Sports medicine course for nursesSports medicine course for nurses

Dr Law KY, BillyDr Law KY, BillyMBChB (CUHK), MRCS (Ed), MScSMHS (CUHK), FRCSEd (Orth) FHKAM (OrMBChB (CUHK), MRCS (Ed), MScSMHS (CUHK), FRCSEd (Orth) FHKAM (Orth Surg), FHKCOSth Surg), FHKCOSResident specialistResident specialistDepartment of Orthopaedics and Traumatology, Prince of Wales HosDepartment of Orthopaedics and Traumatology, Prince of Wales Hospitalpital

Meniscus & Cartilage injury of knee

Meniscus anatomyMeniscus anatomy

FibrocartilagenousFibrocartilagenous structurestructure

Located between femoral Located between femoral condylecondyle & & tibialtibial plateauplateau

Crescents shapeCrescents shape

Triangular cross sectionTriangular cross section

Cover 1/2 Cover 1/2 –– 2/3 tibia plateau 2/3 tibia plateau articulararticular surfacesurface

Meniscus Meniscus anatomyanatomy

Medial meniscusMedial meniscusC shapeC shapeAttached to Attached to medial capsular structuremedial capsular structure, deep MCL, deep MCLTear more common in chronic ACL deficient kneeTear more common in chronic ACL deficient knee

Secondary restrain of anterior tibia translationSecondary restrain of anterior tibia translation

Lateral meniscusLateral meniscusCircular shapeCircular shapeAttachment: coronary ligament / Attachment: coronary ligament / meniscomenisco--femoral femoral ligamentligamentMore mobileMore mobile than medial meniscusthan medial meniscusTear more common in acute ACL tearTear more common in acute ACL tear

AnterolateralAnterolateral translation during ACL injurytranslation during ACL injury

Meniscus functionMeniscus functionShock absorptionShock absorption

Increase surface area of contact Increase surface area of contact decrease contact stressdecrease contact stress

Complete Complete menisectomymenisectomyDecrease contact area by 40 Decrease contact area by 40 –– 75%75%Increase contact stress by 136 Increase contact stress by 136 –– 236%236%

Major fiber orientation Major fiber orientation circumferentialcircumferentialResist compressive loadingResist compressive loadingBy creating hoop stressBy creating hoop stress

Mid substance fibers Mid substance fibers radialradial orientationorientationResist Resist longitudinal splitlongitudinal split

Surface fibersSurface fibers wovenwoven patternpatternResist Resist sheersheer stressstress

Meniscus functionMeniscus functionJoint stabilityJoint stabilityJoint lubricationJoint lubricationPropioceptionPropioception

Blood supplyBlood supplyMedial & lateral Medial & lateral geniculargeniculararteriesarteries

Vessels form Vessels form perimeniscalperimeniscalcapillary plexus within synovial capillary plexus within synovial & capsular tissue of knee joint& capsular tissue of knee joint

Supply peripheral 1/3 of Supply peripheral 1/3 of meniscusmeniscus

ieie medial 2/3 of meniscus medial 2/3 of meniscus relative relative avascularavascularRed Red –– RedRed zonezoneRed Red –– white zone / White white zone / White –– WhiteWhitezonezoneDifferent healing potentialDifferent healing potential

Meniscus tearMeniscus tear

HistoryHistoryRotation as the flexed knee move toward an extended Rotation as the flexed knee move toward an extended positionpositionLess mobile medial meniscus trap between the Less mobile medial meniscus trap between the femoral femoral condylecondyle and and tibialtibial plateau plateau teartear

Meniscus tear symptomsMeniscus tear symptoms

EffusionEffusionPainPainLockingLocking

Inability to extend kneeInability to extend knee

Chronic caseChronic caseClicks, catches, snaps Clicks, catches, snaps as knee movesas knee moves

Physical examPhysical exam

EffusionEffusion

Local tenderness over Local tenderness over joint linejoint line

Range of motionRange of motionMechanical blockMechanical block

McMurray testMcMurray test

McmuarryMcmuarry testtest

Medial meniscus

ER + Varus

Lateral meniscus

IR + Valgus

XRXR

Not to confirm diagnosis of torn meniscusNot to confirm diagnosis of torn meniscusExclude Exclude

OsteocartilaginousOsteocartilaginous loose bodyloose bodyOsteochondritisOsteochondritis dissecansdissecans

That mimic torn meniscusThat mimic torn meniscus

MRIMRI

Sensitivity 83%Sensitivity 83%Specificity 84%Specificity 84%

Look for concomitant ligament, cartilage Look for concomitant ligament, cartilage injuriesinjuries

TreatmentTreatment

NonoperativeNonoperativeOperativeOperative

NonNon--operativeoperative

Incomplete tearIncomplete tear

Small (5mm) stable peripheral tear with no Small (5mm) stable peripheral tear with no other pathological condition other pathological condition egeg ACL tearACL tear

Treat non operatively with good resultsTreat non operatively with good results

Operative treatmentOperative treatmentLocked kneeLocked knee

Bucket handle tearBucket handle tear

Associated Associated cruciatecruciate ligament ligament injuryinjury

Chronic tear with Chronic tear with superimposed acute injurysuperimposed acute injury

Fail conservative treatmentFail conservative treatment

Operative choicesOperative choicesPrinciple: Preserve as much as possiblePrinciple: Preserve as much as possibleMeniscus repairMeniscus repairPartial Partial menisectomymenisectomyMeniscus allograftMeniscus allograft

Meniscus repairMeniscus repairSuccess rate higherSuccess rate higher

Red Red –– RedRed zonezonePattern of tearPattern of tearChronicityChronicityConcomitant ACL Concomitant ACL reconstructionreconstruction

biochemical / mechanicalbiochemical / mechanical

Meniscus repairMeniscus repair

Arthroscopic techniqueArthroscopic technique

Medial meniscusMedial meniscusRisk of Risk of saphenoussaphenous nerve nerve injuryinjury

Lateral meniscusLateral meniscusRisk of Risk of peronealperoneal nerve nerve injuryinjury

Rehabilitation after meniscus repairRehabilitation after meniscus repair

VariesVariesPattern of tear Pattern of tear

longitudinal longitudinal vsvs radialradial

Stability of repairStability of repairSurgeon preferenceSurgeon preferencePatient demandPatient demand

Hinge braceHinge brace 00--90d x 490d x 4--6 wks6 wksPWBPWB x 4x 4--6 wks6 wksReturn to sports 4 Return to sports 4 –– 6 months6 months

Partial Partial menisectomymenisectomy

Try to Try to avoid total avoid total menisectomymenisectomyRemoval 1/3 of meniscus increase joint Removal 1/3 of meniscus increase joint contact force by 40contact force by 40--70%70%Increasing degenerative changes in post Increasing degenerative changes in post total total menisectomymenisectomy kneeknee

Partial Partial menisectomymenisectomy

Symptomatic, fail conservative careSymptomatic, fail conservative careTear beyond salvageTear beyond salvage

Allow faster rehabilitationAllow faster rehabilitationImmediate full weight bearImmediate full weight bearImmediate range of motion exerciseImmediate range of motion exercise

ConclusionConclusionMeniscalMeniscal injuryinjuryCommon, may associate with Common, may associate with ligament injuryligament injuryMost can be treated conservativelyMost can be treated conservativelyExceptExcept

Lock kneeLock kneeAssociate Associate cruciatecruciate injuryinjuryFail conservative treatmentFail conservative treatment

Surgical treatmentSurgical treatmentMeniscus repairMeniscus repairPartial Partial menisectomymenisectomy

ChondralChondral lesion in a young patientlesion in a young patient

What is cartilage?What is cartilage?What is the patientWhat is the patient’’s problem?s problem?What should I do? What should I do? What are the options? Challenge? What are the options? Challenge?

ArticularArticular cartilagecartilageSpecialized connective tissueSpecialized connective tissue

Biphasic materialBiphasic materialSolid matrixSolid matrix

Water fluid phaseWater fluid phase

MatrixMatrixWater (70%), collagen, Water (70%), collagen, proteoglycanproteoglycan

ChondrocyteChondrocyteProduction of matrixProduction of matrix

AvascularAvascular, no neural supply, no neural supply

NutritionNutritionDiffusion from synovial fluidDiffusion from synovial fluid

Mechanical propertyMechanical property

ViscoelasticViscoelastic property allow tissue response to property allow tissue response to stressstressMechanical spongeMechanical sponge which absorb tremendous which absorb tremendous compressive forces, compressive forces, Load distributionLoad distributionLow frictionLow friction surface for motionsurface for motion

Response to injury Response to injury PoorPoorPoor blood supplyPoor blood supply

Few Few chondroblastchondroblastchondrocytechondrocyte

Full thickness tear Full thickness tear healed in healed in fibrocartilagefibrocartilage

Suboptimal biomechanical Suboptimal biomechanical propertyproperty

Problem of poor healingProblem of poor healing

Poor healingPoor healingPersistent cartilage defectPersistent cartilage defectAbnormal load distributionAbnormal load distribution

PainPainEarly osteoarthritis, disabilityEarly osteoarthritis, disability

What should I do? What should I do?

RegenerateRegenerateFibrocartilageFibrocartilageCartilageCartilage

ReplaceReplaceJoint Joint replacementreplacement

UKAUKATKR

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TKR

RegenerateRegenerateMechanical techniqueMechanical technique

Arthroscopic Arthroscopic lavagelavage & debridement& debridement

Marrow stimulation techniqueMarrow stimulation techniqueSubchondralSubchondral drillingdrillingMicrofractureMicrofracture

ResurfacingResurfacingOsetochondralOsetochondral autograftautograftAutologousAutologous chondrocytechondrocyte implantationimplantation

ResurfacingResurfacingJoint replacementJoint replacement

Success in cartilage regenerationSuccess in cartilage regeneration

Must ensure kneeMust ensure kneeStableStable

Treat concomitant ligament injuryTreat concomitant ligament injury

Normal alignmentNormal alignmentCorrect deformityCorrect deformity

………………before you go and tackle the before you go and tackle the cartilage defectcartilage defect

Arthroscopic Arthroscopic lavagelavage & debridement& debridementRemoval of impinging Removal of impinging osteophytesosteophytes, , inflammedinflammed synoviumsynovium, , loose loose chondralchondral debrisdebris

Removal of degradation enzymes, factors that cause painRemoval of degradation enzymes, factors that cause pain

Advantage: minimal invasive / simple surgery / easy rehab.Advantage: minimal invasive / simple surgery / easy rehab.

Short term improvement observed, especially patient with Short term improvement observed, especially patient with clear mechanical symptomsclear mechanical symptoms

No long term benefitNo long term benefit

Marrow stimulation techniqueMarrow stimulation technique

Creation of bleeding Creation of bleeding fibrin clot fibrin clot invade by undifferentiated cell invade by undifferentiated cell chondrocytechondrocyte like celllike cell

Synthesize matrix Synthesize matrix collagen, collagen, proteoglycanproteoglycan

DrillingDrilling

0.062 K wire0.062 K wireHoles 2Holes 2--3mm apart3mm apartDeep to Deep to cancellouscancellous boneboneTourniquet releasedTourniquet releasedBleedingBleeding

Healing with Healing with fibrocartilagefibrocartilageProblem: thermal necrosisProblem: thermal necrosis

MicrofractureMicrofractureDebridement of loose Debridement of loose cartilage edgecartilage edgeRemoval of calcified layerRemoval of calcified layerSmall holes by hand awlSmall holes by hand awl4mm depth hole4mm depth hole33--4mm apart4mm apartFormation of blood clot, rich Formation of blood clot, rich in in pluripotentialpluripotential marrowmarrow(release of tourniquet to (release of tourniquet to confirm bleeding)confirm bleeding)

Advantage: no thermal Advantage: no thermal necrosisnecrosis

Ideal candidate for Ideal candidate for microfracturemicrofracture

Lesion < 2cmLesion < 2cm22

Preoperative symptoms < 1 yrPreoperative symptoms < 1 yrAge < 40 yrsAge < 40 yrs

MithoeferMithoefer etaletal. High impact athletics after knee . High impact athletics after knee articulararticular cartilage repair: a prospective cartilage repair: a prospective evaluation of the evaluation of the microfracturemicrofracture technique. AJSM 2006technique. AJSM 2006KreuzKreuz etaletal. Is . Is microfracturemicrofracture of of chondralchondral defects in the knee associated with different defects in the knee associated with different results in patients aged 40 years or younger. Arthroscopy 2006results in patients aged 40 years or younger. Arthroscopy 2006

Post op rehabilitationPost op rehabilitationCPMCPM

Improve quality of repair tissueImprove quality of repair tissueNutritionNutritionAccelerate cellular differentiation of marrow Accelerate cellular differentiation of marrow mesenchymalmesenchymal cells into matrix producing cells into matrix producing fibrochondrocytefibrochondrocyte

Early protected motionEarly protected motionTouch down walking x 6 weeksTouch down walking x 6 weeksGradual strengthening exerciseGradual strengthening exerciseReturn to sportsReturn to sports

44--6 months6 months

MicrofractureMicrofracture

Regenerated tissueRegenerated tissueHybrid of hyaline cartilage & Hybrid of hyaline cartilage & fibrocartilagefibrocartilage

Initial result deteriorate over time due to Initial result deteriorate over time due to poor wear poor wear characterticscharactertics of repair tissueof repair tissue

OsteochondralOsteochondral autograftautograft transplantationtransplantation

Cylindrical Cylindrical osteochondralosteochondral pulgspulgs from relative from relative non weight bearing area of knee non weight bearing area of knee

insertion to insertion to articulararticular defectdefectArthroscopic / Open surgeryArthroscopic / Open surgery

OsteochondralOsteochondral autograftautograft transplantationtransplantation

Donor siteDonor sitePatellar groovePatellar grooveArea proximal to Area proximal to intercondylarintercondylarnotchnotchSuperior medial margin of Superior medial margin of femoral notchfemoral notch

DifficultyDifficultyLimited donor siteLimited donor siteOnly suitable for small defect ~ Only suitable for small defect ~ < 2.5 cm< 2.5 cmDifficulty to reDifficulty to re--create normal create normal articulararticular contourcontour

MosaicplastyMosaicplasty --Advantages

Mosaicplasty -DisadvantagesAdvantages

Hyaline cartilageHyaline cartilage

Superior biomechanical Superior biomechanical properties

Graft dislodgementGraft dislodgement

Incongruent surface Incongruent surface →→OA of opposing surfaceOA of opposing surface

Small grafts may breakSmall grafts may break

Failure of grafts to healFailure of grafts to heal

OA of donor sites if too OA of donor sites if too many grafts and too large many grafts and too large →→ limited size of treatable limited size of treatable defect

properties

defect

AutologousAutologous ChondrocyteChondrocyte implantationimplantation

2 surgeries2 surgeries

11stst surgerysurgeryNormal host cartilage harvested Normal host cartilage harvested cell culturecell culture

22ndnd surgerysurgeryTransplant the cells under a harvested Transplant the cells under a harvested periostealperiostealpatch through patch through arthrotomyarthrotomy

Better wear Better wear charateristicscharateristics of repair tissue than of repair tissue than microfracturemicrofracture

AdvantageAdvantagePotential to restore Potential to restore normal hyaline normal hyaline cartilage

DisadvantageDisadvantageHighly technique Highly technique dependentdependentRequire 2 stage Require 2 stage procedureprocedureLaboratory supportLaboratory supportExpensive

cartilage

Expensive

Management of Management of chondralchondrallesionlesion

No perfect solutionNo perfect solution

Each technique pros & consEach technique pros & consSimple Simple –– ComplexComplexSize of defectSize of defectDonor morbidityDonor morbidityCostCostPatient demandPatient demand

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