The Bone vet metachrotic engineer

By william t mccartney

This book is intended for all to read. It is a combination of veterinary surgery, engineering and science. It outlines of the various disciplines and problems that a surgeon must deal with day to day. Examples of actual cases are provided to bring all the science and medicine together. Each topic is explored and teased out in a certain way to me

• Language: English
• Publisher: william mccartney
• Release date: May 17, 2022
• ISBN: 9781739654115

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Pennyburn Highmoor Publishing

Author : William T McCartney

[e-mail]

www.bonevet.org.uk

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©William T McCartney 2022

Pennyburn Highmoor Publishing 2022

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This work is this subject to copyright. All rights are reserved by the publisher, whether in whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms, or any other physical way, and transmission of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar means now known or hereafter. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. The names of persons or animals have been changed to protect their identity. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published images and affiliations.

INTRODUCTION

When I started writing this book, I considered my target audience to be just those interested in the intricacies of orthopaedic surgery. Then I changed tack and opened it up to everyone. This has caused many problems for me trying to steer a course between highly scientific language and straight open writing. At times I have not achieved this balance and respectfully request the reader to bear with me. I have not included all of the references as then there would be many pages extra. But if some reader wants to request a reference, I can reply to them using the e mail below. Excuse my liberty to create a new word out of the word metachrosis but it looked to fit best. The names used in the clinical cases discussed have been changed to protect their identity.

I would like to thank my family and friends for their support and patience during production. I simply could not have completed the book without their help.

DEDICATION

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Dedicated to all those who choose to trust

TEMPUS MUTANDI

About the Author

Dr William McCartney   MVB, Dipl ECVS, DSAS (Orth), PhD, C Eng, MIMechE, FRCVS

is a Specialist Veterinary Surgeon and Chartered Engineer with over 30 years of experience in orthopaedics and surgery.

Abbreviations

Mpa : Megapascal

TTA: Tibial Tuberosity Advancement

Nb  : Niobium

Al : Aluminium

Sn : Tin 

Zr : Zirconium

Ta : Tantalum

Co : Cobalt

Cr : Chromium

V : Vanadium

Ni : Nickel

Mo : Molybdenum

N : Nitrogen

GPa : Gigapascal

Mrad : Milliradian

kGy : Kilogray

CONTENTS

1. Surgineering

2. No need to re-invent the wheel

3. Forces enemy and ally

4. Bone

5. Soft Tissue

6. Spine

7. Materials

8. Materials and body reaction

9. Design

10. Human implant regulation

11. Veterinary implant regulation

SURGINEERING

One afternoon in 1993, by total chance, I found myself sitting in a room full of mechanical engineers. Each one had a different area of specialisation appropriate to the biomedical field. I was there as a guest.  The topics focused mainly on orthopaedic problems related to implant technology. If I had closed my eyes and just listened, the conversation could have been between orthopaedic surgeons. The crossover of knowledge was impressive and the detail deliciously complicated. It made me think that really orthopaedic surgeons are like engineers, after all what defines an engineer.

Perhaps there is no actual precise definition of an engineer, except to say that it may be more appropriate to say problem solve like an engineer. I will go through the sequences of how an engineer solves a problem and allow the reader to draw their own conclusion as to whether a surgeon works in a similar way. How does an engineer deal with a problem? Firstly, they may analyse the problem and look to the need, to the final goal. Next consider the problem and goal at its optimum level then break it down into parts by deconstruction followed by reconstruction but better. Using a modular system from the deconstruction of the issue allows for each component to be individually analysed.  At this point one should open their mind to every angle of possible solution, including considering the solutions found for other completely unconnected problems, but with a subtle commonality. Like an integration of multiple working solutions or ideas from every walk of life. By actively looking beyond the workings of one system and imagine the facet being used in a totally different system could lead to a solution. Basically, seeing beyond what is the whole object and deeply analysing the composition. Then come the trade-offs as always happens there may be different routes to go, but some will affect the reaching of the ultimate goal more than others e.g., wing design, strength, materials and weight. A very significant part of the problem-solving process is optimisation and this can involve many models and even prototypes coupled with analysis. The engineer has to apply scientific principles, mathematics and all other associated disciplines together to solve problems and design the solution. Also, balance is a key part of how engineers must consider all matters and that includes when dealing with nature, as ultimately for a solution to work it cannot upset the balance within or around it. Only by doing extensive experimentation and analysis can the optimum solution be uncovered. For example, through his controversial experiments and trials Hugh De Haven helped to develop the first three-point seat belt along with Roger Griswold. Later refined and redeveloped further by engineer Nils Bohlin to the modern-day ubiquitous seat belt.  Considered now to one of the greatest life saving devices ever designed.

The story of penicillin is another example. Alexander Fleming discovered penicillin by chance, then Ernst Chain and Howard Florey isolated and demonstrated its anti-bacterial properties, but engineer Margaret Hutchinson finally managed to produce penicillin in large quantities to be useful just in time to help World War two injured soldiers. Without the ability to produce large quantities there would have been so many more deaths. Margaret actually solved the seemingly insurmountable problem by bringing concepts from engineering in the refinery business. However, only Fleming, Chain and Florey received the Nobel prize in 1945. A classic case of applying the solutions of one engineering system to another by deconstructing the problem into as many stages as possible. Maybe in the future Margaret will receive a Nobel prize posthumously.

Then there are more steps in the problem solving process as one needs to consider the constraints to final design. To reach your goal then first you ignore some of the constraints then you slowly add each constraint and trade off to reach the final design. How one deals with the constraints is paramount to success. Civil engineer William Bazalgette faced multiple