Total knee replacement (TKR) involves replacing the weight-bearing surfaces of the knee joint to relieve pain and correct deformities. The document discusses the anatomy of the knee joint, common conditions requiring TKR such as osteoarthritis and rheumatoid arthritis, the evolution of TKR implant designs, surgical approaches, the procedure, goals of alignment and balancing, and potential complications. Computer-assisted technology can provide real-time feedback on bony cuts and alignment during surgery. While TKR successfully relieves pain in most patients, some may still experience complications such as stiffness, infection, or loosening of implants.

1. TOTAL KNEE REPLACEMENT
Presenter : Dr. Saumya Agarwal
Junior resident Dept of Orthopaedics
J.N .Medical College and Dr. Prabhakar
Kore Hospital and MRC, Belgaum

2. INDEX
• Anatomy of the knee joint
• Common conditions leading to TKR
• Evolution of TKR
• Total knee replacement

3. • Approaches
• Procedure
• Complications
• Computer assisted technology
• Questions

4. Anatomy Of The Knee Joint
• Three bones and three compartment

5. Knee Stabilizers
• Medial
• Lateral
• Anterior
• Posterior
• Rotatory

8. Osteokinematics
Gross movements of bones at joints
Flexion / extension
Abduction / adduction
Internal rotation / external rotation
Arthrokinematics
Small amplitude motions of bones at joint surface
Roll
Glide (or slide)
Spin

9. INTRODUCTION
Arthroplasty is the surgical reconstruction of a
joint which aims to relieve pain , correct
deformities and retain movements of a joint.
Total Knee Arthroplasty(TKA) is the surgical
procedure to replace the weight-bearing
surfaces of the knee joint.

10. Common Conditions That Lead To TKR
• OSTEOARTHRITIS
Primary (idiopathic)
Secondary
Post traumatic arthritis
• RHEUMATOID ARTHRITIS

11. Evolution of TKR
• Fergussen(1860) resection arthroplasty
• Verneuil performed first interposition arthroplasty
• 1940s- first artificial implants were tried when molds
were fitted in the femoral condyle
• 1950s- combined femoral and tibial articular surface
replacement appeared as simple hinges

12. Evolution ….
• Frank Gunston(1971), developed a metal on
plastic knee replacement
• John Insall(1973), designed what has become
the prototype for current total knee
replacements. This was a prosthesis made of
three components which would resurface all 3
surfaces of knee - the femur, tibia and patella

13. Classification of Implants Design
• Unconstrained
– Cruciate retaining
– Cruciate substituting
– Mobile bearing knees
• Constrained (Hinged)
• Unicondylar Prosthesis
• Total Condylar Prosthesis

14. Prosthetic Design
Femoral rollback
– Posterior translation
femur with flexion
– Controlled by PCL
– Improves Quad
function and knee
flexion

15. Unconstrained TKR

16. Cruciate retaining
Intact PCL
Varus < 10
Valgus < 15
• Advantage
1. Avoid post cam impingement/ dislocation
2. More closely resembles knee kinematics
3. Bone preserving
4. Improved proprioception
• Disadvantage
1. Tight PCL – Increased poly wear
2. Rupture PCL – flexion instability

17. Cruciate stabilized
• Cam and post mechanism
• Insert more congruent / dished
Advantages
Easier to balance knee
More range of motion
Disadvantages
Cam jump
Post wear
Patellar clunk syndrome
Additional cut from distal femur
ABSOLUTE INDICATION
•Previous patellectomy
•Inflammatory arthritis
•Deficient PCL

18. Cruciate sacrifice / retain - Evidence
PS increased ROM –
No functional improvement
No difference in ROM
between PS and CR
PCL does not work in CR
knees
Increased wear Ps knee –
cam & post
Cochrane review – No difference in
function whether cruciate retained
or sacrificed

19. Mobile Bearing Design
• Poly Rotates over tibial
base plate
• Reduced poly wear
• Bearing spin out

20. Fixed Bearing or mobile bearing -
Evidence
• No advantage of mobile bearing over fixed
bearing
• Increased wear in undersurface of mobile
bearing

21. Constrained TKR

22. Constraint
– Ability of prosthesis to provide varus – valgus and
flexion –extension stability in presence of
ligamentous laxity / bone loss

23. Constrained Hinged design
• Linked femoral and
tibial components
• Tibial bearing rotates
around yoke
Aseptic loosening
Large amount bone
resection
INDICATION
Global ligamentous
deficiency
Hyperextension instability

24. Hi Flex Design
• Cultural / pt expectation
• Cut more posterior
condyle
Preop flexion - most significant - Gatha etal 2008
No difference in ROM - Mehin JBJS 2010
No difference in ROM Sumino Int Ortho 2010

25. Uni condylar TKR

26. Advantages of Unicondylar TKR
• Shorter rehabilitation time
• Greater average post-op range of movement
• Preservation of proprioception function of
cruciate ligaments

27. CONTRA-INDICATIONS
a) Inflammatory conditions
b) Damage to articular cartilage
c) Flexion contracture of 5° or more
d) Preoperative arc of motion less than 90°
e) Angular deformity of more than 15°
f) ACL deficiency

28. Total Knee Replacement Today
• Large variety is available
• Majority of TKR today are condylar
replacements which consist of the following
– Cobalt-chrome alloy femoral component
– Cobalt-chrome alloy or titanium tibial tray
– UHMWPE tibial bearing component
– UHMWPE patella component

29. Who Is A Candidate For TKR
• Quality of life severely affected
• Daily pain
• Restriction of ordinary activities
• Evidence of significant radiographic changes of
the knee

30. INDICATIONS
• Severe arthritis
• Young pts with systemic arthritis with multiple joint
involvement
• Osteonecrosis with subchondral collapse of a
femoral condyle
• Severe pain from chondrocalcinosis and pseudogout
in elderly
• Severe patello femoral arthritis rarely

31. CONTRA-INDICATIONS
• Recent/current knee sepsis
• Remote source of ongoing infection
• Extensor mechanism discontinuity
• Recurvatum deformity secondary to muscle weakness
• Presence of painless, well functioning knee arthrodesis

32. What Is The Time For Replacement
• Old age with more sedentary life style
• Young patients who have limited function
• Progressive deformity
• Other treatment modalities have failed

33. TKR should be done before things get out of
hand and the patient experiences a severe
decrease in ROM, deformity, contracture,
joint instability or muscle atrophy

34. Evaluation Of Patient Before Surgery
• A Complete Medical History
• Thorough Physical Examination
• Laboratory Work-up
• Anesthesia Assessment
34

35. Recommended Preoperative Radiographs in
Knee Replacement Surgery
1. Standing full-length anteroposterior radiograph
from hip to ankle
2. Lateral knee x ray
3. Merchant’s view

36. Radiographs
• Standing Ap & Lateral
• Sunrise – Merchant view
• Hip to ankle x- rays
– Bony deformity
– Short stature ( < 150 cm)
– Very tall ( > 190 cm)

37. Radiographs
• Femoral and tibial cut
• Position of femoral canal entry
• Bone defects
• Joint subluxation
• Ligament stretch out – Varus Thrust
• Ligament release
• Constraint needed

38. Goal of TKR
• Pain relief
• Restoration of normal limb alignment
• Restoration of a functional range of motion

39. Successful Results Depends upon:
• Precise surgical technique
• Sound implant design
• Appropriate material
• Patient compliance with rehabilitation

40. Technical Goals Of Knee Replacement
Surgery
1. The restoration of mechanical
alignment
2. Preservation (or restoration) of the joint
line
3. Balanced Ligaments
4. Maintaining or restoring a normal Q angle

41. Mechanical Alignment
TKA aims at restoring
the mechanical axis of
the lower limb by:
Sequential soft
tissue releases
Correction of bone
defects by grafts or
prosthetic augments

42. Ligament Balancing
a. Coronal Plane
– For varus deformities
– For valgus deformities
b. Sagittal Plane
– Flexion contractures
– Extension contractures

44. Procedure

45. Procedure

46. Procedure

47. Procedure

48. Procedure

49. Procedure

50. Procedure

51. VIDEO

52. APPROACHES

53. Medial parapatellar approach
• Most common
• Surgeon are familiar

54. Lateral parapatellar approach
• Valgus knee
• Allows access to lateral
side
• Technically demanding
• Medial patellar eversion
difficult

55. Midvastus approach
• Spares VMO insertion
Advantages
Accelerated rehab.
Improved patellar tracking
Disadvantages
Less extensile
Difficult in obese & flex
contracture

56. Subvastus approach
• Vastus medialis lifted off
Lateral intermuscular
septum
Advantages
Intact quad
Preserved vascularity of
patella
Disadvantage
Least extensile
Denervation of VMO
possible

57. Femoral Cut
• Valgus cut angle
• AAF – MAF
• Between 5 – 7 deg
• Intramedullary guide

58. Tibial Cut
• Angle between AAT –
MAT
• Tibial cut angle- Zero
• Tibial deformity – cut
perpendicular to MAT
• Intra or extramedullary
guide

59. Joint line preservation
• Inserting prosthesis same size as removed bone
and cartilage
Elevate joint line -
mid flexion instability
Abnormal patellofemoral tracking
Equivalent to Patella Baja
Lowering joint line -
Lack of full extension

60. Knee Balancing
• Balance in Coronal and
saggital plane
• Concave side –
ligaments contracted –
release
• Convex side – ligaments
stretched – Fill gap

61. Varus Knees
HenriK Schroeder – Boesch – Ligament balancing in TKR

62. Grade 1 release

63. Grade 2a release
Grade 2A

64. Grade 2b release
• Grade 2b release
Posterior part
tight in
extension
Anterior part
tight in flexion

65. Grade 3 release
• Grade 2a + 2b

66. Grade 4 release

67. Valgus deformity
• Osteophytes
• Lateral capsule
• Iliotibial band - Tight in extension
• Popliteus – Tight in flexion
• LCL

69. Pie crusting

70. Flexion contracture
• Osteophytes
• Posterior capsule
• Gastrocnemius ( Medial and lateral head)
• Inreased distal femoral cut

71. Saggital plane balancing
• Mc Pherson’s rule
Symmetric gap – address tibia
Asymmetric gap – address femur

72. Tight in Extension
Tight in flexion
Symmetric gap Cut more tibia
Loose in Extension
Loose in Flexion Symmetric gap
•Thicker poly
•Tibial Metal
augmentation

73. Extension good
Loose in flexion
Asymmetric gap
1. Increase size
femoral
component
2. Translate
femoral
component
posterior
3. Use thicker
poly and
readdress as
tight extension
gap

74. Extension Tight
Flexion Good
Asymmetric Gap 1. Cut more
distal femur
2. Release
posterior
capsule

75. Extension Good
Flexion Tight
Asymmetric gap 1. Decrease
femoral
component
size
2. Recess PCL
3. Check slope
of tibia

76. Extension Loose
Flexion Good
Asymmetric gap 1. Distal femoral
augmentation
2. Decrease
femoral
component
size and
thicker poly

77. Patellofemoral Alignment
• Most common complication
• Maintain Q angle
• Proper component rotation
• Maintain normal patellofemoral tension

78. • Maintain Q angle
Avoid
1. Int rotn fem
component
2. Medial rotn fem
component
3. Int rotn tibia
4. Patella prosthesis
lateral rotn

79. Femoral component rotation
• Ap Axis ( whiteside line)
• Transepicondylar axis
• Post condylar axis
• Tibial alignment axis
• Gap balance

80. Tibial component
• Int rotn tibia – increased Q angle

81. Patellar component
• Centre or medialized
• Avoid lateralizing
• Increases Q angle and
cause patella
maltracking

82. Patella Baja
• Patellar component
superior
• Lower joint line
• Transfer tibial tubercle
cephalad
• Patellectomy

83. Patella resurfacing vs non resurfacing
• Resurfacing
– Component loosening
– Clunk
– Fracture
– AVN
• Non resurfacing
– Anterior knee pain
– May require second
resurfacing

84. Patellar resurfacing Vs non resurfacing
- Evidence
• Metal backed patella higher complications
• Patellar replacement does not gurantee
painless Patellofemoral joint
• No significant benefit of patellar replacement

85. Complication
• Femoral notch
Saw cuts into anterior femoral cortex
Increases chance of periprosthetic fracture
Femoral stem extension

86. Complication
Peroneal Nerve palsy ( .3 to 2 %)
Pre op Flexion and Valgus
Tourniquete time > 120 min.
Epidural anaesthesia post op
Aberrant retractor placement
EMG & NCV at 3 months
Nerve decompression at 3 months

87. Complication
• Vascular complication ( <.17% - .2%)
• Risk factor
– Sharp dissection
– Posterior retractor placement
– Pre existing vascular disease
– Immediate vascular repair

88. Complication
• Extensor mechanism rupture ( .17% - 2.5% )
– Direct repair with suture - < 30 % avulsion
– Primary repair and augment with graft
– Allograft repair

89. Complication
• Stiffness
– Flexion contracture 10 – 15 % deg
– Flexion < 90 deg
• Treatment
– Manipulation under Anaesthesia
– Arthroscopic lysis of adhesion
– Revision TKR

90. Complication
• Hypersensitivity
Rare ( nickel)
• Patch testing
• Lymphocyte transformation test
• Revise to non allergic metal prosthesis

91. Summary
• Choose correct pt
• Plan properly
• Adequate exposure
• Follow principles to align and balance knee
• Meticulous closure
Hope for the best
because 20 % of pt.
with well performed
TKR are not happy !!

92. Post Operative Rehabilitation
– Rapid post-operative mobilization
• Range of motion exercises started
• CPM
• Passive extension by placing pillow under foot
• Flexion- by dangling the legs over the side of
bed
• Muscle strengthening exercises
• Weight bearing is allowed on first post op day

93. Prosthesis Survival
Different studies shows different results
• Ranawat et al (Clin Orthop Relat Res )
95% at 15 years
91% at 21 years
• Gill and Joshi (Am J Knee Surg)
96% at 15 years
82% at 23 years
• Font-Rodriguez (Clin Orthop Relat Res )
98% at 14 years

94. COMPUTER-ASSISTED ALIGNMENT
TECHNIQUE
• The technique involves the attachment of active or
passive trackers on femur and tibia, which are then
tracked by a computer-assisted camera.
• Computer gives real-time feedback about alignment
of bony cuts in all three anatomic planes, which
allows surgeon to make changes and to measure
the accuracy of the bony cuts.

95. • Computer navigation systems also can aid in
determining the proper implant size as well as
alignment. Soft tissue balancing and measurement
of flexion and extension gaps during the procedure
are other significant advantages to computer-
assisted TKA.
• Objective measurement of the gaps ensures proper
soft tissue balancing and gaps that will provide a
stable joint throughout a range of motion.
• Another advantage of computer navigation is
avoidance of violation of the femoral intramedullary
canal, which may reduce blood loss and cardiac-
related complications because fewer emboli are
placed into the venous system than with placement
of an intramedullary alignment rod.

96. Questions in exams ??
Long Question?
1) Describe in detail about the kinematics of knee and
enumerate the indications, procedure and complications
of TKR
Short Questions?
1) Approaches for TKR
2) Hi flexion type implant in TKR
3) Computer assisted technology for TKR
4) Complications post TKR