The goals of surgery are to ablate the hypoplastic component and to create a stable and well-aligned thumb with a good pinch-function besides a maximum of mobility. Yet this aim is seldom achieved by simple ablative surgery alone which often results in a residual deformity and loss of function. The objective of this review is a critical analysis of the used surgical techniques in 113 cases of thumb duplication.
Using the classification proposed by Wassel to grade the thumb duplication the most frequent types were IV with 53 cases (48%), II with 27 cases (24%). Patient age at the time of initial surgery varied from 5 months to 26 years with a mean age of 20 months. 11 patients underwent previous surgery in another institution and had a second surgery at our hospital. 8 Patients underwent only simple ablation, in 88 cases there was an excision combined with reconstruction of collateral ligaments, in 51 cases combined with a tendon transfer or release and reinsertion. Osteotomy of the metacarpal bone or proximal phalanx was performed in 47 cases. 5 patients received a Bilhaut-Cloquet procedure. The most common complications were joint deviation (n = 12), joint stiffness (n = 2), joint instability (n = 11), nail deformity (n = 5) and scarring (n = 7). The 10 patients who under-went primary surgery at another institution and had to be reoperated are included in this listing. The type of secondary reconstruction was in 7 cases scar release, in 6 cases a ligament reconstruction, 4 patients received an arthrodesis and 6 patients needed a corrective osteotomy.