Effects Of The Healing Process Of Open Tibial Fractures In Rabbits Coupled With Seawater Immersion

Objective: To observe the effects of the healing process of open tibial fractures in rabbits coupled with seawater immersion.Methods: 44 New Zealand rabbits were randomly divided into two groups:22 rabbits in group A,22 rabbits in group B.Two groups suffered with open fracture.The wounded limbs of group A were exposed in the air for three hours. And group B were immersed in seawater for three hours.Followed, suture the wound after debridement.The rabbits were sacrificed on days 7,14,21,28 respectively after surgery.Then,samples were collected for histopathology through electron microscope and light microscope.Meanwhile the expression of vascular endothelial growth factor (VEGF) and transforming growth factor-β1(TGF-β1) in tissues were observed.Results: By electron microscopy,osteoblasts of group B were observed injury early after the fracture.Performance as cell membrane and nuclear membrane damage,mitochondrial swelling and vacuolation,nuclear dissolution of necrosis.21 and 28 days of osteoblasts of group B morphology returned to normal. Immunohistochemistry showed that the expression of VEGF and TGF-β1 of group A gradually increased to the peak at 14th day after fracture,and then decreased;the expression of VEGF and TGF-β1 of group B is also present from weak to strong and then gradually decreasing in ,peak within 14th to 21th days after fracture,but the expression intensity of each period were significantly weaker than group A.28 days for group A, bone callus were 15 limbs,accounting for 75%,mixed bone callus (cartilage and bone callus) were 5 limbs, accounting for 25%;group B bone callus completely were 6 limbs,accounting for 30%,mixed bone callus were a total of 14 limbs,accounting for 70%,compared the two groups differ significantly (P<0.05).Conclusion: Seawater immersion injure the osteoblasts in tissues near the breaked bone,decrease expression intensity of VEGF and TGF-β1,and then impact the process of cartilaginous ossification and intramembranous ossification,delay fracture healing.