ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

PREOPERATIVE ANALYSIS OF THE STABILITY OF A PATIENT-
SPECIFIC SURGICAL GUIDE: A CASE STUDY
ABSTRACT
J. Van den Broeck 1 , R. Wirix-Speetjens 2 and J. Vander Sloten 3
In orthopaedic surgery, one technique to transfer a preoperative planning to the
operating room uses patient-specific surgical guides. With the number of applications
for surgical guides increasing, modelling the guide design requirements becomes an
important issue, as this affects the design efficiency. We have developed a
computational model to predict the stability of a surgical guide, looking at both
translational and rotational stability. This model was used to compare different guide
designs with respect to their stability on the contact surface and this comparison was
validated experimentally. We conclude that the computational model developed here is
capable of predicting the feeling of stability of a surgical guide.
1. INTRODUCTION
The use of three-dimensional (3D) preoperative planning has quickly gained popularity
over the past decade. Preoperative planning requires a 3D reconstruction of the patient’s
anatomy using medical imaging techniques as computed tomography or magnetic
resonance imaging. Once the preoperative plan is defined, this should be transferred to
the operation room. One technique for such transfer uses patient-specific devices that
guide various surgical instruments [1]. In literature this customized instrumentation is
also known as guides [2], jigs [3] or templates [4].
A number of applications have been documented to benefit from the use of surgical
guides, where a drilling or cutting direction is provided to the surgeon. A first successful
commercial application was found in dental implantology, where the drilling direction
of the dental implants is provided by a guide and an improved accuracy is proven [5]. In
orthopaedics, research started off with spinal interventions [6], but the use of patientspecific
surgical guides for total knee arthroplasty became quickly a commercial
success [7]. Recent research explored the use of guides for unicompartmental knee
arthroplasty [8], radius osteotomy [9] and hip resurfacing [2].
The use of a preoperative plan and an accompanying surgical guide has the potential to
result in a more accurate outcome than a conventional surgery [10] [11]. Three criteria
are defined to achieve this result: the guide needs to fit on a unique position on the
anatomy, this position needs to be stable and the surgeon has to be able to identify the
correct position of the guide on the patient’s anatomy [12]. If the guide doesn’t meet
these conditions, it can be applied incorrectly by the surgeon; this could result in poor
outcome.
1 PhD Student, Section Biomechanics, KU Leuven, Celestijnenlaan 300C, 3001 Leuven, Belgium –
Materialise NV, Technologielaan 15, 3001 Leuven, Belgium
2 PhD, Materialise NV, Technologielaan 15, 3001 Leuven, Belgium
3 Professor, Section Biomechanics, KU Leuven, Celestijnenlaan 300C, 3001 Leuven, Belgium