I-Assist Personalized Knee replacement in India

I-Assist personalized guidance
system
Dr.A.K.Venkatachalam
MS Orth, DNB Orth, FRCS, M.Ch Orth
Consultant Orthopaedic surgeon
www.kneeindia.com
E mail-drvenkat@kneeindia.com

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

Improperly aligned knee replacement
Implants are tilted and leg is bowed

Properly aligned Knee replacements

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.

Pre op x-rays

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.

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.

I Assist components

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.

How does it work?
• It is inserted into the bones of the knee joint
itself.

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.

Surgeon is focused on the knee

Knee is moved to get Green light

Fine adjustment to get green light
on the display itself.

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.

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.

What does it differ from?
1) Computer navigation 2) Patient specific instruments ( PSI)
( CAS)

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.

Two areas to focus on

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

Which patients benefit
All age groups of patients
benefit particularly
• Young patients undergoing
knee replacement for any
reasons like injury, obesity,
rheumatoid arthritis etc.
Young patient had Computer
assisted knee replacement in 2008

Which patients benefit?
• Young patients with bad
accidents and deformed
bones.
• In these patients, other
methods like computer
assisted surgery & patient
specific instruments can’t 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.

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

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.

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.

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

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

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.

E mail- drvenkat@kneeindia.com
Visit www.kneeindia.com

I-Assist Personalized Knee replacement in India

Recommended

Recommended

More Related Content

What's hot

What's hot (7)

Viewers also liked

Viewers also liked (18)

Similar to I-Assist Personalized Knee replacement in India

Similar to I-Assist Personalized Knee replacement in India (20)

More from Alampallam Venkatachalam

More from Alampallam Venkatachalam (20)

Recently uploaded

Recently uploaded (20)

I-Assist Personalized Knee replacement in India