This document summarizes the history and process of hip resurfacing surgery. It discusses how hip resurfacing procedures aim to mimic the natural hip joint using 2-3 components: an acetabular component and bearing surface, and a femoral component. The document then outlines the design process for the femoral component, including reconstructing the proximal femur through sketches, sweeps, and blend operations in CAD software. Finite element analysis is conducted to test the implant design and ensure stress levels are below yield strengths when subjected to loads up to 2-3 times body weight. The conclusion is that the implant design has low chances of failure based on the FEA results.

1. Hip ResurfacingFemoral Component-Ujwal ParikhSmith & Nephew, Inc

2. History of Hip Resurfacing Hip resurfacing procedures are performed since last 30-40 years but failed due to poor design.First performed by Dr. Derek Mc Minnand Dr. Roman Treacy.They performed the first metal on metal prosthesis at Royal Orthopedic Hospital Birmingham in 1996.FDA first approved BHR in 2006 by Smith & Nephew, Inc

3. What is HR?A conservative surgical technique of arthoplastyof hip.Done to mimic natural hip and have normal biomechanics, load transfer & range of motion at hip joint.Consists of 2-3 components:- Acetabular Component & Bearing surface- Femoral component

4. Who needs HR?Patients suffering from primary & secondary arthritis.Primary arthritis usually occurs in patients above 60 years.Secondary arthritis common in young patients and due to ankylosingspondylitis, rheumatoid arthritis, dysplasia and avascular necrosis of femoral head.

5. Design InputBUECHEL-PAPPAS™ HIP REPLACEMENT SYSTEM – RESURFACING, ENDOTECH

6. Femur….Femoral HeadFemoral NeckGreater & Lesser Trochanters

7. Reconstruction of Proximal FemurScale ModelSketch TrajectoryCreate Datum PlanesCreate SketchesUse Swept Blend

8. Reconstruction of Proximal Femur

9. Lateral ViewAnterior View

10. Things To Remember…..Trajectory in center of bone and must follow bone curve.Vertex for all sketches should be at the same point.Use of blend should be in the same direction for all sketches VISUALISE!!!!

11. Construction of Femoral Component

12. Construction of FC

13. FCDimensions:Material Used:Titanium Alloy- Ti6Al4V

14. Family TableFT to avoid step cut if implant used to cut bone

15. Cut Out

16. Assembly (Bone + Implant)

17. Finite Element Analysis (FEA)Material Properties:

18. FEAAverage male weight= 190 lbfTo test the implant we consider 2-3 times body weight = 450 lbfThe Peak Load Axis is at 30 deg. with the vertical.

19. FEA

20. ConclusionThe max. stress on implant and bone is less than ultimate yield strength for the implant and bone material .Thus our implant has less chances for failure

21. Thank You !!!

22. Referenceswww.endotec.comSmith & Nephew, Inchttp://www.hipresurfacingindia.com/http://russellmeldrum.com/hips.html#Fundamentals of Biomechanics- OzkayaNihat, Nordin, MargaretaWikipedia.org