Diffuse reflectance spectroscopy, a potential optical sensing technology for the detection of cortical breaches during spinal screw placement

• Published in: Journal of biomedical optics 2019-01, Vol.24 (1), p.1-11
• Main Authors: Swamy, Akash, Burström, Gustav, Spliethoff, Jarich W, Babic, Drazenko, Reich, Christian, Groen, Joanneke, Edström, Erik, Elmi Terander, Adrian, Racadio, John M, Dankelman, Jenny, Hendriks, Benno H W
• Format: Article
• Language: English
• Subjects: Accuracy; Adipose Tissue - diagnostic imaging; Aged; Back surgery; Blood; Bone surgery; Cadaver; Cadavers; Cancellous bone; Computer Simulation; Cortical bone; Diffuse reflectance spectroscopy; Experiments; Female; Humans; Image Processing, Computer-Assisted - methods; Insertion; Light; Male; Medical research; Medicin och hälsovetenskap; Middle Aged; Minimally Invasive Surgical Procedures - methods; Monte Carlo Method; Optical Imaging - instrumentation; Optical Imaging - methods; Optical properties; Pedicle Screws; Photon scatter; Photons; Radiation; Reflectance; Scattering, Radiation; Sensing; Simulation; Spectra; Spectrophotometry - instrumentation; Spectrophotometry - methods; Spectroscopy; Spectrum analysis; Spinal Fusion; Spine; Surgeons; Surgery; Surgery, Computer-Assisted - methods; Surgical instruments; Vertebrae
• ISSN: 1083-3668; 1560-2281; 1560-2281
• DOI: 10.1117/1.JBO.24.1.017002

Safe and accurate placement of screws remains a critical issue in open and minimally invasive spine surgery. We propose to use diffuse reflectance (DR) spectroscopy as a sensing technology at the tip of a surgical instrument to ensure a safe path of the instrument through the cancellous bone of the vertebrae. This approach could potentially reduce the rate of cortical bone breaches, thereby resulting in fewer neural and vascular injuries during spinal fusion surgery. In our study, DR spectra in the wavelength ranges of 400 to 1600 nm were acquired from cancellous and cortical bone from three human cadavers. First, it was investigated whether these spectra can be used to distinguish between the two bone types based on fat, water, and blood content along with photon scattering. Subsequently, the penetration of the bone by an optical probe was simulated using the Monte-Carlo (MC) method, to study if the changes in fat content along the probe path would still enable distinction between the bone types. Finally, the simulation findings were validated via an experimental insertion of an optical screw probe into the vertebra aided by x-ray image guidance. The DR spectra indicate that the amount of fat, blood, and photon scattering is significantly higher in cancellous bone than in cortical bone (p