Numerous small hard nodules of varying sizes.

Nodules of metaplastic cartilage in the synovium of large joints such as hip and knee. The cartilage nodules may be embedded within the synovium covered by a layer of flattened synovial cells or lie freely within the joint cavity.

https://www.webpathology.com/image.asp?n=1&Case=369

Synovial osteochondromatosis

Sejenis “loose body” dijumpai di dalam sendi dan kebiasaannya akan menjejaskan lutut, pinggul atau bahu pesakit . Arthritis adalah salah satu punca. Kadangkala, ia boleh merosakkan sendi, menyebabkan osteoarthritis.