British Society for Computer Aided Orthopaedic Surgery BS CAOS UK

The British Society for Computer Aided Orthopaedic Surgery CAOS

CAOS UK,
Orthopaedics Department,
Golden Jubilee National Hospital,
Beardmore Street,
Clydebank,
G81 4HX
Fax:- +44 (0) 871 263 7811

admin{at}caosuk.org

About Us

Welcome to the website for CAOS UK, an organisation dedicated to supporting those applying, developing and supporting modern techniques for orthopaedic surgery. We are a chapter of CAOS International, although our operation for the most part is independant of this organisation.

This organisation connects surgeons, scientists, industry and computer engineers, who have together revolutionised the way orthopaedics is practised. This allows us not only to understand the biomechanics of normal and prosthetic joints and soft tissue, but also gives us the tools to apply this understanding with the precision required to achieve successful treatment.

We are a registered charity organisation with the primary objective being to relieve sickness by promoting research into, and disseminating knowledge of, the field of Computer Aided Orthopaedic Surgery

CAOS UK (Computer Aided Orthopaedic Surgery UK) is a non-profit organisation focused on a rapidly advancing technological aid to Orthopaedic Surgery. No other single aspect of the development of modern day orthopaedics is likely to have as far reaching impact as CAOS.
CAOS UK hopes to be a platform for an exchange of ideas, experience and knowledge. Although based in the UK, it will work co-operatively with surgeons, software and hardware engineers and vendors from all over the world.
Its goals will be to promote research and accelerate awareness and acquisition of expertise in this field. Peer reviewed articles, conferences and resources will be made available. CAOS UK will also be providing workshops to help train surgeons. It will allow vendors and computer scientists to describe ther technologies to surgeons, while allowing surgeons to describe their needs and problems with regards these technologies.
CAOS UK will hold annual conferences inviting poster and podium presentations. It will publish peer-reviewed articles in an e-journal. It will provide (sponsored) funding for fellowships and awards.
It will be regulated and governed by its members, with an elected executive committee.
More information can be found in our FAQ section, including information about the exciting CAOS Meta-Reviews system, currently under development.
CAOS remains fully accountable to its members and will publish reports about its activities at regular intervals.

CAOS stands for Computer Assisted Orthopaedic Surgery. Our understanding of the biology and the mechanics of joints have grown over the years. With it our need for precision surgical technology. Previously surgical precision was dependant on the use of relatively simple jigs, or the need for X-rays intra-operatively. Though these work well in the majority of situations, inaccuracies may mean that implants may be placed in less than perfect alignment. Such lack of precision is not tolerated in other aspects of our lives. Our car's tyres, for example, are balanced by computer, to make sure we have a stable ride, and so that the tyres do not wear out rapidly. The same applies to artificial joints. The longevity, the stability and the range of movements in a knee for example, may be compromised by the lack of precision. CAOS UK promotes understanding of joint function and the technologies that allow the application of this understanding precisely.

CAOS UK hopes to a medium for exchange of ideas that promote our understanding of human biomechanics using the ideas and technologies from a wide spectrum of expertise. CAOS is a product of collaboration of people many skills with the single aim of providing better treatment of our patients. By sharing ideas and discoveries we hope to facilitate the transfer innovative technologies and techniques from the lab to the operating theatre. By sharing the experience and results of the implementation of CAOS we hope to improve the results of procedures on patients.

Minimally invasive surgery is attempt at reducing the damage to the tissues required to perform any treatment. It is not new, and in fact the use of arthroscopes (key hole surgery) has long been a success. The term is more often applied recently with the performing of procedures such as joint replacements through smaller incisions than conventional . Typically an incision less than 10cm is reagrded as being "minimally invasive". Quite apart from the cosmetic aspects of smaller incisions the principle objective is actually to damage the soft tissue less. This should allow a quicker recovery for the patient.

Naturally a smaller wound poses certain challenges for the surgeon. Instruments have to be specially designed to operate in small spaces, and further more as the operative view is smaller, there is the potential for positioning the implant less than optimally. This can be offset by using navigated surgery, combining the benefits of both surgical techniques.

CAOS aims to allow surgeon a degree of precision not possible with conventional means. Accurate positioning of implants leads to: -
* Longer life of the implant It is likely that implants not positioned in a way that distributes the forces across the joint accurately, leads to stresses both between the implanted components and between the implant and the bone. These stresses could lead to
* Optimal range of movementsBy placing the implants so that the match the normal position in relation to the soft tissue as closely as possible, a better range of movements is achievable
* Better joint alignment As arthritic joint wear out, the joints may take up abnormal shape and alignment. Navigation allows the surgeon to restore the alignment precisely. Leg length differences are less with Navigated surgery.
* Better stability One reason why joints may be unstable is because the implants are placed imprecisely, in relation to what is normal, and also in relation to the soft tissue tension. It is possible to reduce these imprecision with navigated surgery.
* Decreased possibility of a revision surgery By increasing implant survival and reducing failure because of improper positioning of implants or instability, the potential for a more radical revision surgery is reduced.
* Makes Minimally Invasive Surgery more accurate This means that the quicker recovery that MIS offers, is available with less risk of less than optimal implant position.
* Less Blood Loss, Less Fat Embolus These are complications that are possibly linked to passing a rod in the bone marrow space of a long bone such as the tibia or the femur. Navigated surgery, because it does not entail the use of such rods, may possibly reduce these complications.

Why discuss risks? Many sites on the web are evangelical about navigation. This is perhaps related to need to market a product or service. CAOS UK, while keen to promote the benefits of navigated surgery, hopes to remain purely objective. While our conferences may be sponsored by industry, our scientific programme and our activities are geared towards being independent of industrial pressures and bias. We also recognise that Navigated surgery is not for every one, and understand that currently most surgeons do not use CAOS. Our objective is to relay the scientifically verifiable evidence for (or against) navigation. On the whole modern navigated surgery is a safe procedure. The risks some feel may be: -

* Longer operation Navigated surgery involves a long period when the joint is "regsitered" before the operation actually starts. This may be offset by speedier subsequent steps, but for most surgeons, navigated surgery takes longer and increases the period of anaesthesia for the patient
* Potential for Fractures Often navigated surgery uses trackers that are drilled into bone. This has on very rare occasions caused fractures. It must be noted that even non-navigated surgery carries the risk of fracture
* "Garbage in garbage out" It is entirely possible that errors in registration will make the surgeon place the bone cuts and implants incorrectly. Training is required to achieve reproducibly good results. CAOS UK provides workshops and training for surgeons to help reduce errors.
* Benefits of navigation in the short term may be difficult to prove Conventional surgery has already got a high success rate. The improvement in implant life with navigation may not be apparent for some time. The longevity can be however estimated by laboratory stress studies. Evidence to date seems to favour navigaton.

2009 BS CAOS British Society for Computer Aided Orthopaedic Surgery, 4th Annual Congress CAOSUK London, UK Mar 16 - 18 2009