To establish an ultrasonographic grading for semi-quantitative evaluation of the femoral condylar cartilage of knee osteoarthritis (OA), in vitro, and compare the ultrasonographic grading with the histologic grading.
Thirty-four patients going to receive total knee arthroplasty because of OA of the knee were recruited. Specimens of the distal medial and lateral femoral condyles were taken during the operation. The anterior and middle areas of the articular cartilage in each specimen were graded by in vitro ultrasonography (US) examination and histologic evaluation. The correlation between the US and histologic findings was analyzed.
Sixty-seven specimens were collected. Both US and histologic changes were graded from I to IV. The correlation between the grading of US and histology was good in both anterior and middle areas (Rho=0.78, 0.89, P<0.001). The correlation between US grading over anterior area and histology grading over middle area was moderate (Rho=0.70, P<0.001).
The moderate correlation between in vitro US and histology might permit quantitative in vivo assessment of cartilage.