Microfluidic force sensors developed to aid soft tissue balancing

New microfluidic force sensors are being developed within the University of Cambridge, in the laboratory of Professor Sohini Kar-Narayan in close collaboration with Mr Vikas Khanduja consultant orthopaedic surgeon at Addenbrooke’s Cambridge University Hospitals NHS Trust. 

This initiative has won the Armourers and Brasiers Venture Prize. New smart sensors, which assist in the soft tissue balancing and correct positioning of an orthopaedic implant during hip replacement, are expected to prolong implant lifetimes and reduce the chances of patients needing difficult revision surgery.

Currently, implant survival rates are 89% after 15 years, but drop to 58% after 25 years. Thus, particularly for younger patients, it is crucial to improve implant survival lifetimes to reduce the need for multiple revision surgeries when they grow older.

Mr Vikas Khanduja said: “This is a key clinical unmet need, particularly for the hip joint. Improper implant positioning, where forces on the implant are not balanced, can lead to premature wear and necessitating complex and expensive revision procedures.

“Integrating sensors within the trial liners during surgery, will provide real-time objective feedback to facilitate soft tissue balancing and accurate implant placement, thereby potentially prolonging the longevity of the implant.”

To facilitate commercialisation, the team has incorporated a spin-out company, ArtioSense.

ArtioSense’s smart sensor-embedded trial liners that fit in the hip implant will aid surgeons in determining the optimum, force-balanced positioning of the implant via real-time measurements obviating the sole reliance on ‘feel’ for positioning and balance.

Once the optimum position is set, the surgeon will remove the ArtioSense sensor-embedded liners and fit in the final liner. Thus the ArtioSense product will only be used as a trial during surgery, and will not be left in the patient.

A market report by technology management consultancy IP Pragmatics revealed that over 2.1 million hip replacements are performed annually across the globe. This number is expected to grow further due to the increasing global life expectancy and a growing proportion of younger patients opting for elective joint replacement.

In the UK, the 2020 figure of around 80,000 hip replacemnents is expected to rise to around 96,000 by 2035. While in the US, the number of people undergoing primary total hip replacement procedures is expected to increase from 498,000 in 2020 to 850,000 in 2030 and 1,429,000 in 2040.

The ArtioSense sensors will be integrated directly into trial inserts that are already used during surgery. There is no need to change the surgical process and the sensors add functionality to the existing surgical workflow to improve outcomes.

Professor Kar-Narayan said: “This makes our technology attractive to both the surgeon, as well as the implant manufacturers, who simply need to integrate our technology into an already existing manufacturing workflow. In addition, the sensors will be fabricated from inexpensive materials so will not add significantly to costs.”

Professor Bill Bonfield, chairman of the Armourers and Brasiers Venture Prize judging panel, said: “ArtioSense is showing how research and innovation has the potential to improve the quality of life of patients receiving joint replacements. Our prize looks to encourage scientific entrepreneurship in the UK and provide funding to help innovative developments like this realise their potential.”

Professor Kar-Narajan added: “Our primary focus is on developing our smart trial liners for hip implants. However, the technology is versatile and customisable, and can be applied to similar use in other joints such as the knee, shoulders and ankles and could be adapted for use in veterinary surgery as well.”

Along with Professor Sohini Kar-Narayan and Mr Vikas Khanduja, the co-founders include Dr Jehangir Cama, a biophysicist specialising in microfluidics, and Dr Alexander Samoshkin a biomedical technology transfer specialist.

ArtioSense wish to combine the £25,000 Venture Prize win with its planned seed-funding round to support the development and finalisation of product specifications, for the hip implant prosthesis, in advance of first-in-human trials.

A patent application covering ArtioSense’s microfluidic force sensing technology has been filed through Cambridge Enterprise (CE), the commercialisation arm of the University of Cambridge who are also assisting Artiosense with its commercialisation plans.