Orthopaedic Implant Design-Miniseries Part One

I have been involved in orthopaedic research, implant design and innovation for more than ten years. It has been a very exciting journey with all the highs and lows you may encounter in any innovation work. In the following series of small articles, I will try to shed light on how I experienced innovation in medical devices in general and orthopaedic implants in particular.

When it comes to innovation in medical device field, one should consider the hard reality that taking an innovative concept all the way through to a clinically available product/service may sometimes take as long as ten years. This is mainly due to regulatory hurdles which a product must rightly pass before it is granted access to clinical use. Depending on the level of the innovation, you may need to carry out in-vitro lab tests, animal and human trials to demonstrate that your procedure is safe and effective. Computer simulations have also gained more acceptability, especially for cardiovascular devices, among regulatory bodies recently, but will not replace experimental tests and trials.

Another factor which must be kept in mine is the constantly changing clinical practice and regulatory landscape; meaning that by the time you have spent many years and a great amount of investment on the development and clinical trial of your product, a better solution enters the market and changes the clinical practice or new regulations are placed so that you have re-develop at least part of your product.

My solution to this is to be more aware, agile and responsive to the changes so that, if necessary, you can make in time modifications to your product. This is indeed easier for smaller organisations like start-ups with less stake in place than the large organizations with a well in-place culture and position in the market.

For this reason, I believe innovation takes place more effectively in smaller ‘innovation companies’ rather than big corporations. However, this must be done under a regulatory expert supervision to prevent unpredicted issues down the line which are easily overlooked by those who do not have experience in the process. Once the technology seems to be working in the lab, then, regulatory approval can be outsourced to those who specialise in testing the product according to the standards and generate relevant regulatory documents. If the technology is proved to be working and attractive to the early users, then it can be acquired by a larger organisation who can make it widely available to the public.

This is already taking place in Pharma industry where majority of innovation is carried out in academia or start-up companies, then tested by Control Research Organisations (CRO) and, if promising, is taken up by large Pharma organizations. However, innovation and product development in an academic environment has its own concerning issues, at least in medical devices based on my experience, which needs to be addressed. In the next series, I will try to discuss these issues further.

Hamidreza Alidousti, PhD, MEng
Research Associate – Biomechanics
Department of Mechanical Engineering
Imperial College London
South Kensington

Inspiration and Perspiration – A Surgeons Alternative Vocation

Alastair Darwood, Jan 2018

From prosthetic valves to pacemakers, cardiopulmonary-bypass machines to joint replacements, surgeons have a prolific reputation as medical device inventors and innovators within their field. Surgery is by nature a personal affair requiring dynamic thinking and necessarily tactile interventions. Each patient is unique in their own way demanding real-time innovation no matter the surgical complexity. A surgeon must physically interact with a patient’s anatomy in order to carry out a fixed, well defined task. These characteristics create a fertile space for innovation to flourish as surgeons not only see problems first hand, but are trained to dynamically problem solve with the tools they have available.

This physical interaction with a patient’s anatomy and physiology creates a special case in healthcare innovation. In the medical field, revolutionary advances over the last few decades often take the form of new drugs requiring the research and development might of multinational corporations. In contrast, surgical interventions allow even individual inventors with a laptop and kitchen table the potential to create genuinely new ideas and devices as seen throughout the history of surgery.

If this is the case, where are the vast swathes of surgical trainees and consultants jostling to present their latest innovations or the university technology transfer offices sagging under the weight of this constant workload?

I believe we are seeing a fundamental problem in surgical training and education that has genuine ramifications on the pace of clinical progress.

In my own experience, the skill sets and knowledge base required for successful medical device development are largely excluded from both UK medical schools and speciality training curriculums. Conversations with junior doctors, speciality registrars and even consultants further confirm this with understandably sparse knowledge in areas such as intellectual property, prototyping skills and the device design and development process.

In addition, academic surgery seems to strongly emphasise scientific research rather than innovative design and development of hardware and software. From junior house officers to the most senior of registrars, research projects and PhD’s tend to focus primarily on data capture and analysis rather than the development of new devices and technologies. Researchers work to understand the science behind surgical interventions generating a wealth of vital data with huge untapped potential for subsequent innovation.

Sadly, in academic institutions development work maybe left to pure engineers and designers relegating surgeons to a supporting role of ‘clinical advisor’. At worst, many surgeons leave the device development process to faceless corporations and simply buy and use the resulting products as end consumers.

This skill set and knowledge gap is a huge hindrance to the progress of surgical device innovation. Trainees and consultants should be armed with the tools they need to conceptualise, prototype and assess any invention they may conceive, whether a new intraoperative device or software utility.

The process of inventing and innovation has drastically changed over the last few years. From new prototyping modalities such as 3D printing to accessible CAD/CAM software, the tools available to surgeon inventors today would be the envy of their peers from yesteryear. There has never been a more exciting time to put on an inventor’s hat, and to question the status quo of the existing surgical landscape.

In little more than a century, surgery has gone from a barber shop side-line, to the cutting edge of technological and physiological sophistication. To fuel this wave of innovation we urgently need to democratise medical device development, equipping existing and future surgeons with the skills they need to take charge of the innovation process.


The use of Augmented Reality in hip and knee arthroplasty

The use of Augmented Reality in hip and knee arthroplasty



Mr Charles Rivière, MD,PhD
Consultant Hip & Knee Surgeon,


Augmented reality (AR) is a technological tool that might help at improving total joint replacement (TJR) implants positioning by providing a real-time intra-operative feedback to the surgeon. By enabling intraoperative comparison of the planning and the surgical performing (=implant positioning quality control), AR might help the surgeon to better restore the individual patient’s joint anatomy likely improving patient’s clinical outcomes.

Regarding the total hip replacement procedure, the cup rotational positioning (anteversion and inclination) is mainly dictated by the transverse acetabular ligament (anatomical landmark) and the cup medio-lateral positioning is mainly influenced by the bone quality, that is a bleeding spherical bony acetabular bed. This makes cup positioning not likely to substantially benefit from any assistive tool at the exception of rare cases where a severe spine-hip syndrome make cup positioning adjustment needed. In contrast, the restoration of the proximal femoral anatomy, that is the recreation of the native instantaneous femoral center of rotation by a proper femoral stem positioning (version, height) and selection of its offset, is difficult to achieve and is one of the main factor influencing generation of good patient’s functional outcomes and leg length after hip replacement. By facilitating restoration of the proximal femoral anatomy, AR might improve outcomes of hip replacement and should therefore benefit patients and society.

Regarding the total knee replacement procedure, patient-specific technique for implant positioning (kinematic alignment technique) is being promoted as it shows to improve early to mid-term clinical outcomes of TKA. Femoral implant kinematic positioning with manual generic instrumentation has been demonstrated to be reliable (Riviere et al.) and would therefore not substantially benefit from additional assistive tool. In contrast, the tibial component kinematic positioning is likely to be technically more demanding, frequently necessitate bone recut(s), and would therefore probably be improved by the AR technology.

We are working at the MSK Lab (Imperial College London) on 2 AR projects: 1) Assessing the precision of AR system to restore the native proximal femur anatomy (native instantaneous femoral center of rotation) when performing a kinematically aligned total hip replacement, and 2) Assessing the precision of AR system to restore the native proximal tibia anatomy when performing a kinematically aligned total knee replacement.

Happy New Year!

Happy New Year! We will during this year discuss technological innovations in healthcare with a focus on orthopaedic surgery. We will have a regular update on our blog with new posts written by different stakeholders involved in the innovation process of new technology in healthcare.