King Saud University College of Engineering Industrial Engineering Department Custom-Made Artificial Knee By Abdullah AlNuiam Supervised By Prof. Saied

King Saud UniversityCollege of EngineeringIndustrial Engineering Department

Custom-Made Artificial Knee

By

Abdullah AlNuiam

Supervised ByProf. Saied Darwish

Outline

1) Introduction

2) Objective

3) Artificial Knee joint

4) Biomaterial

5) Mastercam

6) CNC Machine

7) G-codes

8) Conclusions King Saud University

Industrial Engineering Department

Introduction: Biomedical engineers have long been working on solutions to

design a better replacement joints to improve the lives of the thousands of patients every year

The design, manufacture and placement of these artificial joints require a high degree of skill and a thorough knowledge of physics, biology and chemistry

Some examplesSome examples::

•Artificial hips, knees and other joints. •Ultrasound, magnetic resonance imager (MRI) and other medical imaging techniques.

King Saud UniversityIndustrial Engineering Department

Types of joints

Ball and socket joints Gliding joints Hinge joints Saddle joints


Knee Joint

The knee is the largest joint in the body Normal knee function is needed to perform

routine everyday activities The most common reason for having a knee

replaced is osteoarthritis.

Problem definition

This project aims to manufacture a custom made knee joint locally using MasterCAM to design and CNC machine to manufacture.


Normal Knee :

The knee is the largest joint in the body

Normal knee function is needed to perform routine everyday activities

It consists of: Femur: which rotate the

upper end of the shin bone (tibia)

Tibia: which is the shin bone

Patella (knee cap): which slides in a groove on the end of the femur.


What Is a Knee Replacement?

The most common reason for having a knee replaced is osteoarthritis.

Knee replacement, is a surgical procedure in which the diseased parts of the knee joint are removed and replaced with new artificial parts.

The goals of knee replacement surgery

include increasing mobility, improving the

function of the knee joint, and relieving pain.


Surgical Considerations:

When choosing an implant, the surgeon will consider many factors, including the patient's:

Age Weight Gender Anatomy Activity level Medical history General health


How Are Knee Problems Diagnosed

Diagnostic tests depend on the findings of the medical history and physical exam, such as:

X-ray Computerized axial tomography (CAT) scan Bone scan (radionuclide scanning) Magnetic resonance imaging (MRI) BiopsyThose tests are needed in designing “custom-made” knee

joint; they show angles and sizes needed to produce a replacement knee that matches this human's body structure.


Injuries

1. Osteoarthritis (OA)

2. Rheumatoid

3. Avascular Necrosis

4. Malalignment of Knee Joint


Project Objective:

The custom-made is the only solution for tumor patients .

Hospitals need to convert the x-ray into solid models that can be manufactured.

The Objective is to test the visibility of manufacturing a custom-made artificial knee joint locally.

This is to develop a special design to suit each patient with the minimum possible time and minimum cost


Knee Replacement

The complexity of the knee joint has presented special challenges in the design and insertion of an artificial joint.

The knee needs to allow movement from zero (straight) to 90 degrees at least.


Components of Artificial Knee

Femur (top) Tibia (bottom) Polyethylene (in between)


Types of Knee Replacements

Depending on the degree of mechanical stability provided by the design of the artificial knee, there are three basic categories of knee replacement:

Non- constrained Semi- Constrained Unicondylar


Progresses in Knee Replacement

Technology has led to the development of materials used.

Major advancements in knee replacement have greatly improved the outcome of the surgery

Artificial joint replacement for arthritis of the knee is one of the most successful surgeries of the last century

95% of people are able to begin walking the day following surgery and pain relief is achieved.


Advantages of Knee Replacement

This operation produces very effective and long lasting relief from joint pain

It gives a joint which functions normally The recovery period from the operation is

very short The patient is able to walk from the 2nd or the

3rd day after the operation. The patient regains a normal lifestyle and

mobility with significant improvement in quality of life


Biomaterial Biomaterial are materials used for surgical or dental

instruments and for external prostheses.

A biomaterial placed within the interior of the body must be biocompatible.

It should possess adequate physical and mechanical properties to serve as replacement of body tissues

It should be amenable to be formed into different shapes, have relatively low cost, and be readily available


Biomaterial

The primary materials used in Total Knee System implant components include cobalt chromium molybdenum alloy (Co-Cr-Mo)

Cross Section of CO-Cr-Mo formal cross sections of tibia base plate


Types of Wear

Abrasive Wear Adhesive Wear Fatigue Wear Third Body Wear


Role of Industrial Engineer

Gather information about joint/bones dimensions using x-rays to come up with suitable knee replacement sizes

Develop models for patients come up with an appropriate combination of cement thickness, offset distance and femoral head size that will accommodate the patient's size.

Implementing CAD/CAM and extracting CNC codes to manufacture the appropriate knee replacement for Saudi patients

Predict the durability of the replacement by modeling the progress of the wear behavior of replaced components


Mastercam

MasterCAM is a commercial Computer Aided MasterCAM is a commercial Computer Aided Manufacturing software package includes a CAD Manufacturing software package includes a CAD environment, a geometry-to-G-code translator, and environment, a geometry-to-G-code translator, and a G-code simulator.a G-code simulator.

MasterCAM provides full 2D and 3D design capability for drawing mechanical parts, and creates output code for programming CNC


Advantages of MasterCAM

1) Mastercam can build work-holding fixtures, complex 3D form fixtures, and to build assemblies.

2) Mastercam allows for fast and easy development of tool paths.

3) Fast and easy translation between CAD and CAM files.

4) You can check your work for errors before the actual machining began, saving the time and money.


Manufacturing Process

•The dimensions of the femur of the artificial knee joints were measured to get the following dimensions:

Procedure of Manufacturing

1) The blank for the job is prepared by Material cutting, milling and surface grinding.

2) The workpiece is WIRECUT in the WEDM machine and so is the holder

3) The workpiece is machined in the upside-down direction to finish all bottom operations with material for a screw hole in the center


Procedure of Manufacturing

4) The workpiece is fixed to the holder with the screw. The job is held at 45degree to run a CAM program generated in that direction.

5) The workpiece is than held at another angle of -45degree to run another CAM program generated in that direction.

6) The job is polished to achieve the required finish


Final Shape


Machine

The machine used to manufacture this artificial femur knee joint was a Huron kx-15 five axis machine

That device is very appreciated for the machining of very technical and complex work pieces


CNC Controller

CNC stands for "Computer Numeric Control". It's referring to machinery that is under automated control, as opposed to manually by an operator.```


G-Codes

What is G-code?

When the designed product is produced using CNC When the designed product is produced using CNC machine tools, the machine tool controller needs machine tools, the machine tool controller needs explicit instructions describing the type and order of explicit instructions describing the type and order of individual steps required to perform a given task. individual steps required to perform a given task. These instructions are provided to the controller in These instructions are provided to the controller in the form of alphanumeric codes (G-code) and are the form of alphanumeric codes (G-code) and are usually called a part program.usually called a part program.


Sample of G-Codes

%(PROGRAM NAME - Knee joint)N100G21N102G0G17G40G49G80G90(UNDEFINED TOOL - 1 DIA. OFF. - 41 LEN. - 1 DIA. - 6.)N104T1M6N106G0G90G54X-101.307Y2.758A0.S50M5N108G43H1Z60.N110Z-.354N112G1Z-5.354F0.N114X-101.21Z-5.137N116X-101.043Z-4.837N118X-100.959Z-4.66N120X-100.71Z-4.24N122X-100.691Z-4.203N124X-100.622Z-4.095N126X-100.41Z-3.839N128X-100.248Z-3.676N130X-100.126Z-3.542N132X-99.986Z-3.416N134X-99.824Z-3.314


Sample of G-Codes

N1178X-37.64Z-7.54N1180X-37.614Z-7.595N1182X-37.451Z-8.398N1184X-37.356Z-8.975N1186Z-3.975N1188G0Z-2.858N1190X-39.326Y48.883N1192G1Z-3.886N1194Z-8.886N1196X-39.808Z-8.589N1198X-57.292Z-8.59N1200X-57.547Z-8.841N1202Z-3.841N1204G0Z-3.84N1206X-81.326N1208G1Z-3.886N1210Z-8.886N1212X-81.808Z-8.589N1214X-99.292Z-8.59N1216X-99.547Z-8.841N1218Z-3.841N1220M5N1222G91G0G28Z0.N1224G28X0.Y0.A0.N1226M30%


Tool path for the model Video of ProcessVideo of Process

1st set up

2nd set up


Conclusions

The present work shows that artificial knee joint could be manufactured locally.

The MasterCAM proved sufficient, not only to represent the femur part of the joint, but also to generate tool path and G-codes necessary to manufacture the femur part of the joint.

This success will hopefully have a reflection on the manufacture of custom-made artificial knee. This is expected to help reduce the suffering of our patients.


Thank You…


Special thanks to my adviser Prof. Darwish

Documents

King Saud University College of Engineering Industrial Engineering Department Custom-Made Artificial Knee By Abdullah AlNuiam Supervised By Prof. Saied