The document discusses total knee arthroplasty, a surgical procedure aimed at relieving pain and correcting deformities in the knee joint. It encompasses various aspects such as knee anatomy, mechanics, types of knee prostheses, materials used, and contraindications for surgery. Additionally, it outlines the complexities of knee kinematics and the considerations in choosing implants for knee replacement surgeries.

1. PRESENTED BY DR. U. KARTHIKEYAN
MODERATOR DR. PRAMOD KUMAR, PROFESSOR
BASICSOFKNEEARTHROPLASTY

2. • Arthroplasty is the surgical reconstruction of a joint which aims to relieve pain, correct
deformities and retain movements of a joint.
• Arthroplasty, or joint replacement, can be most simply defined as the functional substitution of
the articulating surfaces of the joint
• Total knee arthroplasty- surgical procedure to replace the weight bearing surfaces of the knee
joint.
ARTHROPLASTY

3. • THE KNEE JOINT IS THE LARGEST ARTICULATION IN THE BODY
• KNEE IS A TROCHO-GINGLYMOUS JOINT (A PIVOTAL HINGE TYPE JOINT)
• FOR STABILITY IT DEPENDS ON LIGAMENTS AND SURROUNDING
MUSCLES
• MUSCLES ARE ACTIVE STABILISERS
• LIGAMENTS ARE PASSIVE STABILISERS
• KNEE JOINT IS COMPREISED OF
• TIBIOFEMORAL JOINT
• PATELLOFEMORAL JOINT
KNEEANATOMY

4. ARTICULARGEOMETRY

5. • The medial femoral condyle (MFC) and lateral femoral condyle (LFC) are different sizes and
have a different radius of curvature.
ARTICULARGEOMETRY

6. • IT IS DEFINED AS THE SCIENCE OF THE ACTION OF
FORCES ON A LIVING BODY
• The knee joint has six degrees of freedom
• 3 rotational
• Flexion & extension
• Varus & valgus movements
• Int & ext rotation
• 3 translational
BIOMECHANICS

7. • The medial tibial plateau is larger than the lateral tibial
plateau
• The medial femoral condyle is larger than the lateral
• The asymetry between the two compartments is the
cause of sliding hinge movement
• Movements of knee joint
• Flexion axis – helical fashion
• Posterior translation of femur medial condyle by 2mm -
lateral condyle by 21mm
Tibiofemoraljoint

8. • Medially based pivoting of the knee explains the ER and IR of tibia
during extension and flexion, respectively
• IT IS DUE TO THE DIFFERENCE IN SIZE OF THE FEMORAL
CONDYLES
SCREWHOMEMECHANISM

9. • Primary function of patella: increase the lever
arm of the extensor mechanism around the
knee, improving the efficiency of quadriceps
contraction.
• Patella displaces the force vectors of
quadriceps and patellar tendon away from
the center of the rotation of the knee.
PATELLOFEMORALJOINT

10. • Varying extensor lever arm
• Function of trochlear geometry
• Varying PF contact areas
• Varying center of rotation of knee
• Patellofemoral stability
• Articular surface geometry
• Soft tissue restraint
• Variations in the area of contact between the patella and
the trochlea of the femur
PATELLOFEMORALJOINT

11. • The angle between the extended anatomical axis of the
femur and the line between the center of the patella
and the tibial tubercle.
• The quadriceps acts primarily in line with the
anatomical axis of the femur, with the exception of
Vastus medialis obliquis, which acts to medialize the
patella in terminal extension.
• Limbs with larger Q-angles have a greater tendency for
lateral patellar subluxation. Increase in Q-angle can be
caused by : Increased external rotation of tibia &
Excessive tibio-femoral angle
Q-ANGLE

12. • MECHANICAL AXIS
• ANATOMICAL AXIS
• JOINT LINE
ALIGNMENTOFKNEE

13. • The mechanical axis of the lower extremity is a straight
line drawn from the center of the femoral head to the
center of the tibial plafond.
• It typically crosses the knee joint in the center between
the two tibial spines just medial to the medial tibial spine.
MECHANICALAXIS

14. • A line bisecting the canal of the bone is known
as the anatomical axis.
• The femoral anatomical axis is usually in
about 5°-7° of varus relative to the mechanical
axis of the femur
• The tibial anatomical and mechanical axes are
usually the same
ANATOMICALAXIS

15. • The line tangential to the distal femoral articular
surfaces or tangential to the proximal tibial articular
surfaces.
• In a standard TKA these angles are simplified by
cutting the tibia perpendicular to the mechanical/
anatomic axis, which is 0°.
• All of the femoral cuts are then adjusted to line up with
this tibial cut.
JOINTLINE

16. • Now combining everything together. On the femoral side, the
joint line is in 9° of valgus relative to the anatomic axis
• 6° from the femoral center to the mechanical axis and then
• 3° more from the mechanical axis to the line across the
distal femoral condyle
• On the tibial side, the joint line is in 3° of varus relative to the
anatomic axis
• 0° from the tibial center to the mechanical axis because
these two are parallel
• 3° from the mechanical axis to the tibial joint line).
JOINTLINE

17. • The Knee is more complex than a simple hinge joint.
• Motion occurs not only in flexion-extension, but also involves rotation, pivot, and gliding
movements.
• The best way to understand our knee motion is to first understand that it is controlled by
three things:
• The articular geometry
• The ligamentous balance
• Muscular tension.
KINEMATICS

18. • The MFC radius of curvature is relatively uniform and so the MFC remains mostly stationary during knee flexion
• The LFC travels posteriorly on the tibia (posterior rollback) due to the change in radius of curvature.
ARTICULARGEOMETRY

19. • Rollback is essential to achieve full deep flexion
ARTICULARGEOMETRY

20. • It determines the point of terminal flexion.
• Rollback is essential to achieve full deep flexion (which is seen with squatting or deep bends).
• Without rollback, the back of the femoral diaphysis will impinge on the tibia around 90°,
• however, if the distal femur moves posteriorly in relation to the tibia, it increases the clearance
before impingment, and thus allows for extra flexion.
ARTICULARGEOMETRY

21. • The knee is only partially guided by the geometry of the
articular surface. The surrounding ligaments and
muscles also play a central roll
• Collateral Ligaments: control coronal plane stability.
• Cruciate Ligaments: provide stability in the sagittal
plane.
• Meniscus: increase contact area to reduce joint
forces
SOFTTISSUEANATOMY

23. KNEEDEFORMITY

24. • Preservation of the joint line
• Restoration of a normal mechanical axis, i.e. 0°
• Balanced flexion and extension bone gaps
• Balanced soft-tissue restraints, maintaining adequate medial/lateral (coronal) and
anteroposterior (sagittal) joint stability
• Good patellar tracking (maintaining or restoring a normal Q angle).
GOALSOFTKR

25. • Relieve pain caused by severe arthritis, with or without deformity.
• Young patients with limited function due to systemic arthritis with multiple joint involvement.
• Osteonecrosis with subchondral collapse of a condyle.
• Severe patellofemoral arthritis.
• Severe deformity associated with moderate arthritis and variable pain.
1°INDICATIONS

26. • Recent knee sepsis.
• Source of ongoing infection elsewhere in body.
• Extensor mechanism discontinuity or dysfunction.
• Painless, well functioning knee arthrodesis.
ABSOLUTECONTRAINDICATIONS

27. • Severely osteoarthritic ipsilateral hip which should be operated first because it is easier to
rehabilitate a THR with the OA knee than to rehabilitate a TKR with a OA hip.
• Atherosclerotic disease of operative leg.
• Venous stasis disease with recurrent cellulitis.
• History of osteomyelitis in proximity of knee.
• Morbid obesity BMI > 40
• Medical conditions that is patients ability to withstand anesthesia, metabolic demands of
surgery and wound healing.
RELATIVECONTRAINDICATIONS

28. • Femoral component
• Tibial component (tray)
• Tibial articular surface (spacer)
• Patellar component (button)
PARTSOFATOTALKNEEPROSTHESIS

29. • The femoral and tibial components are typically made of
metals such as cobalt chrome or titanium
• the articular and patellar components are typically made
of ultra-high-molecular-weight polyethylene (UHMWPE).
MATERIALS

30. • IT IS ULTRA HIGH MOLECULAR WEIGHT
POLYETHYLENE
• It is a subset of the thermoplastic polyethylene
• It has extremely long chains, with a high molecular mass 1]
which serves to transfer load more effectively to the
polymer backbone by strengthening intermolecular
interactionsresults in a very tough material, with the
highest impact strength
TIBIALINSERT

31. • It is highly resistant to corrosive chemicals except
oxidizing acids
• Low moisture absorption and a very low coefficient of
friction
• UHMWPE was first used clinically in 1962 by Sir John
Charnley and emerged as the dominant bearing material
for total hip and knee replacements in the 1970
PROPERTIES

32. • Highly cross-linked UHMWPE materials were clinically introduced in 1998
• These new materials are cross-linked with gamma or electron beam radiation (50–105 kGy)
and then thermally processed to improve their oxidation resistance
• In 2007, manufacturers started incorporating anti-oxidants into UHMWPE for hip and knee
arthroplasty bearing surfaces.[1]
• Vitamin E (a-tocopherol) is the most common anti-oxidant used
• The anti-oxidant helps quench free radicals that are introduced during the irradiation process,
imparting improved oxidation resistance to the UHMWPE without the need for thermal
treatment
VARIANTS

33. • The femoral component is usually made of cobalt chromium
• Although non reactive in most of the patients tends to cause allergic reactions in some due to
the presence of nickel in the alloy
• It is due to the wear of the metallic component due to friction with plastic insert leading to
release of free ions which causes the reaction
FEMORALCOMPONENT

34. • TKA Metal Hypersensitivity is a complication of TKA that may
lead to persistent knee pain and stiffness as a result of an
allergic reaction to the metallic components.
• Diagnosis involves careful patient history, and ruling out
infection or aseptic loosening. Patch testing may be helpful in
diagnosis.
• Treatment generally involves component exchange to a
hypoallergenic femoral component with all-polyethylene tibial
component.
METALLOSIS

35. • chromium and cobalt and they are known to release
metal ions inside your body.
• Patients who suffer from metal allergy tend to
experience inflammation in the knee joint because of the
metal ions released by the regular implants.
• Eventually, they develop complications such as meta
deposition on synovial membrane, loosening up of the
joint and persisting knee pain
TITANIUMNOBIUMNITRATE

36. • Outstanding biocompatibility
• Hardness superior to cobalt chromium-based alloys
• Low Friction articulation Superior abrasion resistance for
longevity
• Long-term chemical stability Avoids inflammation and
loosening
• Allergy prevention
• Very high surface strength ensuring less wear and tear and
more load bearing.
TITANIUMNOBIUMNITRATE

37. • 8 times harder than a regular CoCr product
• It is twice as hard as the Zirconium Oxide implants
• most biocompatible non-allergic surface material
• 0.0008 times ionic release compared to that of regular Cobalt Chromium products
• Friction in the knee caused by the implant is also less than half
TITANIUMNOBIUMNITRATE

38. • METAL ON PLASTIC
• CERAMIC ON PLASTIC
• CERAMIC ON CERAMIC
• METAL ON METAL
TYPESBASEDONMATERIALS

39. • This is the most common type of implant
• Metal femoral component that rides on a polyethylene
plastic spacer
• Least expensive type of implant and has the longest track
record for safety and implant life span
• Immune reaction triggered by tiny particles that wear
away from the spacer
METALONPLASTIC

40. • This type uses a ceramic femoral component instead of metal
(or a metal component with a ceramic coating)
• It also rides on a plastic spacer
• People who are sensitive to the nickel used in metal implants
might get the ceramic type
• Plastic particles from this type of implant also can lead to an
immune reaction.
CERAMICONPLASTIC

41. • The femoral and tibial components are both made of
ceramic
• Ceramic parts are the least likely to react with the
body
• Make a squeaking noise when you walk
• In rare cases, they can shatter under heavy pressure
into pieces that must be removed by surgery
CERAMICONCERAMIC

42. • The femoral and tibial components are both made of
metal
• Rarely used in recent years because of concerns over
traces of metal leaking into the bloodstream.
• Traces of metal can cause inflammation, pain, and
possibly organ damage
•
METALONMETAL

43. • CONSTRAINED
• NON HINGED
• HINGED
• NONCONSTRAINED
• CRUCIATE RETAINING
• CRUCIATE SUBSTITUTING / POSTERIOR STABILIZING
• EACH OF THESE COULD BE WITH FIXED BEARING OR ROTATING PLATFORM
DESIGNSOFCONTEMPORARYIMPLANTS

44. • Constraint in TKA refers to, “the extent to which forces other than axial load are
transferred from one component of the knee implant to the other”
• Constrained implant is defined as the one that restricts motion in all three planes
• The level of constraint in a prosthesis design refers to the degree to which the eventual
stability of the knee is due to the prosthesis
• Theoretically, the greater the level of constraint, the greater the level of stress transfer to
the implant–bone interface, and hence a higher risk of implant loosening.
•
CONSTRAINT

45. • FIXED
• BEARING IS FIXED TO TIBIA BASE
PLATE
• PREFERRED FOR MOST CASES
• NO ISSUE OF BACKSIDE WEAR
• MOBILE
• NOT FIXED SO MOVES WITH KNEE
FLEXION AND EXTENSION
• FOR MORE ACTIVE INDIVIDUALS
INVOLVED IN SPORTS
• BACKSIDE WEAR ISSUE PRESENT
FIXEDVSMOBILEBEARING

46. • The main decisions regarding implant type and configuration are:
• PCL-retaining versus substituting
• fixed versus mobile bearing tibial articular surface
• level of constraint
• whether stems are necessary
• whether to resurface the patella or not.
CHOOSINGIMPLANTTYPE

47. • This is the simplest knee design and the
design with the least constraint.
• It requires removal of the ACL and
retention of the PCL
CRUCIATERETAINING

48. • Better kinematics by facilitating joint line preservation,
may translate into less mid-flexion instability
• Facilitates physiological ‘roll-back’ of the femur on the
tibia during high knee flexion, thus increasing knee
flexion
• Femoral component is more bone-conserving
• Preservation of proprioception associated with the PCL
• Preservation of anatomic structures and bone
• Theoretical decrease in implant shear stress,
transmitting less load to the bone-prosthesis interface
• Possible enhanced stair climbing
•
CRUCIATERETAINING
• Soft-tissue balancing more difficult
• Subsequent loss of PCL competency may render the
knee unstable
• Tibial articular surface is flatter to allow roll-back and
hence less conforming; this increases stresses on the
polyethylene and may increase wear
• Potential late PCL instability with a likely increased
risk in inflammatory arthritis
• Less congruent surface geometry with potential for
high articular stress
• Technically more difficult to balance in severe
deformities

49. • AKA POSTERIOR STABILISATION
• This is the next knee implant up in the hierarchy of
complexity of implant design.
• The CAM is a bar-like structure that runs across the
posterior condyles of the femoral component and the
post is a vertical projection of polyethylene from the
center of the tibial insert.
• There is usually a box in the femoral component to
accommodate for this mechanism
•
CRUCIATESACRIFICING

50. • Technically easier, procedure more easily
reproducible
• More conforming articular surface reduces
contact stresses and wear
• Fixed rollback
• More congruent surfaces
• Allows easier correction of moderate to
severe fixed deformities
• More flexibility with joint line restoration
CRUCIATESACRIFICING
• More conforming articular surface will, however,
transfer more stresses to the implant–bone
interface, increasing the risk of loosening
• Absence of roll-back may reduce flexion Greater
disruption of knee kinematics and
proprioception
• Patella-Clunk syndrome7
• Possible loss of PCL proprioception
• More bone resection
• Less stress transfer to soft tissues

52. • Design features such as a high anterior lip and deep
trough for increased articular congruence, help guide
femoral rollback and drive knee kinematics
• Greater knee stability during flexion and stair
climbing
• This increased contact surface area allows for
decreased contact forces and allows femoral rollback
throughout the knee ROM
• Thick anterior lip on the tibial insert essentially
functions as a PCL
ULTRACONGRUENT

53. • bicruciate stabilizing (BCS) implants use an
asymmetric cam-post mechanism, to substitute for
both the ACL and PCL.
• In contrast to standard PS bearings, BCS implants
have an asymmetric and medially conforming tibial
plateau
BICRUCIATESTABILISING

54. • This stability is obtained by reducing the
tolerances between the post of the
polyethylene insert and the box of the
femoral component.
• These designs require the polyethylene
insert to be robustly locked into the tibial
base plate as the increased torque
generated by the constraint could dislodge
the polyethylene insert from the base-plate.
CONSTRAINEDNONHINGED

55. • This stability is obtained by reducing the
tolerances between the post of the
polyethylene insert and the box of the
femoral component.
• These designs require the polyethylene
insert to be robustly locked into the tibial
base plate as the increased torque
generated by the constraint could dislodge
the polyethylene insert from the base-plate.
CONSTRAINEDNONHINGED

56. • Stems are rods that can be attached to the femoral or
tibial components, and placed intramedullarly.
• Transfer stresses away from the implant–bone
interface, and improve implant stability on the cut
bone surfaces.
• Thus, stems are often used in instances when the
host bone is poor and/or deficient
• Also, with implants with higher levels of constraint,
stems help to reduce the stresses at the principal
component–bone interface
ROLEOFSTEMS

57. • These are fully constrained prosthesis
• The femoral and tibial components are linked.
• Such a design does not depend on the integrity of the
surrounding soft tissues, and is useful in cases of
substantial disruption of the soft tissues
• It gives stability not only in the coronal plane but also in the
sagittal plane
HINGED

58. • STANDING XRAY OF KNEE AP AND LATERAL VIEW
• SCANNOGRAM OF THE LOWER LIMG
• MERCHANTS VIEW OF PATELLA
PREOPEVALUATION

59. APXRAYOFKNEE

61. SCANNOGRAMANDPATELLA

62. SURGICAL APPROACHES
• MEDIAL PARAPATELLAR APPROACH
• MID VASTUS APPROACH
• SUBVASTUS APPROACH
• MINIMALLY INASIVE APPROACH
COMPLEX PRIMARY OR REVISION TOTAL KNEE ARTHROPLASTY
• MEDIAL PARAPATELLAR
• QUADRICEPS SNIP
• V-Y TURN DOWN
• TIBIAL TUBERCLE OSTEOTOMY

63. MEDIAL PARAPATELLAR
APPROACH
• Excellent exposure
• Compatible with primary and
revision TKR
Advantages
• Possible failure of medial capsular
repair
• Development of lateral patellar
subluxation
• Access to lateral retinaculum less
direct
Disadvantages • midline incision 5cms above superior
pole of patella to the level of tibial
tubercule.
• The VMO is detached from its
insertion into the quad tendon,
leaving a cuff of tendon (~5 mm)
attached to the VMO proximally and
a cuff of tendon attached to the
medial edge of the patella distally to
facilitate repair at closure.
• The patella is either dislocated or
dislocated + everted.

64. MIDVASTUS APPROACH
• Similar approach to medial parapatellar that spares
VMO insertion.
Advantages
• Vastus medialis tendon not disrupted
• Accelerated rehabilitation due to intact extensor
mechanism
• Patellaer tracking better.
Disadvantages
• Less extensile
• Exposure difficult in obese patients
• Difficult in flexion contractures
• Potential for partial VMO denervation.

65. SUBVASTUS APPROACH
• Muscle belly of vastus medialis is lifted off
intermuscular septum.
Advantages
• Patellar vascularity preserved
• Extensor mechanism remains intact
• Minimal need for lateral retinacular release.
Disadvantages
• Least extensile

66. QUADRICEPS SNIP
APPROACH
• snip made at apex of quadriceps
tendon obliquely across tendon at a
45-degree angle into vastus lateralis
Advantages
• no change in post-operative
protocol
• minimal, if any, long-term
consequences
Disadvantages
• not as extensile as a turndown or
tibial tubercle osteotomy

67. V-Y TURNDOWN APPROACH
• straight medial parapatellar arthrotomy with diverging
incision down the vastus lateralis tendon towards lateral
retinaculum.
Advantages
• allows excellent exposure
• allows lengthening of quadriceps tendon
• preserves patellar tendon and tibial tubercle
Disadvantages
• extensor lag
• may affect quadriceps strength
• knee needs to be immobilized post-operatively

68. TIBIAL TUBERCULE
OSTEOTOMY
• 6-10 cm bone fragment cut from medial to lateral
• fixed with screws or wires.
Advantages
• excellent exposure
• avoids extensor lag seen with V-Y turndown
• avoids quadriceps weakness
Disadvantages
• some surgeons immobilize or limit weight-bearing
post-operatively
• tibial tubercle avulsion fracture
• non-union
• wound healing problems

69. • There are currently three schools of thought regarding the techniques of TKA;
• Measured resection,
• Gap balancing
• Kinematic alignment.
• All three philosophies have a common goal of achieving balanced flexion and extension gaps leading to well-
balanced medial and lateral collateral ligaments.
• Measured resection and Gap balancIng techniques have a common goal in achieving a neutral mechanical
axis
• Kinematic alignment aims to reconstruct the patient’s pre-arthritic alignment, be it constitutional varus
or valgus.
CURRENTPHILOSOPHIESINTKA

70. BONECUTS

71. • In this technique, the femoral and tibial cuts are made
independent of each other followed by ligament
balancing using appropriate releases
MEASUREDRESECTION

72. • Mark the transepicondylar line and the AP axis of the femur
(Whiteside’s line)
• A 9 mm drill-point drill a hole into the medullary canal, just
medial to the center of the notch OR just above the insertion
of the PCL
• Too anterior has risk of perforating the anterior cortex.
• Drilling in the midline of the femoral condyles to avoid an
abnormal valgus angulation of the distal cut

73. • After aspiration of the canal to reduce embolization of marrow
contents, insert an intramedullary guide rod (preferably fluted)
into the femoral canal.
• Apply a distal femoral cutting jig to the intramedullary rod
• Choose the distal femoral cut angle based on the preoperative
templating.
• Pin the jig to the bone and make the distal cut of the femoral
condyles with an oscillating saw.
• This cut should be perpendicular to the mechanical axis of the
femur.
DISTALFEMORALCUT

74. • Apply an AP sizing guide to the distal femur,
perfectly flat on the distal cut.
• The feet of the jig should be firmly and equally
resting on the posterior condyles.
• Attach a stylus to the sizing guide and place it on
the anterior cortex of the femur measuring off
the highest point on the lateral anterior cortex.
SIZINGOFFEMORALCOMPONENT

75. • The sizing guide usually doubles as the external
rotation guide.
• Using this device, adjust the transverse axis of the
femoral component to be perpendicular to
Whiteside’s line, parallel to the TEA
• at about 3o
–5o
externally rotated to the posterior
condylar axis. Drill pinholes to mark this rotation
DETERMININGEXTROTATION

76. • Mount a 4-in-1 cutting jig of the chosen femoral
component size on the distal femur in the chosen
external rotation determined by the holes made
for the guide/mounting pins from the previous
step.
• Fix the jig in place with oblique pins and make the
four bone cuts with an oscillating saw
ANTPOS&CHAMPFERCUTS

81. • The anterior cut on the femoral condyles should leave a higher
and longer prominence laterally, and the removed bone
fragment typically looks like a mountain, called the Matterhorn
sign or the grand piano sign
GRANDPIANOSIGN

82. • THE DISTAL FEMORAL CUT AFTER MADE
SHOULD HAVE A FIGURE OF 8 APPEARANCE
FIGUREOF8

83. PREPARINGTHETIBIA

84. • Proximal tibial cut: There are 3 parameters to achieve
with this single cut.
– Varus/valgus
– Depth of the cut –
Tibial slope
• The proximal tibial cut should be perpendicular to the
tibial mechanical axis and therefore in zero degrees of
valgus/varus
• The depth of cut should match at least the minimum
thickness of the tibial component with the poly insert.
• The slope is based on the patient’s natural tibial slope
or per the manufacturer’s recommendation. In general
TIBIALCUT

85. • Choose the tibial component size that covers the
largest possible area of the cut surface of the tibia
while avoiding overhang of the tibial plateau.
• The AP axis of the tibial component should intersect
the medial 1/3rd
of the Tibial tubercle when looked at
from above
PREPARINGTHETIBIA

86. • While loose gaps create instability, a tight gap limits
motion
• The tibia is responsible when the knee is tight in both
flexion + extension,
• The distal femur is responsible for extension only
tightness, and
• The posterior femur is responsible for flexion only
tightness.
GAPBALANCING

87. GAPBALANCING

88. OSTEOPHYTEREMOVAL
Resect the residual
osteophytes and soft tissue
from the femoral margin.
Next, resect the residual
osteophytes from the
tibial margin.
Remove osteophytes from
the posterior condyles.
Also remove osteophytes from
hidden capsular pouches,
like the subpopliteal recess (beneath the
popliteal tendon) in this example

89. • Soft tissue balancing is essential to providing a stable
joint after TKA.
• After bone preparation is completed, the flexion and
extension gaps should be evaluated for symmetry for
equal height in flexion and extension.
• Before release of any anatomical soft tissue supporting
structure about the knee, all peripheral osteophytes
should be removed from the femur and tibia.
• The removal of osteophytes alone may be enough to
balance existing coronal plane deformities.
LIGAMENTOUSBALANCING

90. • Steps of medial release
• Step 1 Deep MCL Release To Mid-Coronal Plane Of Tibia
• Step 2 Medial Osteophyte Removal
• Step 3 Release Posteromedial Corner (Posterior Oblique Ligament)
• Step 4 Medial Tibial Reduction Ostectomy
• Step 5: Consider PCL Release/Substitution If Imbalance Persists At This Point (If Substitution Not Initially
Chosen)
• Step 6 Release Semimembranosis (Especially If There Is An Associated Flexion Contracture)
• Step 7 Pie Crust Superficial MCL (Favor Use Of 18 Gauge Needle)
• Step 8 Complete Superficial MCL Release / Pes Anserinus
VARUSKNEECORRECTION

91. VARUSKNEECORRECTION

92. • Lateral release in order
• Step 1 osteophytes
• Step 2 posterolateral capsule
• Step 3 iliotibial band if tight in extension with pie crust or release off Gerdy's tubercle
• Step 4 popliteus if tight in flexion (release if tight in flexion) release the anterior part of its insertion for severe
deformities release both the iliotibial band and the popliteus
• Step 5 LCL
• Step 6 Intermuscular septum (from the vastus lateralis)
• Step 7 Posterior cruciate ligament
• Step 8 Biceps tendon off fibula head (usually the last to bereleased).
VALGUSKNEECORRECTION

93. VALGUSKNEECORRECTION

94. • In varus or valgus knee after assessment pie crusting of
lateral or medial soft tissue sleeve is done.
• Multiple stab incisions with scalpel blade or large needle
parallel to joint line are made to effectively elongate areas
of soft tissue sleeve that are under tension.
PIECRUSTING

95. • Most preoperative flexion deformities improve with appropriate soft tissue balancing for coronal plane deformity.
• If a flexion contracture persists despite balanced medial and lateral soft tissues, the shortened posterior
structures must be effectively lengthened.
• If the contracture persists, the joint line may need to be elevated by increasing the amount of distal femoral bone
resection.
• Posterior release order
• 1) posterior femoral & posterior tibial osteophytes
• 2) posterior capsule
• 3) additional resection of distal femur
• 4) gastronemius muscles (medial and lateral)
CORRECTIONOFFFD

96. CORRECTIONOFFFD

97. GAPBALANCING

98. • Gap balance and trial:
• Use a spacer block to check that the gaps are equal.
• If not, make appropriate adjustments.
• The flexion and extension gaps should have surfaces that
are parallel to each other.
• Now insert the trial femoral and tibial components with
the appropriate trial bearing size.
• Move the knee through a range of motion to test ligament
balance, stability, and the equality of flexion and extension
spaces. See above perform releases as necessary.
TRIAL

99. • The Kinematically aligned TKA (KA-TKA) is based on the
premise that there are three main kinematic axes that
should be reconstructed during a TKA
• The primary flexion-extension axis of the knee:
• 2. The flexion-extension axis of the patella:
• 3. The longitudinal axis of the tibia:
KINEMATICALIGNMENT

100. • Across most device companies, the standard
thickness of the Patellar Button is 9 mm.
• The standard patellar cut should thus be 9
mm.
• Measure the depth of the native patella,
subtract 9 mm, and then set the patellar
cutting guide to that number
PATELLARRESURFACING

101. • It functions as a ‘grout’ that forms an intimate sleeve between the implant and interdigitates
into the cancellous structure of the bone.
• Poor cementation techniques risk premature implant loosening. Careless removal of excess
cement results in micro and macroscopic third body particles, which can entrap within the joint
articulation and cause catastrophic polyethylene wear.
CEMENTINGTHECOMPONENTS

102. CEMENTINGTHECOMPONENTS

103. CEMENTINGTHECOMPONENTS

104. CEMENTINGTHECOMPONENTS

105. • IF TIBIAL DEFECT <5MM - CEMENT
AUGMENTATION
• IF TIBIAL DEFECT 5-10 MM - BONE GRAFT
• IF TIBIAL DEFECT >10MM - WEDGE
MANAGEMENTOFBONEDEFICIENCIES

108. • PAIN MANAGEMENT
• Continuous epidural
• Parentral posterior capsule analgesia
• Drains to be removed after 48 hrs
• Thromboprophylaxis like LMWH to be started on the evening of surgery for a week
• Staples removed on day 12-14
POSTOPMANAGEMENT

109. • Start rom exercises on day 1
• Made to stand on day 2 with support and walking initiated
• To do knee flexions and straight leg raises
• Encouraged to increase activity with walker for 2 weeks
• 2-4 weeks walking frame can be replced with a walking stick
• After that patinet can adjust activity as tolerated
REHABILITATION

110. • Standard exercises that are used for early postoperative knee replacement include:
• Quadriceps strngthening
• Terminal knee extension
• Heel slides
• Straight leg raising
• Pillow squeezes
REHABILITATION

111. • SYSTEMIC
• THROMBOEMBOLISM
• FAT EMBOLISM
• LOCAL
• WOUND DRIANAGE
• VASCULAR COMPLICATIONS
• NEUROLOGICAL COMPLICATIONS
COMPLICATIONS

112. • SURGICAL SITE INFECTION
• PERONEAL NERVE PALSY
• EXTENSOR MECHANISM INJURY
• TORNIQUET RELATED ISCHEMIC INJURY
• ARTERIAL INJURY
• INTRA OP FRACTURE
• LIGAMENT INJURY
IMMEDIATECOMPLICATIONS

113. • Blood loss
• Perioperative blood loss during TKA can be minimized by using blood-saving techniques
(tourniquet, topical agents, systemic agents).
• Using these strategies, intraoperative blood loss is generally low.
• Following transfusion guidelines and perioperative protocols to reduce bleeding (ie, tranexamic
acid and local infiltration analgesia), the rate of intraoperative transfusion can be reduced to
nearly 0 percent
IMMEDIATECOMPLICATIONS

114. • THROMBOEMBOLISM
• The development of deep vein thrombosis (DVT) with the potential to propagate a potentially
lethal pulmonary embolus (PE) is one of the most feared complications of TKA.
• The reported incidence of DVT following TKA without prophylaxis ranges from 40 to 88
percent [6-8].
• The incidences of asymptomatic PE, symptomatic PE, and mortality range from 10 to 20
percent, 0.5 to 3 percent, and up to 2 percent, respectively.
EARLYCOMPLICATIONS

115. • ASEPTIC LOOSENING
• JOINT INSTABILITY
• SUB ACUTE AND CHRONIC PERIPROSTHETIC INFECTIONS
• POLYETHYLENE WEAR
• OSTEOLYSIS
• ARTHROFIBROSIS, JOINT STIFFNESS
• PERSISTANT PAIN
• METAL HYPERSENSITIVITY
INTERMEDIATE&LATECOMPLICATIONS

116. • Patellofemoral instability
• Patellar fracture
• Patellar component failure
• Patellar component loosening
• Patellar clunk syndrome
• Extensor mechanism rupture
PATELLOFEMORALCOMPLICATIONS

117. • Patellar clunk syndrome occurs when scar tissue builds up at
the superior pole of the patella and becomes trapped in the
intercondylar housing of a posterior stabilized femoral
component
• minimized if the design of a posterior stabilized femoral
component has a smooth and lowered transition from the
trochlea into the intercondylar housing.
• Also by surgical removal of all residual synovium from the
quadriceps tendon just above the superior pole of the patella
.
PATELLACLUNKSYNDROME

118. • NAVIGATIONS SYSTEMS
• ROBOTICS
RECENTADVANCES

119. • It provides surgeons with a precision tool for carrying out surgery
• Possibility of intraoperative simulation and objective control over various anatomical and
surgical parameters
• Basically used to control the alignment of bone cutting referenced to the mechanical axis of the
lower limb
• Also component rotation, ligament balancing and arranging the symmetry of flexion and
extension spaces
• Better alignment of the lower-limb axis has been widely proven
NAVIGATIONSYSTEMS

120. • A - OPTICAL TRACKING CAMERA
• B - COMPUTER
• C - MONITOR
NAVIGATIONSYSTEMS

121. • Surgeon inputting to the system the anatomical
reference point indicated on the monitor, using
a pointer coupled to a rigid body.
NAVIGATIONSYSTEMS

122. • Screen simulating the femoral cut after carrying
out the tibial cut. All the variables (sizes of
femur and insert, rotation and height of the
femoral cut) can be modified and their effect on
the lateral and medial flexion and extension
spaces can be observed.
NAVIGATIONSYSTEMS

123. • PASSIVE SYSTEMS
• ACTIVE SYSTEM
• INTERACTIVE SYSTEM
• TELE OPERATED SYSTEM
ROBOTICS

124. • Donot directly carry out the procedure
• Usually handheld devices that guide the surgeon
• Eg. Conventional navigation systems
PASSIVESYSTEMS

125. • These use preop and intraop data to perform surgical steps independentlywithout surgeons
participation
• Surgeon makes standard approach
• Positions pins ans navigation markers
• The robotic reaming tools once activated makes tibial and femoral cuts
• Eg. Robodoc 1986
ACTIVESYSTEM

126. ROBODOC

127. • Customized foot and thigh holder.
ROBODOC

128. • Rigid mating of the patient to the
system
ROBODOC

129. • Digitization of femoral & tibial
landmarks
ROBODOC

130. • TCAT miller working on femur.
• Virtual surgery conducted using
TPLAN3D workstation.
ROBODOC

131. ROBODOC

132. • These systems are remotely controlled by the
surgeons
• Eg. Davinci robot
TELEOPERATEDSYSTEMS

133. THANKYOU