Knee arthroplasty for FRCS Orth course Newcastle

KNEE ARTHROPLASTY KNEE ARTHROPLASTY

Professor Deiary F Kader Department of Sport, Exercise, Northumbria University, Newcastle

Knee Surgeon, Nuffield Hospital/Newcastle

Postgraduate Orthpaedics FRCS(Tr&Orth) Revision Course

Knee ArthroplastyKnee ArthroplastyPLANPLAN

ANSWER EXAM QUESTIONSANSWER EXAM QUESTIONS

POSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

What are the indications for What are the indications for doing a TKR?doing a TKR?


Primary Indication Primary Indication

Is to relieve pain caused by severe Is to relieve pain caused by severe arthritisarthritis


PAINPAIN

The pain should be significant and disabling. The pain should be significant and disabling.

Night pain Night pain is particularly distressing and is particularly distressing and significant.significant.

But if But if dysfunction dysfunction significantly affecting the significantly affecting the patient’s quality of life then this should be patient’s quality of life then this should be taken into account. taken into account.


DEFORMITY DEFORMITY ????????

Correction of significant deformity is an Correction of significant deformity is an important indication but is rarely used asimportant indication but is rarely used as

the primary indication for surgery the primary indication for surgery


X-RAYX-RAYWhat specific views can help in What specific views can help in

diagnosing OA?diagnosing OA?

X-Ray findings must correlate with clinical X-Ray findings must correlate with clinical finding.finding.

Patients who do not have a significant loss Patients who do not have a significant loss of joint space tend to be less satisfied with of joint space tend to be less satisfied with their clinical result after TKR. their clinical result after TKR.


What X-Rays views?What X-Rays views?


RosenbergRosenbergLyon schuss viewsLyon schuss views


What are your Differential Dx?What are your Differential Dx?

ExcludeExclude

Radicular painRadicular pain

Spinal diseaseSpinal disease

Hip referred painHip referred pain

Peripheral vascular diseasePeripheral vascular disease

Meniscal pathologyMeniscal pathologyPOSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

TKRTKRWhat are your What are your

absolute and absolute and relative relative

contraindications? contraindications?


Contraindications Contraindications AbsoluteAbsolute

Localised sepsis Localised sepsis including previous including previous osteomyelitisosteomyelitis

RemoteRemote source of ongoing infection source of ongoing infection

ExtensorExtensor mechanism dysfunction mechanism dysfunction

Severe Severe vascularvascular disease disease

RecurvatumRecurvatum deformity secondary to deformity secondary to muscular weaknessmuscular weakness

Well functioning knee Well functioning knee arthrodesisarthrodesis. . POSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

ContraindicationsContraindicationsRelativeRelative

• Skin conditions within the field of surgery e.g Skin conditions within the field of surgery e.g psoriasispsoriasis

• NeuropathicNeuropathic joint joint• Morbid obesityMorbid obesity• Poor Poor hygienehygiene• Excessive drinking and smokingExcessive drinking and smoking

Medical conditions that preclude Medical conditions that preclude – Safe anesthesiaSafe anesthesia– The demands of surgeryThe demands of surgery– Rehabilitation. Rehabilitation. POSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

ConsentingConsentingDVTDVT

Pulmonary embolism and presentationPulmonary embolism and presentation

Infection Infection

CVA or MICVA or MI

Skin numbnessSkin numbness

Pain postop-3months-one year-long termPain postop-3months-one year-long term

Implant longevityImplant longevity


Consenting 2Consenting 2

Rehab-Golden 2 weeksRehab-Golden 2 weeks

SmokingSmoking

Skin problemsSkin problems

Remote infectionRemote infection

Nickel allergyNickel allergy

Blood transfusionBlood transfusionPOSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

Consenting 3Consenting 3

Fracture Intraop and postopFracture Intraop and postop

Neurovascular injuryNeurovascular injury

Delayed wound healingDelayed wound healing

Instability of the Knee replacementInstability of the Knee replacement

Extensor mechanism injuryExtensor mechanism injury

DeathDeath


TKRTKRSURGICAL TECHNIQUESURGICAL TECHNIQUE

Preoperative EvaluationPreoperative EvaluationSoft tissue status around the knee. Soft tissue status around the knee.

Vascular status to the limb.Vascular status to the limb.

Extensor mechanism.Extensor mechanism.

Preoperative range of motion.Preoperative range of motion.

Standing (AP) view, a lateral view of the knee, and Standing (AP) view, a lateral view of the knee, and a skyline view of the patella. a skyline view of the patella.

Knee Arthroplasty surgical techniqueKnee Arthroplasty surgical technique Skin incisionSkin incision

Anterior longitudinal midline skin incisionAnterior longitudinal midline skin incision

Skin blood supply is in the subcutaneous fat so Skin blood supply is in the subcutaneous fat so avoid underminingavoid undermining

Medial vessels are relatively large so in cases Medial vessels are relatively large so in cases where there are multiple scars use the most lateral where there are multiple scars use the most lateral

Deep dissectionDeep dissection

Medial parapatellar in most casesMedial parapatellar in most cases

Subvastus, midvastusSubvastus, midvastus

Lateral parapatellar (very valgus knee, laterally subluxed Lateral parapatellar (very valgus knee, laterally subluxed patella)patella)

Tibial tubercle osteotomy (Whiteside)Tibial tubercle osteotomy (Whiteside)

Rectus snipRectus snip

Quadriceps turn-downQuadriceps turn-down

Previous open fracturePrevious open fracture


What are the What are the Biomechanical aims of Biomechanical aims of

TKR?TKR?

The primary aim of TKRThe primary aim of TKR is to achieve: is to achieve:

RRestoring estoring mechanical axis mechanical axis of 0 (+/- 3º)of 0 (+/- 3º)

Preserving the Preserving the joint line joint line height that is height that is perpendicular to the weight-bearing lineperpendicular to the weight-bearing line

Balanced Balanced ligaments ligaments ( 1 to 2 mm play)( 1 to 2 mm play)

Restoring normal Restoring normal Q angle Q angle and joint alignmentand joint alignment

Anatomic and mechanical Anatomic and mechanical axes axes

The mechanical axis The mechanical axis 1.2º1.2º of of varusvarus

the line from the centre of the hip the line from the centre of the hip

to the centre of the tibiotalar jointto the centre of the tibiotalar joint

Tibiofemoral angle Tibiofemoral angle 5º–6º of valgus5º–6º of valgus

The valgus cut angleThe valgus cut angle

The angle between the femoralThe angle between the femoral

anatomical and mechanical axesanatomical and mechanical axes

Rotational alignment of the Rotational alignment of the femoral component femoral component

Anatomical landmarks Anatomical landmarks for reference:for reference:1.1. Anteroposterior axis ( Whiteside’s line)Anteroposterior axis ( Whiteside’s line)

2.2. Epicondylar axisEpicondylar axis

3.3. Posterior condylar axisPosterior condylar axis

4.4. The ant cortex of the femurThe ant cortex of the femur

Anteroposterior (AP) axis Anteroposterior (AP) axis Whiteside’s lineWhiteside’s line

The AP axis is a line drawn from the deepest part The AP axis is a line drawn from the deepest part of the trochlear groove anteriorly to theof the trochlear groove anteriorly to the

Centre of the intercondylar notch posteriorly Centre of the intercondylar notch posteriorly

Difficult to IdentificationDifficult to Identification– in trochlear dysplasia or destructive arthritisin trochlear dysplasia or destructive arthritis– knees with significant varus or valgus deformityknees with significant varus or valgus deformity

What are the 2 EA called??What are the 2 EA called??

Surgical

Anatomic

The epicondylar axis The epicondylar axis

Difficult to define Difficult to define Epicondylar peaks are often obscured by the everted Epicondylar peaks are often obscured by the everted patella,patella,

Overlying collateral ligaments and adipose tissue. Overlying collateral ligaments and adipose tissue.

Use of the surgical epicondylar axis rather than the Use of the surgical epicondylar axis rather than the clinical epicondylar axis clinical epicondylar axis

The posterior condylar axisThe posterior condylar axis

ProblemsProblems

Inaccurate in severe arthritisInaccurate in severe arthritis

Anatomy of the femur variesAnatomy of the femur varies

Gender variationGender variation

Valgus knee hypoplastic LFCValgus knee hypoplastic LFC

Varus knee MFC largerVarus knee MFC larger

4- The Anterior Femoral Cortical Line4- The Anterior Femoral Cortical Line

Problems withProblems withInternal rotation of the femoral componentInternal rotation of the femoral component

Shift into valgus alignment with flexionShift into valgus alignment with flexionIncrease in Q angle Increase in Q angle Patella mal-tracking/InstabilityPatella mal-tracking/InstabilityFast patella OA/Severe wear if resurfacedFast patella OA/Severe wear if resurfacedAsymmetric flexion gapAsymmetric flexion gap

Asymmetric tibial component loadAsymmetric tibial component load

Equal flexion/extension gap Equal flexion/extension gap

Flexion and extension gap is symmetrical, adjust tibiaFlexion and extension gap is symmetrical, adjust tibia If the gap is asymmetrical, adjust the femur (majority of If the gap is asymmetrical, adjust the femur (majority of

cases)cases)Resect the distal femur to increase the extension gapResect the distal femur to increase the extension gap Increasing the tibial slope increases the flexion gapIncreasing the tibial slope increases the flexion gapPCL excision increases the flexion gapPCL excision increases the flexion gap

Balancing Flexion and Balancing Flexion and Extension GapsExtension Gaps


Cementing TechniqueCementing Technique

EvidenceEvidence

SummarySummaryStability of surface-cemented tibial Stability of surface-cemented tibial

components is related to the depth of components is related to the depth of cement penetrationcement penetration..

Preloading improves cement penetrationPreloading improves cement penetrationApply cement to Both surfaces on the tibiaApply cement to Both surfaces on the tibiaApply cement to bone ant and distal on the Apply cement to bone ant and distal on the

femurfemur

CRUCIATE RETAINING CRUCIATE RETAINING VSVS

CRUCIATE SACRIFICING CRUCIATE SACRIFICING

Constraint ladder inConstraint ladder in implant design implant design

PCL-retaining (cruciate-retaining, or CR) PCL-retaining (cruciate-retaining, or CR) Rotating platform Rotating platform PCL-substituting (posterior-stabilized, or PS)PCL-substituting (posterior-stabilized, or PS)Unlinked constrained condylar implant or Unlinked constrained condylar implant or

VVC VVC Linked, constrained condylar implant Linked, constrained condylar implant

(rotating-hinge knee, RHK). (rotating-hinge knee, RHK).


PCL-retention or PCL-substitution ?PCL-retention or PCL-substitution ?


PCLPCLMajor Major stabilizingstabilizing ligament. ligament.Tightens the flexion spaceTightens the flexion spaceSecondary Secondary mediolateralmediolateral stabiliser in flexion. stabiliser in flexion.

PCL excision increases the PCL excision increases the

flexion gap by 4-5mm and flexion gap by 4-5mm and

extension gap by 1-2 mmextension gap by 1-2 mm


GII PS + PatGII PS + Pat


PCL retaining (CR)PCL retaining (CR)

Provides least Provides least constraintconstraintLess forces at the Less forces at the interfaceinterfacePreserves Preserves proprioceptiveproprioceptive fibres (intact PCL) fibres (intact PCL)Greater stability during Greater stability during stairstair climbing climbing

(quadriceps strength)(quadriceps strength)Less risk of condylar Less risk of condylar fracturefracture


PCL retaining (CR) 2PCL retaining (CR) 2

Fewer Fewer patellapatella complications complicationsPreserve Preserve bone stockbone stock on the femoral side on the femoral sideBetter Better kinematicskinematics but relatively less predictable but relatively less predictableAvoids the tibial Avoids the tibial post–cam post–cam impingementimpingementEase of management of supracondylar Ease of management of supracondylar fracture fracture

(plate/nail)(plate/nail)


PCL retaining PCL retaining (CR) (CR) DisadvantagesDisadvantages

Less conforming surfaces to allow roll-back Less conforming surfaces to allow roll-back Slide/shear stress causes poly delaminationSlide/shear stress causes poly delaminationTechnically difficult to balance Technically difficult to balance Late PCL dysfunctionLate PCL dysfunction


PCL ReleasePCL Release


PCL substitution/sacrificing PCL substitution/sacrificing IndicationsIndications

Previous Previous patellectomypatellectomyRheumatoidRheumatoid arthritis arthritisStiff knee in Stiff knee in post-traumatic post-traumatic arthritisarthritisPrevious high tibial osteotomy Previous high tibial osteotomy (HTO)(HTO)Large Large deformity,deformity, over-released PCL over-released PCL


PCL substitution/sacrificing PCL substitution/sacrificing AdvantagesAdvantages

PCL histologically and kinematically PCL histologically and kinematically abnormalabnormalThe cam-post mechanism improves The cam-post mechanism improves AP AP

stabilitystabilityProvides a degree of Provides a degree of VVCVVCConforming surfaces allowing Conforming surfaces allowing roll-backroll-backNo component No component slideslide


PCL substitution/sacrificing PCL substitution/sacrificing AdvantagesAdvantages

Higher degree of Higher degree of flexionflexionLess Less joint line joint line sensitive (Restored within 8-sensitive (Restored within 8-

9mm, Figgie)9mm, Figgie)Congruent joint surfaces reduces Congruent joint surfaces reduces wearwearFacilitates Facilitates deformitydeformity correction correctionSuperior and more reproducible Superior and more reproducible kinematicskinematicsTechnically Technically easiereasier than CR and reproducible than CR and reproducible


PCL substitution/sacrificing PCL substitution/sacrificing DisadvantagesDisadvantages

High stresses at fixation High stresses at fixation interfaceinterface (loosening) (loosening)Femoral Femoral bonebone loss/fracture loss/fractureTibial peg increases Tibial peg increases wearwearPost Post dislocationdislocationThree times greater Three times greater joint line joint line alteration alteration

compared to CRcompared to CRPatella Patella clunk/ crunch syndromeclunk/ crunch syndrome


Patella Clunk SyndromePatella Clunk Syndrome


SummarySummaryBoth CR & PS knees work very wellBoth CR & PS knees work very wellLong term outcome comparable Long term outcome comparable One design wont fit allOne design wont fit allPS knees outcome is more predictablePS knees outcome is more predictableWe should be able to do both when it is We should be able to do both when it is

indicatedindicated


Mobile Bearing surfacesMobile Bearing surfacesLab data mobile bearing TKR reduce wear →Lab data mobile bearing TKR reduce wear →

but has not translated into any difference in but has not translated into any difference in terms of clinical outcomes.terms of clinical outcomes.

Other literature has shown increased total Other literature has shown increased total wear attributed to the additional bearing wear attributed to the additional bearing surface of a mobile bearing implant.surface of a mobile bearing implant.

Additional complications of mobile bearing Additional complications of mobile bearing surfaces are bearing dislocation and soft tissue surfaces are bearing dislocation and soft tissue impingement due to translationimpingement due to translation

Theoretical advantagesTheoretical advantagesMBTMBT

Maximum Maximum conformityconformity without an increase in component without an increase in component

looseningloosening

Increased survivorship and restoration of more natural Increased survivorship and restoration of more natural

knee kinematics knee kinematics

Increased contact area in both sagittal and coronal planesIncreased contact area in both sagittal and coronal planes

Minimal constraintMinimal constraint

Reduced component sliding during flexionReduced component sliding during flexion


• • Reduced shear stresses on the polyethylene insertReduced shear stresses on the polyethylene insert

• • Allows self-correction of tibial component in rotational Allows self-correction of tibial component in rotational

malalignmentmalalignment

• • Facilitates patellar trackingFacilitates patellar tracking

• • Better kinematics in gaitBetter kinematics in gait

• • Low polyethylene wearLow polyethylene wear


Theoretical advantagesTheoretical advantagesMBTMBT

DisadvantagesDisadvantagesMBT MBT

Relies on 0 degree slope- this can be Relies on 0 degree slope- this can be difficult to achieve every time. difficult to achieve every time. (Remember (Remember slope CR5,PS3,MB0)slope CR5,PS3,MB0)

Bearing instability (0.12%)Bearing instability (0.12%)Backside wear (Rare)Backside wear (Rare)

Theoretical disadvantagesTheoretical disadvantagesMobile BearingMobile Bearing

Bearing dislocation and spin out if the soft Bearing dislocation and spin out if the soft tissues are imbalancedtissues are imbalanced

Underside bearing wear creating small Underside bearing wear creating small debris, hence more osteolysisdebris, hence more osteolysis

Technically difficult, less forgiving soft-Technically difficult, less forgiving soft-tissue imbalance.tissue imbalance.


18. Luna JT, Sembrano JN, Gioe TJ (2010) Mobile and fixed-bearing (all-polyethylene tibial component) total knee arthroplasty designs surgical technique. Journal of Bone and Joint Surgery [Am], 92-A: 240–9.19. Oh KJ, Pandher DS, Lee SH, Joon SDS Jr, Lee ST (2009) Meta-analysis comparing outcomes of fixed-bearing and mobile-bearing prostheses in total knee arthroplasty. Journal of Arthroplasty, 24(6): 873–84.

Medial release for Medial release for varus kneevarus knee


Medial release for varus kneeMedial release for varus knee

Osteophytes excisionOsteophytes excisionDeep MCL to posteromedial cornerDeep MCL to posteromedial cornerSemimembranosus aponeurosisSemimembranosus aponeurosisSuperficial MCLSuperficial MCLPes anserinus insertionPes anserinus insertionPCLPCL


Pie-Crusting TechniquePie-Crusting Technique

Anterior MCL loose in extension


Rage of Ligament restraint Rage of Ligament restraint medial kneemedial knee

H Schroeder-BoerschPOSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

Varus DeformityVarus Deformity


Fixed flexion deformityFixed flexion deformity

Less than 10º can be corrected by cutting boneLess than 10º can be corrected by cutting boneMay need to resect more bone from the femurMay need to resect more bone from the femurRemove posterior osteophytesRemove posterior osteophytesFor very severe FFD, use a Cobb to lift For very severe FFD, use a Cobb to lift

posterior capsule of femurposterior capsule of femur


Valgus kneeValgus knee

The normal tibiofemoral angle is 5°–6°The normal tibiofemoral angle is 5°–6° The valgus knee can be defined as a tibiofemoral angle The valgus knee can be defined as a tibiofemoral angle

greater than 10°greater than 10° Valgus knee is associated with bony and soft-tissue Valgus knee is associated with bony and soft-tissue

abnormalityabnormality There are acquired or pre-existing bony deficienciesThere are acquired or pre-existing bony deficiencies There is lateral subluxation of the patellaThere is lateral subluxation of the patella There is lateral capsule and ligament contractureThere is lateral capsule and ligament contracture Elongated PCL may become dysfunctional in severe valgusElongated PCL may become dysfunctional in severe valgus There is distal femoral rotational deformity with externally There is distal femoral rotational deformity with externally

rotated epicondylar axis up to 10°.rotated epicondylar axis up to 10°.POSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

SoSoft-tissue release in the valgus kneeft-tissue release in the valgus knee

Osteophyte excisionOsteophyte excision Lateral patellofemoral ligament releaseLateral patellofemoral ligament release Release posterolateral capsule off the tibia Release posterolateral capsule off the tibia Sacrifice PCL in moderate-severe valgus.Sacrifice PCL in moderate-severe valgus. Flexion and extension tightnessFlexion and extension tightness

Release (or pie-crust) lateral collateral ligament (LCL) Release (or pie-crust) lateral collateral ligament (LCL) from the femur.from the femur.

Flexion tightnessFlexion tightness

Release PopliteusRelease Popliteus Extension tightnessExtension tightness

Release (or pie-crust) the iliotibial band at Gerdy’s Release (or pie-crust) the iliotibial band at Gerdy’s tubercletubercle


Rage of Ligament restraint Rage of Ligament restraint LateralLateral knee knee

H Schroeder-BoerschPOSTGRAD ORTH Deiary Kader POSTGRAD ORTH Deiary Kader

PatellaPatella


Patellofemoral MaltrackingPatellofemoral Maltracking

To Improve trackingTo Improve trackingExternally rotate the femoral componentExternally rotate the femoral componentLateralize the femoral componentLateralize the femoral componentMedialize the patella buttonMedialize the patella button


Patellofemoral maltrackingPatellofemoral maltracking

DODO NOT NOTOverstuff the patella. Overstuff the patella. Oversize the femoral componentOversize the femoral componentInternally rotate of the tibial component (increases Internally rotate of the tibial component (increases

the Q angle)the Q angle)

Avoid an excessive valgus angleAvoid an excessive valgus angleAvoid raising the joint lineAvoid raising the joint lineAvoid inferior placement of the patella componentAvoid inferior placement of the patella component


Patella resurfacing debatePatella resurfacing debate22

ForForReduces anterior knee painReduces anterior knee painImproves knee strength in flexion (stair Improves knee strength in flexion (stair

descent)descent)Less likely to revise the knee for AKPLess likely to revise the knee for AKPSecondery resurfacing results are inferiorSecondery resurfacing results are inferiorBetter resultes in RABetter resultes in RA


Patella resurfacing debatePatella resurfacing debate33

AgainstAgainstNo difference in outcomeNo difference in outcomeIncrease wear particlesIncrease wear particlesLong-term problems with patellar Long-term problems with patellar

fracturefracture Early technical complicationsEarly technical complications


Indications for selective patella Indications for selective patella replacement: replacement:

Advanced osteoarthritic patellaAdvanced osteoarthritic patellaRheumatoid arthritisRheumatoid arthritisPreoperative patellofemoral painPreoperative patellofemoral painObese patientsObese patientsOverweight femalesOverweight femalesChondrocalcinosisChondrocalcinosis


prospective, randomized, double-blinded study of 350 TKRprospective, randomized, double-blinded study of 350 TKR

with selective patellar resurfacingwith selective patellar resurfacing

Follow-up of 7.8 years demonstrated that satisfaction was Follow-up of 7.8 years demonstrated that satisfaction was higher in patients with a resurfaced patella. higher in patients with a resurfaced patella.

Followed for at least 10 years, no significant difference was Followed for at least 10 years, no significant difference was found. No difference was found in KSS scores, survivorship found. No difference was found in KSS scores, survivorship and no complications of resurfacing were identified. and no complications of resurfacing were identified.

The vast majority of patients with remaining patellar The vast majority of patients with remaining patellar articular cartilage do very well with TKA regardless of articular cartilage do very well with TKA regardless of patellar resurfacing. Knees with exposed bone on the patellar resurfacing. Knees with exposed bone on the patellar articular surface were excluded patellar articular surface were excluded


Patella Resurfacing Patella Resurfacing (Development)(Development)

Early TKR 30% Ant knee painEarly TKR 30% Ant knee painHalf replacement by flangeHalf replacement by flange1974 polyethylene dome (Insall)1974 polyethylene dome (Insall)Initial resultsInitial results

– Less ant knee painLess ant knee pain– Better stair activitiesBetter stair activities

Resurfacing remain controversialResurfacing remain controversial

Patella resurfacing in TKR Patella resurfacing in TKR (Randomised trial)(Randomised trial)

Barrack et alBarrack et al Sept 2001 JBJSASept 2001 JBJSA

118 TKR F/U >five years 118 TKR F/U >five years No difference in outcomeNo difference in outcomeAnt knee pain relate toAnt knee pain relate to

– Component designComponent design– Surgical techniqueSurgical technique

Patella resurfacing in TKR Patella resurfacing in TKR (Randomised trial)(Randomised trial)

Wood et alWood et al Feb 2002 JBJSAFeb 2002 JBJSA

220 TKR mean F/U 48 months220 TKR mean F/U 48 monthsSuperior results in term ofSuperior results in term of

– Stair descentStair descent– Ant knee pain 16 % compared to 31%Ant knee pain 16 % compared to 31%– 10 % had revision in the resurfacing gp10 % had revision in the resurfacing gp

Circumpatellar electorcautery Circumpatellar electorcautery

Recent RCT published in BJJ in 2014 Recent RCT published in BJJ in 2014

300 knees improved clinical outcome with 300 knees improved clinical outcome with electrocautery denervation compared with electrocautery denervation compared with

no electrocautery of the patella is no electrocautery of the patella is not not maintainedmaintained at a mean of 3.7 years' at a mean of 3.7 years' follow-up. follow-up.


Complications of Patella Complications of Patella Resurfacing Resurfacing

PF InstabilityPF InstabilityComponent dissociation / loosening / Component dissociation / loosening /

wearwearPatella #Patella #Patella tendon rapturePatella tendon raptureResidual Ant Knee painResidual Ant Knee painOsteonecrosisOsteonecrosisPatella “clunk”Patella “clunk”

SummarySummary

Use patella friendly implantUse patella friendly implantBalance the PFJ gapBalance the PFJ gapRealign the extensor mechanism Realign the extensor mechanism Watch the joint height Watch the joint height


Complications of TKR

Aseptic complications after TKRAseptic complications after TKRExtensor Mechanism complicationsExtensor Mechanism complicationsWound healingWound healingStiffnessStiffnessPeriprosthatic fracturesPeriprosthatic fracturesLooseningLooseningNeurologic injuriesNeurologic injuriesVascular injuriesVascular injuriesThromboembolic diseaseThromboembolic disease

Popliteal fossa


Distal Femur ReplacementDistal Femur Replacement


MCL InjuryMCL Injury


Hinged KneeHinged Knee


InfectionInfection


OsteolysisOsteolysis


Patella tendon rupture after TKRPatella tendon rupture after TKR

Uncommon 0.2-1.4% of PtsUncommon 0.2-1.4% of PtsIntraoperative avulsion (exposure)Intraoperative avulsion (exposure)Late from Late from

– MUA >6wksMUA >6wks– TraumaTrauma– Impingement on tibial insertImpingement on tibial insert

Wound Healing (TKR)Wound Healing (TKR)

Vascular anatomyVascular anatomySoft tissues blood supply Soft tissues blood supply

randomrandomDermal plexus is within subcut Dermal plexus is within subcut

fasciafasciaPeripatellar anastomotic ring Peripatellar anastomotic ring

Wound Healing (TKR)Wound Healing (TKR)Biomechanical factorsBiomechanical factors

Surgical trauma, skin tension, incision Surgical trauma, skin tension, incision sitesite

– Decline in skin oxygenation by 67% post opDecline in skin oxygenation by 67% post op

– Midline incision (smaller hypoxic lateral Midline incision (smaller hypoxic lateral flap)flap)

– Tissue expander & M Flap in atrophic skinTissue expander & M Flap in atrophic skin

Wound Healing (TKR)Wound Healing (TKR)Patients risk factorsPatients risk factors

Nicotine vasoconstrictionNicotine vasoconstriction Skin atrophySkin atrophy Obesity (fat necrosis/ dead space/ retraction)Obesity (fat necrosis/ dead space/ retraction) Diabetes alter collagen synthesisDiabetes alter collagen synthesis Steroids inhibit fibroblastsSteroids inhibit fibroblasts RA, Low albumin and leucopeniaRA, Low albumin and leucopenia Wound drainage risk of infectionWound drainage risk of infection

Stiffness post TKRStiffness post TKRSoft tissue tensionSoft tissue tension

Overstuffing/improper release/tight PCL/ rotationOverstuffing/improper release/tight PCL/ rotation

Inadequate analgesia post opInadequate analgesia post opOverzealous or lack of timely physioOverzealous or lack of timely physioPoor pts motivation/ pain thresholdsPoor pts motivation/ pain thresholdsLow grade infectionLow grade infectionArthrofibrosisArthrofibrosisRSDRSD

Stiffness post TKRStiffness post TKR

TreatmentTreatmentImprove Surgical techniqueImprove Surgical techniqueAnalgesia/ physioAnalgesia/ physio6-8 wks MUA gentle6-8 wks MUA gentleLater Later Arthrolysis open or AxArthrolysis open or AxRevision Revision

– Capsular/ligamentous releaseCapsular/ligamentous release– Polyethylene exchange Polyethylene exchange

Thank you

• When would you consider arthrodesis of When would you consider arthrodesis of the knee? the knee?

• How would you perform it? How would you perform it?

• and what position would you fuse it in?and what position would you fuse it in?


Knee ArthrodesisKnee ArthrodesisIndicationsIndications

• • Failed knee replacementFailed knee replacement

• • Uncontrollable sepsisUncontrollable sepsis

• • Neuropathic jointNeuropathic joint

• • Young patient with severe articular joint disease and Young patient with severe articular joint disease and ligamentous damageligamentous damage

• • Disruption of extensor mechanismDisruption of extensor mechanism

• • Poor soft-tissue envelopePoor soft-tissue envelope

• • Systemically immunocompromisedSystemically immunocompromised

• • Resistant microorganismsResistant microorganisms

• • Post-traumatic arthrosis in a heavy manual labourer.Post-traumatic arthrosis in a heavy manual labourer.


ContraindicationsContraindications

• • Bilateral knee diseaseBilateral knee disease

• • Ipsilateral ankle or hip diseaseIpsilateral ankle or hip disease

• • Ipsilateral hip arthrodesisIpsilateral hip arthrodesis

• • Severe segmental bone lossSevere segmental bone loss

• • Contralateral limb amputation.Contralateral limb amputation.


Optimal position for knee Optimal position for knee fusionfusion

• • 7°–10° of external rotation7°–10° of external rotation

• • Slight valgusSlight valgus

• • 10°–20° of flexion10°–20° of flexion

• • The above may be easier to achieve with The above may be easier to achieve with external fixator rather than IM nail.external fixator rather than IM nail.


TechniquesTechniques

Intramedullary arthrodesis:Intramedullary arthrodesis:External fixation:External fixation:Plate fixation:Plate fixation:


ComplicationsComplications

Non-unionNon-unionMalunionMalunionDelayed unionDelayed unionRecurrent infection.Recurrent infection.


Through Knee Amputation: Through Knee Amputation: What are the What are the indications for indications for

knee disarticulation? knee disarticulation?


INDICATIONS:INDICATIONS:

A more distal amputation level, e.g., an ultra-short A more distal amputation level, e.g., an ultra-short transtibial amputationtranstibial amputation

Important alternative to transfemoral amputations.Important alternative to transfemoral amputations. Possible for any etiology Possible for any etiology New indications are infected and loosened total New indications are infected and loosened total

knee replacements.knee replacements.


Knee disarticulation and through-knee Knee disarticulation and through-knee amputationamputation

Superior compared to a transfemoral Superior compared to a transfemoral stumpstump

Thigh muscles are all preservedThigh muscles are all preserved Hip ROM is not limited. Hip ROM is not limited. Easy to fitted with a prosthesisEasy to fitted with a prosthesis Bilateral knee disarticulation can walk Bilateral knee disarticulation can walk

"barefoot”"barefoot” Enhanced proprioceptionEnhanced proprioception A long lever armA long lever arm Preservation of adductor muscle insertionPreservation of adductor muscle insertion Decreased metabolic cost of ambulationDecreased metabolic cost of ambulation


46 Knee disarticulation 2004-2012 46 Knee disarticulation 2004-2012 indications for surgery included infection indications for surgery included infection

(56%), arterial thrombosis (35%), and (56%), arterial thrombosis (35%), and trauma (9%) trauma (9%)


Nail-Patella SyndromeNail-Patella SyndromeHereditary osteo-onychodysplasia (HOOD synd)Hereditary osteo-onychodysplasia (HOOD synd)

Nail dysplasia, Patellar hypoplasia or aplasia, and NephropathyNail dysplasia, Patellar hypoplasia or aplasia, and Nephropathy

Autosomal dominante genetic disorder Ch9Autosomal dominante genetic disorder Ch9 Lean body buildLean body build Patellar affected in 90% of pts, patellar aplasia in only Patellar affected in 90% of pts, patellar aplasia in only

20%.20%. The elbows limited pronation, supination, extensionThe elbows limited pronation, supination, extension Subluxation of the radial head may occur.Subluxation of the radial head may occur. General hyperextension of the joints can be present.General hyperextension of the joints can be present. Exostoses ("iliac horns") 80% of patientsExostoses ("iliac horns") 80% of patients Kidney failure and teeth weaknessKidney failure and teeth weakness Family with Hood Neuropathy --- Child risk ¼ sameFamily with Hood Neuropathy --- Child risk ¼ same


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Knee arthroplasty for FRCS Orth course Newcastle

Health & Medicine

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