Supporting the collateral ligament complex in radial polydactyly type Wassel IV

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.

Modified method for reconstruction of thumb abduction function in children undergoing surgical treatment of thumb duplication

PURPOSE

This study was performed to evaluate a modified method of reconstructing the thumb abduction function in children undergoing surgical treatment of thumb duplication.

METHODS

This retrospective study included 33 children (38 thumbs) with Wassel type III to VII thumb duplication who underwent excision of the polydactylism and osteotomy of the preserved thumb. Among them, 16 children (19 thumbs) underwent reconstruction of the attachment of the articular capsule and collateral ligament of the metacarpophalangeal joint, abductor pollicis brevis and flexor pollicis brevis by the anchor technique (Group A), while 17 children (19 thumbs) underwent suturing the attachment of the above-mentioned soft tissues to the periosteum (Group B). All children were followed up for six years after surgery. The appearance, function and joint stability of the preserved thumb were compared between the two groups; the bone alignment and development were observed.

RESULTS

The deformity rate of preserved thumbs and the positive rate of lateral stress test were significantly lower in Group A than B (p < 0.05). The modified Tada score and the distance of first web were significantly higher in Group A than B (p < 0.05). Flexion, extension, adduction, abduction and palmar movement of the thumbs were good; bone alignment and development were good and no osteophyte or anchor shadow was left in the preserved thumbs in Group A.

CONCLUSION

Reconstruction of the abduction function using the anchor technique is effective in children undergoing surgical treatment for Wassel type III to VII thumb duplication and it may be superior to the conventional technique.

LEVEL OF EVIDENCE

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.

[Recent progress in research of congenital polydactyly]

Surgery is still the main treatment for congenital polydactyly, and the aim of surgical reconstruction is to obtain a thumb with excellent function and appearance. A systematic assessment of polydactyly is required prior to surgery, including bone stress lines, joint deviation, joint activity and joint instability, size and development of finger and nail. Bone shape, joint incongruency, and abnormal tendon insertions must be corrected completely, in order to obtain good function and to avoide secondary surgery. Bilhault-Cloquet procedure can reconstruct the size of the finger and nails. Fine manipulation can improve the postoperative nail deformity, so that the reconstructed nail reaches a satisfactory aesthetic score.

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.

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.