THREE-DIMENSIONAL (3D) MODELLING OF THE ANKLE

IMPLANTS

By Dr. S. P. ANGELINE KIRUBHA

Assistant Professor(Sr.G) Department of Biomedical Engineering

School of Bioengineering

 

To construct Customized Ankle Implant and conventional ankle Implant

Aim

To construct the 3D model of the Ankle joint.

To design the conventional Ankle implant To design the New Wave Implant To perform stress analysis for both the

implant. To perform the comparison of stresses for

both the implants.

Objective

Need For Ankle Implant

In the field of sports and rehabilitation and pathological situation the Ankle implant helps the patient to walk on his own legs.

The New WAVE implant helps the patient to move ankle joint like original ankle.

Need For Ankle Implant

Patient CT Scan MIMICS Geomagics Catia ProE Hypermesh Ansys

Requirements

Experimental Procedure

IMPORT

Geomagic Surface Generation from point cloud

ProE for design and Drafting of implant

ProE for Fitting of implantHypermesh for quality meshingMaterial assignment based on ISO standardsValidation(stress test) using Ansys

Segmentation in MIMICS

65 year old Woman with Arthrities

65 years old lady with Arthrities was taken into study.

65 year old Woman with Arthritis

Internal ViewExternal ViewHypersensitivity Type 3 reaction leads to joint inflamation

Import Mimics Data Gemagics

Surface Generation in Geomagics

loosening 22-75%◦ greater in constrained designs◦ cemented prosthesis

wound complications with subsequent infection◦ amputation rate not insignificant

ankylosis following arthroplasty difficult salvage including arthrodesis

Modes of Failure of Ankle Arthroplasty

2D Drawing of STAR Ankle ImplantAnd Drafting in ProE For Polymer Component

2D Drawing of STAR Ankle ImplantAnd Drafting in ProE For Talar Component

2D Drawing of STAR Ankle ImplantAnd Drafting in ProE For Tibia Component

3D View of STAR Implant Created in ProE

3D Modelling of Tibia Component oF WAVE Implant

3D Modelling of Cartilage Component Component oF WAVE Implant

3D Modelling of TalusComponent oF WAVE Implant

Cutting of The Bone to Fix Implant

3mm

3mm

D6

The Implant are Fixed in the Bone

Fits like lock and key No restriction in motion Patient specific Cheap New Doctors Can Easily Fit it The implant is made for the old women

considering her physical activity like it is under stood that she cannot jump from a height she can do her daily life activity but the sports man can do many activity

Advantage of Wave implant

Meshing in Hypermesh as per CT image

CT image Measurement

Intact Model STAR implant Fitted Model

WAVE implant Fitted Model

Axis of Rotation in Talar Joint

Intact Model STAR implant Fitted Model

WAVE implant Fitted Model

Material PropertiesComponent Material Young’s

Modulus E (Mpa)

Poisson’s Ratio,V

Cortical Bone 19000 0.3Trabecular Bone 500 0.3

Cartilage 1 0.4Interosseous Membrane

99.5 0.49

Polyethylene Component

UHMWPE 557 0.46

Talar and Tibia component of (STAR)

Co-Cr-Mo 210000 0.3

Talar and Tibia component of (WAVE)

Ti 110000 0.33

Force Acting on Tibia and Fibula

Moment Acting on Tibia and Fibula

FE model with boundary condition

Finite Element Analysis After meshing the the geometry contains

finite number of elements and Vonmises stress is applied as it acts on all the directions

Intact Model

Star Implant

Wave Implant

Position Neutral(0 degree)Concentrated Force(N)Z-Component(axial Force) 1343.27Y-Component(anterior –posterior Force)

-144.116

X-Component (interior – Exterior Force)

220.303

Moment (N)Z-Component(axial Torque) -2172.71

Y-Component(anterior –posterior Torque)

10103.8

X-Component (interior – Exterior Torque)

31151.1

Force and Momentum applied To the Tibia in Neutral Position(0 degree)

Intact Model

Star Implant

Wave Implant

Discussion Load By Arvicar work

Discussion Load by Sofia Work

Intact Model

Star Implant

Wave Implant

0 50 100 150

Maximum StressMinimum Stress

The total ankle arthroplasty (TAA) is an alternative procedure to the arthrodesis as the cartilage cannot grow and damaged cartilage leads to pain. In the treatment of advanced arthritis in the ankle joint and joint damage due to physical injury, total ankle arthroplasty (TAA) is an alternative procedure

The use of CAD and CAM helps us to make the bone joint like the original one

Conclusion

Thank You

[1] van den Heuvel, A., Van Bouwel, S., and Dereymaeker, G., Total ankle replacement. Design evolution and results. Acta Orthop Belg, 2010. 76(2): p. 150-61.

[2] American Academy of Orthopaedic Surgeons [cited 2013 February 16]; Available from: http://orthoinfo.aaos.org/topic.cfm?topic=A00214.

[3] PubMed Health Home. [cited 2013 February 16]; Available from: http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002223.

[4] WebMD®. [cited 2013 February 16]; Available from: http://www.webmd.com/osteoarthritis/guide/arthritis-basics.

[5] Arhritis Foundation®. [cited 2013 February 16]; Available from: http://www.arthritis.org/conditions-treatments/understanding-arthritis/.

[6] Centers for Disease Control and PreventionTM [cited 2013 February 16]; Available from: http://www.cdc.gov/arthritis/basics/osteoarthritis.htm.

[7] Chou, L.B., Coughlin, M.T., Hansen, S., Jr., Haskell, A., Lundeen, G., Saltzman, C.L., and Mann, R.A., Osteoarthritis of the ankle: the role of arthroplasty. J Am Acad Orthop Surg, 2008. 16(5): p. 249-59.

Refrences