An intramedullary nail coated with antibiotic and growth factor nanoparticles: An individualized state-of-the-art treatment for chronic osteomyelitis with bone defects.

Among various infections, chronic osteomyelitis is one of the most challenging in terms of treatment. This infection is more common among patients with open fractures and those who have undergone elective orthopedic procedures. The treatment of osteomyelitis requires high antibiotic doses and an aggressive and multifaceted surgical approach. The use of parenteral antibiotics alone, without debridement, is not sufficiently effective, due to the formation of sequestra and the low vascularity of the affected area. The surgical options available for patients with chronic osteomyelitis include sequestrectomy, curettage, and intramedullary reaming, although these procedures usually result in bone defects that require further surgical intervention. Polymethyl methacrylate or calcium phosphate beads, impregnated with antibiotics, are commonly placed in such cases; however, this option has several disadvantages, including the need for future removal of cement, uncontrollable local release of antibiotics, and the need for broad-spectrum agents. The resulting bone defects also require additional treatments involving vascularized fibula grafting, intramedullary nails, use of techniques like Masquelet and Ilizarov, and even soft tissue transfers. All of these methods have certain limitations, such as the eventual requirement of more than one surgical event. Certain growth factors aid in the development and vascularization of new bone, such as bone morphogenetic proteins (BMPs) and insulin-like growth factor I (IGF-1). We propose that nanoparticles of BMPs, IGL-1, and microorganism-specific antibiotics can be placed on the surface of intramedullary nails. These nanoparticles can be attached to various different polymeric materials such as poly(d,l-lactide), which is a biocompatible and biodegradable polymer, and can be positioned in several layers, to ensure controlled and systematic release. The placement of nanoparticles at the infection site alone will also ensure local delivery of the drugs only to the required areas. Moreover, these intramedullary nails will be useful for both infected non-unions and mal-unions. Over time, the nanoparticles will eradicate the infection and stimulate new healthy bone formation, whereas the intramedullary nail itself will provide constant stability and immobilization. This model provides new and revolutionary ideas for the development of individualized technologies in medicine.