title: Knee effusions.
abstract: There are many questions concerning knee effusions and the basic diagnostic approach to them. The case of a young female with gonococcal arthritis presenting to the Emergency Room with an isolated knee effusion is discussed. From the errors in diagnosis of this case, a basic outline in the approach and work-up of a knee effusion is detailed, including history and physical examination, and the use of synovial fluid analysis as a further diagnostic aid. Procedural instructions and contraindications for knee arthrocentesis are given, as well as data related to interpretation of pertinent laboratory findings of synovial fluid in disease states.
mesh_terms: D000293:Adolescent; D001170:Arthritis, Infectious / Q000175:diagnosis* / Q000188:drug therapy; D005122:Exudates and Transudates / Q000382:microbiology; D005260:Female; D006069:Gonorrhea / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D007719:Knee Joint; D009344:Neisseria gonorrhoeae / Q000302:isolation & purification; D010406:Penicillins / Q000627:therapeutic use; D011677:Punctures; D013582:Synovial Fluid / Q000382:microbiology
chemical_list: D010406:Penicillins