Download pdf - Rehabilitation Protocol for Patellar Realignment · Rehabilitation Protocol for Patellar Realignment 333 38th St. New York, NY 10016 (646) 501 7047 newyorkortho.com! The knee consists

Dr. Laith M. Jazrawi Chief, Division of Sports Medicine Associate Professor Department of Orthopaedic Surgery

Rehabilitation Protocol forPatellarRealignment

333 38th St. ▪ New York, NY 10016 ▪ (646) 501 7047 ▪ newyorkortho.com!

Thekneeconsistsoffourbonesthatformthreejoints.Thefemuristhelargeboneinyourthigh,anda9achesbyligamentsandacapsuletoyour;bia,thelargeboneinyourshin.Nexttothe;biaisthefibula,whichrunsparalleltothe;bia.Thepatella,commonlycalledthekneecap,isembeddedinthequadricepsandpatellartendonandar;culateswiththefrontofthefemur.Thisisthepatellofemoraljoint.Thepatellaactsasapulleytoincreasetheamountofforcethatthequadricepsmusclecangenerateandhelpsdirecttheforceinthedesiredupwarddirec;on.1Thepatellasitsinagrooveontheendofthefemurcalledthetrochleargroove.Thisgroovevariesindepthfrompersontoperson.Whilethekneeexes(bends),thepatellatravelsdownthegrooveandasthekneeextends(straightens)itmovesupthegroove.Asthepatellatravelsupanddowninthefemoralgrooveitmaintainsacongruentboneyalignment.ThispatellarmovementinthefemoralgrooveisoGenreferredtoaspatellartracking.Thereareseveralstructuresthatworktogethertokeepthepatellaalignedandstabilizedinthefemoralgrooveproperly,specificallytopreventthepatellafromexcessivelateralmovement.Thelateralaspectofthetrochleargrooveisnormallyabout1cmhigherthanthemedialwhichhelpstokeepthepatellainthetrochleargroovebyprovidingabu9ressonthelateralside(Figure1).2Thisprovidesthemainresistancetolateralpatellartransla;on(whichisthemostcommondirec;onofdisplacement),especiallybeyond20degreesofkneeexion.3Peoplewhohaveashallowtrochleaaremoresuscep;bletopatellarinstability.Properstabiliza;onofthepatellaisalsoaffectedbythesoG;ssuestructures(ligamentsandmuscles)surroundingtheknee.Themedialpatellofemoralligament(MPFL)isacon;nua;onofthedeepre;naculumandvastusmedialisoblique(VMO)musclefibers(innerpor;onofthequadricepsmuscle)ontheinsideoftheknee.Thesestructuresprovideasignificantforce(near60%total)againstlateraldisplacementofthepatella,astheirforceisdirectedinwardormedially.2,4TheMPFListheprimaryrestrainttolateraldisplacementofthepatelladuringthefirst20-30degreesofkneeexion.3Thisligamentisapassivestabilizerandextendsfromtheupperinnersideofthepatellatomedialaspectofthefemur.



Thepatellomeniscalligamentandre;naculumalsocontributeover20%oftherestrainingforce.Theseligamentscanbeinjuredandtornwithanini;alacutetrauma;cpatellardisloca;on(kneecapquicklygoingoutofplaceduringasportrelatedmovement).Themostcommonmechanismforanini;aldisloca;onisaforcefulinwardrota;onofthekneeonaplantedfoot.Theradiographbelowisthatofa12yearoldboyintheemergencyroomaGersuchaninjury(Figure2).OGen;mesthepatellawillgobackintoplace(orrelocatetothegroove)asthekneeisgentlystraightened.Inthiscasethepa;entwasunabletostraightenhiskneeandhispatellaremaineddislocatedlaterally.Noteontheradiographthatthereisnooverlapofthefemurandpatella.Anindividualcanalsohaveatrauma;cinstability.Inthissitua;ontheinstabilityismorelikelytobeapar;aldisloca;onorsubluxa;onandnotcreatedbyalargeforcefulone;meinjury.Peoplewithatrauma;cinstabilityusuallyhavepredisposingfactorsthataltertheirnormalpatellartracking.Thealignmentofthepelvisandfemurcanaffectpatellartracking.Thealignmentofthepelvisandfemurcanbestructurallyalteredbasedonapar;cularindividual’sangleofthequadricepsmuscle,alsoknownas“Qangle”.The“Qangle”isformedbythesuperiorlineofthequadricepspull(fromthehip)andthepatellartendon(inser;onontothefrontofthe;bia)astheyintersectatthepatella(Figure3).2Thealignmentofthepelvisandfemurcanalsobefunc;onallyalteredinaweightbearingposi;onduetohipweaknessorpronated(flat)feet.



Patellofemoralstresssyndrome(kneecappain)andpatellarinstabilityresultfromadevia;oninthenormaltrackingofthepatella.MostoGenabnormaltrackingresultsinlateralposi;oningofthepatella(towardtheoutsideoftheknee).Lateraldisplacementcanoccurfromthefemurrota;nginwardorthepatellabeingpulledoutward.Thiscanhappenasaresultofinjuryorrepe;;vestress.Instabilitycanoccurasamildsubluxa;on(slightlossofjointalignment),orasacompletedisloca;on(Figure2).Patellardisloca;ontypicallyinvolvesastrongquadricepscontrac;oncombinedwithaflexedandvalguskneeposi;onandaninternallyrotatedfemurrela;vetothe;bia.2InsportsthisoGenoccurswhenanathleteplantshis/herfoottopivotandthekneeturnsinwardwhiletheupperbodyandhipsareturningoutward.Annualincidenceofpatellardisloca;onsinpeopleunder16yearsofagewasfoundtobe43per100,000.Thisincidencelowersto31per100,000intheseconddecadeoflife,followedby11per100,000inthethirddecade,andevenfurtherto1.5-2per100,000inthosebetween30-59yearsofage.2Peoplewithrecurrentdisloca;onsofthepatellaoGenhaveanatomicalvaria;onsormalalignmentincludingpatellaaltaorahigherquadriceps“Qangle”(Figure3),whichpredisposethemtoinstability.3,4.Patellaaltadescribesahigh-ridingpatellawhichengagesthetrochlealaterinflexionthannormal,givingthepatellalessboneystability.4Manyop;onsexistfortrea;ngpatellarinstability.Rehabilita;onistypicallyrecommendedfollowinganini;aldisloca;on;howeverrecurrentdisloca;onisreportedtobeashighas48%withnon-opera;vetreatment.2Opera;vetreatmentistypicallyperformedonthosewithanunderlying,predisposinganatomicalvaria;ons/malalignmentasnotedabove.Opera;vetreatmentisalsoperformedonpeoplewhohavehadreoccurringdisloca;ons,astheseindividualstypicallyhavecon;nuedapprehensionandprogressivejointdamage.Specificopera;vetreatmentisselectedbasedonthepar;cularneedsoftheindividualincluding:extentofmalalignment,individual’sage,levelofac;vity,ligamentousinjury(MPFL)andjointcondi;on.Examplesofproceduresusedinclude:proximalrealignment,MPFLrepairorreconstruc;on,lateralrelease,anddistalrealignment.



Proximalrealignmentaltersthemedial-lateralposi;onofthequadricepsmuscletothepatellathroughappropriatemanipula;onofthe;ssuesatorabovethelevelofthepatella.Anincisionismadeoverthekneeandspecificproceduresinclude:lateralre;nacularrelease(lengtheningthestructuresontheoutsideofthepatella),VMOadvancementandMPFLrepairandreconstruc;on(shorteningthemuscleorligamentsontheinsideofthepatella).2Thisprocedureissome;mesdoneincombina;onwithadistalrealignmentprocedure.DistalrealignmentisoGendonetoreducethe“Qangle”.Thisisperformedthroughanincisionoverthekneeinwhichaninstrumenttocutthe;bialtubercle(theboneyprominenceonthetopofthe;biawherethepatellartendona9aches)isused.Thisiscalledanoteotomy.Thebasicpurposeofthistypeofosteotomyistomovethe;bialturberclemedially(towardtheinside).Thetypeofosteotomyperformedwilldeterminehowmuchofthisbonewillbecut.Becauseofthisdifferencetherewillalsobesubsequentdifferencesinwhenthesepa;entscanbeginweightbearing.Thepatellartendonandbonewhichwascutisthenmovedmediallywhichalterstheposi;onofthepatella.Theboneisrea9achedinthisnewposi;ontothe;biawithscrews(Figure4).Aqualitypost-opera;verehabilita;onprogramisessen;altohavingasuccessfuloutcomefromapatellarstabiliza;onprocedure.Thegoalsofrehabilita;onwillini;allyfocusonprotec;onforhealing,mobilityandrangeofmo;on.AGerthisearlyphasetherewillbeastrongemphasisonstrengtheningthroughouttheen;relegandcore.Inthefinalstagesrehabilita;onthefocuswillbeoncontrolofsportspecificmovements,suchaschangeofdirec;onandrota;onalmovements.