gms | German Medical Science

Objectives/Interrogation: The patients of severe types (Blauth type IIIB and IV) of hypoplastic thumb are classically treated by pollicization. However, pollicization is not equivocally acceptable due to differences in parents' expectations. Furthermore, the concept of a 4-digit hand is culturally unfavorable, particularly in Asian countries. The objectives of this study was to introduce the method of digit preservation treatment for type IIIB or IV hypoplastic thumb using a non-vascularized metatarsal transfer and staged reconstruction and report the early results.

Methods: From June 2013 to June 2016, a digit preservation treatment method was performed for 42 type IIIB and IV hypoplastic thumbs using a non-vascularized metatarsal graft and staged functional and aesthetic reconstruction. The 4th metatarsal was transferred for the reconstruction of the 1st metacarpal and CMC joint. The iliac bone graft or half of the 3th metacarpal was used to reconstruct the donor metatarsal defect. The Huber procedure or the ring finger FDS transfer was performed at the second stage for opponensplasty. The free fat graft or local flap was performed to improve the cosmetic appearance of the reconstructed thumb as required.

Results and Conclusions: Thirty-three cases had complete follow up data. The average follow-up was of 27 months and the average age at operation was 19 months. All patients achieved reasonable hand function and all the parents were satisfied with the appearance of the 5-digit hand. There were 3 partial skin flap necrosis at the recipient site. There is one bony nonunion at the recipient site and healed with iliac bone graft. There was no obvious complication at donor site.

The staged functional and aesthetic reconstruction is a feasible method for patients with type IIIB and IV hypoplastic thumb. It allows the preserving of a 5-digit hand with acceptable functional and cosmetic outcome.