Can ultrasound predict histological findings in regenerated cartilage?

Objective: To evaluate regenerated articular cartilage quantitatively by introducing an ultrasonic probe into the knee joint under arthroscopy and analysing the A-mode echogram by means of wavelet transformation.

Methods: Three experimental rabbit models (spontaneous repair model, large cartilage defect model, treatment model) were examined using our ultrasonic evaluation system and a histological grading scale. From resulting wavelet map, the percentage of maximum magnitude was selected as the quantitative index of the ultrasonic evaluation system.

Results: The percentage maximum magnitude in the spontaneous repair model was 61.1%, that in the large defect model was 29.8% and that in the treatment model was 36.3%. There was modest correlation between the percentage maximum magnitude and the histological grading scale (r = -0.594)

Conclusion: Our findings indicate that ultrasound analysis can predict the microstructure of regenerated cartilage.