title: Acute apatite podagra with negative birefringent spherulites in the synovial fluid.
abstract: We describe a young male patient who presented with acute podagra after jogging activity. He had no underlying pathology. Polarized light microscopy of the synovial fluid from his first metatarsophalangeal joint revealed numerous negative birefringent spherulites about 6 microns in diameter, presenting the typical appearance of Maltese crosses. The molar calcium/phosphorus ratio of these spherulites as determined by X-ray energy dispersive analysis was virtually identical to that of synthetic or pathologic apatite.
authors.affiliation: Division of Rheumatology, Hôpital du Sacré-Coeur, Université de Montréal, PQ, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Beaudet
authors.forename: R
authors.initials: R
authors.lastname: de Médicis
authors.forename: P
authors.initials: P
authors.lastname: Magny
authors.forename: A
authors.initials: A
authors.lastname: Lussier
mesh_terms: D000208:Acute Disease; D000328:Adult; D001031:Apatites / Q000032:analysis* / Q000378:metabolism; D015210:Arthritis, Gouty / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D001718:Birefringence; D006801:Humans; D002479:Inclusion Bodies / Q000737:chemistry / Q000648:ultrastructure*; D008297:Male; D008683:Metatarsophalangeal Joint; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D013582:Synovial Fluid / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D014961:X-Ray Diffraction
chemical_list: D001031:Apatites