Method for generating transparent porcine tibia showing the intraosseous artery

BACKGROUND: The occurrence of nonunion after tibial fracture surgery is mainly related to insufficient blood supply. Therefore, anatomical study of the internal and external tibial artery is very important, but there is no good method for displaying the intraosseous artery clearly and intuitively. This hinders the protection and reconstruction of it by surgeons, as well as the development of new instruments and techniques by researchers. OBJECTIVE: To develop a transparent specimen that could clearly display the intraosseous artery of the tibia. METHODS: In 10 isolated pig calves with popliteal vessels, the popliteal artery was exposed and a tube was placed. A casting agent was then injected at constant pressure, and the tissue around the blood vessel was preliminarily removed after solidification. The perivascular tissue and periosteum were further removed via alkali corrosion, and the tibia was fixed with an external fixator to protect the non-corrosive areas at both ends. Alternate acid corrosion and flushing were then applied until the intraosseous artery was completely exposed. The distribution and branches of intraosseous nutrient arteries were observed with the naked eye and via microscopy. Three-dimensional (3D) scanning and 3D printing filling techniques were used to make transparent tibia specimens with preservation of intraosseous arteries. RESULTS: A cast specimen of the intraosseous artery of porcine tibia was successfully generated via epoxy resin perfusion combined with acid–alkali etching, and the intraosseous artery was clearly visible. The 3D printing and filling technique successfully produced a transparent tibia specimen with preservation of internal bone arteries, and accurately restored the external shape of the tibia. The foramen of the nutrient artery appeared near the middle upper third of the lateral edge of the tibia. After entering the tibia, the nutrient artery proceeded forward, medial, and downward for a certain distance, twisted and turned near the midpoint of the medullary cavity, and divided into the ascending and descending branches. After going in the opposite direction for a distance, the ascending trunk sent out 2–3 branches, and the descending trunk sent out 2–3 branches. CONCLUSION: The cast specimen of pig intraosseous artery generated via the above-described perfusion corrosion method provides methodological guidance for the study of anatomical characteristics of the intraosseous artery, and a theoretical basis for the study of new methods of internal fixation and reconstruction of the blood supply of the lower tibia.