Study On Movement Method Selection And Its Mechanism After Internal Fixation Of Tibial Platform Fractures In Rabbits Based On Dynamic And Static Combination

Objective: "Combination of static and dynamic" theory is an effective method of fracture treatment in traditional Chinese medicine.In this study,the effects of passive,active and combined exercises on knee joint function are observed after tibial plateau fracture surgery in rabbits,in order to select the best rehabilitation method and study its mechanism,and provide the theoretical basis for selecting the most effective rehabilitation method after tibial plateau fracture surgery.Methods:A rabbit intelligent treadmill was desinged and made by ourself for active treadmill exercise intervention equipment when a rabbit knee joint automatic flexion and extension instrument was made for continue passive motion intervention.A rabbit wireless range of motion detector was made which could detect rabbit dynamic range of motion of knee joint.Twenty-four male 6-month-old New Zealand rabbits with combination of general anesthesia and local anesthesia method were used to establish a model of Schatzker IV fracture of the tibial plateau of the right knee joint and internal fixation with screw.At the end of the modeling,the rabbits were divided into four groups using random number table:6 rabbits in each group,continue passive exercise group(CPM),continue passive exercise group+treadmill exercise group(CPM+TRE),treadmill exercise group(TRE),and sedentary group(free movement in cage,SED):The CPM group began continue passive exercise on the first day after surgery for 4 consecutive weeks.The CPM+TRE group began continue passive exercise on the first day after surgery for 4 consecutive weeks,and began active treadmill exercise on the 15 th day after surgery for 2 consecutive weeks.The TRE group began the active treadmill exercise on the 15 th day after surgery for2 consecutive weeks.No exercise intervention in the SED group.All rabbits were measured the average dynamic knee range of motion within 15 minutes after the 4 weeks intervention on the treadmill,and then the rabbits modelled knees were observed with X-slices to compare the gaps of the knee joints,the growth of the callus at the fractures site,and the deformity at the fractures site;the degree of coronal plane deformity,osteophyte growth,deformity and continuous cortical bone were observed with three-dimensional CT.After the imaging examination of each group,the rabbits were taken and the tibia and articular cartilage gastrocnemius muscle tissues were surgically removed.The callus growth of tibial plateau fracture site was observed by HE staining,and the repair of articular cartilage was observed by HE staining and Safranin-O fast green staining.The BMP-2,IGF-1,TGF?-1 in the bone tissue of the tibia fracture site of each group was detected by immunoblotting;the left and right sides gastrocnemius muscles of the same rabbit were weighted to subtract and get the difference of wet weight,Part of it was used for HE staining to observe the pathological structure of gastrocnemius,and the other part was used to detect the protein content of IGF-1 and GDF-8 by immunoblotting.Results:The intelligent rabbit treadmill has accurate running speed and precise speed adjustment.The intelligent rabbit knee flexion and extension instrument runs stably,the bending and extension angle is accurate,and the wireless rabbit joint mobility measuring instrument is stable,which can accurately measure the rabbits knee range of motion during exercise.General observation:(1)weight and knee range of motion:4 weeks after surgery,there was no difference in body weight between the groups,in the knee range of motion comparison:compared with the SED group,the CPM+TRE group,the CPM group knee joint had the larger range of motion,there were statistical differences(P<0.05).(2)Comparison of the difference between the wet weight of gastrocnemius in each group:compared with the SED group,the difference between the CPM+TRE group,the CPM group and TRE group wet weight difference value was smaller,with statistical difference(P<0.05);compared with the TRE group,the difference between the CPM+TRE group and the CPM group wet weight difference value was smaller,with statistical difference(P<0.05);compared with the CPM+TRE group and the CPM group,there was statistical difference(P<0.05).(3)General appearance of tibial surface cartilage:4 weeks after operation,there were a lot of hyaline cartilage on the surface of articular cartilage in the CPM group,with transparent color and uneven thickness distribution;the color of articular cartilage in the CPM+TRE group was as usual,with smooth surface,normal transparency,thick and even cartilage layer,and flat articular surface;the color of articular cartilage in the TRE group was gray,with poor transparency and thin cartilage layer;the surface of cartilage in the SED group was not smooth,with irregular edges and surface defects.The imaging data showed:(1)The results of X-ray showed that the joint space of the SED group was the most narrow,the joint space of the TRE group was narrow,the joint space of the CPM group and the CPM+TRE group was significantly higher than the other two groups;the fracture area deformity of the SED group was more serious,the fracture area deformity of the TRE group was larger,the fracture of the CPM group was more smooth,and the fracture shaping of the CPM+TRE group was the most smooth,close to normal;the callus growth of the SED fracture site was poor,with transparent area,in the TRE group there was obvious fuzzy translucent areas appeared at the fracture site,and the callus growth of the CPM group fracture site was better,the fracture line was fuzzy,the callus growth of the CPM+ TRE group was the best,the fracture healing was close to normal.(2)The general appearance of CT three-dimensional scanning reconstruction showed:The joint space of the SED group was the most narrow,the deformity at the fracture site was the most obvious,and the deformity continued to the tibial shaft;the joint space of the TRE group was also relatively narrow,and the deformity at the fracture site was obvious,but did not continue to the tibial shaft;the joint space of the CPM group was wider than that of the former two groups,and there was slight deformity at the fracture site;the joint space of the CPM+TRE group was normal,with the smallest deformity at the fracture site,and the fracture site was smooth.Three dimensional CT reconstruction of sagittal plane showed : in the SED group,three-dimensional CT reconstruction showed that callus growth was poor in sagittal plane,and deformity was obvious in coronal plane;in the TRE group,there was obvious translucent area in sagittal plane,callus growth was poor,and deformity was obvious in coronal plane;in the CPM group,callus growth was better in sagittal plane than former groups,and deformity was small in coronal plane;in the CPM+TRE group,callus growth was the best in sagittal plane,with continuous bone cortex and coronal plane.It shows the smallest deformity and the best shaping.The pathological data showed:(1)The trabecular bone was scarce in the SED group,and the inflammatory response was obvious.The TRE group had less trabecular bone and the structure was sparse.The CPM group had more trabecular structures and arranged neatly.The trabecular bones of the CPM+TRE group are dense and arranged neatly.(2)HE staining of rabbit gastrocnemius compared left and right gastrocnemius muscle staining results:There was no significant difference in fiber density between the left(normal knee joint)and the right(internal fixation knee joint)gastrocnemius in the CPM+TRE group.The right gastrocnemius muscle fiber in the CPM group was slightly lower than the left side.The right muscle fiber density in the TRE group was lower than that on the left side,and the muscle fiber size was more uniform.The SED group was thinner than the left side muscle fiber and the muscle fiber size was uneven.Comparison of cross sectional area difference value between left and right gastrocnemius in each group:Compared with the SED group,the CPM+TRE group,the CPM group and the TRE group had Smaller difference in cross-sectional area with statistical difference(P <0.05);compared with the TRE group,the CPM+TRE group and the CPM group had smaller difference in cross-sectional area with statistical difference(P < 0.05);the CPM+TRE group and the CPM group had statistical difference(P<0.05).(3)HE staining of tibial surface cartilage showed:In the CPM+TRE group,the whole layer of cartilage was thicker,the new layer of cartilage was more,the arrangement of cartilage was regular,the cell layer was clear and the surface was flat;in the CPM group,the dominant tissue in the defect area was hyaline cartilage,the surface cartilage layer was thicker,many new hyaline cartilage on the surface of cartilage,the arrangement of chondrocytes was neat,the cell layer was clear;in the TRE group,the arrangement of cartilage was more orderly,the new cartilage was less,the cartilage layer was thinner;in the SED group,the cartilage layer was more regular disordered arrangement,few new cartilage,unclear cell layer and surface defect.(4)The Safranin-O fast green staining of tibial surface cartilage showed:In the CPM+TRE group,the cartilage was thicker,the subchondral bone was thicker and the tidal line was tidy;in the CPM group,the cartilage layer is thinner,the chondrocytes gather on the surface,the density is larger,and the tide line is clear;in the TRE group,the subchondral bone is more orderly,the new cartilage is less,the cartilage layer is thinner,the surface cartilage is thinner,the tide line is clear,and the cartilage arrangement density is large;in the SED group,the cartilage and subchondral bone are disorder,the tide line is not clear,and the chondrocytes are clear low density,surface defect.The immunohistochemical examination showed:(1)Four weeks after operation,in the comparison of the expression of growth factors in bone tissue,compared with the SED group and the TRE group,the expression of BMP-2,IGF-1and TGF?-1 in CPM+TRE group and the CPM group was higher,with statistical difference(P < 0.05);compared with the CPM group,the expression of three growth factors in the CPM+TRE group was higher,with statistical difference(P < 0.05).(2)Comparison of the expression of cytokines in gastrocnemius:Compared with the SED group and the TRE group,the expression of IGF-1 was higher in the CPM+TRE group and the CPM group,with statistical difference(P<0.05);compared with the CPM group,the expression of IGF-1 was higher in the CPM+TRE group,with statistical difference(P<0.05).Compared with the SED group,the expression of GDF-8 in the CPM+TRE group,CPM group and the TRE group was lower,with statistical difference(P <0.05);compared with the TRE group,the expression of GDF-8 in the CPM group and the CPM+TRE group was lower,with statistical difference(P<0.05);there was statistical difference between the CPM+TRE group and the CPM group(P<0.05).Conclusion:(1)In this research,A set of equipment for rabbit sports rehabilitation and knee joint function detection has been developed by ourselves,which provides a set of solutions for future intervention and detection in animal basic rehabilitation research.It runs reliably and provides objective data.(2)Postoperative rehabilitation exercise is more conducive to the recovery of limb function.Continuous passive exercise plays a role in repairing bone tissue and preventing skeletal muscle atrophy.Active exercise promotes the repair of articular cartilage.The combination of active and passive exercise is the best method for the rehabilitation of tibial plateau fracture after operation.It provides the most effective way for the selection of rehabilitation after operation of tibial plateau fracture.The experimental basis also provides a new content for the interpretation of the theory of "dynamic static combination" in the treatment of fracture by traditional Chinese medicine.