gms | German Medical Science

Objectives/Interrogation: Parents usually want a five-digit-hand for the child with Type IIIb hypoplastic thumb, though pollicization has excellent function results but 4-digit hand. Most parents concern more about the number of digit than the function of the hand. We reported our technique with half 2nd metacarpal transfer to reconstruct the 1st CMC joint and followed by tendon transfer to reconstruct the main function of the thumb.

Methods: We reported 14 thumbs of 12 children with IIIb hypoplastic thumb. The average age of surgery was 1.5 years (one year two months to two years one month). The surgery was performed in two stages. The first stage was to reconstruct the proximal part of the 1st metacarpal with half of the proximal 2nd metacarpal. Half year later, the second stage was performed with tendon transfer. Thumb extension was reconstructed with EDI tendon and thumb opposition with FDS from ring finger, MP joint was stabilized by tendon transfer in the meantime. All the children were followed up. The growth and the function of the reconstructed thumb were recorded and compared with contralateral thumb.

Results and Conclusions: The complete union of the bone transfer was seen in 10 of 12 children, and the other two with non-union was fixed with K-were during the second stage of surgery. The growth to reconstructed thumb still slower than the contralateral thumb, the grip and pinch power was less than the contralateral one, however, the parents were satisfied with five-digit thumb and the function.

In conclusion, the reconstruction of the Blauth type IIIb hypoplastic thumb with half second metacarpal and tendon transfer is an acceptable alternative to those who can not accept the procedure of pollicization.