Surgical Technique and Outcomes of Reconstruction for Blauth Type III Thumb Hypoplasia.

Background: Historically, amputation and pollicization has been the recommended surgical treatment for Blauth type III hypoplastic thumbs. However, due to aesthetic objections or cultural preferences, some parents seek out alternative surgical options. The present study describes a nontraditional technique that preserves and augments the hypoplastic thumb.
Methods: Patient charts were retrospectively reviewed to identify patients with Blauth type III hypoplastic thumbs who underwent thumb reconstruction at our institution from 2008 to 2018. The reconstruction procedure involved toe phalanx transfer, staged tendon transfers, and lengthening as needed. Motion was assessed categorically as ability to flex, extend, or oppose the thumb. Functionality was assessed as ability to pinch and grasp with the surgical hand. Patient- or parent-reported improvement in thumb function was also recorded.
Results: Of the 13 patients, 100% could flex, extend, and oppose the thumb to some degree. Eleven patients (85%) had functional one-handed grasp, and 9 (69%) had a functional pinch. Eleven patients (85%) reported no functional limitations of the operative hand. Thirteen patients (100%) reported improvement in hand function after surgery as compared to pre-operatively. There were 2 minor complications (15%), both of which resolved after intervention. No patients experienced donor-site morbidity.
Conclusions: Reconstruction of Blauth III thumbs is a nontraditional technique that allows for digit retention by salvaging the hypoplastic thumb. In the present study, the majority of patients had functional thumbs and all reported postoperative improvement. Overall, our results suggest that reconstruction is a viable surgical option for Blauth III hypoplastic thumbs.