Current concerns regarding healing of bone defects

Introduction Bone tissue usually heals spontaneously, but in complicated conditions such as pathological fractures or those situations leading to large bone defects, the healing process fails. Therefore, it is still a challenge for orthopaedic surgeons to treat and reconstruct large bone defects, delayed unions and non-unions. A variety of therapeutic modalities have been developed to enhance the healing response and fill the bone defects. Different types of glycosaminogl ycans, growth factors, stem cells, natural grafts (auto-, allo- or xenografts) and biologic- and synthetic-based tissue-engineered scaffolds are some of the examples. Nevertheless, these organic and synthetic materials and therapeutic agents have some significant limitations, and there are still no well-approved treatment modalities to pass all the expected requirements. Bone tissue engineering is a newer option than traditional grafts, which may overcome many limitations of the bone graft usage. To select an appropriate treatment strategy in achieving a successful and secure healing, more information concerning injuries of bones, their healing process and knowledge of the factors involved are required. Hence, this paper reviews how the bone fractures heal. It is hoped that this review will provide useful information to orthopaedic surgeons and investigators working in the field of bone healing. Conclusion There are many natural and synthetic biomaterials, but it is very difficult to treat large bone defects. Finding a composite graft has been very difficult. Development of techniques for bone tissue engineering has shown promise. All strategies show limitations; thus, we call for further studies pertaining to bone fracture healing to help us improve the bone healing methods.