1. INTERNSHIP REPORT
TOTAL KNEE REPLACEMENT
SUBMITED BY: DOAN VIET SANG (21203090)
Faculty Advisor: Dr. Pham Huy Hoang.
Guided by: Dr. Thunyaseth Sethaput.
THAILAND, AUGUST 2016

2. INTERNSHIP REPORT
Total Knee Replacement.
by
Doan Viet Sang
Eng.B Mechanical Engineering
Ho Chi Minh City University of Technology
Submitted to Department of Manufacturing Engineering
In fulfillment of Requirements of Graduated Internship for
Degree of Bachelor of Mechanical Engineering
at the
Ho Chi Minh City University of Technology
Signature of Author…………………….. Doan Viet Sang
Faculty of Mechanical of Engineering
1st
August 2016
Certified by ……………………………….. Dr. Pham Huy Hoang
Associate Professor of Mechanical Engineering
Thesis Supervisor
Accepted by ………………………………

3. Preface
I have completed my 4th year in bachelor degree of mechanical Engineering at Ho Chi Minh
City University of Technology. This internship is the final internship and I am going to do my
thesis in next semester. I choose to do internship abroad because I want to experience myself
in international research environment. In addition, I want to develop new sets of skills. One
of my goal is improving English skill to preparation of studying abroad in the future.
Sirinhorn International Institute of Technology (SIIT) is a reputation research place in Thailand,
which is supported by Nippon Keidanren, Federation of Thai Industries and Thammasat
University. SIIT provides courses would be taught in English by highly qualified faculty
members with doctoral degrees.
In this internship report, I will describe my experiences during my internship period. The
internship contains overview of SIIT, my project topic “total knee replacement”.

4. For this opportunity, I thank:
Dr. Thunyaseth Sethaput, who is my advisor at Sirindhorn International Institute of
Technology (SIIT), Thammasat University. I want to thank him for giving me opportunity to
follow my internship at SIIT. He had the kindness to accept me in his laboratory and guide me
throw my internship by giving advices, feedback and tips.
ASS, Prof Pham Huy Hoang, who is my advisor at Ho Chi Minh City University of Technology
(HCMUT). He supported to complete the application for my internship at SIIT, Thailand.
Mr. Amila Hemantha, who is currently doing master course at SIIT. He help me to adapt the
life in Thailand at the beginning of my internship.
Besides my internship, I really enjoy my stay in Bangkok, Thailand. It was a good time with
unforgettable experience.

5. CONTENTS
1. General Information of SIIT. ………..………..………..………..………..………..………..……….……… 1
2. Research Topic. ………..………..………..………..………..………..………..………..………..………..……….. 2
2.1. Introduction. ………..………..………..………..………..………..………..………..………..………..………. 2
2.1.1. Medical Background. ………..………..………..………..………..………..………..………..……….. 2
2.1.2. Total Knee Replacement. ………..………..………..………..………..………..………..…………… 3
2.2. Custom-made Total Knee Replacement ………..………..………..………..………..………..… 4
2.2.1. Patient Data. ………..………..………..………..………..………..………..………..………..…………… 4
2.2.2. Creating 3D model of femur part by using CAD software ………..………..……….. 6
2.2.3. Rapid Prototype of Femur Part. ………..………..………..………..………..………..………….. 6
FIGURES
Figure 1: Sirindhorn International Institute of Technology ………..………..………..………..………..… 1
Figure 2: Knee Components ………..………..………..………..………..………..………..………..………..……….. 2
Figure 3: Knee caused by Osteoarthritis………..………..………..………..………..………..………..……….. 2
Figure 4: Total Knee Replacement ………..………..………..………..………..………..………..………..……… 3
Figure 5: Patient Data from Thammasat Hospital………..………..………..………..………..………..…… 4
Figure 6: CT scan Data mistakes………..………..………..………..………..………..………..………..………..… 5
Figure 7: CAD model transferred from CT scan by Mimics………..………..………..………..………..… 5
Figure 8: Using Loft feature of SolidWorks ………..………..………..………..………..………..………..…… 6
Figure 9: 3D Model by SolidWorks ………..………..………..………..………..………..………..………..……… 6
Figure 10: How FDM 3D printing works ………..………..………..………..………..………..………..……….. 6
Figure 11: Properties Adjustment ……………………………………………………………………………………… 7
Figure 12: Toolpaths Generation ………………………………………………………………………………………… 7

6. PAGE 1
1. General Information of SIIT.
Sirindhorn International Institute of Technology (Thai: สถาบันเทคโนโลยีนานาชาติสิรินธร) is established
in 1992 within Thammasat University. SIIT is known as a premier research university in
Thailand which has many fields such as science, technology and engineering, as well as
management programs. All are international program with English.
SIIT has 5 schools and 1 department:
School of Bio-Chemical Engineering and Technology
hosts chemical engineering and environmental technology programs
School of Civil Engineering and Technology
hosts civil engineering and infrastructure planning programs
School of Information, Computer and Communication Technology
hosts information technology, computer science, and Electronics and communication
engineering programs
School of Management Technology
hosts management technology and engineering management programs
School of Manufacturing Systems and Mechanical Engineering
hosts mechanical engineering and industrial engineering programs
Department of Common and Graduate Studies
Figure 1: Sirindhorn International Institute of Technology
In the Academic year 2003, SIIT showed the highest number of research publications of any
academic division in the university. In 2007, Thai Research Fund put SIIT in the top of all
Engineering Faculty in Kingdoms.

7. PAGE 2
2. Research Topic.
2.1. Introduction.
2.1.1. Medical Background.
Knee
Knee is one of complex joints in human
body. The main function of knee is
connecting Femur bone and Tibia
bone. Besides two major bones, knee
includes Fibula which runs alongside
the Femur bone and Patella (knee cap)
which makes knee joint.
Tendons connect the knee bones to
the leg muscles that move the knee
joint. Ligaments join the knee bones
and remain stability to the knee:
 The anterior cruciate ligament
prevents the femur from sliding
backward on the tibia (or the tibia sliding forward on the femur).
 The posterior cruciate ligament prevents the femur from sliding forward on the tibia
(or the tibia from sliding backward on the femur).
 The medial and lateral collateral ligaments prevent the femur from sliding side to side.
Osteoarthritis
Osteoarthritis is the most common form of arthritis
as well as the most popular disease of knee, which
affects millions of people worldwide. It occurs when
the protective cartilage on the ends of your bones
wears down over time.
Country impact
 United Kingdom
In England and Wales between 1.3 and 1.75 million
people have symptomatic OA. In 2000 more than
80,000 hip or knee replacements were performed at
a cost of £405 million.
As a cause of disability (such as walking and climbing
stairs) in the elderly OA is second to cardiovascular
disease.
Altogether 10% to 15% of adults over 60 have some degree of OA.
Figure 2: Knee Components
Figure 3: Knee caused by Osteoarthritis

8. PAGE 3
 Germany
Four million people out of 82 million people (4.8% of population) suffer from some form of
autoimmune conditions affecting joints.
 Canada
The direct and indirect costs of arthritis in Canada equates to approximately $18 billion per
year.
Over four million Canadians out of 31,014,000 people have arthritis.
Currently there are approximately 270 rheumatologists in Canada; however, 150 of them are
close to retirement leaving 120 rheumatologists to care for 4 million suffering arthritis
patients.
There are approximately 37,000 hip and knee replacement surgeries every year in Canada.
 Japan
Population of 127 million people.
17% of population is over 65 (this percentage is expected to grow by 25% in the next three
decades).
5% of the population has some form of arthritis.
2.1.2. Total Knee Replacement.
Total Knee Replacement is a surgical
procedure to replace the damage surfaces
of the knee joint to relieve pain and
disability. It is used for osteoarthritis, and
also for other knee diseases such
as rheumatoid arthritis and psoriatic arthritis.
Total Knee Replacement has a long history
development and it is becoming common
as the population of the world. Artificial
Knee Replacement can be classified in two
basic types: cemented prosthesis and non-
cemented prosthesis. Cemented
prosthesis consists a type of epoxy cement
for fixation, whereas non-cemented
prosthesis has a smooth surface intended
for bone to grow into and attach the
prosthesis to the bone. In addition, Total
Knee Placement can be performed as partial or full knee replacement.
Figure 4: Total Knee Replacement

9. PAGE 4
2.2. Custom-made Total Knee Replacement
Custom-made Total Knee Replacement is a form of Total Knee Replacement. Comparing to
Standard Total Knee Replacement, Custom-made Total Knee Replacement helps patients
avoid removing undamaged part and less painful.
In this Internship, I worked on femur part of Custom-made Total Knee Replacement which is
3 main works:
 Collecting and Processing Patient Data.
 Design Femur Part of Total Knee Replacement based real data, supported by CAD
Software.
 Using Rapid Prototype to create 3D model.
2.2.1. Patient Data.
Patient Data is collected by the computer tomography (CT) Scanner and processed by Mimics
software. This 60 years old patient data is provided by Thammasat Hospital (TH), Thammast
University Thailand. According to TH, this patient has suffered from Osteoarthritis for 3 years
and It has made serious consequences by limitation of knee movements. Beside other methods, Total
Knee Replacement Surgery is a consideration treatment for this case.
There are many unnecessary parts and holes from rough data. The reasons of this problem is the
accuracy of CT scan machine. Mimics technic is applied to get patients data accurately and fill up the
holes
Figure 5: Patient Data from Thammasat Hospital

10. PAGE 5
By using Mimics, CT scan images can be transfer into 3D model.
Figure 6: CT scan Data mistakes
Figure 7: CAD model transferred from CT scan by Mimics

11. PAGE 6
2.2.2. Creating 3D model of femur part by using CAD software.
There are numerous methods to create
femur part of Total Knee Replacement but
in this internship, I decided to use loft
feature by SolidWorks, including draw
definition line following 3D model from CT
scan.
The revolution of loft feature is 1 mm which
is the distance of spline lines. The spline
guide line will be generated automatically
by the software. The distance could be
smaller by drawing more spline definition
lines but the results I got is not better so 1
mm is the best option.
After recreation of Knee model, I complete the model
by cutting assembly surfaces. According to
recommendation of Thammasat hospital doctor, the
assembly surface must be less painful for patient as
well as avoiding removing undamaged part.
2.2.3. Rapid Prototype of Femur Part.
Principles of FDM (Fused Deposition Modeling)
Figure 8: Using Loft feature of SolidWorks
Figure 9: 3D Model by SolidWorks
Figure 10: How FDM 3D printing works

12. PAGE 7
Using Catalyst EX to control FDM 3D Printer
Adjustment of Properties
 Layer resolution: The thickness of each layer.
 Model interior: Inside Structure of Model.
 Support fill: Type of Support Fill
 Number of copies: Number of model printing out.
Generating toolpaths
Figure 11: Properties Adjustment
Figure 12: Toolpaths Generation