An alternative method to reconstruct grade-3 hypoplastic thumb by hemi-metacarpal transfer.

We designed a new method using hemi-longitudinal second metacarpal bone to reconstruct grade-3 hypoplastic thumbs. Seven patients were treated in two stages. In the first stage, the second metacarpal was split longitudinally and transferred to reconstruct the first metacarpal. In the second stage, opponensplasty was performed by transferring the FDS tendon. Bone union was achieved in all cases. All patients could oppose to their middle finger at least. They managed to do daily activities such as writing, eating, using smartphones and so on. This is a useful procedure to preserve a 5-digit hand with good function in treating grade-3 hypoplastic thumbs, with no harm to the foot and no need for vascular anastomosis. LEVEL OF EVIDENCE: IV.