Intraarticular nodular fasciitis causing limitation of knee extension: a case report

We report a patient with intraarticular nodular fasciitis who developed mechanical symptoms in the knee, limiting knee extension. A 24 year-old man presented with mechanical restriction of extension and pain at maximum extension. MRI revealed an intraarticular mass within the knee joint. The mass was excised arthroscopically. Histological examination of the excised tissue led to a diagnosis of nodular fasciitis. Pain and limitation of motion of the knee disappeared from one day after surgery. No recurrence was found after 1 year. Intraarticular nodular fasciitis is rare, and although this lesion within the knee has been reported previously, it has not been associated with mechanical symptoms. This case indicates that intra-articular fasciitis should be considered in the differential diagnosis of a patient presenting with mechanical limitation of knee extension and a mass lesion inside the knee joint.