Ultrasound diagnosis of primary synovial osteochondromtosis of the knee

Objective To explore the ultrasound appearance of primary synovial osteochondromatosis (PSO) of the knee. Methods Thirty-eight cases with PSO were confirmed by pathology, their ultrasound features were analyzed retrospective. Results Two hundred and sixty calcify nodules showed medium echo and several motting or bolus strong echo. Two hundred and eighty-nine ossify nodules showed slightly strong echo or strong echo,or only showed arc strong echo with rear sound shadow near nodules. Twenty-six mixed type nodules showed promiscuity moderately strong echo or with rear sound shadow. Forty introsynovium cartilage lesser nodules showed synovium thickening and similar round low echo nodules,30 sursynovium lesser nodules showed high echo, with a pedicel connected to synovium, can shift deform or sway because of the pressure from transducer, often concomitance other type nodules. Ten cartilage greater nodules showed similar round or lobulated low or medium echo tuberculum. Conclusions Ultrasound can show multiple nodules of PSO of the knee, especially noncalcific nonage smaller cartilage nodules. It is helpful for clinicians to decide more reasonable operation strategy. Key words: Ultrasonography;  Knee joint;  Chondromatosis, synovial