CME OnDemand: 2022 AOFAS Annual Meeting-Comparison of arthroscopic, radiographs and MRI T2 mapping findings for varus ankle osteoarthritis

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This study compared the findings from arthroscopic examination (A/S), radiographs, and MRI T2 mapping (T2M) for varus ankle osteoarthritis. The A/S classification for varus ankle osteoarthritis was previously reported, and in this study, the relationship between A/S findings, radiographs, and T2M was investigated. It was found that radiographs tended to underestimate the condition of articular cartilage, while T2M tended to overestimate it. However, T2M showed a higher concordance rate with A/S findings compared to radiographs, indicating that T2M is more useful for evaluating cartilage and determining the appropriate operative method for varus ankle osteoarthritis.<br /><br />The study included 19 joints of 19 patients, with a mean age of 65.2 years. The A/S findings were classified into five categories, ranging from grade 1 (fibrillation of the malleolar articular alone) to grade 5 (eburnation covering 50% of the talocrural joint). The concordance rate between A/S and radiographs measurements was 100% for grade 2, 46.7% for grade 3, and 0% for grade 4. Radiographs underestimated the condition of the articular cartilage compared to A/S findings in all unmatched joints. On the other hand, the concordance rate between A/S and T2M measurements was 50% for grade 2, 80% for grade 3, and 100% for grade 4. T2M occasionally overestimated or underestimated compared to A/S findings.<br /><br />T2M is a noninvasive imaging technique that can detect cartilage lesions better than conventional MRI. The high concordance between A/S and T2M findings may be due to the clear visualization of the articular cartilage and the well-defined boundary between the cartilage and the eburnation area in T2M. However, it should be noted that in the presence of a talar osteochondral lesion, the cartilage-eburnation boundary is not well defined on T2M.<br /><br />There are limitations to this study, including the small number of cases, evaluation of only the coronal plane, and visual measurements made by the examiner. Further research with more cases and quantitative measurements will be needed in the future. Overall, T2M is a valuable tool for evaluating cartilage and determining the appropriate treatment for varus ankle osteoarthritis.

Asset Subtitle

Naohiro Hio, MD and Masanori Taki, MD

Keywords

arthroscopic examination

radiographs

MRI T2 mapping

varus ankle osteoarthritis

articular cartilage

operative method

concordance rate

malleolar articular

talocrural joint

noninvasive imaging technique