Comparison between radiography and MRI features in evaluation of osteoarthritis of knee joint

Abstract

Background: Osteoarthritis (OA) is a widely prevalent disease worldwide and is a major public health problem that primarily affects the elderly. The present study was undertaken to define the radiographic findings of osteoarthritis (OA) of knee joint using Kellgren-Lawrence (K-L) scores and to define cartilage abnormalities on magnetic resonance imaging (MRI).Materials & Methods: Present study was conducted on 50 patients presenting with knee pain and clinical suspicion of osteoarthritis. Antero-posterior radiographs of the knee were obtained in a weight-bearing extended position by using a standard radiographic technique. All radiographs were assigned scores by using the Kellgren-Lawrence scoring system. Cartilages alterations on MRI were assigned grades as follows: grade 0, normal; grade I, internal signal intensity alteration only; grade IIA, defect of cartilage of less than 50%; grade IIB, defect of cartilage of 50%–99%; grade IIIA, 100% defect of cartilage with no bony changes; or grade IIIB, 100% defect of cartilage with subjacent bony changes. Radiographic and MR imaging findings were compiled and analysed using appropriate statistical tests.Results: Among 26 patients of grade 0 K-L score, 6, 4, 6, 4, 4 and 2 patients had grade 0, grade 1, grade 2A, grade 2B, grade 3A and grade 3B Cartilage abnormality (On MRI) respectively. Among 8 patients of grade 1 K-L score, 2, 2, 2 and 2 patients had grade 0, grade 2A, grade 2B and grade 3A Cartilage abnormality (On MRI) respectively. Among 14 patients of grade 2 K-L score, 1, 4, 4 and 5 patients had grade 2A, 2B, 3A and grade 3B Cartilage abnormality (On MRI) respectively. Among 2 patients of grade 3 K-L score, both of these had grade 3B Cartilage abnormality (On MRI).Conclusion: Conventional radiography being easily available is a common investigation tool to diagnose osteoarthritis knee. But MRI reveals structural changes of articular cartilage, joint effusion and meniscal extrusion or tear etc. thereby helping in early diagnosis. This can lead to timely management and hence better functional outcome in OA knee cases.