Arthroscopic microscopy of articular cartilage using optical coherence tomography.
BACKGROUND
Optical coherence tomography is an echograph of infrared light that can yield microscopic cross-sectional images of articular cartilage without removing or damaging the tissue.


OBJECTIVE
To determine whether optical coherence tomography images of human cartilage can be acquired arthroscopically and whether the resulting images have high correlation with histopathology.


METHODS
Optical coherence tomography was configured into an arthroscope and used to image 2 human cadaver knees and 45 cores harvested from 9 osteoarthritic knees. The imaged cartilage was then processed for histological analysis. Optical coherence tomography images and histology were graded using a modified Mankin structural score. Agreement was determined using weighted kappa statistics. Morphometric analysis performed on optical coherence tomography images was correlated with histomorphometric analysis using linear regression.


RESULTS
Imaging of the medial and lateral femoral condyles and trochlea was readily accomplished using the optical coherence tomography arthroscope. Modified Mankin surface scores for specimens with the earliest structural changes (grades 0-3) had high agreement with scores assigned to histology (kappa= 0.87). Fibrillation indices calculated from optical coherence tomography had near-perfect correlation to that of histology (R = 0.98)


CONCLUSIONS
Arthroscopic optical coherence tomography may be clinically useful for early detection of articular cartilage injury and nondestructive assessment of articular cartilage repair.
Chu
Constance R
CR
Department of Orthopedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania 15232, USA. chucr@upmc.edu
Lin
Diana
D
Geisler
Jessica L
JL
Chu
Charleen T
CT
Fu
Freddie H
FH
Pan
Yingtian
Y
D001182:Arthroscopy / Q000379:methods*; D002358:Cartilage, Articular / Q000473:pathology*; D005336:Fiber Optic Technology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D014054:Tomography / Q000379:methods*