The vascular blood supply of the second metacarpal bone: anatomic basis for a new vascularized bone graft in hand surgery. An anatomical study in cadavers.

After traumatic loss of the index finger the second metacarpal bone is often used as a free graft to reconstruct bony defects of the thumb. Since clinical experience has shown numerous advantages of using a blood supplied bone graft, an anatomical study was performed in 104 cadaveric hands to investigate the vascularization supply of this bone. After dye injections into the arterial system the vascular situation of the second metacarpal was studied and a classification was made. Six variations in arterial vascularization were found. The nutrient vessels to the bone originate from the radial artery or from the deep palmar arch and correspond to variable metacarpal arteries. Selective injection studies via the respective pedicles showed sufficient perfusion and complete dye distribution in the bone. Further dissections could demonstrate the feasibility of raising a pedicled bone graft only partially with preservation of the index finger. The second metacarpal as a vascularized graft may be harvested entirely in serious injuries with destruction of the index finger in emergency cases of skeletal thumb reconstruction or partially as an elective procedure. All types have a useful arc of rotation and their pedicles allow transpositions within the radial side of the hand, especially for applications in the thumb and carpus. The clinical application of these procedures could be shown in five cases. The results of this study therefore provide the anatomical basis for transposition or free microvascular transplantation of the second metacarpal as a vascularized bone graft for a variety of indications in hand surgery.