Knee Arthroplasty Guide

KNEE ARTHROPLASTYKNEE 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 Arthroplasty
PLANPLAN
ANSWER EXAM QUESTIONSANSWER EXAM QUESTIONS
POSTGRAD ORTH Deiary KaderPOSTGRAD ORTH Deiary Kader

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

Primary IndicationPrimary Indication
Is to relieve pain caused by severeIs to relieve pain caused by severe
arthritisarthritis

PAINPAIN
The pain should be significant and disabling.The pain should be significant and disabling.
Night painNight pain is particularly distressing andis particularly distressing and
significant.significant.
But ifBut if dysfunctiondysfunction significantly affecting thesignificantly affecting the
patient’s quality of life then this should bepatient’s quality of life then this should be
taken into account.taken into account.

DEFORMITYDEFORMITY ????????
Correction of significant deformity is anCorrection of significant deformity is an
important indication but is rarely used asimportant indication but is rarely used as
the primary indication for surgerythe primary indication for surgery

X-RAYX-RAY
What specific views can help inWhat specific views can help in
diagnosing OA?diagnosing OA?
X-Ray findings must correlate with clinicalX-Ray findings must correlate with clinical
finding.finding.
Patients who do not have a significant lossPatients who do not have a significant loss
of joint space tend to be less satisfied withof 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?

RosenbergRosenberg
Lyon 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 pathology

TKRTKR
What are yourWhat are your
absolute andabsolute and
relativerelative
contraindications?contraindications?

ContraindicationsContraindications
AbsoluteAbsolute
Localised sepsisLocalised sepsis including previousincluding previous
osteomyelitisosteomyelitis
RemoteRemote source of ongoing infectionsource of ongoing infection
ExtensorExtensor mechanism dysfunctionmechanism dysfunction
SevereSevere vascularvascular diseasedisease
RecurvatumRecurvatum deformity secondary todeformity secondary to
muscular weaknessmuscular weakness
Well functioning kneeWell functioning knee arthrodesisarthrodesis..

RelativeRelative
• Skin conditions within the field of surgery e.gSkin conditions within the field of surgery e.g
psoriasispsoriasis
• NeuropathicNeuropathic jointjoint
• Morbid obesityMorbid obesity
• PoorPoor hygienehygiene
• Excessive drinking and smokingExcessive drinking and smoking
Medical conditions that precludeMedical conditions that preclude
– Safe anesthesiaSafe anesthesia
– The demands of surgeryThe demands of surgery
– Rehabilitation.Rehabilitation. POSTGRAD ORTH Deiary KaderPOSTGRAD ORTH Deiary Kader

ConsentingConsenting
DVTDVT
Pulmonary embolism and presentationPulmonary embolism and presentation
InfectionInfection
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 transfusion

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

TKRTKR
SURGICAL TECHNIQUESURGICAL TECHNIQUE

Preoperative EvaluationPreoperative Evaluation
Soft 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, andStanding (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 soSkin blood supply is in the subcutaneous fat so
avoid underminingavoid undermining
Medial vessels are relatively large so in casesMedial vessels are relatively large so in cases
where there are multiple scars use the most lateralwhere 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 subluxedLateral 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 theWhat are the
Biomechanical aims ofBiomechanical aims of
TKR?TKR?

The primary aim of TKRThe primary aim of TKR
is to achieve:is to achieve:
RRestoringestoring mechanical axismechanical axis of 0 (+/- 3º)of 0 (+/- 3º)
Preserving thePreserving the joint linejoint line height that isheight that is
perpendicular to the weight-bearing lineperpendicular to the weight-bearing line
BalancedBalanced ligamentsligaments ( 1 to 2 mm play)( 1 to 2 mm play)
Restoring normalRestoring normal Q angleQ angle and joint alignmentand joint alignment

Anatomic and mechanicalAnatomic and mechanical
axesaxes
The mechanical axisThe mechanical axis 1.2º1.2º ofof varusvarus
the line from the centre of the hipthe line from the centre of the hip
to the centre of the tibiotalar jointto the centre of the tibiotalar joint
Tibiofemoral angleTibiofemoral 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 theRotational alignment of the
femoral componentfemoral component
Anatomical landmarksAnatomical 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) axisAnteroposterior (AP) axis
Whiteside’s lineWhiteside’s line
The AP axis is a line drawn from the deepest partThe 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 posteriorlyCentre 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??

The epicondylar axisThe epicondylar axis
Difficult to defineDifficult to define
Epicondylar peaks are often obscured by the evertedEpicondylar 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 theUse of the surgical epicondylar axis rather than the
clinical epicondylar axisclinical 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 with
Internal rotation of the femoral componentInternal rotation of the femoral component
Shift into valgus alignment with flexionShift into valgus alignment with flexion
Increase in Q angleIncrease in Q angle
Patella mal-tracking/InstabilityPatella mal-tracking/Instability
Fast patella OA/Severe wear if resurfacedFast patella OA/Severe wear if resurfaced
Asymmetric flexion gapAsymmetric flexion gap
Asymmetric tibial component loadAsymmetric tibial component load

Equal flexion/extension gapEqual 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 ofIf 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 gap
PCL excision increases the flexion gapPCL excision increases the flexion gap

Balancing Flexion andBalancing Flexion and
Extension GapsExtension Gaps

Cementing TechniqueCementing Technique

SummarySummary
Stability of surface-cemented tibialStability of surface-cemented tibial
components is related to the depth ofcomponents is related to the depth of
cement penetrationcement penetration..
Preloading improves cement penetrationPreloading improves cement penetration
Apply cement to Both surfaces on the tibiaApply cement to Both surfaces on the tibia
Apply cement to bone ant and distal on theApply cement to bone ant and distal on the
femurfemur

CRUCIATE RETAININGCRUCIATE RETAINING
VSVS
CRUCIATE SACRIFICINGCRUCIATE SACRIFICING

Constraint ladder inConstraint ladder in
implant designimplant design
PCL-retaining (cruciate-retaining, or CR)PCL-retaining (cruciate-retaining, or CR)
Rotating platformRotating platform
PCL-substituting (posterior-stabilized, or PS)PCL-substituting (posterior-stabilized, or PS)
Unlinked constrained condylar implant orUnlinked constrained condylar implant or
VVCVVC
Linked, constrained condylar implantLinked, constrained condylar implant
(rotating-hinge knee, RHK).(rotating-hinge knee, RHK).

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

PCLPCL
MajorMajor stabilizingstabilizing ligament.ligament.
Tightens the flexion spaceTightens the flexion space
SecondarySecondary mediolateralmediolateral stabiliser in flexion.stabiliser in flexion.
PCL excision increases thePCL excision increases the
flexion gap by 4-5mm andflexion 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 leastProvides least constraintconstraint
Less forces at theLess forces at the interfaceinterface
PreservesPreserves proprioceptiveproprioceptive fibres (intact PCL)fibres (intact PCL)
Greater stability duringGreater stability during stairstair climbingclimbing
(quadriceps strength)(quadriceps strength)
Less risk of condylarLess risk of condylar fracturefracture

PCL retaining (CR) 2PCL retaining (CR) 2
FewerFewer patellapatella complicationscomplications
PreservePreserve bone stockbone stock on the femoral sideon the femoral side
BetterBetter kinematicskinematics but relatively less predictablebut relatively less predictable
Avoids the tibialAvoids the tibial post–campost–cam impingementimpingement
Ease of management of supracondylarEase of management of supracondylar fracturefracture
(plate/nail)(plate/nail)

PCL retainingPCL retaining (CR)(CR)
DisadvantagesDisadvantages
Less conforming surfaces to allow roll-backLess conforming surfaces to allow roll-back
Slide/shear stress causes poly delaminationSlide/shear stress causes poly delamination
Technically difficult to balanceTechnically difficult to balance
Late PCL dysfunctionLate PCL dysfunction

PCL ReleasePCL Release

PCL substitution/sacrificingPCL substitution/sacrificing
IndicationsIndications
PreviousPrevious patellectomypatellectomy
RheumatoidRheumatoid arthritisarthritis
Stiff knee inStiff knee in post-traumaticpost-traumatic arthritisarthritis
Previous high tibial osteotomyPrevious high tibial osteotomy (HTO)(HTO)
LargeLarge deformity,deformity, over-released PCLover-released PCL

AdvantagesAdvantages
PCL histologically and kinematicallyPCL histologically and kinematically abnormalabnormal
The cam-post mechanism improvesThe cam-post mechanism improves APAP
stabilitystability
Provides a degree ofProvides a degree of VVCVVC
Conforming surfaces allowingConforming surfaces allowing roll-backroll-back
No componentNo component slideslide

AdvantagesAdvantages
Higher degree ofHigher degree of flexionflexion
LessLess joint linejoint line sensitive (Restored within 8-sensitive (Restored within 8-
9mm, Figgie)9mm, Figgie)
Congruent joint surfaces reducesCongruent joint surfaces reduces wearwear
FacilitatesFacilitates deformitydeformity correctioncorrection
Superior and more reproducibleSuperior and more reproducible kinematicskinematics
TechnicallyTechnically easiereasier than CR and reproduciblethan CR and reproducible

High stresses at fixationHigh stresses at fixation interfaceinterface (loosening)(loosening)
FemoralFemoral bonebone loss/fractureloss/fracture
Tibial peg increasesTibial peg increases wearwear
PostPost dislocationdislocation
Three times greaterThree times greater joint linejoint line alterationalteration
compared to CRcompared to CR
PatellaPatella clunk/ crunch syndromeclunk/ crunch syndrome

Patella Clunk SyndromePatella Clunk Syndrome

SummarySummary
Both CR & PS knees work very wellBoth CR & PS knees work very well
Long term outcome comparableLong term outcome comparable
One design wont fit allOne design wont fit all
PS knees outcome is more predictablePS knees outcome is more predictable
We should be able to do both when it isWe should be able to do both when it is
indicatedindicated

Mobile Bearing surfacesMobile Bearing surfaces
Lab data mobile bearing TKR reduce wear→Lab data mobile bearing TKR reduce wear→
but has not translated into any difference inbut has not translated into any difference in
terms of clinical outcomes.terms of clinical outcomes.
Other literature has shown increased totalOther literature has shown increased total
wear attributed to the additional bearingwear attributed to the additional bearing
surface of a mobile bearing implant.surface of a mobile bearing implant.
Additional complications of mobile bearingAdditional complications of mobile bearing
surfaces are bearing dislocation and soft tissuesurfaces are bearing dislocation and soft tissue
impingement due to translationimpingement due to translation

Theoretical advantagesTheoretical advantages
MBTMBT
 MaximumMaximum conformityconformity without an increase in componentwithout an increase in component
looseningloosening
 Increased survivorship and restoration of more naturalIncreased survivorship and restoration of more natural
knee kinematicsknee 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 rotationalAllows 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 advantages
MBTMBT

MBTMBT
Relies on 0 degree slope- this can beRelies 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 disadvantages
Mobile BearingMobile Bearing
 Bearing dislocation and spin out if the softBearing dislocation and spin out if the soft
tissues are imbalancedtissues are imbalanced
Underside bearing wear creating smallUnderside 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 forMedial release for
varus kneevarus knee

Medial release for varus kneeMedial release for varus knee
Osteophytes excisionOsteophytes excision
Deep MCL to posteromedial cornerDeep MCL to posteromedial corner
Semimembranosus aponeurosisSemimembranosus aponeurosis
Superficial MCLSuperficial MCL
Pes anserinus insertionPes anserinus insertion
PCLPCL

Pie-Crusting TechniquePie-Crusting Technique
Anterior MCL loose in extension

Rage of Ligament restraintRage of Ligament restraint
medial kneemedial knee
H Schroeder-BoerschPOSTGRAD ORTH Deiary KaderPOSTGRAD 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 bone
May need to resect more bone from the femurMay need to resect more bone from the femur
Remove posterior osteophytesRemove posterior osteophytes
For very severe FFD, use a Cobb to liftFor 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 angleThe valgus knee can be defined as a tibiofemoral angle
greater than 10°greater than 10°
 Valgus knee is associated with bony and soft-tissueValgus 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 externallyThere is distal femoral rotational deformity with externally
rotated epicondylar axis up to 10°.rotated epicondylar axis up to 10°.

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 tibiaRelease 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’sRelease (or pie-crust) the iliotibial band at Gerdy’s
tubercletubercle POSTGRAD ORTH Deiary KaderPOSTGRAD ORTH Deiary Kader

Rage of Ligament restraintRage of Ligament restraint
LateralLateral kneeknee
H Schroeder-BoerschPOSTGRAD ORTH Deiary KaderPOSTGRAD ORTH Deiary Kader

PatellaPatella

Patellofemoral MaltrackingPatellofemoral Maltracking
To Improve trackingTo Improve tracking
Externally rotate the femoral componentExternally rotate the femoral component
Lateralize the femoral componentLateralize the femoral component
Medialize the patella buttonMedialize the patella button

Patellofemoral maltrackingPatellofemoral maltracking
DODO NOTNOT
Overstuff the patella.Overstuff the patella.
Oversize the femoral componentOversize the femoral component
Internally rotate of the tibial component (increasesInternally rotate of the tibial component (increases
the Q angle)the Q angle)
Avoid an excessive valgus angleAvoid an excessive valgus angle
Avoid raising the joint lineAvoid raising the joint line
Avoid inferior placement of the patella componentAvoid inferior placement of the patella component

Patella resurfacing debatePatella resurfacing debate22
ForFor
Reduces anterior knee painReduces anterior knee pain
Improves knee strength in flexion (stairImproves knee strength in flexion (stair
descent)descent)
Less likely to revise the knee for AKPLess likely to revise the knee for AKP
Secondery resurfacing results are inferiorSecondery resurfacing results are inferior
Better resultes in RABetter resultes in RA

Patella resurfacing debatePatella resurfacing debate33
AgainstAgainst
No difference in outcomeNo difference in outcome
Increase wear particlesIncrease wear particles
Long-term problems with patellarLong-term problems with patellar
fracturefracture
Early technical complicationsEarly technical complications

Indications for selective patellaIndications for selective patella
replacement:replacement:
Advanced osteoarthritic patellaAdvanced osteoarthritic patella
Rheumatoid arthritisRheumatoid arthritis
Preoperative patellofemoral painPreoperative patellofemoral pain
Obese patientsObese patients
Overweight femalesOverweight females
ChondrocalcinosisChondrocalcinosis

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 wasFollow-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 wasFollowed for at least 10 years, no significant difference was
found. No difference was found in KSS scores, survivorshipfound. 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 patellarThe vast majority of patients with remaining patellar
articular cartilage do very well with TKA regardless ofarticular cartilage do very well with TKA regardless of
patellar resurfacing. Knees with exposed bone on thepatellar resurfacing. Knees with exposed bone on the
patellar articular surface were excludedpatellar articular surface were excluded

Patella ResurfacingPatella Resurfacing
(Development)(Development)
Early TKR 30% Ant knee painEarly TKR 30% Ant knee pain
Half replacement by flangeHalf replacement by flange
1974 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 TKRPatella resurfacing in TKR
(Randomised trial)(Randomised trial)
Barrack et alBarrack et al Sept 2001 JBJSASept 2001 JBJSA
118 TKR F/U >five years118 TKR F/U >five years
No difference in outcomeNo difference in outcome
Ant knee pain relate toAnt knee pain relate to
– Component designComponent design
– Surgical techniqueSurgical technique

Patella resurfacing in TKRPatella 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 months
Superior 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 electorcauteryCircumpatellar electorcautery
Recent RCT published in BJJ in 2014Recent RCT published in BJJ in 2014
300 knees improved clinical outcome with300 knees improved clinical outcome with
electrocautery denervation compared withelectrocautery denervation compared with
no electrocautery of the patella isno electrocautery of the patella is notnot
maintainedmaintained at a mean of 3.7 years'at a mean of 3.7 years'
follow-up.follow-up.

Complications of PatellaComplications of Patella
ResurfacingResurfacing
PF InstabilityPF Instability
Component dissociation / loosening /Component dissociation / loosening /
wearwear
Patella #Patella #
Patella tendon rapturePatella tendon rapture
Residual Ant Knee painResidual Ant Knee pain
OsteonecrosisOsteonecrosis
Patella “clunk”Patella “clunk”

SummarySummary
Use patella friendly implantUse patella friendly implant
Balance the PFJ gapBalance the PFJ gap
Realign the extensor mechanismRealign the extensor mechanism
Watch the joint heightWatch the joint height

Aseptic complications after TKRAseptic complications after TKR
Extensor Mechanism complicationsExtensor Mechanism complications
Wound healingWound healing
StiffnessStiffness
Periprosthatic fracturesPeriprosthatic fractures
LooseningLoosening
Neurologic injuriesNeurologic injuries
Vascular injuriesVascular injuries
Thromboembolic 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 Pts
Intraoperative avulsion (exposure)Intraoperative avulsion (exposure)
Late fromLate from
– MUA >6wksMUA >6wks
– TraumaTrauma
– Impingement on tibial insertImpingement on tibial insert

Wound Healing (TKR)Wound Healing (TKR)
Vascular anatomyVascular anatomy
Soft tissues blood supplySoft tissues blood supply
randomrandom
Dermal plexus is within subcutDermal plexus is within subcut
fasciafascia
Peripatellar anastomotic ringPeripatellar anastomotic ring

Biomechanical factorsBiomechanical factors
Surgical trauma, skin tension, incisionSurgical trauma, skin tension, incision
sitesite
– Decline in skin oxygenation by 67% post opDecline in skin oxygenation by 67% post op
– Midline incision (smaller hypoxic lateralMidline incision (smaller hypoxic lateral
flap)flap)
– Tissue expander & M Flap in atrophic skinTissue expander & M Flap in atrophic skin

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 TKR
Soft tissue tensionSoft tissue tension
Overstuffing/improper release/tight PCL/ rotationOverstuffing/improper release/tight PCL/ rotation
Inadequate analgesia post opInadequate analgesia post op
Overzealous or lack of timely physioOverzealous or lack of timely physio
Poor pts motivation/ pain thresholdsPoor pts motivation/ pain thresholds
Low grade infectionLow grade infection
ArthrofibrosisArthrofibrosis
RSDRSD

Stiffness post TKRStiffness post TKR
TreatmentTreatment
Improve Surgical techniqueImprove Surgical technique
Analgesia/ physioAnalgesia/ physio
6-8 wks MUA gentle6-8 wks MUA gentle
LaterLater Arthrolysis open or AxArthrolysis open or Ax
RevisionRevision
– Capsular/ligamentous releaseCapsular/ligamentous release
– Polyethylene exchangePolyethylene exchange
Thank you

• When would you consider arthrodesis ofWhen 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 Arthrodesis
IndicationsIndications
•• Failed knee replacementFailed knee replacement
•• Uncontrollable sepsisUncontrollable sepsis
•• Neuropathic jointNeuropathic joint
•• Young patient with severe articular joint disease andYoung 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.

•• 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 kneeOptimal 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 withThe 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-union
MalunionMalunion
Delayed unionDelayed union
Recurrent infection.Recurrent infection.

Through Knee Amputation:Through Knee Amputation:
What are theWhat are the
indications forindications for
knee disarticulation?knee disarticulation?

INDICATIONS:INDICATIONS:
 A more distal amputation level, e.g., an ultra-shortA 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 etiologyPossible for any etiology
 New indications are infected and loosened totalNew indications are infected and loosened total
knee replacements.knee replacements.

Knee disarticulation and through-kneeKnee disarticulation and through-knee
amputationamputation
 Superior compared to a transfemoralSuperior 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 walkBilateral knee disarticulation can walk
"barefoot”"barefoot”
 Enhanced proprioceptionEnhanced proprioception
 A long lever armA long lever arm
 Preservation of adductor muscle insertionPreservation of adductor muscle insertionPOSTGRAD ORTH Deiary KaderPOSTGRAD ORTH Deiary Kader

46 Knee disarticulation 2004-201246 Knee disarticulation 2004-2012
indications for surgery included infectionindications for surgery included infection
(56%), arterial thrombosis (35%), and(56%), arterial thrombosis (35%), and
trauma (9%)trauma (9%)

Nail-Patella SyndromeNail-Patella Syndrome
Hereditary 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 onlyPatellar 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

Thank you
KURDISTAN

Knee Arthroplasty Guide

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