Background and objectives: Congenital thumb hypoplasia is a rare deformity of upper extremity. The incidence for thumb hypoplasia grade II–V is 1:10,000 newborns per year in Latvia. A technique for extensor indicis proprius (EIP) tendon transfer with subperiosteal fixation was developed and used for thumb hypoplasia grades II and IIIa. Pollicization or second-toe-to-hand transplantation with metatarsophalangeal (MTP) joint arthrodesis was used for the reconstruction of hypoplasia grade IIIb–V. The aim of this retrospective cohort study is to evaluate the outcomes for reconstruction techniques used in one surgical center during a ten-year period by one surgeon to evaluate functional and aesthetical outcomes for new techniques. Materials and Methods: In total, 21 patients were operated on during 2007–2017, and 18 of these patients were involved in this study. Long-term follow-up was completed to evaluate the functions and aesthetics of the hands. Results: disabilities of the arm, shoulder and hand (DASH) was 9.35 (8–10.7) for the second-toe-to-hand with MTP joint arthrodesis transplantation method for pollicization method 19.8 (6–26.7), and for the EIP tendon transposition, 14.54 (0.9–56.3). Conclusions: The postoperative functional parameters of congenital hand hypoplasia patients, regardless of the surgical method, are worse than the functional results of healthy patients. The use of the second-toe-to-hand with MTP joint arthrodesis transplantation method provides patients with congenital hand IIIb–V hypoplasia a stable and functional first finger formation. The functional results are comparable to the clinical results of the pollicization method while ensuring the creation of a five-digit hand.

The first toe-to-hand transplantation was done in 1898 by Nicoladoni. It was a staged procedure and the toe flap was based on a pedicle. With advancement of optical instruments and microsurgeons’ skills in 1964 the first microvascular toe-to-hand transplantation on a rhesus monkey was done. The technique’s development has not stopped, many authors have modified it to achieve better outcomes for both traumatic and congenital hand defects. The most commonly used toes for transplantation are first, second, and second to third toe block. Well described plantar and dorsal vascular systems for first web space vessels as well as possibility to perform successful perforator anastomosis allows us to improve toe-to-hand transplantation further. There is a paucity of studies on single fourth toe-to-hand transplantation. We performed fourth-toe transplantation for three pediatric patients (mean age, 73 mo) with congenital (n=2) and traumatic (n=1) hand defects. Common plantar digital arteries were used for blood supply to the transplanted toes. No vascular problems occurred, and all transplanted toes survived. Patients and parents are satisfied with functional and esthetic outcomes. Early podometry results show insignificant changes which should not harm the foot in the long-term. We believe the fourth-toe transplantation is a promising method to use to reconstruct congenital or traumatic absence of digits for pediatric population.

Congenital thumb hypoplasia is a rare deformity of the upper extremity. The classification of thumb hypoplasia was created by Blauth in 1967 (types I to V). The base of the first metacarpal bone is absent for hypoplasia types IIIb to V, therefore, toe-to-hand transplantation is not recommended. A stable first carpometacarpal joint has been considered a mandatory factor for a successful toe-to-hand transplantation. The aim of this study is to describe a new technique for thumb reconstruction with the second toe transfer and metatarsophalangeal joint (MTPJ) arthrodesis, which can provide a five-digit hand and restore thumb functionality for thumb hypoplasia IIIb to V. We performed second toe-to-hand transplantation with MTPJ arthrodesis for 3 pediatric patients (mean age, 69 mo) with congenital thumb hypoplasia IIIb (n=2), grade V (n=1). Long-term follow-up evaluated the functions and esthetics of the hands for grade IIIb patients (n=2). We believe the second toe transfer with MTPJ arthrodesis transplantation is a promising method for reconstructing a full-length congenital or traumatic thumb absence for the pediatric population.

Congenital thumb hypoplasia is a rare deformity of the upper extremity. Incidence of thumb hypoplasia type I–V was 2–3 and type IIIb-V was 0.5–1 per 20 000 newborns per year in Latvia. The classification of thumb hypoplasia was created by Blauth in 1967 (type I to V). The base of the metacarpal bone is absent for hypoplasia type IIIb–V; therefore, toe-to hand transplantation is not recommended. A stable first carpometacarpal joint has been considered a mandatory factor for successful toe-to-hand transplantation. A technique for toe-to-hand transplantation for thumb hypoplasia type IIIb–V patients has been described in literature but overall results were not better than pollicisation. The aim of this study is to describe a new technique for thumb reconstruction with a second toe transfer with metatarsophalangeal joint arthrodesis, which can provide a 5-digit hand and restore the functionality of the thumb for thumb hypoplasia IIIb–V. Long-term follow up was done to evaluate the functions and aesthetics of the hands. A survey to evaluate aesthetical outcome for the transplantation method and pollicisation method was completed by 290 respondents. The overall population rated the aesthetic outcomes of the new transplantation method significantly higher than for pollicisation (p < 0.0001).