Long-Term Follow-Up of Surgical Treatment for Thumb Duplication

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.

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.

Prediction of Surgical Outcomes of Radial Polydactyly From the Wassel-Flatt Type and Symmetry of Duplication

BACKGROUND

The Wassel classification is commonly used for cases of radial polydactyly but has not been used to predict surgical outcomes. This study aimed to investigate the predictive factors of surgical outcomes using the Wassel type and symmetry of duplication.

METHODS

Forty-five patients with 47 radial polydactylies were reviewed using the Japanese Society for Surgery of the Hand (JSSH) scores 4.6 years after minor thumb excision and reconstructive surgery. The symmetry index was defined as the metaphyseal width ratio of the minor thumb to the dominant thumb. The relationships between the JSSH scores and operation age, sex, side, follow-up duration, Wassel type, symmetric index, divergent angle, and joint angulation were analyzed by linear regression.

RESULTS

The mean JSSH score of the 47 thumbs was 18.3 points (range, 15-20). Five thumbs had fair or poor outcomes (scores <17), all of which were Wassel type IV. The hypoplastic type had a better JSSH score (19.4) than other Wassel types. The symmetric index had a negative relationship with JSSH scores, especially for Wassel type IV (r=-0.68, P =0.001). Linear regression revealed that the symmetric index was the only independent factor significantly associated with JSSH scores among Wassel type IV polydactylies ( P <0.05). The receiver operating characteristic curve suggested a symmetric index <0.74 could predict good or excellent outcomes.

CONCLUSION

The symmetry of the 2 duplicated thumbs is an important factor for surgical outcomes. The Wassel type IV polydactylies with a symmetric index >0.74 are at greater risk of fair or poor outcomes after excision and reconstruction, and further studies are warranted to confirm whether the Bilhaut-Cloquet procedure is a good choice.

LEVEL OF EVIDENCE

Level IV-Case-control study.

Reoperation after primary operation for pre-axial polydactyly of the hand: A 12-year experience at a single institute

BACKGROUND

This study aimed to evaluate and describe the rate, reasons, and detailed procedures of reoperations for pre-axial polydactyly of the hand at our institute conducted within 12 years.

METHODS

We retrospectively reviewed the medical records and radiographs of 268 patients (292 digits) with pre-axial polydactyly of the hand, who were treated surgically at our institute from November 2006 to May 2018 and followed up for >12 months.

RESULTS

Fifty-two thumbs of 47 patients underwent reoperations, yielding a 17.8% reoperation rate. According to the initial deformity type, the highest reoperation rate was observed in the cases classified under modified Wassel type VIIA (60.9%, 14/23 thumbs), followed by those under type VIIB (44.4%, 8/18 thumbs). Scheduled reoperations were performed in seven type VIIA and four type VIIB cases with a triphalangeal thumb and eight with triangular epiphysis of the distal phalanx. Unexpected reoperations were conducted in 33 cases, 31 (93.9%) of which had deviated thumbs. Various surgical treatments, including corrective osteotomy, collateral ligament plication, and flexor pollicis longus tendon relocation, were performed to correct deviations. A total of 23 cases (74.2% of 31 thumbs) received a corrective osteotomy at the second or third operation.

CONCLUSIONS

The reoperation rate after primary operation for pre-axial polydactyly of the hand was 17.8%. It was higher in the cases initially classified under modified Wassel type VII; however, a considerable number of cases received scheduled reoperations. A deviated thumb was the most common cause of unexpected reoperation, and corrective osteotomy was the most commonly performed procedure. The rate and details of reoperation should be routinely mentioned for preoperative planning and patient education in pre-axial polydactyly.

LEVEL OF EVIDENCE

Therapeutic level IV.

Preoperative angulation as a predictor for operations of Wassel type IV polydactyly

The aim of this study was to find the degree of preoperative metacarpophalangeal (MCP) joint angulation that determines the need for corrective osteotomy and to compare the result for Wassel type IV thumb polydactyly operated by soft tissue reconstruction alone or with corrective osteotomy. The surgical options for correction of the angular deformity of the MCP joint in Wassel type IV thumb polydactyly were retrospectively reviewed. The preoperative angular deformity of the MCP joint and the last postoperative residual deformity at MCP joint were measured from the radiograph of thumb posteroanterior view. The cut-off point of the preoperative MCP angulation that provided less residual deformity in patients who were treated by soft tissue procedures alone was identified from receiver operating characteristic curve. A total of 45 patients with 46 thumb polydactyly (Wassel type IV) were studied. Mean pre and postoperative MCP angulation were 24.01 (range 0-68°) and 14.65 (range 0-39°), respectively. Thirty-four thumbs from 33 patients (73.91%) were operated on by soft tissue procedures alone and 12 thumbs (26.09%) needed corrective osteotomy. The best cut-off point of preoperative MCP angulation that showed less significant residual deformity when treated by soft tissue procedure alone was 30° (96.43% sensitivity and 100% specificity). In MCP angulation ≤30°, soft tissue reconstruction alone was an effective method for correction of angular deformity with predictable outcome of no significant residual deformity (0/27 thumbs). In MCP angulation >30°, corrective osteotomy is recommended over soft tissue procedure alone due to achieve proper thumb position and adequate soft tissue balance. There is also a statistical decrease in significant residual deformity [from 85.71% (6/7 cases, treated by soft tissue procedure alone) to 30% (3/10 cases, treated by corrective osteotomy), P < 0.05]. This study proposes the use of preoperative MCP joint angular deformity as a guide to the type of surgical intervention in Wassel type IV thumb polydactyly.

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.

Evaluation and Management of Preaxial Polydactyly

PURPOSE OF REVIEW

To provide a current review of the embryology, classification, evaluation, surgical management, and clinical outcomes related to preaxial polydactyly.

RECENT FINDINGS

Recent studies include a proposed embryologic link between preaxial polydactyly and other congenital abnormalities, an evaluation of long-term postsurgical outcomes, and an examination of important predictors for postsurgical outcomes. Preaxial polydactyly, while relatively uncommon, is a complex congenital hand abnormality that requires careful preoperative classification and proper surgical intervention timing to yield optimal outcomes.

Congenital Deformities of the Hands

Evaluation of the pediatric musculoskeletal system may be difficult because of differences between children and adults. As children mature, their physical structure approaches that of an adult. However, in the meantime, varying stages of ossification and developmental timelines may confuse the average clinician. Congenital abnormalities of the upper extremity are extremely numerous, but here we present 10 that often are seen in clinical practice. The article discusses the diagnosis, evaluation, treatment, and outcomes of each condition.

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.

Polydactyly of the Hand

Polydactyly is one of the most common congenital hand deformities managed by orthopaedic surgeons. It is most often found in isolation; however, rarely, it may be associated with genetic syndromes. Polydactyly is classified as postaxial, preaxial, or central depending on the radioulnar location of the duplicated digits. Postaxial polydactyly, which affects the ulnar side of the hand, is most common and is typically managed with excision or suture ligation of the supernumerary digit. Preaxial polydactyly, which affects the thumb or radial side of the hand, often requires reconstructive techniques to ensure a functional, stable thumb. Central polydactyly is much less common, and reconstruction can be challenging.

Incidence of Acute Complications Following Surgery for Syndactyly and Polydactyly: An Analysis of the National Surgical Quality Improvement Program Database from 2012 to 2014

PURPOSE

Congenital hand differences are infrequent phenomena, and their treatment represents a relatively small fraction of cases performed by hand surgeons. Little is known about the incidence of wound complications and acute postoperative problems given the relative rarity of these procedures. This study sought to characterize the incidence of complications within 30 days of surgery for congenital hand differences.

METHODS

The National Surgical Quality Improvement Program (NSQIP) contains prospective data regarding 30-day morbidity from 64 pediatric centers across the United States. Data from all available years (2012-2014) were queried for Current Procedural Terminology (CPT) codes pertinent to the treatment of congenital hand differences. Bivariate statistics, Fisher exact tests and Poisson 95% confidence intervals (95% CI) were used to assess the incidence of complications and examine risk factors for these outcomes.

RESULTS

We identified a total of 1,656 congenital hand cases that represented 4 different CPT codes, including surgery for simple syndactyly, complex syndactyly, and polydactyly. The overall incidence of complications was 2.2% (95% CI, 1.6%-3.1%; n = 37) with the most common complication being superficial surgical site infection (1.7%; 95% CI, 1.1%-2.4%) followed by related readmission (0.3%; 95% CI, 0.1%-0.7%). There was a higher incidence of complications observed in patients undergoing complex syndactyly repair (5.2% for complex syndactyly repair vs 2.3% for all others).

CONCLUSIONS

The rate of acute complications following procedures to correct syndactyly and polydactyly is low, the most common of which is superficial surgical site infection. The incidence of acute complications may be helpful in counseling patients and families. We suggest that further research must prioritize collecting data on long-term functional outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

The Duplicated Thumb: A Review

Preaxial polydactyly is a common, often sporadic, congenital anomaly that must be addressed surgically early in life. Ideally, the surgeon seeks to accomplish three goals: construction of a thumb that is adequate in size, preservation of pinch function, and reconstruction of all components in one procedure. Although each case is unique, several classification systems attempt to describe the various types. In this article, the authors discuss the various classification systems, procedures, and outcomes after surgery for pediatric thumb duplication.

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.

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.

Management of complications of congenital hand disorders

This article reviews treatment and presents complications seen in the treatment of 7 common congenital hand differences, including syndactyly, camptodactyly, ulnar and radial polydactyly, thumb hypoplasia, radial longitudinal deficiency, and epidermolysis bullosa. The management of these conditions is challenging but has evolved over the last several decades with refined understanding of the disease processes and treatments. The goal of this article is to synthesize prior knowledge and provide further insights into these conditions that will help the surgeon avoid treatment complications.

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.

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.

Bifid thumb type IV in children: transferring an epiphyseal segment of the proximal phalanx with insertion of the abductor pollicis brevis tendon

OBJECTIVE

To evaluate the clinical and functional results of the surgical treatment of bifid thumb type IV in children.

MATERIALS AND METHODS

A retrospective study was undertaken from January 1995 to December 2006. Clinical and radiographic evaluations were made according to Wassel's classification. The patients were performed by transferring an epiphyseal segment of the proximal phalanx with insertion of the abductor pollicis brevis tendon into the radial side of the epiphyseal proximal phalanx of the ulnar thumb. All patients were operated using one of five surgical procedures for bicephalous metacarpus, cartilaginous connection between the radial and ulnar proximal phalanges, the angular deformity of the metacarpophalangeal joint (MPJ) is >20°, and zigzag deformities. The postoperative results of the patients were evaluated for both function and cosmesis according to Tien's modified Tada scoring system.

RESULTS

One hundred and sixty-four patients (102 females, 62 males) were included in this study. The MPJ was stable in 170 thumbs, 15 thumbs had 10° of radial instability, and new collateral ligaments were augmented in 27 thumbs. The alignment was normal in 75 thumbs, with alignment of the interphalangeal joint (IPJ) in 101 thumbs and alignment of the MPJ in 75 thumbs. Postoperatively, there were zigzag deformities in four thumbs (developed zigzag in two thumbs, recurrent zigzag in two thumbs); there was no first web space in those hands. There were four of 185 thumbs with thumb stiffness. The abductor function of 185 thumbs was as follows: >70° in 158 thumbs (85.4%), 50°-70° in 21 thumbs (11.4%), and <50° in six thumbs (3.2%). At the latest follow-up evaluation, no evidence of physeal growth injury or growth arrest was observed in any patient. Overall, we attained good results in 140 thumbs (75.7%), fair results in 36 thumbs (19.4%), and poor results in nine thumbs (4.9%).

CONCLUSION

We recommend the use of an epiphyseal segment of the proximal phalanx with insertion of the abductor pollicis brevis tendon into the radial side of the epiphyseal proximal phalanx of the ulnar thumb and to restore anatomical insertion of the abductor pollicis brevis muscle. The technique is simple, safe, and effective for thumb abductor function in the treatment of bifid thumb type IV in children.

Reconstruction of Wassel type IV thumb duplication

The most common thumb duplication is a Wassel type IV with duplication of the proximal and distal phalanges. The term "split-thumb" seems more appropriate as neither element is as robust as a normal thumb. The split parts may share bony elements, tendons, ligaments, joints, neurovascular structures, and nails. The surgical principles are preservation and augmentation of the dominant thumb and ablation of the lesser counterpart. The soft tissue(s) from the ablated thumb are used to augment the retained thumb. This article will discuss the indications, timing, and technique of surgical reconstruction for the Wassel type IV thumb duplication.

Congenital hand surgery: what's new and what's coming

Congenital hand surgery has advanced during the last 10 years with surgical technique improvements, the incorporation of new technologies, and an enhanced understanding of the basic pathology of upper extremity anomalies. This article reviews the literature with a survey of 70 articles from seven leading journals published in the last 12 years. The author concludes that the next decade should be even more exciting with the incorporation of an improved understanding of tissue engineering and molecular genetics into classification and treatment algorithms. Understanding the genetic pathways of normal, and therefore abnormal, development should allow improved classification schemes and intervention to prevent, modify, or remedy these birth abnormalities.

Thumb size and appearance following reconstruction of radial polydactyly

PURPOSE

To evaluate thumb size, shape, and appearance after surgical correction of radial polydactyly.

METHODS

Thirty-one reconstructed thumbs in 26 children with radial polydactyly were evaluated at an average of 45 months after surgery. The length, girth, nail width, and joint angulation were measured and compared with the contralateral side of patients with unilateral polydactyly and with standard thumb measurements for patients with bilateral involvement. A surgeon, therapist, and caregiver each subjectively assessed the aesthetic outcome, using a visual analog scale (VAS); raters also provided the principal reasons for their assessment of the altered appearance.

RESULTS

The average length of the reconstructed thumb relative to the index finger proximal phalanx was 81%; that of the unaffected, contralateral thumb was 80%. The girth of the reconstructed thumb relative to the index finger was 102%; that of the contralateral thumb was 103%. Thumbnail width in proportion to index fingernail width was significantly decreased in the reconstructed thumbs, at 111% (compared with the contralateral value of 136%). The VAS scores averaged 7.7; the most common reason cited for decreased VAS score was an angulated thumb. Lower VAS scores were associated with Wassel type VI and VII thumbs and with increased interphalangeal, but not metacarpophalangeal, joint angulation.

CONCLUSIONS

Thumb polydactyly reconstruction typically provides a satisfactory thumb appearance. The primary issues affecting appearance after reconstruction are reduced nail width, interphalangeal joint angulation, and presence of type VI and VII radial polydactyly.