title: Primary lipoma arborescens of the knee may involve the development of early osteoarthritis if prompt synovectomy is not performed.
abstract: BACKGROUND
  Primary lipoma arborescens (LA) is a rare, benign intra-articular hyperplastic tumor that has been associated with osteoarthritis (OA). The aim of this study was to determine whether prompt synovectomy could avoid progressive joint degeneration in cases of primary LA of the knee.
  
  
  METHODS
  A review of currently available literature about the disease was carried out. The clinical, histological and radiological records of a series of nine knees with primary LA diagnosed and treated between 2002 and 2012 were retrospectively reviewed. Eight of the knees had histological confirmation of LA and none had evidence of condropathy on the initial magnetic resonance image or degenerative changes at the initial radiographic examination.
  
  
  RESULTS
  At the final follow-up no evidence of OA was found in the three knees that underwent synovectomy when symptoms did not last more than 1 year. The five knees in which synovectomy was delayed developed progressive joint degeneration.
  
  
  CONCLUSIONS
  In this series, primary LA of the knee involved the development of early osteoarthritis when prompt synovectomy was not performed. Timely synovectomy is strongly recommended, if not mandatory.
  
  
  METHODS
  IV.
authors.affiliation: Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, C/Sant Antoni Maria Claret 167, 08025, Barcelona, Spain, lnatera@santpau.cat.
authors.forename: Luis
authors.initials: L
authors.lastname: Natera
authors.forename: Pablo E
authors.initials: PE
authors.lastname: Gelber
authors.forename: Juan I
authors.initials: JI
authors.lastname: Erquicia
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Monllau
mesh_terms: D000328:Adult; D001859:Bone Neoplasms / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007719:Knee Joint; D008067:Lipoma / Q000150:complications* / Q000175:diagnosis / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019637:Orthopedic Procedures / Q000379:methods*; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D012189:Retrospective Studies; D000074402:Synovectomy; D013583:Synovial Membrane / Q000473:pathology