A 69-year-old man presents with long-standing pain in his left knee since 5 years. He is a moderately built and well-nourished individual with no signs of systemic illness. On examination, mild tenderness is noted over the left knee with no limitation of movements. No swelling or redness was noted at the site of pain. Blood routine, ESR and CRP were normal. An X-ray and MRI were taken and are attached. What is the most likely diagnosis?
Source: Afshar, Ahmadreza, and Afshin Mohammadi. Iranian Journal of Radiology 8.4 (2011): 245–248. PMC. Web. 9 Sept. 2016.
