Use of a Medial Femoral Condyle Free Flap for Metacarpal Reconstruction of Type IIIC Congenital Thumb Hypoplasia

This is a case report of a 14-year-old girl with a Blauth Type IIIc hypoplastic thumb who underwent metacarpal reconstruction with a medial femoral condyle flap to preserve a five-digit hand. At the patient's 9-month follow-up, imaging demonstrated complete bone healing at both the first metacarpal recipient site and the donor site. At 17 months after surgery, the patient is satisfied with the appearance and improved function as she now has a stable post with a small amount of thumb abduction and adduction, with minimal donor site morbidity. The patient has elected not to undergo the planned second stage of opposition transfer, first webspace deepening, and tendon transfer for the time being, although these procedures may increase her function further. This case presents a novel application of the MFC flap to preserve a five-digit hand in a patient with congenital thumb hypoplasia, with minimal donor site morbidity.