Case Study

Shock absorbing surgical tool reduces fracture risk

Date: March 2, 2020

The IKC’s flexible approach has enabled Dr Jonathan Jeffers to use an unexpected set-back in one surgical innovation to develop an entirely new one. 

Dr Jeffers from Imperial College London secured IKC funding to create a novel titanium device to repair joints or correct their alignment. Developed in collaboration with a multinational additive manufacturing company, the 3D printed device has a unique lattice structure which matches the stiffness and mechanical properties of bone.  A Velcro-style fixing system enables it to be implanted without needing screws.  

Trials in two animal models showed that the device successfully allowed the location and pace of bone regrowth to be controlled. It is now in the early stages of clinical adoption, thanks to £2 million follow-on funding from an NIHR fellowship awarded to Dr Jeffers. 

Keen to further enhance the device’s properties, Dr Jeffers secured a second IKC grant to investigate swapping the titanium alloy with a resorbable magnesium alloy which would enable the implants to dissolve over time. However, this project hit a wall when the magnesium alloy was suddenly recalled by the manufacturer following safety concerns.   

 “It was a real blow: the main pillar of our project crumbled overnight,” says Dr Jeffers. “Thankfully, the IKC team were very supportive and allowed us to revert to developing our titanium device instead. This flexibility opened up a new opportunity to develop a surgical tool which solves a significant and costly problem.” 

Seizing the opportunity 

Talking to orthopaedic surgeons, Dr Jeffers had discovered that during hip replacement surgery, the force used to hammer the implant into position can fracture the femur. This occurs with 5-8,000 patients a year in the UK. This is devastating for patients who undergo further operations with additional clinical risks, and it is also extremely costly for the NHS.  

One thing our original titanium lattice structures do very well is absorb impact energy,” says Dr Jeffers. “So we realised that we already had a solution to limit the force being applied to the femur.”   

The result is an ‘introducer’ (a metal rod which surgeons use to line up the hip implant before insertion) incorporating a disposable lattice cartridge. The cartridge acts as a shock absorber, preventing the surgeon from hammering too hard and reducing the risk of the femur breaking. The tool has been patented and is currently being commercialised through a spin-out company, Additive Instruments. 

 “The great thing about working with the IKC team is that they get the balance of managing project just right,” says Dr Jeffers. “They’re involved and on hand for support, but never dictate the direction. When our planned project derailed, this approach gave us the freedom to rethink and apply our technology to deliver a completely unexpected innovation that addresses a clinical need.” 

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