Rice bodies of synovial origin in the knee joint.

Rice bodies are free corpuscles of synovial origin with a cartilage-like appearance that may reach hundreds in number in the intra-articular space. Rheumatologic or infectious pathologies that may produce synovial hypertrophy play a major role in the etiology. Already recognized by rheumatologists, this entity is rarely reported in orthopaedic literature. Numerous particles in the size and form of rice bodies were noted in the knee joint of an 11-year-old patient who underwent arthroscopic drainage and partial synovectomy. Histopathologic examination showed that some of the rice bodies consisted only of fibrin and some of them included a collagenous nucleus surrounded by a fibrin layer. No evidence of recurrence was observed by orthopaedic and rheumatologic evaluations within 2.5 years after the arthroscopic procedure.