Enhancing arthoscopic diagnostics using visible near-infrared fiber optic spectroscopy

Arthroscopy is one of the most performed orthopedic surgeries in the United States with approximately 1.8 million procedures completed annually. Although these highly prevalent procedures include widespread diagnostic applications for hip, shoulder, and knee joints, current assessment techniques lack the capability to quantitatively assess and monitor tissue defects. Visible-near infrared (VNIR) spectroscopy, an analytical technique based on the response of valence electrons and molecular bonds to electromagnetic frequencies in the visible (400 – 700 nm) (25,000 cm-1 – 14286 cm-1) and near infrared NIR (800 – 2500 nm) (12,500 cm-1 –4000 cm-1) regions, offers potential to determine compositional information regarding a variety of musculoskeletal tissues and degenerated tissue states. Because this technique is both nondestructive and utilizes nonionizing radiation, there is a strong motivation to implement the technology for in vivo applications. The overall objective of this work was to further develop a fiber optic VNIR probe with the overarching goal of establishing readiness for clinical studies. Because VNIR characterization of cartilage and osteochondral tissues have been primarily completed though ex vivo studies, there are methodological challenges that require evaluation prior to implementation of a clinical device for arthroscopic evaluation of tissue. Several of these key challenges were investigated within the following aims: evaluation of the impact of irrigation fluid in arthroscopic settings (Aim 1), verification of spectral tissue characterization in translational models through spectra collection in an equine femoropatellar joint and ex vivo human tissues (Aim 2), and design optimization of the probe through evaluation of optical spectra collection, evaluation of probe performance following sterilization, mechanical analysis of the probe design, and development of methodology for tissue contact detection (Aim 3). Through completion of these studies, strategies can be developed to both improve the device for clinical assessment and establish protocol for spectra analysis and interpretation with consideration to the challenges that arise from data collection in arthroscopic environments.