Graduation presentation for my Technical Medicine study at the University of Twente. In cooperation with the Masanga Hospital research department and 3D-lab RadboudUMC.

1. Low-cost 3D-printed transtibial
prosthetic sockets in a rural
area of Sierra Leone

2. Introduction
• A 3D lab in the Masanga Hospital in Sierra Leone
• 2019: Feasibility study on 3D-printed arm
protheses and medical aids

3. Introduction
• Amputations often happen in Sierra Leone
• Complex wounds
• Traffic accidents
• Serious infections
• Civil war
• Delays in patient presentation
• Traditional healing

4. Introduction
• Only 5-15% of people in countries with low and
middle income have medical aids
• Knowledge
• Availability of materials
• Trained staff
• Low quality
• High costs
R. Matter, M. Harniss, T. Oderud, J. Borg, and A. H. Eide, “Assistive technology in resource-
limited environments: a scoping review,” Disabil. Rehabil. Assist. Technol, Feb. 2017.

5. • 65 amputations in 2018 in Masanga Hospital
• Of which 44 leg amputations
• A leg protheses cost around $100 – 200 USD
• Average income of $490 USD a year
Introduction

6. Research questions
Main question
• Is it possible to produce low-cost transtibial prosthetic sockets using
the relatively easy to use printing technique Fused Deposition
Modeling (FDM) in a rural area of Sierra Leone?

7. Research questions
Sub questions
• Suitable printing material for FDM
• Design transtibial prosthetic socket
• International ISO guidelines for testing sockets
• Production method transtibial prosthetics in Sierra Leone
• Clinical research transtibial prosthetics in Sierra Leone

8. Transtibial prosthesis
• Prothesis consists of:
• Socket
• Tube
• Foot

9. Traditional method sockets

10. Traditional method sockets
1. Negative copy of the stump is made using plaster cast

11. Traditional method sockets
1. Negative copy of the stump is made using plaster cast
2. Positive mold of the stump

12. Traditional method sockets
1. Negative copy of the stump is made using plaster cast
2. Positive mold of the stump
3. This positive mold will be shaped

13. Traditional method sockets
1. Negative copy of the stump is made using plaster cast
2. Positive mold of the stump
3. This positive mold will be shaped
4. Final socket using polypropylene

14. Traditional method sockets
• Time consuming
• Labor-intensive
• Highly dependent on experience and skills
• High material costs

15. Making prostheses using 3D-scanning and 3D-printing

16. Fused deposition modeling (FDM):
What is it?

17. Suitable printing material for FDM
Materials: Material consisting of: Producer: Costs/kg (€):
PA6/66-CF20 Polyamide reinforced with 20% carbon fibers Clariant 160
Novamid 1030-CF10 Polyamide reinforced with 10% carbon fibers DSM 107
PLA-HI-GF10 Polylactic acid reinforced with 10% glass fibers Clariant 85
PET Polyethylene Terephthalate Clariant 60
Tough PLA Tough polylactic acid Ultimaker 53

18. Suitable printing material for FDM
Tested in two print directions
Longitudinal printed: Transversal printed:

19. Suitable printing material for FDM
Tested in the tensile testing machine
• Tensile strength
• Tensile modulus
• Tensile elongation at break

20. Suitable printing material for FDM
Tensile Strength (MPa) Tensile Modulus (MPa)
Tensile elongation at
break (%)
Costs/kg (€):
Novamid 1030-CF10 79.6 11.6
PA6/66-CF20 72.9 9.5
PLA-HI-GF10 59.5 17.8
PET 53.0 17.6
Tough PLA 47.2 27.9
Prosthetic material 36.2

21. Suitable printing material for FDM
Tensile Strength (MPa) Tensile Modulus (MPa)
Tensile elongation at
break (%)
Costs/kg (€):
Novamid 1030-CF10 79.6 11.6 2683.3 750.0
PA6/66-CF20 72.9 9.5 3450.0 416.7
PLA-HI-GF10 59.5 17.8 2525.0 1466.7
PET 53.0 17.6 1375.0 1150.0
Tough PLA 47.2 27.9 1583.3 1316.7
Prosthetic material 36.2 1533.3

22. Suitable printing material for FDM
Tensile Strength (MPa) Tensile Modulus (MPa)
Tensile elongation at
break (%)
Costs/kg (€):
Novamid 1030-CF10 79.6 11.6 2683.3 750.0 7.5 2.6
PA6/66-CF20 72.9 9.5 3450.0 416.7 9.5 6.9
PLA-HI-GF10 59.5 17.8 2525.0 1466.7 4.4 1.7
PET 53.0 17.6 1375.0 1150.0 8.6 2.2
Tough PLA 47.2 27.9 1583.3 1316.7 31.8 3.7
Prosthetic material 36.2 1533.3 13.3

23. Suitable printing material for FDM
Tensile Strength (MPa) Tensile Modulus (MPa)
Tensile elongation at
break (%)
Costs/kg (€):
Novamid 1030-CF10 79.6 11.6 2683.3 750.0 7.5 2.6 107
PA6/66-CF20 72.9 9.5 3450.0 416.7 9.5 6.9 160
PLA-HI-GF10 59.5 17.8 2525.0 1466.7 4.4 1.7 85
PET 53.0 17.6 1375.0 1150.0 8.6 2.2 60
Tough PLA 47.2 27.9 1583.3 1316.7 31.8 3.7 53
Prosthetic material 36.2 1533.3 13.3

24. Tough PLA is the most suitable printing
material for FDM printed prosthetic sockets

25. 3D-Printed socket

26. Prototype testing
International Standard Structural Testing of Lower
Limb Prostheses
• Static test:
• Required: 4025N
• Durable test:
• Required: 3 million cycles, 1200N

27. Prototype testing
International Standard Structural Testing of Lower
Limb Prostheses
• Static test:
• Required: 4025N
• Durable test:
• Required: 3 million cycles, 1200N

28. Prototype testing
International Standard Structural Testing of Lower
Limb Prostheses
• Static test:
• Required: 4025N
• Achieved: 6700 N

29. Prototype testing
International Standard Structural Testing of Lower
Limb Prostheses
• Static test:
• Required: 4025N
• Achieved: 6700 N

30. Prototype testing
International Standard Structural Testing of Lower
Limb Prostheses
• Static test:
• Required: 4025N
• Achieved: 6700 N
• Durable test:
• Required: 3 million cycles
• Achieved: 2.33 million cycles

31. Prototype testing
X-ray

32. FDM printed sockets using Tough PLA
almost comply with international
standard for structural testing of lower
limb prostheses

34. Prosthetic workflow
1. Physical examination

35. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump

36. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump
3. Landmarks drawing on the stump

37. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump
3. Landmarks drawing on the stump
4. 3D-Scanning

38. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump
3. Landmarks drawing on the stump
4. 3D-Scanning
5. Design of the socket

39. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump
3. Landmarks drawing on the stump
4. 3D-Scanning
5. Design of the socket
6. 3D-Printing

40. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump
3. Landmarks drawing on the stump
4. 3D-Scanning
5. Design of the socket
6. 3D-Printing
7. Attachement of other prosthetisc parts

41. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump
3. Landmarks drawing on the stump
4. 3D-Scanning
5. Design of the socket
6. 3D-Printing
7. Attachement of other prosthetisc parts
8. Foot was made form wood

42. Prosthetic workflow
1. Physical examination
2. Apply pressure to the stump
3. Landmarks drawing on the stump
4. 3D-Scanning
5. Design of the socket
6. 3D-Printing
7. Attachement of other prosthetisc parts
8. Foot was made form wood
9. Aesthetic appearance of the prosthesis

43. Time for clinical reseach

44. Clinical research
• From February until March 2020
• Eight participants living in Masanga
• Three participants previously had an
old prosthesis
• Informed consent
• Ethical approval

45. Clinical research
• From February until March 2020
• Eight participants living in Masanga
• Three participants previously had an
old prosthesis
• Informed consent
• Ethical approval
Age (years) 43.1 (SD: 15.4)
Gender
(male:female)
3:5
Amputation years
ago
5.6 (SD: 5.5)
Cause of amputation 3/8 leprosy
3/8 chronic ulcer
1/8 tropical ulcer
1/8 accident
Education 6/8 none
1/8 elementary
school
1/8 middle School
Daily job/activity 4/8 housewife
1/8 weaver
1/8 taylor
1/8 business
1/8 none

46. Clinical research
Pre-prosthetic phase
• Amputation occurred at least four months ago
• No wounds on the stump
• Bandage in case of fluid retention
• Walking independently with crutches

47. Clinical research
Qualitative research with self-made questionnaires
• Questionnaires
• Before obtaining the prostheses
• During follow-up after 5-6 weeks
• Questionnaire categories
• Personal goal by the participants
themselves

56. Questionnaire results after 5-6 weeks
Max/min score Measuring moment: Mean (n=3):
Current level of mobility: Min: 3, low mobility
Max: 15, high mobility
Old prosthetic 7.7
3D prosthetic 9.3
Comparison old prosthetic VS 3D-printed prosthetic of three patients:

57. Questionnaire results after 5-6 weeks
Max/min score Measuring moment: Mean (n=3):
Current level of mobility: Min: 3, low mobility
Max: 15, high mobility
Old prosthetic 7.7
3D prosthetic 9.3
Overall impression of the
prosthesis:
Min: 5, dissatisfied
Max: 25, very satisfied
Old prosthetic 20.3
3D prosthetic 25.0
Comparison old prosthetic VS 3D-printed prosthetic of three patients:

58. Questionnaire results after 5-6 weeks
Max/min score Measuring moment: Mean (n=3):
Current level of mobility: Min: 3, low mobility
Max: 15, high mobility
Old prosthetic 7.7
3D prosthetic 9.3
Overall impression of the
prosthesis:
Min: 5, dissatisfied
Max: 25, very satisfied
Old prosthetic 20.3
3D prosthetic 25.0
Use of the prosthesis: Min: 2, no use
Max: 10, maximum use
Old prosthetic 7.7
3D prosthetic 10.0
Comparison old prosthetic VS 3D-printed prosthetic of three patients:

59. Questionnaire results after 5-6 weeks
Max/min score Measuring moment: Mean (n=3):
Current level of mobility: Min: 3, low mobility
Max: 15, high mobility
Old prosthetic 7.7
3D prosthetic 9.3
Overall impression of the
prosthesis:
Min: 5, dissatisfied
Max: 25, very satisfied
Old prosthetic 20.3
3D prosthetic 25.0
Use of the prosthesis: Min: 2, no use
Max: 10, maximum use
Old prosthetic 7.7
3D prosthetic 10.0
Possible complications: Min: 3, all complications
Max: 15, no complications
Old prosthetic 14.7
3D prosthetic 13.7
Comparison old prosthetic VS 3D-printed prosthetic of three patients:

60. Discussion
Mass of the prostheses
• 3D printed transtibial prosthesis:
• 1560 grams (SD 78, n=8)
• Local prostheses:
• 1945 grams (SD: 148, n=2)

61. Discussion
Cost
• 3D printed socket: +/- $20 USD filament costs
• Imported prosthetic parts: $62 USD
• The prosthetic foot: $5 USD +
$87 USD (excl. VAT)

62. Discussion
Cost
• 3D printed socket: +/- $20 USD filament costs
• Imported prosthetic parts: $62 USD
• The prosthetic foot: $5 USD +
$87 USD (excl. VAT)
• Participant's contribution: $15 USD

63. Discussion
Further research: usage of local products
• Problem:
• Prosthetic products are expensive
• Dependent on import from other countries
• Replace the imported parts for local products
• Cost reduction: of 50 USD
• Cost protheses: +/- 40 USD

64. Discussion
Further research: Improved prosthetic strength
• Round shape
• Use of inserts instead of nuts
• Annealing
• Improved print settings

65. Discussion
Further research: automatization of the design process
• Socket design: complex step in making
the prostheses
• Design program
• Standardization
• Carried out by the local population itself

66. Discussion
Further research: Long-time follow-up
• In the coming months/years: long-term follow-up

67. Discussion
Further research: wider range of prostheses
• Knee disarticulations
• Upper leg prosthetics

68. Conclusion
Is it possible to produce low-cost transtibial prosthetic sockets using
Fused Deposition Modeling (FDM) for in a rural area of Sierra Leone?
• The first clinical results seem to be positive
• Long-term follow-up is needed to prove sustainability

69. Luc Verhamme
3D Lab radboudumc
Arico Verhulst
3D Lab radboudumc
Throy en Idrissah
Physiotherapists Masanga Hospital
Lars Brouwers
Surgeon in training
Prof. Kees Slump
Technical Medicine
University of Twente
Marco Papenburg
Papenburg Orthopedie
Jonathan Vas Nunes
Tropical docter Masanga
Hospital
Prof. Martin Grobusch
Head of Tropical Medicine
Center and research
department Masanga
Prof. Thomas Maal
Director 3D Lab
Radboudumc
Thanks to all supervisors,
physioterapists in
masanga and students
who participate in this
project

70. Thank you for your attention!
Questions?