biostudies-literatureUnknown4(5)Sarin JK<h4>Purpose</h4>To develop the means to estimate cartilage histologic grades and proteoglycan content in ex vivo arthroscopy using near-infrared spectroscopy (NIRS).<h4>Methods</h4>In this experimental study, arthroscopic NIR spectral measurements were performed on both knees of 9 human cadavers, followed by osteochondral block extraction and in vitro measurements: reacquisition of spectra and reference measurements (proteoglycan content, and three histologic scores). A hybrid model, combining principal component analysis and linear mixed-effects model (PCA-LME), was trained for each reference to investigate its relationship with in vitro NIR spectra. The performance of the PCA-LME model was validated with ex vivo spectra before and after the exclusion of outlying spectra. Model performancArthroscopy, sports medicine, and rehabilitatione1767-e1775https://www.ebi.ac.uk/biostudies/studies/S-EPMC9596902biostudies-literatureNear-Infrared Spectroscopy Enables Arthroscopic Histologic Grading of Human Knee Articular Cartilage.PMC9596902Shaikh RTorniainen JToyras JKroger HSarin JKJoukainen AAfara IOPrakash MfalseNear-Infrared Spectroscopy Enables Arthroscopic Histologic Grading of Human Knee Articular Cartilage.<h4>Purpose</h4>To develop the means to estimate cartilage histologic grades and proteoglycan content in ex vivo arthroscopy using near-infrared spectroscopy (NIRS).<h4>Methods</h4>In this experimental study, arthroscopic NIR spectral measurements were performed on both knees of 9 human cadavers, followed by osteochondral block extraction and in vitro measurements: reacquisition of spectra and reference measurements (proteoglycan content, and three histologic scores). A hybrid model, combining principal component analysis and linear mixed-effects model (PCA-LME), was trained for each reference to investigate its relationship with in vitro NIR spectra. The performance of the PCA-LME model was validated with ex vivo spectra before and after the exclusion of outlying spectra. Model performanc2022-01-01T00:00:00Z2022 Oct2025-04-22T02:08:00.32Z2025-04-05T20:14:14.097ZS-EPMC95969023631272810.1016/j.asmr.2022.07.002