By using 3D modeling software SOLIDWORKS, a fixation plate is tested for stabilizing a 45 degree break in a tibia model. COMSOL software was used to test the mechanical properties of the plate and the effects on the tibia bone.

1. Stabilizing 45 Degree Break
in Tibia Model
Katherine Riley Martin, Henry
Chan, and Sean Stovall

2. PVC Mechanical Properties
● OD- 1.25 inches
● ID- 1 inch
● Length- 15 inches
● Young’s Modulus: 3.3E9 Pa
● Poisson Ratio: 0.4
● Density: 1467 kg/ m3
Mechanical Properties of PVC Pipe

3. Titanium Alloy- Ti6Al4V Grade 5
Benefits
● High level of biocompatibility
● Low level of corrosion
● Elastic Modulus is similar to bone
Current uses
● Fracture plates and intramedullary rods
Material Properties:
Young Modulus: 17.26 E9
Pa
Poisson: 0.37
Density: 4.512 Mg/m3

4. Baseline Compression Force (z-axis: 2000 N)

5. Baseline Bending Force (y-axis: 1414 N, 45
degrees)

6. Baseline Torsion Force (y-axis two point loads ±
400 N)

7. Baseline Combined Forces

8. Comparison in Design Processing
1. Henry’s screws short and were near the break
2. Riley’s screws were on the outside of the break
3. Sean’s screws went through the break

9. Design 1: Henry
2 Bone Plates: 10in x 0.6in x 0.125in
12 Long screws: D = 0.14in, L = 1.35in
4 Short Screws: D = 0.18in, L = 0.5in

10. Screws Inserted Into Bone Plate and Bone

11. Compressive Force 2000N
Design 1: Henry

12. 1st Principal Stress

13. 1st Principal Strain

14. Bending Force 1414N
Design 1:Henry

15. 1st Principal Stress

16. 1st Principal Strain

17. Torsional Force 400N
Design 1: Henry

18. 1st Principal Stress

19. 1st Principal Strain

20. Combined Forces: Compressive 2000N, Bending
1414N, and Torsional 400N
Design 1: Henry

21. 1st Principal Stress

22. 1st Principal Strain

23. Comments On Design 1
Pros
● Effective for Compression and Torsion Forces compared
to other Designs and Baseline.
● Bone Plates are thin and would not require large incisions
to implant the bone plates.
● There are many screws, which would greatly divide the
total forces and minimizes the forces on the individual
screws.
Cons
● There are many screws, this may cause excessive injury
to the tibia bone.
● There are two bone plates on opposite sides, would
require multiple incisions during surgery.

24. Design 2: Riley
● Inner Radius: 0.625 inches
● Outer Radius:0.825 inches
● Horizontal screws: D=0.15 inches, L=1.85 inches
● Vertical screws:D=0.15 inches, L=1.50 inches
● Depth:0.200 inches
● Length: 7.00 inches

25. Compressive Force 2000N
Design 2: Riley

26. First Principal
Stress

27. First Principal
Strain

28. Bending Force 1414N
Design 2: Riley

29. First Principal
Stress

30. First Principal
Strain

31. Torsional Force 400N
Design 2: Riley

32. First Principal
Stress

33. First
Principal
Strain

34. Combined Forces: Compressive 2000N, Bending
1414N, and Torsional 400N
Design 2: Riley

35. First Principal Stress

36. First Principal Strain

37. Comments On Design 2
Pros
● Only 6 Screws
● Two Long Screws in Middle Help Stabilize Bone
● With Interlocking Design, If Lose a Screw, Still Have One in Place
● Perfect for Active Person When Looking At Combined Tests
Cons
● Large Amount of Material = Expensive
● Didn’t Win Every Test Against Competition
● Big Plate = Big Insertion Area
● Would Need to Pre-Measure Bone to Design
● With Large Amount Of Plate, Could Hurt Bone Regeneration

38. Design 3: Sean
Dimensions
● Bone plate: L=6 inches,
OD=1.29inches,
ID=1.25 inches
Depth=0.04 inches
● 4 short screws: D=0.4
inches, L=1.3 inches
● 1 long screw: D=0.2
inches, L=1.52 inches

39. Compressive Force 2000N

40. 1st Principal Stress

41. 1st Principal Strain

42. Bending Force 1414N
Design 3: Sean

43. 1st Principal Stress

44. 1st Principal Strain

45. Torsional Force 400N
Design 3: Sean

46. 1st Principal Stress

47. 1st Principal Strain

48. Combined Forces: Compressive 2000N, Bending
1414N, and Torsional 400N
Design 3: Sean

49. 1st Principal Stress

50. 1st Principal Strain

51. Comments On Design 3
Pros
● Has 5 screws
● One incision for surgery
● Not much material for plate
● Screw at an angle through break to stabilize
Cons
● Screws go through both ends- slower healing
process
● Other designs had less stress and strain
● Only has plate on one side so forces acting on other
side of plate could have significant impact.
● Screw in middle didn’t reduce stress/ strain
comparative to other designs.

52. Design Results
● Design 1 had the lowest torsion results
● Design 2 had the lowest bending results
● Design 2 had the lowest combined results
● The best design is the 2nd one.
● Think About Walking, Running, and Jumping
● Tibia experiences all forces
● Compression, Bending, and Torsion

53. Picked Design
Pros
● Only 6 Screws
● Two Long Screws in Middle Help Stabilize Bone
● With Interlocking Design, If Lose a Screw, Still Have One in Place
● Perfect for Active Person When Looking At Combined Tests
Cons
● Large Amount of Material = Expensive
● Affects Surrounding Muscles and Tissues
● Didn’t Win Every Test Against Competition
● Big Plate = Big Insertion Area
● Would Need to Pre-Measure Bone to Design
● Would Need to Do 3D Mold of Tibia to Apply Plate
● With Large Amount Of Plate, Could Hurt Bone Regeneration

54. Shortcomings in Design Process
● Design 1: There were too many screws which may cause excessive injury
to the bone. Also two plates would require additional incisions during
surgery.
● Design 2: Too Much Material, Large Incision, Possible Adverse Reactions
● Design 3: Screws go through both ends- slower healing process, Only has
plate on one side so forces acting on other side of plate could have
significant impact, screw in middle didn’t reduce stress/ strain
comparative to other designs

55. Research Papers
1. Charry, E., Wenzheng Hu, M. Umer, A. Ronchi, and S. Taylor. "Study on Estimation of Peak Ground Reaction Forces Using Tibial Accelerations in
Running." 2013 IEEE Eighth International Conference on Intelligent Sensors, Sensor Networks and Information Processing (2013): n. pag. Web. 2 May
2017.
2. Standing, walking, running, and jumping on a force plate Rod Cross Physics Department, University of Sydney, Sydney, New South Wales 2006,
Australia
3. Ryuji Kawamoto1 , Yusuke Ishige2 , and Shenshi Fukashiro. " Non-Invasive Quantification of Torsional Shear Stresses Along the Tibia During Running"
(n.d.): n. pag. Keio University. Web. 2 May 2017. <https://isbweb.org/images/conf/2003/longAbstracts/KAWAMOTO_293-316_SPO_LONGE.pdf>.
4. Kawamoto, Ryuji, Yusuke Ishige, Koji Watarai, and Senshi Fukashiro. "Quantitative Investigation of Torsional Loading of the Tibia during Quick
Change of Running Direction." International Journal of Sport and Health Science 1.1 (2003): 24-33. Web. 2 May 2017.
<https://isbweb.org/images/conf/2001/Longabstracts/PDF/0100_0199/0165.pdf>.
5. Tomasulo, Patricia. "Searching Medscape®." Medical Reference Services Quarterly 19.3 (2000): 63-70. Web.
<https://www.researchgate.net/profile/Timothy_Derrick/publication/281142251_Bone_Stress_in_Runners_with_Tibial_Stress_Fracture/links/55db6383
08ae9d65949360bc.pdf?origin=publication_list>.
6. Tomasulo, Patricia. "Searching Medscape®." Medical Reference Services Quarterly 19.3 (2000): 63-70. Web.
<http://emedicine.medscape.com/article/1230554-overview#a5>.
7. "Properties: Titanium Alloys - Ti6Al4V Grade 5." AZoM.com. N.p., n.d. Web. 30 Apr. 2017. <http://www.azom.com/properties.aspx?ArticleID=1547>.
8. AZoM, Written By. "Stainless Steel and Titanium in Surgical Implants." AZoM.com. N.p., 10 June 2013. Web. 30 Apr. 2017.
<http://www.azom.com/article.aspx?ArticleID=7156>.

56. Questions

57. Von Mises Stress Sean Bending

58. Von Mises Stress Sean Compression

59. Von Mises Stress Sean Torsion

60. Von Mises Stress Sean Combined

61. Compression Contour Lines Sean

62. Von Mises Stress Combined Henry’s Design

63. Von Mises Stress Henry’s Design Compression

64. Von Mises Stress Torsion Henry

65. Von Mises Stress Bending Henry

66. Von Mises Stress Riley Compression

67. Von Mises Stress Riley
Combined

68. Von Mises Stress
Bending Riley

69. Von Mises Stress Riley Torsion

70. Von Mises Stress
Torsion Riley

71. Contour Riley Bending

72. Contour Displacement
Combined Riley

73. Contour
Bending
Riley

74. First Principal Stress Riley Compression

75. Contour Riley Compression

76. Arrow Line Displacement
Riley Combined

77. Contour Line Displacement

78. First Principal Stress Riley Old Slides

79. Cross Section-Combined
Riley Old Slides

80. First Principal Strain Riley Old Slides

81. Arrow Line Torsion
Riley

82. Arrow Volume Compression Riley

83. Cross Section-Bending
Riley

84. Cross Section Compression Riley Compression

85. Arrow Plot
Bending
Riley