Table 4.

Raman spectroscopic markers of cartilage and bone composition calculated for spectra collected at various sites on femoral condyles. Cartilage state, intact, completely eroded or focal lesion, was assessed visually at the time of collecting spectra and documented with digital photography. Average values are presented ± standard deviation where applicable, and N values are the number of different sites of measurement for each cartilage state. These preliminary results show differences in the Raman spectroscopic markers at sites of eroded cartilage and reflect the effect of cartilage thickness on recovery of subchondral bone signal

Cartilage State	Cartilage to Bone	Mineralization	Carbonate Substitution	Crystallinity
Intact cartilage (N=4)	0.96 ± 0.30	2.54 ± 1.0
Focal lesion (N=1)	0.20	9.09	0.32	0.048
Eroded cartilage (N=3)	0.11 ± 0.05	8.95 ± 1.26	0.24 ± 0.08	0.052 ± 0.001