Mechanical Stability of Cementless Implants: The Glenoid Replacement

Mechanical Stability of Cementless Implants: The Glenoid Replacement

Suarez Venegas, D.R.

Van Keulen, F. (promotor)
Rozing, P.M. (promotor)

Mechanical, Maritime and Materials Engineering

Precision and Microsystems Engineering

2011-01-25

The aim of this project is to evaluate the contribution of different variables to the mechanical (in)stability of a cementless glenoid component. This is done using both numerical and experimental methods that allow the measurement or estimation of the bone-implant interface micromotions around the glenoid component in several scenarios that are clinically relevant. Minimum bone-implant interface micromotions not only imply an adequate mechanical stability of the implant within the bone, they are also an essential requirement for a successful bone ingrowth into the porous coating of the implant and, subsequently, a long term implant fixation. This book consists of ten chapters that can be divided in four main sections. The first section covers a short theoretical background about glenoid components, their most common failures, cementless fixation (Chapter 2) and a description of a cadaver-specific finite element model that is used along the entire study (Chapter 3). A second section is dedicated to the study of the influence of implant positioning, as a surgeon and technique-related variable, on the initial mechanical stability of the glenoid component (Chapter 4). Both computational tools and an experimental technique are used in the second section to study the effect of the implant design and primary fixation on the initial mechanical stability. Comparisons of the bone-implant interface micromotions are made when the joint conformity of the implant changes (Chapter 5) or when different types and number of screws are used for the initial fixation of the cementless glenoid component (Chapter 6). The influence of patient-related variables on implant stability is the main topic of the third section. The computational model described in the first section is used to evaluate how the clinical status of patient’s soft tissues (Chapter 7) and bone (Chapters 7 and 8) may hamper the initial mechanical stability of the implant and, thus, the subsequent bone ingrowth. The last and fourth section deals with the possible bone adaptation around a cementless glenoid component and a long-term prediction of its mechanical stability. This is done through the previously described numerical model and the implementation of a bone remodelling algorithm together with a realistic range of loading conditions after surgery (Chapter 9). After the fourth section, this work concludes with a short review of the obtained results, the conclusions and recommendations for further work (Chapter 10).

prosthesis
cementless
interface micromotions

http://resolver.tudelft.nl/uuid:4bd7b1ab-ab6c-4ec5-8195-3028ba681e50

2013-04-01

0978949110406

Institutional Repository

doctoral thesis

(c) 2011 Suarez Venegas, D.R.