title: A case of intra-articular synovial lipoma of the knee joint causing patellar dislocation.
abstract: Intra-articular synovial lipoma is rare and clinically manifested mostly by mass effect and occasionally by torsion of the stalk. Patellar dislocation rarely occurs owing to a mass effect of intra-articular tumor of the knee joint. The authors present a case of large intra-articular synovial lipoma at the lateral gutter of the knee joint, which presents as patellar dislocation. A 19-year-old man visited our clinic due to pain and limitation of motion owing to mass at his left knee. MRI revealed an intra-articular soft tissue mass at the lateral gutter of the knee joint with considerable mass effect displacing patella from the trochlear groove. Excisional biopsy confirmed the diagnosis of lipoma, and the final diagnosis was intra-articular synovial lipoma with clinical information. The final radiograph showed well-aligned patella on the trochlear groove. After marginal excision, there was no recurrence or tumor-related morbidity.
authors.affiliation: Department of Orthopaedic Surgery, Soonchunhyang University Hospital, Bucheon, 1174 Jung-dong, Wonmi-gu, Bucheon-si, Gyeonggi-do, 420-767, South Korea.
authors.forename: Kyoung Dae
authors.initials: KD
authors.lastname: Min
authors.forename: Jae Ho
authors.initials: JH
authors.lastname: Yoo
authors.forename: Hyun Seok
authors.initials: HS
authors.lastname: Song
authors.forename: Byung Ill
authors.initials: BI
authors.lastname: Lee
mesh_terms: D018771:Arthralgia / Q000209:etiology; D006801:Humans; D031221:Knee Dislocation / Q000209:etiology*; D008067:Lipoma / Q000175:diagnosis* / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D010329:Patella; D012983:Soft Tissue Neoplasms / Q000175:diagnosis* / Q000601:surgery; D000074402:Synovectomy; D013583:Synovial Membrane / Q000473:pathology*; D055815:Young Adult