Introduction: Although radial polydactyly is a common congenital hand malformation, its co-occurrence with thumb hypoplasia is rare, as the two are seen as opposite ends of a developmental spectrum. Radial polydactyly with thumb hypoplasia poses a significant diagnostic challenge, often leading to under-recognition and -treatment of the hypoplastic component. This study reviews our experience with the comprehensive management of this complex association. Methods: This retrospective study reviewed 13 cases (11 males) with a mean age of 28.2 months. Radial polydactyly with thumb hypoplasia cases that presented between 2017 and 2024 were reviewed. All patients underwent a tailored surgical strategy based on the Wassel classification and Blauth grade of hypoplasia in either single or two-stage procedures. Results: The majority of patients were classified as Wassel VII, and the most common thumb hypoplasia grading was Blauth II. At follow-up (13–88 months), reconstructed thumbs exhibited favourable aesthetics and functional opposition. Using the Japanese Society for Surgery of the Hand ratings, four patients were rated excellent, seven were rated good, and two were rated fair. Kapandji scores ranged from 6 to 9. Conclusion: Optimal outcomes in preaxial polydactyly require a high index of suspicion for potential thumb hypoplasia, even in its subtle forms. A comprehensive surgical plan that integrates the correction of both anomalies is fundamental to achieving reliable functional and aesthetic outcomes. Type of study/level of evidence: Therapeutic IV.
Yu et al. (Fri,) studied this question.