New medical device looks to redefine arthroscopy By integrating multiple technologies into one device, researchers with the MIRACLE project aim to make arthroscopy more objective. Health © Peter Porrini, Shutterstock Osteoarthritis (OA), or degenerative joint disease, is caused by the breaking down of the cartilage within a joint. The most common type of arthritis, the disease affects millions of Europeans – and numbers continue to grow. In fact, according to a special report by ‘The Economist’, in 2019, over 57 million people in western Europe had OA, up 54 % since 1990. In general, OA is difficult to diagnose, as there is no definitive test on the market. Instead, most orthopaedic surgeons use arthroscopy, a minimally invasive procedure where only small cuts are made for checking and repairing the joint. Making arthroscopy more objective The problem with arthroscopy is that it is highly subjective and thus not always accurate. “The current practice involves the individual surgeon’s visual assessment of the condition of the tissue inside the joint and is highly dependent on the naked eye and personal experience,” explains Gabriela Lorite, coordinator of the EU-funded MIRACLE project. According to Lorite, the MIRACLE project is working to redefine arthroscopy. “We want to develop an innovative medical device that will make arthroscopy more objective,” she says. “Used during arthroscopy, this device will provide orthopaedic surgeons with information on the status of a patient’s articular cartilage, allowing them to make an accurate, fact-based diagnosis that will lead to a more effective treatment plan.” Starting from scratch Creating something new means starting from scratch. For the MIRACLE project, that meant not only developing new technologies, but also combining those technologies into a single diagnostic solution. As to the former, the key technology components developed during the project included tailored quantum cascade lasers (QCLs), integrated beam combiners, and a mid-infrared sensing probe. “A lot of research and time went into miniaturising and fabricating the sensing probe according to the specifications established by orthopaedic surgeons,” notes Lorite. However, advancing technology also means overcoming challenges along the way, and the MIRACLE technology was no exception. For example, during testing, researchers discovered that the signals obtained via the sensing probe were not pronounced and strong enough to ensure a reliable measurement. To overcome this challenge, the project team had to further optimise the electronics and optical system. “We ultimately succeeded in integrating all the developed key technologies into a unique device providing the anticipated analytical data,” remarks Lorite. “It was a much-celebrated victory!” A tremendous step forward In addition to the technology and its combination, MIRACLE also aimed at validating the device as a medical tool. This process required the analysis of hundreds of samples and the development of appropriate data evaluation models capable of classifying healthy versus damaged cartilage. But here too the researchers faced challenges: a lack of healthy human cartilage samples. As Lorite explains, creating a reliable model capable of distinguishing healthy and damaged tissue requires having a large range of samples, including healthy and unhealthy cartilage. However, because most human samples are obtained via donated cadavers, many of which are aged or the victims of accidents, most of the project’s samples fell on the unhealthy side of the spectrum. This meant researchers had to supplement the human samples with animal samples, which allowed them to move forward with the validation tests. “Despite these challenges, the MIRACLE project represents a tremendous step forward in the use of mid-infrared-based devices in future clinical practice and serving as an effective tool for diagnosing osteoarthritis,” concludes Lorite. Keywords MIRACLE, medical device, arthroscopy, osteoarthritis, degenerative joint disease, arthritis, orthopaedic surgeons
