Atypical thumb polydactyly with duplicated metacarpal bone: a report of 2 cases

Wassel VI Thumb Duplication With Triphalangeal Radial and Ulnar Thumbs: Anatomy and Surgical Reconstruction

A 6-year-old otherwise healthy girl presented with a Wassel VI duplication of the left thumb metacarpal and triphalangeal radial and ulnar thumbs. The patient underwent successful thumb reconstruction by transposition of the distal ulnar thumb onto the radial thumb metacarpal. To the best of our knowledge, this case report represents the first published anatomical dissection and surgical reconstruction of a Wassel VI duplication with triphalangeal radial and ulnar thumbs.

On-Top Osteotomy of the Phalanx Base Combined With Modified Bilhaut: Cloquet Procedure for Atypical Radial Polydactyly

In this report, we present the combination of on-top plasty with a modified Bilhaut-Cloquet procedure for treating atypical radial polydactyly with duplication at the metacarpophalangeal (MP) joint and triphalangism of the radial and ulnar phalanges, hypoplastic middle phalanx of the radial thumb, and hypoplastic phalanx base of the ulnar thumb. To preserve the stable MP and interphalangeal joints of the radial and ulnar thumbs, respectively, on-top plasty involved osteotomizing the middle phalanx and transferring the distal end of the middle phalanx of the ulnar finger to the phalanx base of the radial thumb. A modified Bilhaut-Cloquet procedure was used to combine the tips and nails of both thumbs. Twelve months postoperatively, good joint alignment and thumb tip appearance were achieved. On-top plasties effectively combined the desirable parts of both thumbs. The modified Bilhaut-Cloquet technique is particularly well-suited for atypical cases, such as the present case.

Improving Metacarpophalangeal Joint Instability by Joint Implantation in Parallel From a Supernumerary Thumb in Severely Hypoplastic Duplicated Thumbs

ABSTRACT

Here, we present 2 cases of a severely hypoplastic duplicated thumb classified as Wassel types 5 and 6 and discuss whole-joint implantation from a supernumerary thumb as an alternative to stabilize the hypoplastic metacarpophalangeal (MCP) joint. The aim of the surgical treatment of thumb polydactyly is to reconstruct a functional and aesthetically pleasing thumb. Hypoplasia of joint components and abnormal tendon alignment lead to unpleasing results with angular deformity of the reconstructed thumb. In 2 cases, the MCP joint of the dominant digit was hypoplastic and unstable in all directions. The main problem was underdevelopment of the affected MCP joint, and it was reasonable to attempt to stabilize the unstable joint by adding another redundant joint in parallel. Whole-joint implantation with a flap on a vascular pedicle is useful to repair both joint instability and soft tissue hypoplasia, as in case 1. The vascularized joint can maintain balanced growth potential. However, nonvascularized interphalangeal (IP) joint implantation is a simple solution for repairing MCP joint instability, as in case 2. These joints have no tendon insertions, so we believe they are acting as a splint supporting the hypoplastic joint for a long period. The transfer of composite tissues from the foot has been reported for reconstruction of finger and thumb hypoplasia. Duplicated thumb operation is usually recommended at 1 year old. Similarly, nonvascularized joint implantation in parallel may be a promising choice to overcome MCP joint instability and to maintain range of motion in hypoplastic cases with a duplicated thumb.In conclusion, joint implantation in parallel from a supernumerary thumb could prevent angular deformity and is an alternative to overcome MCP joint instability in cases of a severely hypoplastic duplicated thumb without any donor morbidity.

Nail-based reconstruction strategies for Wassel-Flatt type IVh thumb polydactyly with a floating ulnar digit: A preliminary report with 63 thumbs

PURPOSE

To present a surgical regimen based on nail morphology for Wassel-Flatt type IVh thumb polydactyly with a floating ulnar digit.

METHODS

Cases within six years were retrospectively analyzed and followed up for an average of 18 months. Three types of classifications were defined based on nail morphology ‒ ulnar nail dominant type with two subtypes of nail lateral fold symmetric or asymmetric, radial nail dominant type, and equal nail size type. One out of three procedures, on-top plasty (Ⅰ), soft tissue augmentation (Ⅱ), and the combination of the above two (Ⅲ), was performed. The Tada scoring system was used to evaluate the results.

RESULTS

Sixty-three thumbs were enrolled, forty-one of better ulnar nail type underwent top transposition, and in cases of asymmetric nail lateral fold subtype, the result of procedure Ⅲ was better than that of procedure Ⅰ, thirteen of the radial nail dominant type and nine of equal nail size type both had procedure Ⅱ. The equal nail size type was the least effective among groups, with an average Tada of four points. Six cases underwent secondary revision surgery. According to the Tada scoring system, the results were excellent in 61, fair in two.

CONCLUSIONS

Classifications based on the morphology of the nail can guide surgical planning. On-top plasty is suitable for symmetric nail lateral fold subtype. Soft tissue augmentation is ideal for radial nail dominant type and equal nail size type, and the combination of the two procedures is a better option for asymmetric nail lateral fold subtype.

[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.

"On-Top Plasty" for Radial Polydactyly Reconstruction

PURPOSE

To introduce the "on-top plasty" technique and report our long-term outcomes.

METHODS

We evaluated 5 thumbs in 5 patients who underwent radial polydactyly reconstruction using the "on-top plasty" technique between 1998 and 2003. This technique was used when it was felt that neither thumb possessed adequate proximal and distal structures to provide a functional and aesthetically pleasing thumb. Our study group included 1 Flatt type III and 4 Flatt type VII thumbs. The average age at time of surgery was 1.4 years and at final follow-up was 13.5 years. Subjective patient evaluation, objective outcomes values, and validated patient-oriented outcome measures were obtained.

RESULTS

There was no soft tissue loss and union was achieved in all thumbs with no further surgery required in any thumb. Mean flexion-extension arc for the metacarpophalangeal joint was 60° (range, 10° extension to 70° flexion) and at the interphalangeal joint was 19° (range, 25° extension to 35° flexion). Mean percentage of age-matched norms for lateral, tripod, and tip pinch were 47.0%, 45.9%, and 47.8%, respectively. Mean grip strength was 54.2% of age-matched norm. The mean Pediatric Quality of Life Inventory (PedsQL) score for parent questionnaires was 89.0 and for teen/child questionnaires was 89.1. The Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire revealed a mean score of 4.3.

CONCLUSIONS

For patients with radial polydactyly in which neither thumb possesses adequate distal and proximal components, the on-top plasty is a reliable method of polydactyly reconstruction with durable results at longer than 10 years' follow-up.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic V.

Upper Limb Dimelia

A patient with upper limb dimelia including a double scapula, humerus, radius, and ulna, 11 metacarpals and digits (5 on the superior side, 6 on the inferior side) was treated with a simple amputation of the inferior limb resulting in cosmetic improvement and maintenance of range of motion in the preserved limb. During the amputation, the 2 limbs were found to be anatomically separate except for the ulnar nerve, which, in the superior limb, bifurcated into the sensory branch of radial nerve in the inferior limb, and the brachial artery, which bifurcated into the radial artery. Each case of this rare anomaly requires its own individually carefully planned surgical procedure.

Reconstruction of Wassel Type VI Radial Polydactyly with Triphalangeal Thumb Using an On-top Osteotomy

BACKGROUND

The purpose of this study was to present a novel surgical technique using an on-top osteotomy and to assess the clinical and radiographic outcomes for the triphalangeal Wassel type VI thumb duplication patients.

METHODS

The surgical technique involves ablation of the radial thumb at distal one-third of the metacarpal, corresponding metacarpal osteotomy of the ulnar thumb, with amalgamation of 2 metacarpals and reconstruction of the ulnar thumb by a series of soft tissue procedures. Clinical and radiologic outcomes were evaluated by using the Japanese Society for Surgery of the Hand evaluation form at a minimum of 30 months. The size of the metacarpal was measured and compared to the opposite one to assess the growth of the thumb.

RESULTS

Five patients, including 4 males and 1 female, were observed for an average of 37 months. All amalgamated metacarpal showed bone union in 6 weeks after surgery and revealed growth with the age. The average length of the metacarpal was 86% of the opposite one at the final follow-up. Motion at the metacarpophalangeal and interphalangeal joints showed no restriction after surgery, and they reached excellent function for gripping and pinching. According to the JHHS scoring system, the results were excellent in 3 cases, good in 2.

CONCLUSIONS

This novel surgical technique for the reconstruction of Wassel type VI radial polydactyly with triphalangeal shows encouraging results in both clinical and radiologic evaluations; meanwhile long-term results are under evaluation.

Three-dimensional ultrasonography for visualization of muscular anomalies in type VI and VII radial polydactyly

OBJECTIVE

To describe a technique and its clinical applications of three-dimensional ultrasonography to type VI and VII radial polydactyly for identification of potential muscular anomalies.

MATERIALS AND METHODS

Ultrasonographic examinations were performed at an out-patient department without sedation or an operative room prior to surgery. The palm was scanned in the transverse direction using a 18-MHz linear transducer under speed regulation at 3 mm/s. Sequential images acquired at 0.2 mm intervals were converted into volume data. After validation of the technique, patients with a radial polydactyly in association with triphalangism (type VII) or with polydactylies of metacarpal duplication (type VI) were included for the examination.

RESULTS

Five hands of five patients, one with type VI and four with type VII, were included the study. All the patients were male and the ages at examination ranged from 7 months to 2 years. Of the five patients, four examinations were performed at an out-patient department without sedation and one was under anesthesia just prior to surgery. The muscular abnormalities identified were mal-positions of the thenar muscles in a type VI case and a deficiency of the abductor pollicis brevis muscle in a type VII case with a delta phalanx in the ulnar part.

CONCLUSION

Three-dimensional ultrasound technique could be an aid to plan strategies in radial polydactyly if intrinsic muscular anomalies are suspected to be involved.