Temporal analysis of vascularized and nonvascularized rib grafts in canine spine surgery

The authors have previously reported work demonstrating the superiority of vascularized vs. nonvascularized rib grafts, which were inlaid to bridge three vertebral bodies studied at 3 months postoperatively. They questioned whether the mechanical and biologic properties of the nonvascular grafts would improve over time to approach the performance of the vascularized grafts by 6 months. They found that, with increased time, the vascularized grafts continued to improve, showing hypertrophy, maintenance of cortical integrity, and bonding to the recipient vertebral bodies. The nonvascularized grafts, however, showed porosity, fragmentation, and replacement by spongiosa. Mechanical properties showed increased performance in the vascularized vs. nonvascularized grafts, and no improvement was seen between the nonvascularized grafts from 3 to 6 months.