It entitles all the advances in arthroplasty of hip and knee including robotic and computer navigation with utmost details .

1. Newer modalities in
Arthroplasty
Dr. Yash Thakkar
Junior Resident
Seth GSMC and KEM Hospital

2. Knee
Arthroplasty

3. Indications
● Degenerative OA knee
● Non-degenerative causes of OA
● Osteonecrosis
● Chondrocalcinosis and pseudogout
● Patello-femoral arthritis

4. Contraindications
● Recent/active sepsis.
● Remote infections
● Extensor mechanism insufficiency
● Recurvatum deformity secondary to muscle weakness
● Painless well functioning knee Arthrodesis

5. ● Primary TKR - Effective Rx for severe OA knee
● ~20% post op patients - dissatisfied.
● Newer advances are constantly being made
○ To improve outcomes
○ Broaden the scope of TKR as a treatment
○ Reduce complications

7. TKR
Primary Revision
• Uncemented TKR
• MIKRS
• Oxinium implants
• Customised
• Sensors
• Accelerometer
• Navigation
• Smart tools
• Robotic
• Smart cones
• Wedges
• Sleeves

8. Cementless TKR
-Recent interest in order to improve outcomes by reducing failure
attributed to cement
-To cater to increasing need of TKR in young patient

9. Advantages:
- Shorter operating room time
- Preservation of bone stock
- Ease of revision
- Lower third body wear
- Lower retained loose fragments
- Lower osteolysis
- Biological fixation
Disadvantages:
- Cost
- Requires precise bone cuts

10. Minimally invasive knee replacement (MIKRS)
● Small incision = 4-5 inches
● Causes less pain
● Less blood loss
● Less requirements for
analgesics
● Faster recovery

11. Knee replacement for young patients
● Increasing numbers of patients <50
years seeking knee replacements.
● Special considerations of materials ,
technique needed.
● Oxinium knee is an example of a TKR
for young patients

12. Features of Oxinium knee
● Ceramic surface coating
● Metal base
● Harder than standard implant
● Less Friction
● Durable
● Non allergenic to people with
Nickel allergy

13. Customised TKR
● Customisation can be for instrumentation as well for implantation
Patient specific instrumentation Individualised implant
- Personalised cutting guides
- Accurate bone resections
- According to 3D planning
based on imaging
- Reproduce the native (pre-arthritic)
anatomy of the knee
- Optimize bone implant fit and avoid
prosthetic overhang or under-coverage,
- Personalized cutting blocks

14. Individualised cutting jigs

15. Advantages
● Improve implant positioning.
● “mini-invasive” surgery, with limited exposure.
● Decreased risk of fat embolus and blood loss.
● Increase surgical efficiency
● Reducing operative time and cost compared to robotic-assisted
surgery.
● Reproduce the native anatomy.
● Reduce the thickness of the implants, quantity of bone resection

16. Limitations
● Customised systems do not completely eliminate margin of error
● Tibial component rotation, implant fixation, patellar preparation – surgeon
dependant
● To complete the benefit of an accurate cutting guide - use of sensors.
● Does not take into account ligament balancing - dependent on the surgeon

17. Alignment and Balance
Generally in Traditional TKA most
common alignment preferred is
Mechanical alignment
● Coronal alignment of 0-3°
● All gaps to be equal in flexion ,
extension , medial and lateral
● Sequential soft tissue releases.

19. Sensors in TKA
● For ligament balancing – crucial, often difficult to assess
● “Articular loading quantification device”
● Inserted in the tibial component tray during the surgery
● If the joint shows imbalance on monitor  additional soft tissue
releases or bony resection can be performed.
● Poor ligament balancing  instability, stiffness, pain and TKA revision
or patient dissatisfaction

20. What sensors do?
● Give objective data on soft tissue balancing during TKA.
● Disposable
● Deliver wireless data to an intra-operative monitor
● Allow informed decision-making regarding implant position and soft tissue
releases
● Eg. VERASENSE Knee System (OrthoSensor Inc., Dania Beach, FL, USA).

22. ● Cost
● "Normal range” of joint compartment pressures varies on patient to
patient basis – cannot be universalised
Limitations of sensors

23. Accelerometer
● Smart tools to improve the alignment of components - for functional
restoration - patient satisfaction - TKA survivorship.
● Important for kinematic alignment - error of 3◦ in the component alignment
not acceptable when targeted alignment is already in varus or valgus.
● Portable surgical navigation system
● Handheld, sterile device - Determine the resection planes
● Wireless and imageless and display the data on pods  attached to the
femoral and tibial resection guides within the surgical field.

25. Advantages
● Technique with high precision for alignment, allows verification of bone cuts
after cutting .
● Has shown improved long term survival
● In difficult cases with severe deformities and the impossibility of using an
intramedullary guide . The accelerometer-based navigation is a simple tool to
facilitate a TKA with extra-articular deformity.

26. Limitations
● Higher costs
● Longer learning curves
● Axis of the bone cut is dependent on the reference points chosen on the
patient (surgeon dependent)  If knee center is inaccurate then mechanical
axis will not be as desired
● Does not assist with component sizing, rotation, ligament balancing, target
alignment.

27. Robotic-Assisted Knee Arthroplasty
Natural evolution from computer assisted surgery.
This robotic-assisted system also allows an assessment of
1. Ligament balancing
2. Implant positioning
The aim of robotic systems is not to replace the surgeon, but to improve their
performance.
Current robotic systems require the creation of a 3D plan based on - intraop
bone morphology mapping (image free) OR a preoperative CT scan (image
based)

28. ● Preoperative CT imaging – ankle, hip, knee, to determine mechanical axis.
● A 3D reconstruction - to template component size and positioning. The
surgical planning is completed preoperatively.
● Intraop - very accurate bone cuts
The disadvantages include the cost of the preoperative imaging study, the
patient inconvenience to obtain the study at certified centers, and the radiation
exposure.
Image-Based Surgical Planning

29. ● Intraoperative “registration” of the anatomical surfaces by a manual
bone surface mapping.
● 3D virtual model created - planning performed during surgery.
● Disadvantage the intraoperative registration relies on the surgeon’s
precision of inputting the correct data points, which is subject to
human error.
Image-Free surgical planning

30. 1.Passive Robotic Systems
Three categories exist of robotic system exists .
● A passive system provides a 3D virtual model, which allows accurate
preoperative planning. But there is no system to prepare the bone .
● The passive systems are a computer-assisted or navigation system and
perform accurate surgical planning and guide the tool positioning but bone
removal is performed only by the surgeon.

31. 2.Autonomous systems
With the autonomous robotic-assisted system, the surgeon performs the
surgical plan , the initial approach, and the knee exposure.
● Then the robotic system has the capability of completing the remaining
surgery.
● Nevertheless, the surgeon can control an emergency switch to stop the
procedure or to adjust the plan.
● Examples- CASPAR (Ortho-Maquet/URS, Schwerin, Germany)and
ROBODOC (Curexo Technology Corporation, Fremont, CA, USA) are CT
imaging based .

32. Robodoc
system

33. Caspar
System

34. The semiautonomous robotic-assisted systems combine the benefits of a
navigation system and of an autonomous robotic system.
● The surgical planning is performed by the surgeon, either based on
preoperative 3D imaging or on intraoperative bone surface mapping.
Semiautonomous robots are controlled and manipulated by the surgeon.
● Thanks to a feedback loop, the bone removal is controlled This control
improves the surgeon’s accuracy and decreases the risk of errors.
3.Semi-autonomous system

35. Examples:
1. Image-free robotic Navio system (Smith & Nephew, Memphis, TN,
USA)
2. Image-based MAKO robotic arm (Stryker, Mahwah, NJ, USA)
3. The ROSA knee system (Zimmer Biomet, Warsaw, IN, USA)
4. OMNIBOT (OMNIlife Science, Inc.; Raynham, MA, USA).

36. Mako
system

37. Rosa
system

38. Ligament balancing
● Ligament balancing during knee arthroplasty is critical to obtain good functional
outcomes and maintain normal knee kinematics. These systems can register the
ligament balance or imbalance before the intervention, the planned ligament
balancing, and the balance at the end of the procedure.
● During all of the steps of the surgery, the surgeon can assess the ligament
balancing can make adjustments. Depending on the robotic-assisted system, the
ligament balancing can be assessed in extension and knee flexion at 90◦, or
during all range of motion.

39. Advantages Disadvantages
● Best bone fit
● Soft tissue analysis
● Accurate cuts
● Higher costs
● Long learning curves
● Take longer time compared to
conventional systems

41. Recent developments
1.Patellofemoral
Arthroplasty : it is
probably one of the best
indications for robotic
surgery. It guarantees a
perfect transition area
between the femoral
component and femoral
condyle cartilage prior to
the bone cut.

42. 2. Bicruciate-Retaining Arthroplasty
-It is a technically demanding procedure.
● Robotics have provided considerable
assistance for surgeons in highly
accurate bone preparation.
● Protecting the tibial spines is also
much easier when using a bur guided
by a robotic handpiece.

43. Bicruciate
retaining
Arthroplasty

44. 3.Combined UKA and Anterior Cruciate Ligament (ACL)
Reconstruction
● ACL reconstruction combined with unicompartmental knee arthroplasty is a
tempting solution for anyone keen on unicompartmental procedures.
● The robotic system ensures accurate implant positioning (with tibial slope and
overall alignment control in particular) but also allows the surgeon to visualize
any residual gap before and after implant fixation.
● Both implant position and the polyethylene thickness can be adjusted based
on the dynamic data provided by the robotic system.

45. UKA and ACL
reconstruction

46. 4.Bicompartmental Arthroplasty In young and active patients with
bicompartmental osteoarthritis, there may be an indication for two partial knee
replacements (usually a medial unicompartmental arthroplasty and a
patellofemoral replacement).
● Despite long-standing support for this surgery, in particular from Philippe
Cartier, it is technically challenging.
● The Navio® system can be used to predict and adjust the relative position of
the two implants, making this uncommon procedure more consistent.

48. Uncemted TKR advantages
● Press fit implants , have porous surface .
● have a rough, porous surface that
encourages new bone growth.
● Thought to last longer compared to
cemented implant .
● No complications from cemeting or
cement breakdown .

49. Disadvantages of Uncemted TKR
● we don’t have as much evidence to support long-term effectiveness of these
implants.
● require a longer healing time, because of take time for new bone growth
that is sufficient enough to hold the implant in place.
● not suitable for patients who have poor bone quality due to a condition like
osteoporosis
● knees take on quite a bit of stress from daily activity, microscopic debris
from wear leads to osteolysis.

50. Kinematic Alignment
● KA is true ‘resurfacing’ of the knee joint in which the aim is
for the implant thickness to replace the exact amount of
‘bone/cartilage’ removed .
● aims to restore the native joint lines.

53. Restricted kinematic alignment (rKA)
● In biomechanically inferior knee
anatomy, may have negative
consequences .
● A ‘safe’ range cuts must be within
5° MA and alignment must be
within ±3° of neutral. This is known
as restricted kinematic alignment.

54. Advantages of Kinematic Alignment
1. More physiological
2. Restoring the three kinematic axes of the knee
● trans-epicondylar axis of femur (tibia flexion and extension)
● transverse axis in the femur (patella flexion and extension)
● longitudinal axis in the tibia (tibia rotates internally and externally)
1. Improve gait, feel of the knee and range of motion (ROM) result in
superior patient outcomes.

55. Three axes of knee

56. A retrospective case-control study compared gait parameters between 18 rKA
TKRs and a matched control group of MA TKRs.The authors found the knee
kinematics in KA were more similar to normal healthy controls when compared to
MA.

57. Disadvantages of KA
1. Compartment overload
restoring constitutional varus/valgus of the knee may cause overload in
the medial/lateral compartment respectively, which may lead to early
failure.
1. Risk of patello-femoral junction instability.

58. Revision TKR using Metaphyseal cones and sleeves
Metaphyseal cones and sleeves represent a viable and
feasible option in aseptic and septic revision total knee
arthroplasty with type IIb and III AORI bone defects.
Both methods allow proper bone defects management
with comparable clinical and radiological result and
survival rate.
A fxation closer to articulation facilitates restoration of
the joint line and more control of rotation alignment of
the components.
Primary stability, either axial and or rotational, is
achieved intraoperatively with press-ft tech
nique, the bone ingrowth ensures the secondary
stability.

60. Manual allingement vs kinematic allingement
Limb and knee alignment in KA TKA
was similar to those in MA TKA, and component alignment showed slightly more varus in
the tibial component
and slightly more valgus in the femoral component.
The JLOA in KA TKA was relatively parallel to the foor compared to that in the native knee
and not oblique (medial side
up and lateral side down) compared to that in MA TKA.
The implant survivorship and complication rate of the KA TKA were similar to those of the
MA TKA.

61. Conclusion:
Similar or better clinical outcomes were pro
duced by using a KA TKA at early-term follow-
up and the component alignment differed from
that of MA TKA.

62. Robotic TKR(burr based)
Advantages:
Robotic TKA limits saw action, which reduces iatrogenic bone and soft-tissue
damage.
coronal plane alignment within the range of 3° varus/valgus is associated with better
survival of the prosthesis and this cannot be achieved by conventional method in
30% of cases
R-TKA helps to reduce overall coronal limb alignment outlier form 3° to less than
1.24
component malposition to less than 1°.

63. R-TKA is precise and accurate in terms of component
placement and limb alignment,Whether this improves
clinical outcome, patient’s satisfaction and long-term
survival of TKA needs to be studied in future.
Disadvantages
Takes longer time
Creates irregular bony surfaces

64. Hip arthroplasty

65. Applied Biomechanics

66. Dorr Classification

67. Goals of THR.
Biomechanically sound, stable hip joint
by restoration of normal center of
rotation of femoral head.

68. The location of center of
rotation of femoral head
is determined by
1. Vertical offset.
2. Horizontal (medial) offset
3. Anterior offset (anteversion).

69. Head Neck Ratio

72. Specialized femoral components for replacement of variable length
of proximal femur . Stem can be combined with TKR to replace
entire Femur

74. Indications for proxima or short stem hip
replacement.
● Any patient with hip arthritis for whom a total hip replacement is
the permanent solution but proxima will Preserve more bone than
a total hip arthroplasty.
● Bone stock should be intact.
● Those patients with disease in the head which is more extensive
making “resurfacing “ unsuitable. For eg- Avasacular necrosis.

76. Proxima is a bone preserving hip
replacement.
● Neck portion of femur is preserved.
● Only head is removed.
● The shaft of the femur is not entered
or reamed, once again preserving
bone.

77. Comparison of total hip and
proxima.
● Total hip removes the neck portion.
● In short stem Replacment neck portion
is preserved.

78. Advantages of proxima.
● Less soft tissue dissection.
● Less bony resection.
● Large diameter head - less chance of dislocation.
● Fluid film lubrication- leads to less wear of the
implant.
● Metal on metal bearings - less wear.

79. Hip Resurfacing Surgery

80. Candidates for hip Resurfacing
● Young and active patients with hip arthritis or secondary
osteo arthritis.
● Avasacular necrosis.
● Ankylosing spondylitis.
● Post traumatic arthritis.
● DDH.
● Slipped capital femoral epiphysis.
● Primary osteo arthritis in young patients.

81. Hip Resurfacing Advantages.
● Bone preserving.
● Does not violate femoral canal.
● Primary revision options.
● Enhanced mobility.
● More natural feel
● Inherent stability.

82. Hip Resurfacing Disadvantages
● Serious problems with older designs
● No long term data.
● The more utilization, the more complications from no-developers.
● Fracture of femur is a real and serious complication.
● The fracture rate is 1-2/ 100 cases.
● Metal on metal surface of hip Resurfacing produces circulating metal
in blood stream. Negative effects of Co/Cr unknown.

83. ● Ceramic a better option.
● There is need for independent research to allow better
guidance on this procedure.
● The ideal candidate to receive a hip Resurfacing at all is
unknown by any real data and is conjecture at best.
● Technically more demanding than total hip arthroplasty.

86. Acetabular reaming and
component insertion.
● Uncemented cup.
● Fixation by circumferential fins
(Durom).
● Hydroxy apatite coating.
● Cobalt chrome molybdenum.
● High carbon content.

87. Post op X ray.
● Proper position of femoral
component.
● Proper inclination of
acetabular component.
● Proper depth of acetabular
cup.

88. What Is minimally invasive hip
surgery.
● Uses traditional hip implants.
● 2 different techniques, including mini incision
and two incision.

89. Traditional hip replacement surgery.
● Proven in clinical studies and successfully performed for
decades.
● Allows surgeon full visualization of operative area.
● Larger incision (8-10 inches)
● More disruption of muscles and tissues
● Avg. Hospital stay is 5 days.
● Avg. Recovery time of approx. 3 Months. .

90. minimally invasive hip replacement surgery.
● Long term effects and success are not established.
● Restricted visualization of operative area.
● Smaller incision (2-4 inches.)
● Potentially less disruption of muscles and tissues.
● May lead to less blood loss and post op pain.
● May lead to a shortened hospital stay, less than 5 days.
● May reduce recovery time.

92. Benefits of minimally invasive hip surgery.
● Less trauma to the body.
● Healing and rehab is quicker.
● Shorter hospital stays.
● Allows immediate stability of the hip.
● Lower risk of dislocation.
● Potentially less post op pain.
● Cosmetically appealing.

93. Ideal candidate.
Suffering from hip arthritis.
Failed response to -
1.Medicines.
2.Exercises.
3.Weight managment.

94. Deciding factors include -
1.Medical history.
2.Weight.
3.General health.
4.Body structure.
5.Extend and pattern of arthritis.

95. Inappropriate candidates.
● Severely obese ( BMI of 40 or more).
● Very muscular.
● Undergoing complex revision
surgeries.

96. Minimally invasive hip techniques.
Two incision
● 2 incisions
● Approx. 2 inches of length.
● ON both front and rear of thigh.
● Fluoroscopy may be used.
Mini incision.
● 1 incision.
● Approx. 3 to 4 inches in length.
● Either front or rear.
● Fluoroscopy is not used..

98. Recovery from surgery.
● MIH benefits shown in the first 3 Months of recovery.
● Patient must follow hip precautions.
● Not crossing their legs.
● Take care when bending.
● Avoid high impact and contact sport.

99. Risk factors.
Factors that may affect the rate of complications including.
● Surgeons skill
● Weight, age and overall health of the patient.
● Presence of osteoporosis or other conditions that
weaken bones.
● Patient compliance with physician instructions.

100. Potential complications and risks.
● Hematoma Occurs when blood enter after surgery.
● If excessive, will be drained.
● Hip fracture. Occuring during or after surgery.
● Weak bones
● Falling
● Failure to floow hip precautions.

101. Potential complications and risks.
● Infection.
● Dislocation.
● Blood clots.

103. What is dual mobility?
● Head articulates within a
retentive polyethylene.
● Polyethylene is free to move in
metalback shell in a non
retentive way.

104. Why have dual mobilty
● Improve prosthesis stability significantly
reduce the risk of dislocation.
● Increase amplitude of movement before
impingement.
● To reduce wear ( Low friction
arthroplasty).
● To reduce shear forces at the bone
interface which Contribute to implant
loosening.

105. Indications
● Elderly patients (>65 yr).
● Tumours.
● Joint laxity.
● DDH
● RA
● revision surgeries, with risk of
dislocation.

106. Mallory head artificial joint using the proximal multiporous coated system,
clinical and radiological results were determined to be excellent based on
stable Osseous integration, low revision rate and thigh pain.

107. Thank you