Evaluation of arthroscopic articular cartilage biopsy for osteoarthritis of the knee

Purpose: Arthroscopic evaluation of the articular surface by visualization and palpation has proved to be unreliable; therefore, we investigated arthr oscopically procured biopsy specimens and conventional sections by using th e same histopathomorphologic techniques and compared the results for possib le differences. Methods: Cartilage biopsy specimens of 1.7 mm in diameter a nd conventional cartilage sections (pieces of 8 x 2 mm) were removed from t he lateral femoral condyle of 53 osteoarthritis patients undergoing total k nee arthroplasty. Biopsies and conventional sections were evaluated histolo gically by using Mankin's grading system and immunohistochemically by asses sing the immunoreactivity of the chondrocytes to MMP-1 and MMP-3. Results: The comparison between the biopsies and conventional sections revealed that then were no differences between these forms of obtaining specimens. Moreo ver, the expression of MMP-1 and MMP-3 in biopsy specimens showed a strong correlation with that in conventional sections. Conclusions: We conclude th at in small biopsy specimens taken (e.g., during arthoscopy), the histologi cal grading of osteoarthritis severity and the evaluation of MMP expression yield results similar to those obtained in conventional sections.