Researchers have developed a new algorithm to monitor the joints of patients with arthritis that could allow the effectiveness of new treatments to be assessed more accurately.

The findings, published in the journal Scientific Reports, suggests that the 3D imaging analysis technique, which detects tiny changes in arthritic joints, could enable greater understanding of how osteoarthritis develops. "We've shown that this technique could be a valuable tool for the analysis of arthritis, in both clinical and research settings. When combined with 3D statistical analysis, it could also be used to speed up the development of new treatments," said lead author Tom Turmezei from the University of Cambridge.

Osteoarthritis is normally identified on an X-ray by a narrowing of the space between the bones of the joint due to a loss of cartilage. However, X-rays do not have enough sensitivity to detect subtle changes in the joint over time, the researcher said. For the study, the researchers used images from a standard computerised tomography (CT) scan, which isn't normally used to monitor joints, but produces detailed images in three dimensions.

The semi-automated technique called joint space mapping (JSM), analysed the CT images to identify changes in the space between the bones of the joint. After developing the algorithm with tests on human hip joints from bodies, the team found that it exceeded the current 'gold standard' of joint imaging with X-rays in terms of sensitivity, showing that it was at least twice as good at detecting small structural changes.

Colour-coded images produced using the JSM algorithm illustrate the parts of the joint where the space between bones is wider or narrower, the researchers said. According to the researchers, the success of the JSM algorithm demonstrates that 3D imaging techniques have the potential to be more effective than 2D imaging. "Using this technique, we'll hopefully be able to identify osteoarthritis earlier, and look at potential treatments before it becomes debilitating," Turmezei noted.