The detailed anatomy of the 1,2 intercompartmental supraretinacular artery for vascularized bone grafting of scaphoid nonunions.

Purpose: To describe the configuration of the 1,2 intercompartmental supraretinacular artery (1,2 ICSRA), including the location of the perforators, and to discuss the clinical use of the 1,2 ICSRA for vascularized bone grafting of scaphoid nonunions.

Methods: Thirteen fresh-frozen cadaveric forearms were used to evaluate the variations in the anatomy of the 1,2 ICSRA. After injection of red latex, the 1,2 ICSRA and its perforators were characterized and measured. Pedicle length and distal reach of the transposed 1,2 ICSRA pedicle was evaluated. We noted the relationship of the 1,2 ICSRA to the dorsal scaphoid branch of the radial artery. Another 10 specimens were injected, frozen, and sectioned to evaluate vascular penetration into the dorsal distal radius.

Results: The 1,2 ICSRA branched from the radial artery 1.9 mm proximal to the tip of the radial styloid (range -6.3-3.2 mm), on average. The average pedicle length was 22.5 mm (range 15-31 mm), which permits its application for both dorsal and volar scaphoid. The relationship between the origin of the 1,2 ICSRA and the dorsal scaphoid branch was categorized into 3 types, including--separate, combined, and shared. The average number of perforating vessels arising from the pedicle was 5.5 (range 3-7), with an average of 2.75 (range 1-7) perforators overlying a 1 by 0.5 cm block of the distal radius bone graft. A graft located between 8-18 mm proximal to the articular surface of distal radius would incorporate the greatest numbers of perforators. The most notable vascular penetration of the distal radius was demonstrated at 10.0 mm proximal to the radial styloid.

Conclusions: The detailed anatomy of the 1,2 ICSRA presented in this study may guide in planning and dissection to maximize the vascularity of a pedicled bone graft based on this vessel for the management of scaphoid nonunions.