Optical sensing can meet unmet clinical needs in orthopedic surgery


Knees and hips wear out. The back and neck become unstable. Fortunately, orthopedic surgeons specialize in musculoskeletal repair. And surgeries that previously required open exposure are now performed with minimally invasive techniques. Surgical risks are reduced, as are postoperative pain and recovery time.

Orthopedic surgery is one of the most common types of surgery, especially in developed countries where the population is aging. In the United States alone, surgeries for spinal fusion and knee or hip replacement account for more than one million cases each year.

Imaging methods such as endoscopy, computed tomography, and infrared navigation aid in surgical planning and provide visual or spatial guidance, but the full potential of optical detection in orthopedic surgery remains to be explored. Researchers from the [email protected] of Ireland’s Tyndall National Institute (TNI) partnered with co-authors from Sunnybrook Health Sciences, University of Toronto, South Infirmary Victoria University Hospital and University College Cork, to provide a perspective on the integration of optical detection in orthopedic surgical devices, published in the Biomedical Optics Journal. They describe how optical detection, via spectroscopy or imaging, could address unmet clinical needs in orthopedic surgery.

There are many types of optical detection, and their use depends on the type of information required. For example, optical coherence tomography (OCT) allows imaging of tissue microstructures, while Raman spectroscopy can report molecular signatures of tissues. Such techniques can be applied to help guide a surgical procedure, alone or in combination, at the working tip of a surgical instrument. For example, by detecting the inherent optical properties of bone and its surrounding tissue, an optically equipped surgical drill would discern bone / tissue interfaces to increase surgical precision. Surgeons would benefit from visual cues provided by the optical sensor, such as a green light to indicate when a drill is in the correct bone area, or a warning light when it is approaching a limit, for example. example of collagen, blood, myelin or lipids. Currently, auditory or sensory feedback provides this information.

What is required for optical detection in a drill? Routine hip surgery involves a drill bit with a flexible hollow core, which is a convenient location for optical fibers, but the glass fibers commonly used for optical sensing are not that flexible. The flexible fibers could be plastic, but how long would they last in such an environment? This is just one of the many challenges that must be addressed to enable the integration of optical sensing for delicate surgical instruments.

The team is considering several scenarios in which optical detection would increase accuracy and improve results. Reviewing recent developments in optical orthopedic technologies and unmet clinical needs for surgical instruments, the authors provide pragmatic advice for innovation. Sub-millimeter accuracy is an optimal goal, necessary for spine surgery.

Any optical approach that could come close to CT guidance would be beneficial, as it would reduce the requirements for CT and radiation exposure. “

Carl Fisher, principal author

The identification and incorporation of tissue-specific optical properties for bone and soft tissue, as well as connective tissue and neurovascular tissue, is an important foundation work.

The horizon of opportunities and challenges is vast and inspiring for biomedical engineers. Ultimately, optical devices will improve outcomes in orthopedic surgery and may also support AI-based robotics to guide less experienced surgeons in complex techniques. Of course, before they become routine tools, next-generation surgical devices must undergo rigorous evaluation. With sufficient investments in time and energy, technology will advance rapidly, and repair of musculoskeletal systems will increasingly benefit from advances in optical detection.


SPIE – International Society of Optics and Photonics

Journal reference:

Fisher, C., et al. (2022) Perspective on the integration of optical detection in orthopedic surgical devices. Journal of Biomedical Optics. doi.org/10.1117/1.JBO.27.1.010601.


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