IntroductiontoFractures(EnglishVersion)ChenMTHEFIRSTLESSONOFTHESCHOOLYEAR•MechanismsofFracture•FractureHealing•ComplicationsofFractures•PreventionofFractures01IntroductionDefinitionofFractureFractureisadisruptionintheintegrityofthebonestructure,typicallycausedbyexcessivestressortrauma.Itisacommoninjurythatcanrangefromminortosevere,dependingonthelocationandtypeoffracture.Fracturescanbeclassifiedasopenorclosed,andtheycanalsobecategorizedbasedontheirseverityandcomplexity.TypesofFracturesSimplefracturesCompoundfracturesThesearelinearbreaksinthebonewithoutanyfragmentation.Whenthebrokenbonepiercestheskin,itisreferredtoasacompoundfracture.ComminutedfracturesGreenstickfracturesTheseareseverefracturesinwhichtheboneshattersintomultiplepieces.Theseoccurinchildren'sbones,whicharemoreflexible,andresultinabendingorbowingofthebonewithoutcompletebreaking.CausesofFracturesTraumaFalls,motorvehicleaccidents,sportsinjuries,andotherimpactsarecommoncausesoffractures.DiseasesBonediseaseslikeosteoporosiscanweakenthebonesandmakethemmorepronetofractures.RepetitivestressRepetitivestressinjuries,suchasstressfracturesinathletes,canleadtobonefractures.ViolenceIntentionaltraumainflictedbyanotherpersonisacauseoffracturesinsomecases.01AnatomyoftheBoneCorticalBoneCorticalboneistheouterlayeroftheboneandaccountsforabout80%ofthetotalbonemass.Itisdenseandcompact,providingstructuralsupportandprotectiontothebone.Corticalbonehasahoneycomb-likestructurethatallowsittowithstandcompressiveandtensileforces.Italsohasarichsupplyofbloodvesselsandnerves,providingnutrientsandsensationtothebone.MedullaryBoneMedullaryboneistheinnerpartoftheboneandconsistsofcancellousboneortrabecularbone.Itoccupiesthecentralportionoftheboneandprovidesaspaceforbonemarrowandbloodcellproduction.Medullaryboneislessdenseandmorelightweightcomparedtocorticalbone.Ithasaspongystructurethatallowsforflexibilityandresilience,helpingthebonewithstandimpactandload-bearingforces.BoneMarrowBonemarrowisthesofttissueinsidethebone.Itisresponsiblefortheproductionofbloodcells,includingredbloodcells,platelets,andwhitebloodcells.Therearetwotypesofbonemarrow:yellowmarrowandredmarrow.Yellowmarrowisfoundinthefattyareasoftheboneandisprimarilycomposedofadiposetissue.Redmarrowisfoundinthehematopoieticareasoftheboneandisrichinbloodcellprecursorsandstemcells.01MechanismsofFractureStressShielding应力屏蔽是由于外部应力的减少或消失，导致材料内部应力分布不均，从而引发断裂。当外部应力减小或消失时，如卸载或卸载后，由于材料内部各部分之间的相互作用，使得材料内部应力分布不均，从而引发断裂。FatigueFracture疲劳断裂是由于材料在循环应力的作用下，经过长时间的应力积累，最终导致断裂。疲劳断裂通常发生在材料承受循环应力的环境中，如机械零件、桥梁等。在循环应力的作用下，材料内部的微裂纹逐渐扩展，最终导致断裂。疲劳断裂通常具有明显的疲劳辉纹和断口特征。PathologicalFracture病理性断裂是由于材料内部存在缺陷或损伤，如裂纹、孔洞等，在外力作用下引发断裂。病理性断裂通常与材料的制造、加工、使用环境等因素有关。例如，焊接过程中产生的裂纹、机械加工过程中产生的微裂纹等都可能导致病理性断裂。此外，腐蚀、高温等环境因素也可能导致材料内部损伤，引发断裂。01FractureHealingPrimaryBoneHealingDefinitionPrimarybonehealingreferstotheinitialprocessoffracturehealingwherethebonetissuerepairsitselfdirectlyaftertheinjury.MechanismItinvolvesthedirectappositionofboneendsandtheformationofabloodclotatthefracturesite.Theb...
