| Nonunion is one of the important problems facing the orthopedic clinical，treatment program are more mixed results, the rise of stem cell therapy forbone connected treatment fundamentally a good treatment program, has agood application prospects. Fracture site gathered a sufficient number ofMSCs in the bone repair process. Therefore, to fracture the bone is not evenpart of the introduction of enough MSCs are a prerequisite to promote bonerepair and cytological basis. The resulting stem cells has become the treatmentof nonunion ideal seed cells.Stem cell transplantation for treatment of nonunion with good prospectsfor clinical application, the microdamage environment for the stem cell nicheenvironment, not only a combination of stem cells’ stem feature, but also tointroduce support the development of micro-damage induced differentiationenvironment.Objective: In this experiment, the rabbit radial nonunion model in themicro-damage environment treat by stem cell, a comprehensive response fromthe tracer, pathology, imaging, statistical and so on, stem cell transplantationfor treatment of nonunion reliable efficacy.Methods: The animals controlled trials. Select the20New Zealand rabbitswere randomly divided into two groups of test and control groups. Suctionrabbit tibia bone marrow blood, whole bone marrow adherent culturescreening method were isolated and cultured rabbit of BMSCs. Train to reach107orders of magnitude after SPIO culture mark BMSCs spare. Theapplication of the formation of bone defects fabricated nonunion model. Selectrabbit forelimb middle of radial osteotomy length of15mm, and theobservation time of six weeks. After the modeling, the experimental group in the local micro-damage environment downstream from the iliac bone particlesgrafting, while implantate allogeneic BMSCs transplantation. The controlgroup was only implantate autogenous iliac bone particles.1-12weeks afteroperation were comparative observation of the relevant checks, including:1.The general morphological observation;2.Pathological observation: HE staining and Prussian blue staining, thereaction osteogenesis and cell evolution;3.MRI dynamic in vivo stem cell tracking, scanning sequence:3D fsSPGRE, T2*GRE, T1FSE.4. X-ray imaging observations: After the rabbits X-ray examination,observation of the radial nonunion bone healing and callus change.5.Shida PACS diagnostic imaging workstation system to measure theX-ray film of callus formation area, income two group callus area contrast,application of statistical SPSS software to analyze two sets of data, P <0.05was considered statistically significant.Results:20New Zealand rabbits survived the final analysis.1.BMSCs isolation and culture of the amplification of MSCs inmorphology observed: after the separation of spindle cells and polygonal cellswas significantly increased colony grown, the number gradually increased,showing the long spindle, spindle, digestion and passage of amplified purifiedto3rd generation spare cell count reached107orders of magnitude. The stemcells were spindle and the spindle, and has the physical adherent adhesion andcolony growth characteristics identified as the rabbit of BMSCs.2.Model after six weeks to observe the test rabbits all survived well. Limbincision healed well and good activity, touch defects and radial segmentdepression. X-rays show: the middle of the radius defect without bonyconnection, the ends hardened bone marrow cavity closed.3. nonunion1-12weeks after the bone grafting respectively test group ofstem cell graft and bone graft in the control group compared observed.3.1Gross morphology observed: after3weeks of specimens wereobserved shape differences. The larger the observed stem cell group callus6 weeks after surgery; grafting side visible callus was significantly reduced,bone graft bone particles absorb.8weeks after the test group to see the callusincreased significantly, the implanted bone particles fusion, nonunion defecthealed; grafting side shows most of the bone marrow cavity closed,granulation tissue formation.12weeks of observation after the stem cell groupare fully restored, bone graft absorption of the control group, canal occlusion,and granulation tissue filling.3.2The SPIO-labeled stem cells, labeled BMSCs in T2WI, especially theGRE (T2*WI) sequence signal is significantly reduced, flake bone graft areacan identify the middle dot round signal T1of FSE sequence, and better ableto distinguish stem cells. Gradually reduce over time stem cell nuclearmagnetic imaging, about observation time in about eight weeks showed thatthe stem cells of the8weeks mark still has vitality. The bone graft group nochange.3.3X ray imaging results:2weeks after stem cell bone graft and bonegraft limb radial X-ray examination was no significant difference. Since3weeks it is clear that the bone graft group than in the stem cell bone graft boneparticles density and size decreased significantly reduce. Seen after4weeksthe bone graft group bone particles significantly reduced absorption; stem cellside of the visible defect is visible cloudiness change.6weeks in the controlgroup can be seen most of the bone particles absorbed by the bone marrowcavity is partially occluded; the defect area of the stem cell group was cloudyshadow was large callus part of the bone marrow cavity recanalization. Defectafter8weeks in the control group no connection to the bone, the bone graftabsorption; stem cell side was a large callus defect was the connection of thebone, the marrow cavity recanalization. Defect after12weeks in the controlgroup no connection to the bone ends sclerosis, bone marrow cavity closed;stem cell side of the defect area was the connection of the bone marrow cavityrecanalization and good plasticity.3.4pathological histology:2weeks, two groups of pathological form of contrast is insignificant. Visible fibrous connective tissue, and inflammatory cell aggregation, showingthat a large number of sequestrum debris.3weeks of stem cell group biopsy shows a large area of active proliferationof chondrocytes. The control group the sequestrum number more cartilagehyperplasia poor.6weeks of dry cell group BONE bone graft fusion seen freshmen class ofbone, osteoblasts increased, Prussian blue staining is visible within the localcell cellular blue dye particles stem cells, stem cells have been part of thedifferentiation of osteoblasts; fibrous connective tissue in the control grouptissue ingrowth, cartilage cell proliferation was not obvious, fewer osteoblasts,bone tablets reduce the absorption of the sequestrum more bone tissuestructural disorder, do Prussian blue staining did not see the blue dye particles.Stem cell group a large number of woven bone tissue, showing that moreosteoblasts, arranged in neat, bone structure close to the normal form; bonegraft control group found a large number of granulation tissue at8weeks.Bone defect of the stem cell group at12weeks is fully restored. Controlgroup shows granulation tissue filling the bone connection.3.5X ray image collected to Shida PACS diagnostic imaging workstationto measure the analysis Statistics bone defect area callus area change. SPSS13.0statistical software for analysis using statistical methods, P <0.01statistically significant differences.Conclusion: The bone marrow derived from allogeneic New Zealandrabbits BMSCs in vitro separation, culture, amplification, and a mixture ofautogenous iliac bone crushed in the environment of the micro-damageimplant bone defect of rabbit radius nonunion model. Experimentalcomparison of BMSCs has a more significant induction of osteogenesis andrepair a large section of defect bone is even clear effect, a significant effect. |
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