Stabilization of the hypoplastic thumb type Blauth IIIB using a non-vascularized proximal interphalangeal joint from the toe as an alternative reconstruction when pollicization is not accepted: Description of the surgical technique.

Background: A Blauth IIIB hypoplastic thumb is a significant functional and cosmetic problem for the developing hand in children. The gold standard in treatment is amputation and index pollicization. Despite the good functional results, some parents do not consent to the operation, mainly for cosmetic reasons.

Objectives: The aim is to present a detailed description and features of the technique used in our department for stabilization of a hypoplastic thumb type Blauth IIIB with a non-vascularized proximal interphalangeal joint from the toe. This is the first description of this surgery for this kind of congenital defect, together with the largest group of patients analyzed compared to alternative techniques described in the literature.

Material and methods: Sixteen patients were included in the analysis. The mean age was 3 years (standard deviation (SD) ±2). In most cases, it was a unilateral and isolated defect. We described the surgical technique and postoperative management in detail and assessed intraoperative factors such as donor selection, operative time, technical problems, stabilization time, complication rate, and reoperations. Appropriate statistics were performed.

Results: Most often, the graft was taken from the 3rd toe. The average operation time was 59 ±17.5 min. No technical problems were found during the surgery. The Kirschner wire was removed after an average of 6.5 weeks. The complication rate was 25%, which included the destabilization of Kirschner wires or graft non-union, but it decreased to 6% after reoperation. Five patients underwent tendon transfers.

Conclusions: The presented technique is based on principles such as vascularized metatarsophalangeal joint transplants. It may be an option for stabilizing a hypoplastic thumb if parents do not consent to pollicization. Having microsurgical skills is unnecessary. The operation and anesthesia times are significantly shorter, resulting in less burden on the child's body. The study will continue assessing long-term postoperative functions and the comparison to pollicization.