From an anatomic perspective, this paper delineates the proximal radial bone branches of the radial artery (RA). We also report the successful clinical use of a vascularized proximal radius bone graft (VPRBG), supplied by the RA, in a complex case involving a massive osseous elbow defect. In 10 latex-colored upper limbs from fresh human cadavers, RA branches were dissected under ×2.5 loupe magnification, noting all periosteal and osseous branches for the proximal radius. VPRBG length was measured. In the proximal forearm, the RA provides 10 (range: 7 to 14) periosteal and osseous branches to supply the area from the radial head to the proximal diaphysis. A 15 cm (11 to 17) vascularized bone graft can be harvested from the proximal radius, and RA dissection generates a 12 cm (9 to 15) pedicle with a wide arc of rotation, readily capable of reaching the distal part of the humerus. We used a 14 cm long VPRBG for elbow arthrodesis to fill a 12 cm defect, caused by a previous recalcitrant elbow infection in a 68-year-old man. The patient experienced no postoperative complications and successful consolidation was achieved 6 months postoperatively, with flap survival confirmed. After 2 years of follow-up, the contoured dorsal plate was removed, with no signs of infection. Final Disabilities of the Arm, Shoulder, and Hand and Mayo Wrist scores were 23 and 88, respectively. A VPRBG might be a safe and effective surgical option for massive osseous elbow defects, whenever elbow arthrodesis is planned, where it should be combined with a one-bone forearm technique.