Synovial osteochondromatosis

A 75-year-old man of Fijian-Indian extraction complained of a 3-year history of progressive right knee pain and stiffness which were limiting his mobility. On examination, multiple hard nodules were palpable in the popliteal fossa and along the path of the quadriceps tendon. The joint line was not tender, knee flexion was limited to 60 degrees and there was a fixed flexion deformity of 5 degrees. The knee ligaments were intact. Examination of other joints did not reveal nodules. His past medical history included: (i) polyarticular gout, (ii) osteoarthritis of the left knee requiring total knee joint replacement 7 years previously, (iii) ischaemic cardiomyopathy, (iv) chronic atrial fibrillation, (v) chronic renal impairment, (vi) recent bacteraemic melioidosis without a primary focus, (vii) chronic bilateral rotator cuff tears, (viii) low-grade multiple myeloma and (ix) idiopathic pulmonary fibrosis.