Radiographic vs. MRI vs. arthroscopic assessment and grading of knee osteoarthritis - are we using appropriate imaging?

Abstract

Purpose Radiographs and MRI scans are commonly used imaging techniques in the assessment of knee osteoarthritis. However, it currently remains uncertain how good a representation of the actual condition of the knee joint these investigations provide. By comparing them against arthroscopic findings the aim of our study was to conclude how accurate these imaging techniques are at grading knee osteoarthritis. Methods This was a retrospective study looking at knee arthroscopies performed at a tertiary centre over a 5 year period. The Outerbridge grade given at arthroscopy was correlated with pre-operative radiograph and MRI scores, so as to assess the reliability of these imaging techniques at predicting the actual severity of knee osteoarthritis seen. Results Kellgren-Lawrence (KL) grading of radiographs was moderately correlated with Outerbridge grades from arthroscopy for the medial compartment of the knee (Spearman’s rho (SR) 0.483, p < 0.001), with a milder correlation in the lateral compartment (SR 0.218, p = 0.003). MRI reporting of knee osteoarthritis was moderately correlated with Outerbridge grades in the medial compartment (SR 0.451, p < 0.001), mildly correlated for both the lateral (SR 0.299, p < 0.001) and patellofemoral joint compartments (SR 0.142, p = 0.054). KL and MRI grading was moderately correlated for the medial compartment (SR 0.475, p < 0.001) and mildly correlated for the lateral compartment (SR 0.277, p < 0.001). Conclusion The ability of radiographs to represent the actual condition of knee osteoarthritis is underestimated. KL grading especially best represents the disease seen in the medial compartment of the knee joint, with a moderate correlation to Outerbridge scores given on arthroscopic assessment. We suggest that whilst MRI is a useful tool in the investigation of knee symptoms, it is often unnecessarily used in patients with OA, when in fact, radiographs alone would be sufficient. Evidence level III

The Role of Cone-Beam Computed Tomography CT Extremity Arthrography in the Preoperative Assessment of Osteoarthritis

“…Other clinical advantages of this device were revealed as well. As mentioned in other studies, CBCT allows for the WB investigation of extremities [2,13,15,16,[23][24][25][26][27][28][29][30], which still needs to be further studied. Furthermore, the three-dimensional data of CBCT facilitate more quantitative analyses, such as segmentation, erosion detection, characterization of the subchondral bone architecture, and measurements of bone mineral density [13,30].…”

“…Regarding a comparison with MRI, this technique is commonly used for osteoarthritis assessments; however, comparing MRI, for example for knee osteoarthritis taking arthroscopy as a gold standard, showed that DR could be sufficient for patients who are not symptomatic [27]. Another study compared CT and MRI and found a strong correlation between the two techniques, and the authors highlight the excellent bone-to-soft tissue contrast based on CT analyses [28].…”

“…At present, nevertheless, there are not any readily available methods to evaluate the effective dose (ED) from a hand or wrist examination, i.e., conversion factors from absorbed doses to effective doses for DR or CBCT examinations. The evaluation of the ED could be performed by measuring the organ absorbed doses in the wrist area by inserting dosimeters in a custom-made anthropomorphic RANDO wrist phantom, as performed by Koivisto et al [24][25][26][27].…”

Magnetic Resonance Imaging in the Year Prior to Total Knee Arthroplasty: A Potential Overutilization of Healthcare Resources

“…4 MRI is an additional imaging modality that may be considered to gain information about menisci, ligaments, chondral surfaces, and early degenerative changes that are not well differentiated by radiographs. 2,[5][6][7][8] Although knee MRI is frequently used in younger patients for whom soft-tissue procedures may be considered, 7,9 it is typically not needed for those with advanced degenerative changes of the knee for whom TKA is considered. 10 In assessing healthcare utilization, several studies have suggested MRI overutilization, particularly in the setting of osteoarthritis.…”

“…In assessing healthcare utilization, several studies have suggested MRI overutilization, particularly in the setting of osteoarthritis. 8 , 11 12 13 14 Specifically, Newman et al 8 highlighted the limitations of MRIs to accurately represent conditions of the knee in patients diagnosed with osteoarthritis. Furthermore, Karel et al 11 noted the minimal clinical benefit in patient outcomes provided by diagnostic imaging (MRI and CT) for patients with knee or low back pain.…”