Metaphyseal fracture healing is important in joint-adjacent fractures and appears to differ from diaphyseal healing. We recently found that a biomaterial delivering bone morphogenic protein-2 (BMP-2) and zoledronic acid (ZA) healed the metaphyseal bone in a tibial defect but failed closing the cortical defect. In this study we added a BMP-2 soaked collagen membrane to study cortical healing from the muscle tissue surrounding the bone. We used SD rats and a 4.5 mm