Spontaneous Bone Regeneration in an Open Segmental Fracture of the Forearm with Extruded Middle Segment

Cefazolin/BMP-2-Loaded Mesoporous Silica Nanoparticles for the Repair of Open Fractures with Bone Defects

The study aimed to explore the feasibility of a nanodrug delivery system to treat open fractures with bone defects. We developed a cefazolin (Cef)/bone morphogenetic protein 2 (BMP-2)@mesoporous silica nanoparticle (MSN) delivery system; meanwhile, Cef/MBP-2@ poly(lactic-co-glycolic acid) (PLGA) was also developed as control. For the purpose of determining the osteogenic and anti-inflammatory actions of the nanodelivery system, we cultured bone marrow mesenchymal stem cells (BMSCs) and constructed a bone defect mouse model to evaluate its clinical efficacy. After physicochemical property testing, we determined that MSN had good stability and did not easily accumulate or precipitate and it could effectively prolong the Cef’s half-life by nearly eight times. In BMSCs, we found that compared with the PLGA delivery system, MSNs better penetrated into the bone tissue, thus effectively increasing BMSCs’ proliferation and migration ability to facilitate bone defect repair. Furthermore, the MSN delivery system could improve BMSCs’ mineralization indexes (alkaline phosphatase [ALP], osteocalcin [OCN], and collagen I [Col I]) to effectively improve its osteogenic ability. Moreover, the MSN delivery system could inhibit inflammation in bone defect mice, which was mainly reflected in its ability to reduce the release of IL-1β and IL-4 and increase IL-10 levels; it could also effectively reduce apoptosis of CD4+ and CD8+ T cells, thus improving their immune function. Furthermore, the percentage of new bones, bone mineral density, trabecular volume, and trabecular numbers in the fracture region were improved in mice treated with MSN, which allowed better repair of bone defects. Hence, Cef/BMP-2@MSN may be feasible for open fractures with bone defects.

Reimplantation of a Large Extruded Segment of Tibia in an Open Fracture in a Pediatric Patient

A 6-year-old boy presented with a Gustilo type IIIB open fracture on his left leg with a segment of bone loss in his tibia. The boy's attendants brought two bone fragments recovered from the scene of the accident. The extruded bones were a segment with a length of 5.5 cm and a cortical bone with a length of 4 cm. The extruded fragments were reimplanted after scrubbing with 10% povidone–iodine for 20 minutes, soaking in 2% chlorhexidine solution for 20 minutes, and rinsing with normal saline. Four months after the injury, the extruded fragments were incorporated in the callus of the fracture site and complete fracture union in appropriate alignment was achieved.