Chapter 49
A Comparison of Acoustic Emission
in Cadaveric Specimens and Artificial
Sawbones During Surgical Screw
Implants
S. Grigg, B. J. Wright, and R. Pullin
Abstract The overtightening of cancellous surgical screws is a major problem for
orthopaedic surgeons, especially inexperienced ones. This problem is made worse
still when the patient suffers from osteoporosis, which significantly reduces the
density of the bone. Overtightening a screw leads to stripping of the bone and potential complications to surgery leading to increased recovery time and potential expense
to the health organisation. Acoustic Emission (AE) has previously been investigated
to monitor the insertion of such screws into artificial Sawbones. This paper presents
the testing of two sizes of surgical screws into both artificial Sawbones and cadaveric
femurs monitored for AE using piezoelectric sensors. The results show that there are
some significant differences between the AE given off from the two structures when
the energy and frequency of the waveforms are analysed.
49.1 Introduction
Orthopaedic surgeons use screws in most fracture fixation surgeries. There are,
broadly speaking, two types of screw for the two types of bone: cortical and cancellous. Cortical bone is the outer layer of dense bone whereas cancellous bone is the
inner core, which is typically more porous [1], as shown in Fig. 49.1. To enable cancellous screws to have optimal pull out strength they have an increased thread depth
and reduced cross sectional thickness compared to cortical screws [2]. Cancellous
bone screws are used for a range of orthopaedic surgeries for fixation into the metaphyseal area of bone such as femoral condyles. Cancellous bone, being less dense
than cortical, can be difficult to gain suitable purchase into without risking stripping
the bone, especially in osteopenic patients. Stripping a screw causes micro failure of
material around the screw leading to screw loosening or complete failure. This can
S. Grigg (B) · R. Pullin
Cardiff School of Engineering, Cardiff University, Cardiff, UK
e-mail: griggs@cardiff.ac.uk
B. J. Wright
Vestre Viken, Ringerike Sykehus, Hønefoss, Norway
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
G. Shen et al. (eds.), Advances in Acoustic Emission Technology, Springer Proceedings
in Physics 259, https://doi.org/10.1007/978-981-15-9837-1_49
549
A Comparison of Acoustic Emission
in Cadaveric Specimens and Artificial
Sawbones During Surgical Screw
Implants
S. Grigg, B. J. Wright, and R. Pullin
Abstract The overtightening of cancellous surgical screws is a major problem for
orthopaedic surgeons, especially inexperienced ones. This problem is made worse
still when the patient suffers from osteoporosis, which significantly reduces the
density of the bone. Overtightening a screw leads to stripping of the bone and potential complications to surgery leading to increased recovery time and potential expense
to the health organisation. Acoustic Emission (AE) has previously been investigated
to monitor the insertion of such screws into artificial Sawbones. This paper presents
the testing of two sizes of surgical screws into both artificial Sawbones and cadaveric
femurs monitored for AE using piezoelectric sensors. The results show that there are
some significant differences between the AE given off from the two structures when
the energy and frequency of the waveforms are analysed.
49.1 Introduction
Orthopaedic surgeons use screws in most fracture fixation surgeries. There are,
broadly speaking, two types of screw for the two types of bone: cortical and cancellous. Cortical bone is the outer layer of dense bone whereas cancellous bone is the
inner core, which is typically more porous [1], as shown in Fig. 49.1. To enable cancellous screws to have optimal pull out strength they have an increased thread depth
and reduced cross sectional thickness compared to cortical screws [2]. Cancellous
bone screws are used for a range of orthopaedic surgeries for fixation into the metaphyseal area of bone such as femoral condyles. Cancellous bone, being less dense
than cortical, can be difficult to gain suitable purchase into without risking stripping
the bone, especially in osteopenic patients. Stripping a screw causes micro failure of
material around the screw leading to screw loosening or complete failure. This can
S. Grigg (B) · R. Pullin
Cardiff School of Engineering, Cardiff University, Cardiff, UK
e-mail: griggs@cardiff.ac.uk
B. J. Wright
Vestre Viken, Ringerike Sykehus, Hønefoss, Norway
© The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2021
G. Shen et al. (eds.), Advances in Acoustic Emission Technology, Springer Proceedings
in Physics 259, https://doi.org/10.1007/978-981-15-9837-1_49
549