Clinical, radiological and pathochemical substantiation of osteosubstitution by hydroxyapatite ceramics with β-tricalcium phosphate and platelet-enriched autofibrin in fragmentary bone fractures in dogs

Abstract

Due to the similarity of its composition to bone tissue, bioactive ceramics based on hydroxyapatite are considered the most promising for osteosubstitution of fragmentary fractures, and topical application of pharmacological agents and autologous agents bioactive substances, in particular, platelet-rich fibrin (PRF). The work aims to clinically and radiologically, and pathochemically substantiate osteosubstitution by hydroxyapatite ceramics with β-tricalcium phosphate and platelet-enriched fibrin for fragmentary bone fractures in dogs. A control and two experimental groups of animals were formed, including patients (n = 10) with humerus and forearm fractures. After general and local anesthesia and extracortical osteosynthesis, the first experimental group was injected with platelet-rich autofibrin between bone fragments. The second group was osteosubstituted with a combination of PRF and hydroxyapatite ceramics; in the control group, the defects remained without replacement. For biochemical studies, blood samples were taken after injury no later than 24 hours and on the 3rd, seventh, 14th, 21st, and 42nd day after osteosynthesis. In the postoperative period, clinical and radiological studies were performed. The activity of bone isoenzyme alkaline phosphatase (BAP), tartrate-resistant acid phosphatase (TrAP), the level of total calcium (Ca), inorganic phosphorus (P), and total protein were determined in blood serum. It was found that complete recovery of limb function in the experimental groups was 1.2–1.4 times faster (P < 0.001) compared with the control group and radiologically confirmed earlier consolidation of fractures. In both experimental groups, the maximum activity of BAP was observed on the 14th day, in the absence of a significant difference between these groups, while in control – it peaked on the 21st day. In the case of bone injury, the level of TrAP decreased by 1.2 times (P < 0.05) and then gradually increased, which was significant in the control group on the 42nd day, in the first experimental group on the 21st, and the second on the 14th day. On the third day after osteosynthesis, the concentration of P was still lower in the control (P < 0.05) and the first experimental (P < 0.01) group compared with clinically healthy animals. The concentration of Ca on the third day was reduced in all groups by 1.2 times (P < 0.001) and then gradually returned to normal. The use of PRF with calcium-phosphate ceramics for osteosubstitution helps to optimize regeneration processes in the area of bone injury by activating osteoblastic cells and reducing the intensity of the osteoresorption reaction with an earlier reaction of bone regeneration remodeling.