Experimental Study Of The Different Forms Of Non-vascularized Structural Bone Graft On Bone

Object:Non-vascularized structural bone graft in bone defects in thetarget region to stress in different directions of the trabecular bone orbone grafting on bone healing of the micro-environmental impactanalysis principles and mechanisms that may exist. For further studythrough the determination of the indicators of the microenvironment ofthe bone graft bone defects in the target area, repair and reconstruction ofbone defects of different bone graft from the microscopic structure andmolecular physics and chemistry. To explore new ideas, to provide a newmethod for the clinical treatment of the bone defects.Methods: This study first established bone defect model, choose thesame origin,4-6months, weight2.5-3.5kg38New Zealand white rabbits,male or female, in the middle of the femur osteotomy15mm (includingperiosteum), boneends closed canal, miniplate fixation of femoral bonewax to maintain the bone ends15mm spacing, the X-ray to determinebone defects after12weeks.Select New Zealand white rabbits were made of bone defect model38(reserved2), which were randomly divided into A, B, C and threegroups (n=12). Ear vein injection of3%sodium pentobarbital anesthesia,and to take on the same side for autologous iliac bone graft source, and the iliac cut size equal to8along the trabecular bone or stress direction.Remove the plate and screw which were used to producted the femoraldefect model,and clean up the fibrous tissue of the bone defect, scleroticbone, recanalization of the medullary cavity, reset, on line, fixed bymini-plate and screw. Group A plant iliac in femoral defect with femurstress (bone trabeculae) in the same direction; Group B planting iliacblock in the direction that perpendicular to the explants of femoral stress(trabecular bone); Group C randomly implanted in the femoral defect area.Use homemade splint for2weeks after the operation. Then detected atthe2nd,3rd,4th week, Each time in each group we collect4rabbits,detection the indicators:1, to observe the animals in general, include thebody temperature, activity, spirit, stomach satisfied, and wound healing.2,the experimental side of the femur X-Ray, general observation andsituation of bone defect repair of callus, use computer image processingsoftware to detect the average optical density of the bone graft area,calculate the index of the optical density.3,animals were killed by airembolism rapidly. The specimens were placed in fixative save,decalcified, dehydrated, paraffin block-embedded and other processing,sliced in4um, HE staining, immunohistochemistry of the bone graft areapositive cells in the measuring window area (%) to be recorded and newbone formation.4and8weeks using the same method. Results:1.The reliability of bone defect modelAfter the bone defect model was produced12weeks later, X-rayexamination showed: no bony connection on the bone defect area, canalocclusion, the ends hardened both sides of the ends, a small amount ofcallus. Specimens: a small amount of relatively thin callus, the bonedefect was filled by fibrous scar tissue, the defect range:13-14mm, in linewith standard bone defect (Critical size defect in CSD) requirements.2.Generally observedThree groups of rabbits, one died because the anesthesia, another onedied because of a possible surgical trauma in the second day. Two newrabbits were instead into the experimental procedures. In the entireexperimental period, all animals are analyzing, animal growth is good,weight-bearing activities after anesthesia, no redness, exudation. Eachgroup active normaly before death, No claudication, displacement, plateand screw loosening,secondary to fracture3. gross observationNo bone defect region soft tissue degeneration and necrosis of the surfaceof the fibrous connective tissue in the postoperative period. Late defectshow callus thickening, increased cortical bone continuous.4. X-ray observationsIn two weeks, the bone grafts are smaller than before, boundaries were clear in the three groups of bone defect. Group A, a small amount ofpatchy shadows; group B, the bone defect area has no significant callusformation; group C, the bone defect region, the formation of a smallamount like cloudy shadow.Four weeks, the bone defect area is blurred, there are a lot of callusformation; group B, the bone defect area callus formation, clear lines ofbone graft; in group C, the bone defect area blurred than in group B callusgrowth significantly.Eight weeks, the fuzzy boundary of group A, B, C,, a large number ofcallus formation, cortical bone formation, continuous, and the medullarycavity is not completely the same. Each group of bone defects of theoptical density index tended to increase over time, four weeks, group Aand group B, statistical analysis, P <0.05, statistically significant; GroupC and Group B, P>0.05, no statistical significance; group A and group C,P <0.05, statistically significant.2and8weeks, each group of bonedefect optical density index, P>0.05, not statistically significant.5. specimens of pathological findings5.1immunohistochemistry-positive cells in the measuring window area(%) after two weeks, each group of bone defects regional vascularobvious proliferation of group A> group C> group B, group A and groupB, P <0.05, statistics significance; group C and group B, P <0.05,statistically significant; group A and group C, P <0.05, statistically significant.4weeks after surgery, group A and group B, P <0.05,statistically significant; group C and group B, P>0.05, no statisticalsignificance; group A and group C, P>0.05, not statistically significant.8weeks after surgery, A, B, C, positive cells accounted for the measuringwindow area (%) close to (P>0.05), no significant statistical difference.5.2tissue biopsies new bone formation after2weeks, each group of bonedefects of varying degrees of new bone formation, two weeks, A, B, C, P<0.05, statistically significant;4weeks after surgery groups bone defectnew bone formation compared to two weeks significantly increased ingroup A and group B, P <0.05, statistically significant; group C andgroup B, P <0.05, statistically significant; group A group C, P>0.05notstatistically significant. After8weeks, A, B, C groups, P>0.05, notstatistically significant.Conclusion: The non-vascularized structural bone graft in the treatmentof bone defects, with the derection of trabecular bone or stress directiongrafting is influential in early healing of bone defects, the graft trabeculardirection and the bone in the same direction planting in the early bonehealing is superior to the vertical direction of the bone grafting.