Femoral Head Case Study

Length: 2 weeks (introductory lecture, independent study and presentations)

Aims: To consider the various factors involved in the design, materials selection and production of a ceramic femoral head.

Key Skills: Group working, independent study, written and oral communication.

Student Output: Group report and group presentation



This is a group-based case study that examines the various factors involved in the design, materials selection and production of a ceramic femoral head. At the end of this case study,  students should be able to:

  • Identify the critical design and property requirements and explain why they are critical.
  • Explain why Zirconia and Alumina are the current materials of choice and identify their relative merits.
  • Describe the most appropriate green body fabrication routes and explain the reason why this is the case.
  • Describe the commonly used performance and reliability validation procedures and indicators and relate them to the validation of ceramic femoral head.

After an introductory lecture, students are assigned to their groups. Each group should elect a group co-ordinator who is responsible for co-ordinating the activities of the group. Within the group, members will choose one of the following work tasks:

  • Design Function
  • Materials Selection
  • Materials Processing
  • Materials Properties
  • Component Performance
  • Component Reliability
  • Other relevant issues such as Specific Biocompatibility/Cost etc.

Groups and individuals within each group are expected to organise themselves to gather any relevant information using the Internet, Libraries, Lecture notes etc. plus other resources they locate using their own initiative.

Assessment

Each group must submit a single written report (60% of student’s marks) summarising their main findings and conclusions drawn. The report is to be a maximum of 4 sides of A4 of word-processed text. Each group also needs to prepare a group oral presentation (30% of student’s marks). The group co-ordinator should present the introduction and conclusions. The presentations will be assessed in terms of: Content 15%; Presentation% Finally, groups are expected to carry out peer assessment of individual contributions to the case study (10% of student’s marks).

Resources

http://www.fda.gov/medwatch/safety/1997/hip.htm

http://www.aaos.org/wordhtml/press/loosen.htm

http://www.ceramtec.de/

http://www.ceramtec.de/eng/medical_products/ziolox.html

References

Boehler, M., Knahr, K., Plenk, H., Walter, A. and Salzer, M. (1994) Long-term results of uncemented Alumina acetabular implants, Journal of Bone and Joint Surgery - British Volume 76B: (1) p53-59.

Calloway, G. H., Flynn, W., Runawat, C. S. and Sculco, P. (1995) Fracture of the femoral head after ceramic-on-polyethylene total hip arthroplasty, Journal of Arthroplasty 10: (6) p855-859.

Cooper, J. R., Dowson, D., Fisher, J. and  Jobbins, B. (1991) Ceramic bearing surfaces in total artificial joints - resistance to 3rd body wear damage from bone-cement particles, Journal of Medical Engineering and Technology 15: (2) p63-67.

Dowson, D., Jobbins, B. and Seyedharraf, A. (1993) An evaluation of the penetration of ceramic femoral heads into polyethylene acetabular cups, Wear, 162: (PtB) p880-889.

Dragoni, E. and Andrizano, A. O. (1995) Structural evaluation of ceramic femoral heads - effect of taper friction, support conditions and trunnion compliance, Journal of Biomechanical engineering - transactions of the ASME, 117: (3) p293-299.

Drouin, J. M., Cales, B., Chevalier, J. and  Fantozzi, G. (1997) Fatigue behavior of Zirconia hip joint heads: Experimental results and finite element analysis, Journal of Biomedical Materials Research, 34: (2) p149-155.

Fruh, H. J. and Willmann, G. (1998) Tribological investigations of the wear couple alumina-CFRP for total hip replacement, Biomaterials, 19: (13) p1145-1150.

Heck, D. A., Partridge, C. M., Reuben, J. D., Lanzar, W. L., Lewis, C. G., Keating, E. M. (1995) Prosthetic component failures in hip - arthroplasty surgery, Journal of Arthroplasty, 10: (5) p575-580.

Phipatanakul W P, Johnson S A, Good V, Clarke I C

'The fallacy of evaluating biomaterial wear-rates with water as a lubricant: A hip simulator study of alumina-PTEE abd CoCr-PTFE combinations' Journal of Biomedical Materials Research 39: (2) 229-233 1998

Piconi, C. and Maccauro, G. (1999) Zorconia as a ceramic biomaterial, Biomaterials, 20: (1) p1-25.

Saikko, V. O. (1993) Wear of polyethylene acetubular cups against alumina femoral heads - 5 protheses compared in a hip simulator for 35 million walking cycles, Orthopaedica Scandinavia, 64: (5) p507-512.

Willmann, G. (1994) Alumina ceramic looks back on 20 years of use in medical applications, Biomedizinische Technik, 39: (4) p73-78.

Willmann, G. (1998) Ceramics for total hip replacement - what a surgeon should know, Orthopedics, 21: (2) p173-177.

Willmann, G. (1993) Fretting of Modular Implant Systems, Biomedizinische Technik, 38: (3) p48-52.

Willmann, G. (1995) How safe are ceramic femoral heads for hip endoprotheses, Material Wissenscraft und werkstofftechnik, 27: (6) p280-286.

Willmann, G., Kalberer, H. and Pfaff, H. G. Ceramic cup inserts for hip endoprotheses, Biomedizinische Technik, 41: (4) p98-105.

Willmann G, Pfaff H G, Ricter H G'Improvement of the safety of ceramic femoral heads for total hip replacement' Biomedizinische Technik 40: (12) 342-346 1995

Wordsworth R A, Weightman B 'Laboratory development of a method of attaching ceramic femoral heads to metal stems' Biomaterials &: (2) 83-88 1986

Wroblewski, B. M., Siney, P. D., Dowson, D. and Collins, S. N. (1996) Prospective clinical and joint simulator studies of a new total hip arthoplasty, Journal of Bone and Joint Surgery - British Volume, 78B: (2) p280-285.