title: SYNOVIAL CHONDROMATOSIS.
abstract: A 34-year-old male patient presented severe pain in his left knee in association with functional incapacitation, with no apparent triggering factor. He sought medical attention in December 2006, at which time he was prescribed NSAIDs. After a year, he reported increased swelling and pain at the site. He was referred to a knee specialist with a suspected meniscal injury. Upon examination, severe swelling of the joint, with movement limitation, severe pain and negative joint aspiration, was found. Since the simple radiographic results were normal, an MRI of the knee was requested. The MRI revealed a large accumulation of fluid inside the joint, together with marked synovial proliferation, especially focal thickening in clumps with an intermediate signal in T1 and T2, and a discrete hyposignal in T2 that was suggestive of pigmented villonodular synovitis with intact meniscus and ligaments. The patient underwent arthroscopy on the left knee, which revealed whitish irregular fragments, and then underwent arthrotomy with removal of the lesion and extensive synovectomy. The material was sent for anatomopathological examination, which showed the presence of synovial chondromatosis. Eight months after the surgery, the patient does not have any complaints, with a range of motion of 130° in the left knee without joint effusion or signs of inflammation. Synovial chondromatosis is a rare benign type of metaplasia of the synovial membrane that leads to the formation of cartilaginous free bodies in the joint space. It is difficult to diagnose because 95% of the nodules, when not calcified, can be overlooked radiologically.
authors.affiliation: Titular Professor of the Department of Orthopedics and Traumatology, School of Medical Sciences of Minas Gerais. Head of the Orthopedics and Traumatology Service of the São José University Hospital, School of Medical Sciences of Minas Gerais.(HUSJ-FCMMG).
authors.forename: Neylor Pace
authors.initials: NP
authors.lastname: Lasmar
authors.affiliation: Member of the Knee Surgery Service, São José University Hospital, School of Medical Sciences of Minas Gerais (HUSJ-FCMMG). Adjunct Professor in the Department of Orthopedics and Traumatology, School of Medical Sciences of Minas Gerais.
authors.forename: Rodrigo Barreiros
authors.initials: RB
authors.lastname: Vieira
authors.affiliation: Member of the Knee Surgery Service, São José University Hospital, School of Medical Sciences of Minas Gerais (HUSJ-FCMMG). Adjunct Professor in the Department of Orthopedics and Traumatology, School of Medical Sciences of Minas Gerais.
authors.forename: Juraci de Oliveira
authors.initials: Jde O
authors.lastname: Rosa
authors.affiliation: Member of the Knee Surgery Service, São José University Hospital, School of Medical Sciences of Minas Gerais (HUSJ-FCMMG). Adjunct Professor in the Department of Orthopedics and Traumatology, School of Medical Sciences of Minas Gerais.
authors.forename: Rodrigo Campos Pace
authors.initials: RC
authors.lastname: Lasmar
authors.affiliation: Medical Resident (R3) in the Orthopedics and Traumatology Service of the São José University Hospital, School of Medical Sciences of Minas Gerais. (HUSJ-FCMMG).
authors.forename: André Campos
authors.initials: AC
authors.lastname: Scarpa
keywords: Chondromatosis; Knee; Metaplasia