Clinical imaging assessments of knee osteoarthritis in the elderly: a mini-review

Knee osteoarthritis (OA) in the elderly is one of the most common degenerative age-related joint diseases leading to typical degradation of articular cartilage with severe pain and limitation of joint motion. Its increasing prevalence due to the demographic development of the society has major implications for individual and public healthcare with the increasing necessity for clinical imaging assessment in a high number of individuals. Although conventional X-ray radiographs are widely considered as gold standard for the assessment of knee OA, in clinical and scientific settings they increasingly bare significant limitations in situations when high resolution and detailed assessment of cartilage is demanded. New imaging modalities are broadening the possibilities in knee OA clinical practice and are offering new insights to help for a better understanding of the disease. X-ray analysis in OA of the knee is associated with many technical limitations and increasingly is replaced by high-quality assessment using magnetic resonance imaging or ultrasonography both in clinical routine and scientific situations. These novel imaging modalities enable an in vivo visualization of the quality of the cartilaginous structure and bone as well as all articular and periarticular tissues. Therefore, the limitations of radiographs in knee OA assessment could be overcome by these techniques. This review article should provide an insight into the most important radiological features of knee OA and their systematic visualization with different imaging approaches that can be used in clinical routine.