Ruben Doyle

Ruben DoyleProblem:

Modern surgical implants use ‘press-fit’ and are hammered into place by the surgeon, creating friction that holds the implant in place. If the surgeon impacts the implant too rigorously, the bone may be over-stressed and fracture.

Bone fracture during hip replacement surgery affects between 2% and 8% of patients. If fracture occurs the patient is seven times more likely to need expensive revision surgery and twice as likely to die from complications.


Additive Instruments’ technology is a ‘smart’ surgical tool that can sense the force being applied to the instrument and adjust it to reduce the chances of fracture. By reducing the variation in impaction force, the technology also reduces the learning curve for new surgeons – reducing the likelihood of fracture through inexperience.

In the UK and US, 400,000 hip replacement procedures are conducted every year. If a conservative estimate of 2% of these surgeries were to result in fracture, 8,000 patients would suffer a painful and debilitating injury each year, most requiring revision surgery at great expense. These surgeries are estimated to cost £25 million every year.

Additive Instruments’ technology has been proven in the laboratory, so its next key milestone is to validate the product in a clinical environment, first with specimens and subsequently with live patients. Once the efficacy of the product has been proven, Additive Instruments will apply for a CE mark – a key achievement for any medical device.

Early laboratory development was supported by the Wellcome trust with a product translation award. Following the support of the Royal Academy of Engineering’s Enterprise Hub, Additive Instruments has been awarded an i4i (invention for innovation) award from the National Institute for Health Research (NIHR). This funding will help it achieve its goal of first clinical usage within the next two years.


  • 2019: Msk MEC Sandpit Translation Award
  • 2019: Wellcome Trust Musculoskeletal (Msk) Accelerator
  • 2020: NIHR i4i (Invention for Innovation) Product Development Award
  • 2020: Royal Academy of Engineering Enterprise Fellowship
  • 2021: EPSRC Impact Acceleration Award
  • 2021: Innovate UK Smart Grant
  • 2021: Completed successful trials in the UK and US

“The real value of the Enterprise Fellowship is in the soft support I have received. Business coaching, workshops to develop interpersonal and planning skills, as well as brilliant insights from my mentor have all been hugely useful as Additive Instruments starts its journey into the commercial world.”


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