Advances in surgical technologies, such as robotics, implants, and targeted therapies, have facilitated the changing role of medical imaging. Imaging is no longer primarily used to diagnose a broken bone or to find out whether that swallowed toothpick made its way out alright. Imaging has moved towards therapy and intervention, including preoperative planning, post-operative assessment, designing custom bone implants, and image-guided surgery.

As most surgical technology now relies on some form of imaging, therein lies the opportunity.

This blog article will discuss the potential application of MARS spectral photon-counting computed tomography (MARS CT) in future bone implant surgeries. 

If your foundation isn’t solid, it doesn’t matter how strong your house is – Paul Morrison, OSSIS Limited.

Joint replacement surgery has existed since the 1950s. Although we haven’t achieved “The Six Million Dollar Man” results just yet, the procedure can significantly improve the quality of life for patients with painful bone and joint diseases.

OSSIS Ltd is a New Zealand-based company that designs and manufactures patient-specific bone implants for very complex conditions, such as cancer. Preoperative planning for an oncological custom bone implant involves radiographers, radiologists, surgeons, and engineers. The team uses information from imaging (plain x-ray CT for bone and MRI for soft tissue) to find the margin between tumour and bone, design the patient-specific implant, and place the implant for long-term success.

Huge value lies in understanding bone health and surrounding tissues early – or building that solid foundation. This is why companies like OSSIS get excited about the development of MARS imaging.

MARS imaging could build the foundations necessary to create even better custom implants, its development is very exciting.

Advancements in medical imaging would enhance the surgical planning and patient-specific implant design resulting in a more predictable outcome for the patient.

Plain x-ray and CT scans measure density, which can show areas of scar tissue or hard bone but are vague in identifying important structures such as blood vessels and nerves. Moreover, the margin applied around a tumour is critical for removing all cancer, while at the same time saving every millimetre of healthy bone possible to increase the patient’s chance of a good long-term result. Tumour margins rely on information obtained by MRI, which suffers from poor spatial resolution.

MARS CT imaging could enable a deeper understanding of where ‘good’ bone is and where ‘bad’ bone is by quantitatively measuring calcium and water content, and other bone quality indicators. Studies have shown that knowing bone condition prior to surgery significantly influences the accuracy of implant placement (1).

The resolution of MARS imaging is much higher that MRI, about 35x higher in fact. Greater spatial resolution could increase the accuracy of tumour margins and improve patient outcomes. Furthermore, MARS imaging has the potential to assess osseointegration and implant revision by visualising the bone-metal interface due to reduced metal artefacts (image distortion).

The MARS team are incredibly excited to continue to explore the benefits of MARS imaging in orthopaedics/oncology, as improving healthcare is our goal. Check out the image gallery below of the different imaging techniques mentioned in this blog article!

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