Exploring reconstructive alternatives to pollicization for modified Blauth type IIIB-V congenital thumb hypoplasia: A systematic review.

Background: Although pollicization remains the traditional treatment strategy for modified Blauth type IIIB-V grade congenital thumb hypoplasia, many patients and parents express interest in alternative reconstructive approaches that maintain a five-digit hand. The aim of this study was to provide a summary of these alternative techniques and to assess for differences in their outcomes, with the hypothesis that techniques featuring vascularized bone grafts would have fewer instances of bone resorption or nonunion relative to non-vascularized techniques. Methods: A systematic literature review was conducted in PubMed, Embase, and CINAHL using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies describing the reconstruction of modified Blauth type IIIB-V hypoplastic thumbs were included. Chi squared tests (or Fisher exact tests where appropriate) were performed to compare aggregate complication data. Results: Twenty-four articles met inclusion criteria, yielding 207 patients with 210 thumbs undergoing reconstruction. Mean patient age at surgery was 3.4 years, while the mean follow-up time was 4.2 years. 203 of the 207 patients underwent reconstruction using one of five techniques: PIPJ/MTPJ transfer, hemi-metatarsal transfer, toe and metatarsal transfer, iliac crest transfer, and toe phalanx transfer. PIPJ and MTPJ transfers were the most performed procedures (n = 54, 26 %). Vascularized grafts were used in 89 cases (43 %), while non-vascularized grafts comprised 114 cases (55 %). Rates of bone resorption and nonunion were higher in non-vascularized grafts, though not significantly so (n = 203, p = 0.19). Conversely, donor site complications were significantly higher in vascularized bone grafting techniques (n = 203, p = 0.0056). The most frequently reported outcome measures were Kapandji scores (46 %) and key pinch strength (46 %). Kapandji scores had a weighted mean of 5.6 (range 3.1-6.7). Conclusion: A variety of alternative techniques exist for reconstructing severely hypoplastic thumbs, though no technique demonstrates clear superiority. Vascularized grafts trend towards a lower bone resorption/nonunion rate relative to non-vascularized grafts, though there is evidence of heightened risks of donor site complications when taking vascularized bone grafts from the foot. Objective outcome measures showed variability across studies limiting comparisons between techniques.