PrintEmailFacebookTwitterDiseases&ConditionsElbowDislocationWhenthejointsurfacesofanelbowareseparated,theelbowisdislocated.Elbowdislocationscanbecompleteorpartial,andusuallyoccurafteratrauma,suchasafalloraccident.Inacompletedislocation,thejointsurfacesarecompletelyseparated.Inapartialdislocation,thejointsurfacesareonlypartlyseparated.Apartialdislocationisalsocalledasubluxation.AnatomyNormalelbowanatomy. ReproducedwithpermissionfromTashjianRZ,KatarincicJA:ComplexElbowInstability.JAmAcadOrthopSurg2006;14:278-286.Threebonescometogethertomakeuptheelbowjoint.Thehumerusistheboneintheupperarm.Twobonesfromtheforearm(theradiusandtheulna)formthelowerpartoftheelbow.Eachoftheseboneshasaverydistinctshape. Ligamentsconnectedtotheboneskeeptheelbowjointtogetherandthebonesinproperalignment.Theelbowisbothahingejointandaballandsocketjoint.Asmusclescontractandrelax,twouniquemotionsoccurattheelbow.Bendingoccursthroughahingejointthatallowstheelbowtobendandstraighten.Thisiscalledflexionandextension,respectively.Rotationoccursthoughaballandsocketjointthatallowsthehandtoberotatedpalmupandpalmdown.Thisiscalledsupinationandpronation,respectively.Injuriesanddislocationstotheelbowcanaffecteitherofthesemotions.Theligamentsoftheelbow ontheinnerside(left)andoutersideofthejoint(right).CauseElbowdislocationsarenotcommon.Elbowdislocationstypicallyoccurwhenapersonfallsontoanoutstretchedhand.Whenthehandhitstheground,theforceissenttotheelbow.Usually,thereisaturningmotioninthisforce.Thiscandriveandrotatetheelbowoutofitssocket.Elbowdislocationscanalsohappenincaraccidentswhenthepassengersreachforwardtobraceforimpact.  Theforcethatissentthroughthearmcandislocatetheelbow,justasinafall.Theelbowisstablebecauseofthecombinedstabilizingeffectsofbonesurfaces,ligaments,andmuscles.Whenanelbowdislocates,anyorallofthesestructurescanbeinjuredtodifferentdegrees.Acompleteelbowdislocation.Asimpledislocationdoesnothaveanymajorboneinjury.Acomplexdislocationcanhavesevereboneandligamentinjuries.Inthemostseveredislocations,the