Comparison of Diagnostic Performance of Semi-Quantitative Knee Ultrasound and Knee Radiography with MRI: Oulu Knee Osteoarthritis Study

Abstract

Osteoarthritis (OA) is a common degenerative musculoskeletal disease highly prevalent in aging societies worldwide. Traditionally, knee OA is diagnosed using conventional radiography. However, structural changes of articular cartilage or menisci cannot be directly evaluated using this method. On the other hand, ultrasound is a promising tool able to provide direct information on soft tissue degeneration. The aim of our study was to systematically determine the site-specific diagnostic performance of semi-quantitative ultrasound grading of knee femoral articular cartilage, osteophytes and meniscal extrusion, and of radiographic assessment of joint space narrowing and osteophytes, using MRI as a reference standard. Eighty asymptomatic and 79 symptomatic subjects with mean age of 57.7 years were included in the study. Ultrasound performed best in the assessment of femoral medial and lateral osteophytes, and medial meniscal extrusion. In comparison to radiography, ultrasound performed better or at least equally well in identification of tibio-femoral osteophytes, medial meniscal extrusion and medial femoral cartilage morphological degeneration. Ultrasound provides relevant additional diagnostic information on tissue-specific morphological changes not depicted by conventional radiography. Consequently, the use of ultrasound as a complementary imaging tool along with radiography may enable more accurate and cost-effective diagnostics of knee osteoarthritis at the primary healthcare level.

Pain in bilateral knee osteoarthritis – correlations between clinical examination, radiological, and ultrasonographical findings.

“…Of note, the authors did not take into consideration the presence of osteophytes at this level so their results could be biased. Podlipska et al [22], using the scale proposed by Koskiet al [32] for evaluating osteophytes and the distance from bone contour for meniscal protrusion, underlined the added value of US over radiography in knee OA management. One of the drawbacks of the study was that the authors did not correlate these findings with pain.…”

“…The ability of US in assessing the periarticular and intra-articular abnormalities in knee OA [18], the reliability [19], and diagnostic performance [20] of the method were already demonstrated. In the last years many studies were performed in order to establish the possible correlations between US findings and patient symptoms (especially pain) in knee OA [2,5,7,18,[21][22][23], but no clear conclusions were drawn. All the authors underlined the need for more work in this field.…”

Imaging of osteoarthritis (OA): What is new?

“…There are a few studies on ultrasound of menisci in the knees, showing fairly good observer reliability and agreement with MRI on meniscal damage and protrusion by both non-weightbearing and dynamic weight-bearing ultrasound examinations [66][67][68]. Although not …”

“…altered echogenicity and thinning) in cross-sectional studies, primarily of large joints such as the knee (Fig. 2) [66][67][68]. The cartilage of knee joints has a normal thickness of about 2 mm, and superficial regions can easily be evaluated by ultrasound [66].…”

The role of radiography and MRI for eligibility assessment in DMOAD trials of knee OA

“…We believe that the advantages of MRI outweigh the inherent limitations of the technique including costs, examination time and availability and we have provided arguments how these may at least partially be overcome. Other modalities have only been marginally discussed as these likely will not be able to represent an alternative to X-ray for eligibility evaluation with the exception of ultrasound potentially being applied for screening patients for signs of inflammation in trials focusing on anti-inflammatory therapeutic approaches or for characteization of osteophyte presence 72–74 . Nuclear medicine techniques like bone scintigraphy or positron emission tomography (PET) do not seem adequate to be applied in large scale endeavors as these imply use of ionizing radiation and pose challenges in regard to logistics (availablility of tracers, transport to sites, etc.)…”