Duplicated triphalangeal thumb is a surgical challenge to create a satisfactory thumb with good mobility opposition, stability, alignment and size. Some authors consider it as a thumb deletion with index duplication or preaxial polydactly due to its lack of opposition, but it does belongs to group VII of Wassel classification. The frequency of his malformation is 1/25,000.

The authors report a familial serial of 10 children treated bilateraly by pollicisation with the same technique, by two senior surgeons. The mean age for surgery was 20 months and the average follow-up is 7 years and a half at the time of the study.

The goal of the study is to point out the functional and cosmetic improvement, with a focus on pre- and post-surgical radiographic aspect of the trapezometacarpal joint.

The results are compared with parents whose some have been operated on one side by resection of the radial component.

All patients improved their pinch and mainly cosmetic appearance. An efficient opposition was achieved and is compared with non-operated parent's thumbs. The authors report 2 tourniquets incidents on the same child, a malignant hyperthermy. Wound healing was delayed in 2 cases.

Author review literature to considerate other surgical methods than pollicisation in Wassel VII thumb duplication but pollicisation of the duplicated index seems the best cosmetic procedure.