title: Spectrocolorimetric evaluation of repaired articular cartilage after a microfracture.
abstract: BACKGROUND
  In clinical practice, surgeons differentiate color changes in repaired cartilage compared with surrounding intact cartilage, but cannot quantify these color changes. Objective assessments are required. A spectrocolorimeter was used to evaluate whether intact and repaired cartilage can be quantified.
  
  
  RESULTS
  We investigated the use of a spectrocolorimeter and the application of two color models (L* a* b* colorimetric system and spectral reflectance distribution) to describe and quantify articular cartilage. In this study, we measured the colors of intact and repaired cartilage after a microfracture. Histologically, the repaired cartilage was a mixture of fibrocartilage and hyaline cartilage. In the L* a* b* colorimetric system, the L* and a* values recovered to close to the values of intact cartilage, whereas the b* value decreased over time after the operation. Regarding the spectral reflectance distribution at 12 weeks after the operation, the repaired cartilage had a higher spectral reflectance ratio than intact cartilage between wavelengths of 400 to 470 nm.
  
  
  CONCLUSIONS
  This study reports the first results regarding the relationship between spectrocolorimetric evaluation and the histological findings of repair cartilage after a microfracture. Our findings demonstrate the ability of spectrocolorimetric measurement to judge the repair cartilage after treatment on the basis of objective data such as the L*, a* and b* values and the SRP as a coincidence index of the spectral reflectance curve.
authors.affiliation: Research Institute for Cell Engineering, National Institute of Advanced Industrial Science and Technology, Amagasaki Site, Amagasaki, Hyogo, Japan. hattori@naramed-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Hattori
authors.forename: Kota
authors.initials: K
authors.lastname: Uematsu
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsumori
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Dohi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Takakura
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohgushi