Conformable and robust microfluidic force sensors to enable precision joint replacement surgery. (July 2022)

• Record Type: Journal Article
• Authors: Ives, Liam; Pace, Alizée; Bor, Fabian; Jing, Qingshen; Wade, Tom; Cama, Jehangir; Khanduja, Vikas; Kar-Narayan, Sohini
• Is Part Of: Materials & design. Volume 219(2022)
• Publication Date: 2022-07
• Subjects: Microfluidics -- Force sensor -- Total hip replacement -- Additive manufacturing -- Orthopaedic surgery; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2022.110747
• Languages: English
• ISSNs: 0264-1275

Abstract

Graphical abstract: Highlights: Additively manufactured conformable microfluidic force sensor to measure forces during joint replacement. Quantitative force data from sensors could aid precise implant positioning and balance. Sensor design optimised using finite element modelling and calibrated within a 3D printed model hip implant. High sensitivity demonstrated at typical forces experienced during hip replacements. Powerful new surgical tool to aid implant positioning, increasing the lifetime of hip replacements. Abstract: Balancing forces within weight-bearing joints such as the hip during joint replacement is essential for implant longevity. Minimising implant failure and the corresponding need for expensive and difficult revision surgery is vital to both improve the quality of life of the patient and lighten the burden on overstretched healthcare systems. However, balancing forces during total hip replacements is currently subjective and entirely dependent on surgical skill, as there are no sensors currently on the market that are capable of providing quantitative force feedback within the small and complex geometry of the hip joint. Here, we solve this unmet clinical need by presenting a thin and conformable microfluidic force sensor, which is compatible with the standard surgical procedure. The sensors are fabricated via additive manufacturing, using a combination of 3D and aerosol-jet printing. We optimised the design using finite element modelling, then incorporated and calibrated our sensors in a 3D printed model hip implant. Using a bespoke testing rig, we demonstrated high sensitivity at typical forces experienced following implantation of hip replacements. We anticipate that these sensors will aid soft tissue balancing and implant positioning, thereby increasing the longevity of hip replacements. These sensors thus represent a powerful new surgical tool for a range of orthopaedic procedures where balancing forces is crucial.