Prosthetics have a transformative impact on patients' quality of life, enabling greater independence and the ability to participate in a wide range of activities. However, the fit of a prosthetic is critically important. No matter how advanced a prosthetic's functional capabilities may be, if it is too uncomfortable to wear for prolonged periods, it becomes impractical for everyday use. Achieving a proper fit is a significant challenge, often requiring five to ten visits to a specialist. This process must then be repeated as the patient's body changes over time, placing a substantial burden on both patients and clinicians.
The oldest known prosthetic, the Cairo Toe, crafted from leather and wood to replace the patient’s big toe, dates back around 3,000 years. This prosthesis was refitted multiple times to suit the wearer's needs. Since then, the development of prosthetic technology has often been driven by major conflicts, which lead to an influx of amputees. For example, World War I marked the first time prosthetics were mass-produced. While this increased accessibility, it came at the cost of bespoke fit and comfort.
The challenge remains today: How can prosthetics be made affordable and accessible while still achieving a tailored fit for each individual?
Innovative companies from the UK and elsewhere, are exploring multiple solutions to address this problem, leveraging technologies like 3D printing, software modelling, and novel attachment systems.
3D Printing: A Customised Fit
The growing accessibility of 3D printing has opened exciting opportunities for prosthetic development. Patients can now have a scan taken of their residual limb, which can be used to 3D print bespoke components that interface with the body. Bristol-based Open Bionics, for instance, has developed a socket-type prosthetic arm that incorporates 3D-printed parts for a customised fit. Their designs also include flexible components that adapt to changes in the body throughout the day, ensuring the prosthetic remains secure and comfortable.
While 3D printing enables the production of custom prosthetics, determining the optimal configuration for a perfect fit remains a challenge. Another Bristol-based company, Radii Devices, is addressing this issue with advancements in predictive planning software. Radii's software uses scans to create a 3D map of the patient's residual limb, together with a model of the socket shape, to model the pressure distribution across the residual limb. The parameters of the socket shape can be adjusted and the pressure distribution recalculated, enabling the most comfortable fit to be determined while reducing the trial-and-error process typically associated with prosthetic fitting.
Exploring Alternatives: Soft Prosthetics and Osseointegration
While socket-type prosthetics remain the most common solution, other innovative approaches are being explored to improve comfort and usability.
London-based Koalaa has developed an alternative to rigid socket systems by using fabric-based ‘soft’ prosthetics. These devices attach to the residual limb using flexible materials that immediately mould to the user's shape and adjust dynamically throughout the day. This flexibility eliminates the need for bespoke parts, making the prosthetics more accessible and adaptable for different activities.
A more radical solution is osseointegration, pioneered by Sweden-based Integrum with their OPRA implant system. In this method, an anchor is surgically attached to the bone of the residual limb, providing a permanent interface for the prosthetic device. A second component, such as a prosthetic arm or leg, attaches to the anchor to provide the desired functionality. By bypassing the soft tissue entirely, osseointegration eliminates issues like pinching or poor fit that can occur with socket systems. Although this approach requires surgery and carries associated risks, it is particularly beneficial for patients with damaged soft tissue or very small residual limbs, where traditional sockets would cause discomfort.
Protecting Innovation Through Intellectual Property
The number of patents directed towards prosthetics published as US, European, or international applications shows a reasonably steady rise until around 2020, after which the number decreases significantly year-on-year to a 20-year low in 2024. This drop is observed in both large entities who historically filed many patents, as well as among smaller companies.
This trend raises important questions about the state of innovation in the field and the role intellectual property has to play in innovation. For SMEs, who, as demonstrated above, are often the drivers of innovation in the prosthetics field, the choice to file patents—or not—carries significant strategic implications.
On one hand, patents provide a crucial competitive advantage by protecting unique technologies and offering exclusivity in the market. This is especially valuable when seeking investment or entering partnerships, as a strong IP portfolio can demonstrate a company’s innovative capabilities and potential for long-term profitability.
On the other hand, the cost and time associated with patenting can be a major barrier for resource-constrained SMEs. This is particularly true for companies working in highly specialized fields like prosthetics, where the market size may not justify the expense of widespread IP protection.
SMEs should focus on strategic patents which protect the most critical and commercially valuable innovations, rather than attempting to patent every aspect. The good news is that, with patent filing numbers at a low point across key jurisdictions, the patent landscape may be less crowded than it once was.
Conclusion
The field of prosthetic development is undergoing rapid innovation at the same time as the number of patent filings for prosthetic inventions in key jurisdictions seems to be falling. It will be interesting to see the interplay between these two realities over the coming years. For example, might SMEs innovating in new areas have less competition for obtaining broad patent protection than would have been the case only a few years ago. Is the prosthetics industry primed for a shake up?
Blog Authors
This blog was co-authored by Andrew Mears and Joe Egelstaff.
Andrew is a Partner and Patent Attorney at Mewburn Ellis. He deals with drafting and prosecuting patent applications at the EPO and UKIPO, as well as global patent portfolio management, Freedom-to-Operate (FTO) work and advising on global patent filing strategies. Andrew works in the engineering and electronics fields, with a focus on medical device technologies. He has spent time working as a patent attorney in Singapore, where he specialised in providing advice on obtaining patent protection throughout South-East Asia, China and the Indian sub-continent. Andrew has also worked in Canada, developing an expertise in obtaining patent protection in North America.
Email: andrew.mears@mewburn.com
