Total knee replacement India with I Assist

1
I-Assist personalized guidance system

• Dr.A.K.Venkatachalam
• MS Orth, DNB Orth, FRCS, M.Ch Orth
• Consultant Orthopaedic surgeon
• www.kneeindia.com

2
Alignment in Knee replacement

• It is one of the factors that ensures long life
  of the implant.
• A proper alignment means the implant is
  perpendicular to the ground.
• Mal aligned knee replacements tend to wear out
  sooner than normal.
• Even experienced surgeons can make errors in
  placement of the components.

Mal-aligned car tyre
Wear on the inside
3
Improperly aligned knee replacement
Implants are tilted and leg is bowed
4
Properly aligned Knee replacements
5
Our patient

• Mrs.Lakshmamma, Housewife, Age- 55 years
• Resident of Guntur district, Seemandhara
• Had both knee replacements on 7/8/14 and 13/8/14
• Female special, Full bending knee implants with
• Prolong Poly insert capable of long life.

6
Pre op x-rays
7
Properly aligned Knee replacements
8
Post op progress

• The patient started walking on the next day after
  surgery on both knees.
• Post - op X-rays of both knees show perfect
  alignment which was made possible by the I-Assist
  device.

9
What is the I-Assist?

• It is a Personalized guidance system designed to
  assist the surgeon in positioning a total knee
  arthroplasty implant components intra
  operatively.
• It uses surgical instruments and position sensors
  to determine alignment axes in relation to
  anatomical landmarks
• To thus precisely position alignment instruments
  implant components relative to these axes.

10
I Assist components
11
What is inside it?

• It consists of 4 half palm sized pods with
  electronic apps like
• Wi-Fi found in smart phones.
• Gyroscope found in air planes.
• The electronic sensors inside calculate the
  alignment. The blinking lights on the display
  face indicate the correct position.
• Red light means improper position and Green light
  means proper position.

12
How does it work?

• It is inserted into the bones of the knee joint
  itself.

13
How does it work?

• After connecting it to the knee the surgeon moves
  the femur in 13 different positions and the tibia
  in 4 positions.
• It calculates the position by the electronic
  devices inside it.
• The surgeon makes fine adjustments so that
• red lights turn to green.
• Blinking green lights indicate zero percent
  error.
• The surgeon can proceed to cut the bone confident
  that his cuts will be perfectly aligned.
• He can then finally place the implant components
  in the correct alignment achieved and validated
  in the previous steps.

14
Surgeon is focused on the knee
15
Knee is moved to get Green light
16
Fine adjustment to get green lighton the display
itself.
17
Advantages

• It guides the surgeon to get perfectly aligned
  cuts intra operatively.
• It gives zero error cuts and again validates it
  in the next step.
• Thus the surgeon gets the right fit during the
  surgery itself.
• This ensures that the total knee implant knee
  components are positioned perfectly in the
  correct alignment.
• Surgeon focusses his eyes in the operating field
  itself and not away from the field.
• It thus saves time.

18
Advantages

• No additional incisions in the leg or thigh in
  contrast to computer assisted surgery.
• As the intra medullary canal of the femur is not
  drilled, there is less blood loss post
  operatively.
• No waiting time for instruments to come from
  abroad unlike Patient specific instruments.

19
What does it differ from?

• 2) Patient specific instruments ( PSI)

1) Computer navigation ( CAS)
20
How does it differ from computer navigation?

• The sensors are attached to the leg on the
  operating table as shown here.
• The position of the cuts is shown on the monitor
  in the background.
• Thus the surgeon has to shift his gaze from the
  leg to the monitor and back repetitively.

21
Two areas to focus on
22
How does it differ from Patient specific cutting
instruments?

• Scans done 6 weeks before surgery.
• Pictures are sent to the laboratory abroad
• 6 weeks waiting period for design, manufacture
  and supply of patient specific cutting blocks
  from abroad.

Patient specific cutting blocks placed on bone
23
Which patients benefit

• Young patient had Computer assisted knee
  replacement in 2008

• All age groups of patients benefit particularly
• Young patients undergoing knee replacement for
  any reasons like injury, obesity, rheumatoid
  arthritis etc.

24
Which patients benefit?

• Young patients with bad accidents and deformed
  bones.
• In these patients, other methods like computer
  assisted surgery patient specific instruments
  cant be used for technical reasons.
• It can be used in severe deformities and bone
  loss, unlike the other modalities like Patient
  specific instruments and computer navigation.

25
Which patients benefit?

• Middle aged patients with severe knee arthritis
  requiring a total knee replacement
• Perfect alignment increases durability of knee
  implant

26
Older patients also benefit

• Even experienced surgeons make errors while
  aligning components of a total knee arthroplasty.
• Neutral alignment is the goal but this is not
  always achieved.
• There is a correlation between perfect alignment
  and longevity of the implant.
• Normal life of a knee is 15- 20 years.
• With advanced techniques like the I-Assist, the
  life can be extended up to 35 years.

27
How patients benefit ?

• Tailor made perfect alignment.
• No waiting time
• Perfect alignment contributes to increased
  longevity of the implant.
• When I Assist is used in conjunction with
  durable materials, life of a knee replacement can
  be extended up to 35 years.

28
Surgeons benefit

• Surgeons benefit as they save time during surgery
  by avoiding back and forth eye movements.
• Reduced operating time decreases risk of
  infection.

29
Hospital benefits

• No capital investment on imaging systems like
  special MRI
• No investment on Computer navigation system which
  costs about 1 crore.

30
I Assist

• Gives perfect alignment during surgery itself.
• Alignment along with durable materials like
  Zirconium and Cross linked polyetheylene increase
  of a knee replacement to 35 years.
• No need for future revision surgery in young
  patients.

31
E mail- drvenkat_at_kneeindia.com Visit
www.kneeindia.com