion was significantly decreased. Pinch and grip strength measurements were normal. A novel and comprehensive assessment scale is introduced, which revealed results of one (2.5%) excellent, 23 (59%) good, 14 (36%) fair and one (2.5%) poor. We consider that greater attention should be directed to the avoidance of mal-alignment and instability to improve these results.

Long-term outcomes following radial polydactyly reconstruction

PURPOSE

To report long-term outcomes (> 10 y) after radial polydactyly reconstruction.

METHODS

We evaluated 43 surgically reconstructed thumbs in 41 patients with radial polydactyly whom we had observed for more than 10 years. The study group included 12 Flatt type II, 8 type III, 17 type IV, and 6 type V. The average age of surgery was 1 year and mean follow-up was 17 years. Objective outcome values and validated patient-oriented outcome evaluations were obtained.

RESULTS

No early postsurgical complications were encountered. Eight patients had 10 revision procedures at an average of 8 years after the initial procedure. Five patients had interphalangeal joint arthrodesis, all for angulation with accompanying pain. The average Tada score was 4.1. Lateral, tripod, and tip pinch strengths were 96%, 86%, and 92%, respectively, of the unaffected side. As a group, the treated thumbs had significantly weaker tip and tripod pinch strengths than the untreated thumbs. The average Disabilities of the Arm, Shoulder, and Hand score was 4.5 and the average Pediatric Quality of Life Inventory score was 87 when administered to both the patient and the parent.

CONCLUSIONS

Long-term results after surgical reconstruction for radial polydactyly were excellent but the revision rate trended upward over time despite maintenance of favorable scores on the objective outcome measures used.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Comparison of functional outcome scores in radial polydactyly

BACKGROUND

A wide range of outcome assessment systems have been used to describe the results and evaluate residual impairment after surgery for radial polydactyly. We conducted a study to determine which of these assessment systems should be considered superior for the most common types of radial polydactyly (types II and IV).

METHODS

Ten outcome assessment systems were selected. Three examiners independently evaluated thirty-seven patients, aged four to twenty-two years, with radial polydactyly. Patients completed two manual activity questionnaires. Interobserver reliability was determined with use of an intraclass correlation coefficient (ICC). Validity was assessed by correlating the results derived with the outcome assessment systems with functional visual analog scale (VAS), aesthetic VAS, and manual activity questionnaire scores.

RESULTS

Thirty-seven patients (forty-one hands with radial polydactyly) were evaluated. All patients were assessed by at least two examiners. Reliability was highest for the Japanese Society for Surgery of the Hand (JSSH), Cheng et al., and Tada et al. assessment systems (overall ICCs ≥ 0.70). The JSSH system had the highest overall correlations (rs ranging from 0.48 to 0.80 and 0.45 to 0.63) with functional and aesthetic VAS scores. No significant correlations were found between the outcome scores and the results of the manual activity questionnaires after an average follow-up time of 112 months.

CONCLUSIONS

Interobserver reliability was highest for the JSSH classification, which also showed superior correlations with both examiner-rated and patient-rated VAS scores for functional and aesthetic outcome compared with the other nine assessment systems. The finding of a poor correlation between the outcome scores and the results of manual activity questionnaires is in agreement with findings in published literature. We recommend the JSSH assessment method for the scientific evaluation of the outcomes, in terms of body structure and function, of the treatment of radial polydactyly.

Prognostic value of age and Wassel classification in the reconstruction of thumb duplication

BACKGROUND

Various surgical techniques for thumb duplication have been described. The main goal in thumb reconstruction is to achieve optimal function, stability, and shape. Few publications have quantified the functional results of each surgical option and factors that may affect these outcomes.

METHODS

We performed a retrospective review during the period from 1990 to 2011 of 115 surgery patients, 99 of whom had a mean postoperative follow-up of 44.1 months. They were classified according to the Wassel classification. We assessed the surgical technique, functional results, and complications, and evaluated the probable prognostic value of age and Wassel classification.

RESULTS

This case series comprised mainly female patients (62 %) and the right hand (74 %), with a mean age at operation of 20 months. The most common group was Wassel type IV (54 %). On the basis of the Tada scoring system, we obtained 91 good results (91 %). Complications occurred in 27 patients (27 %), mainly instability and axis deformation. In a comparison of preoperative factors (age at the time of surgery and Wassel classification) with the final results (Tada score and complications), the association between older age at surgery and complications (p = 0.0001) and Wassel types III and IV and complications (p = 0.0210 and p = 0.0095) was statistically significant.

CONCLUSIONS

Following the basic concepts of anatomical reconstruction, we obtained good results in most patients. The main complications were instability and axial deformity. These were most common in patients who underwent operations at an age of more than 12 months, and patients with Wassel types III and IV deformities.

Radial polydactyly: proposal for a new classification system based on the 159 duplicated thumbs

BACKGROUND

Polydactyly is one of the most common congenital differences that affect the hand. It has various anatomic and morphologic features. Although the Wassel classification has been used widely for radial polydactyly, it is based on the anatomic level of duplication and has some limitations in describing the concrete morphology of the duplication. The authors devised a new classification system based on the anatomic pattern of duplication to facilitate surgical correction of the deformity and evaluated surgical outcomes.

METHODS

A total of 159 duplicated thumbs in 142 patients who were treated surgically from 1990 to 2007 and followed for > 12 months were included in this series. The authors categorized all cases of radial polydactyly into the following: type I (joint type), where the extra digit has its own joint at its origin; type II (single epiphyseal type), where the origin of the extra digit is derived directly from the common epiphysis; type III (osteochondroma-like type), where the origin of the extra digit resembles an osteochondroma; and type IV (hypoplastic type), where the extra digit is connected to the main digit by soft tissue alone. All patients underwent surgical treatment based on this classification. The surgical outcomes were assessed using the Tada score.

RESULTS

Of the 159 radial polydactyly cases, 84 (50%) were classified as the joint type-37 (22%) as the osteochondroma-like type, 33 (19%) as the single epiphyseal type, and 15 (9%) as the hypoplastic type. All the cases were classified with the proposed classification system. In the evaluation of the surgical outcomes, 134 (84%), 17 (11%), and 8 (5%) were rated as good, fair, and poor, respectively.

CONCLUSIONS

This new classification system for radial polydactyly is practical and closely related to the surgical strategies.

LEVEL OF EVIDENCE

Diagnostic IV.

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.

Sushi hand roll dressing for thumb polydactyly

Surgery for thumb polydactyly is a commonly performed orthopaedic procedure in Asia Pacific region. Despite extensive publications on topical dressing methods and dressing materials in paediatric wounds, there is no single design that affords a secure and yet comfortable post-operative wound dressing for thumb polydactyly. We have devised a new dressing method, which can easily be fabricated for such purpose from readily available materials in operation theatre.