Ultrasonographic Assessment of the Normal Femoral Articular Cartilage of the Knee Joint: Comparison with 3D MRI.

Kyösti Kauppinen,Roberto Blanco Sequeiros,Mika T Nevalainen,Victor Casula,Štefan Zbýň,Simo S Saarakkala

doi:10.1155/2021/9978819

Abstract

Objective Ultrasonography (US) has a promising role in evaluating the knee joint, but capability to visualize the femoral articular cartilage needs systematic evaluation. We measured the extent of this acoustic window by comparing standardized US images with the corresponding MRI views of the femoral cartilage. Design Ten healthy volunteers without knee pathology underwent systematic US and MRI evaluation of both knees. The femoral cartilage was assessed on the oblique transverse axial plane with US and with 3D MRI. The acoustic window on US was compared to the corresponding views of the femoral sulcus and both condyles on MRI. The mean imaging coverage of the femoral cartilage and the cartilage thickness measurements on US and MRI were compared. Results Mean imaging coverage of the cartilage of the medial femoral condyle was 66% (range 54%–80%) and on the lateral femoral condyle 37% (range 25%–51%) compared with MRI. Mean cartilage thickness measurement in the femoral sulcus was 3.17 mm with US and 3.61 mm with MRI (14.0% difference). The corresponding measurements in the medial femoral condyle were 1.95 mm with US and 2.35 mm with MRI (21.0% difference), and in the lateral femoral condyle, they were 2.17 mm and 2.73 mm (25.6% difference), respectively. Conclusion Two-thirds of the articular cartilage of the medial femoral condyle, and one-third in the lateral femoral condyle, can be assessed with US. The cartilage thickness measurements seem to be underestimated by US. These results show promise for the evaluation of the weight-bearing cartilage of the medial femoral condyle with US.

Highlights

Ultrasonography (US) examination of the knee joint is a good imaging technique to assess the superficial structures of the knee
Ten healthy volunteers without knee pathology underwent systematic US and MRI evaluation of both knees. e femoral cartilage was assessed on the oblique transverse axial plane with US and with 3D MRI. e acoustic window on US was compared to the corresponding views of the femoral sulcus and both condyles on MRI. e mean imaging coverage of the femoral cartilage and the cartilage thickness measurements on US and MRI were compared
As compared to the conventional radiography, US allows the evaluation of the soft tissues in addition to the bony contour of the knee; effusion, synovial hypertrophy, meniscal extrusion, osteophytes and part of the femoral cartilage can be assessed with US [1]

Summary

Introduction

Ultrasonography (US) examination of the knee joint is a good imaging technique to assess the superficial structures of the knee. US examination is performed with the patient in the supine position with knee fully extended and, subsequently, with 90° to 120° flexion allowing the visualization of the femoral cartilage. Using this maneuver, the cartilage of the superior aspect of the femoral sulcus and both femoral condyles can be evaluated to some extent. The cartilage of the superior aspect of the femoral sulcus and both femoral condyles can be evaluated to some extent It remains unclear whether the actual weight-bearing cartilage of the tibiofemoral joint is visualized.

Methods

Results

Conclusion