Acute Knee Pain in a Child Due to Pigmented Villonodular Synovitis.
BACKGROUND
Pigmented villonodular synovitis (PVNS) is a proliferative condition of the synovium, which is composed of nodules and/or villi and has an abundant number of hemosiderin-laden macrophages.


METHODS
A 10-year-old boy presented with an acute irritable knee. Emergency arthroscopy showed a nodular PVNS in the intercondylar notch. The symptoms resolved after resection of the lesion.


CONCLUSIONS
PVNS of the knee in children is a rare entity. It can be one of the causes of acute irritable knee. Complete resection of the nodular PVNS can cure the disease.
Department of Orthopaedics and Traumatology, North District Hospital, Sheung Shui, NT, Hong Kong SAR, China-
Cheung Man
CM
Hong
Department of Orthopaedics and Traumatology, North District Hospital, Sheung Shui, NT, Hong Kong SAR, China-
Lui Tun
LT
Hing
Pigmented villonodular synovitis; irritable knee; knee; nodular; septic arthritis