49 A Comparison of Acoustic Emission in Cadaveric Specimens …
559
49.6 Conclusion
This paper has presented the results from screw insertion testing into both Sawbones
blocks and cadaveric femurs. The general trend of AE seen was similar in both structures however some major differences were also seen. The most major of these being
the cumulative energy being greater in the cadaveric testing. When frequency analysis was performed on the AE waveforms it showed that there was several significant
differences between the two sets of tests.
The axial load results recorded from the testing showed an increase in axial stripping load with increased BMD, the relationship was strong in Sawbones but weak
in cadaveric testing. As well as the variation in BMD across the bone issues there
is believed to be some error as a result of the load cell not giving a correct reading.
Ways to improve results in future testing would be to use a motor driven constant
rate device to turn the screw or to integrate torque measurement into the test setup.
Acknowledgements Thank you to the Medical Research Council (MRC) for funding of the work
presented within this paper through their Confidence in Concept (CIC) funding scheme. Additional
thanks to the Institute of Mechanical Engineers (IMechE) and the South Wales Institute of Engineers
Educational Trust (SWIEET) for funding to travel to the World Conference on Acoustic Emission
(WCAE).
References
1. J.R. Chapman, R.M. Harrington, K.M. Lee, P.A. Anderson, A.F. Tencer, D. Kowalski, Factors
affecting the pullout strength of cancellous bone screws. J. Biomech. Eng. 118(3), 391–398
(1996)
2. S.M. Perren, Technical and biomechanical aspects of screws used in bone surgery. Int. J. Orthop.
Trauma 2, 31–48 (1992)
3. T. Drew, P. Allcock, A new method of fixation in osteoporotic bone: a preliminary report. Injury
33(8), 685–689 (2002)
4. C. Collinge, B. Hartigan, E.P. Lautenschlager, Effects of surgical errors on small fragment
screw fixation. J. Orthop. Trauma (2006)
5. G.S. Andreassen, P.R. Høiness, I. Skraamm, O. Granlund, L. Engebretsen, Use of a synthetic
bone void filler to augment screws in osteopenic ankle fracture fixation. Arch. Orthop. Trauma
Surg (2004)
6. M.J. Stoesz, P.A. Gustafson, B.V. Patel, J.R. Jastifer, J.L. Chess, Surgeon perception of
cancellous screw fixation. J. Orthop. Trauma (2014)
7. R.A. McGuire, K.R.J. St, S.G. Agnew, Analysis of the torque applied to bone screws by trauma
surgeons. Comparisons based on years of experience and material of implant construction. Am.
J. Orthop. (Belle Mead, NJ) 24(3), 254–256 (1995)
8. B. Li, R.M. Aspden, Material properties of bone from the femoral neck and calcar femorale of
patients with osteoporosis or osteoarthritis. Osteoporos. Int. 7(5), 450–456 (1997)
9. Encyclopædia Britannica Online, “Cancellous Bone [Image] (2019) [Online]. Available: http://
media-3.web.britannica.com/eb-media/57/94557-004-CF63D396.jpg. Accessed: 15-Oct-2019
10. K.J. Reynolds, T.M. Cleek, A.A. Mohtar, T.C. Hearn, Predicting cancellous bone failure during
screw insertion. J. Biomech. 46(6), 1207–1210 (2013)
559
49.6 Conclusion
This paper has presented the results from screw insertion testing into both Sawbones
blocks and cadaveric femurs. The general trend of AE seen was similar in both structures however some major differences were also seen. The most major of these being
the cumulative energy being greater in the cadaveric testing. When frequency analysis was performed on the AE waveforms it showed that there was several significant
differences between the two sets of tests.
The axial load results recorded from the testing showed an increase in axial stripping load with increased BMD, the relationship was strong in Sawbones but weak
in cadaveric testing. As well as the variation in BMD across the bone issues there
is believed to be some error as a result of the load cell not giving a correct reading.
Ways to improve results in future testing would be to use a motor driven constant
rate device to turn the screw or to integrate torque measurement into the test setup.
Acknowledgements Thank you to the Medical Research Council (MRC) for funding of the work
presented within this paper through their Confidence in Concept (CIC) funding scheme. Additional
thanks to the Institute of Mechanical Engineers (IMechE) and the South Wales Institute of Engineers
Educational Trust (SWIEET) for funding to travel to the World Conference on Acoustic Emission
(WCAE).
References
1. J.R. Chapman, R.M. Harrington, K.M. Lee, P.A. Anderson, A.F. Tencer, D. Kowalski, Factors
affecting the pullout strength of cancellous bone screws. J. Biomech. Eng. 118(3), 391–398
(1996)
2. S.M. Perren, Technical and biomechanical aspects of screws used in bone surgery. Int. J. Orthop.
Trauma 2, 31–48 (1992)
3. T. Drew, P. Allcock, A new method of fixation in osteoporotic bone: a preliminary report. Injury
33(8), 685–689 (2002)
4. C. Collinge, B. Hartigan, E.P. Lautenschlager, Effects of surgical errors on small fragment
screw fixation. J. Orthop. Trauma (2006)
5. G.S. Andreassen, P.R. Høiness, I. Skraamm, O. Granlund, L. Engebretsen, Use of a synthetic
bone void filler to augment screws in osteopenic ankle fracture fixation. Arch. Orthop. Trauma
Surg (2004)
6. M.J. Stoesz, P.A. Gustafson, B.V. Patel, J.R. Jastifer, J.L. Chess, Surgeon perception of
cancellous screw fixation. J. Orthop. Trauma (2014)
7. R.A. McGuire, K.R.J. St, S.G. Agnew, Analysis of the torque applied to bone screws by trauma
surgeons. Comparisons based on years of experience and material of implant construction. Am.
J. Orthop. (Belle Mead, NJ) 24(3), 254–256 (1995)
8. B. Li, R.M. Aspden, Material properties of bone from the femoral neck and calcar femorale of
patients with osteoporosis or osteoarthritis. Osteoporos. Int. 7(5), 450–456 (1997)
9. Encyclopædia Britannica Online, “Cancellous Bone [Image] (2019) [Online]. Available: http://
media-3.web.britannica.com/eb-media/57/94557-004-CF63D396.jpg. Accessed: 15-Oct-2019
10. K.J. Reynolds, T.M. Cleek, A.A. Mohtar, T.C. Hearn, Predicting cancellous bone failure during
screw insertion. J. Biomech. 46(6), 1207–1210 (2013)