My knee hurts MSU Emergency Medicine Lansing, MI Dr. Patricia Manhire
What are the Indications for Arthrocentesis?
Indications for Arthrocentesis • Crystal-induced arthropathy • Hemarthrosis • Symptomatic relief of a large effusion • Unexplained joint effusion • Unexplained monarthritis • Suspect interarticular infection
What are the Contraindications to Joint Needle Aspiration?
Contraindications to Joint Needle Aspiration • Absolute • Overlying infection in the soft tissues* • abscess & cellulitis • Severe coagulopathy • Severe overlying dermatitis • Relative contraindication • Bacteremia • Hemophilia • On Warfarin • Uncooperative patient *** Often Acutely arthritic joint symptoms may mimic a soft tissue infection
Review of ProcedureKnee Arthrocentesis
Ultrasound Ultrasound-assisted arthrocentesis can be used as an adjunct to assist in localization and aspiration of joint fluid. • Using a linear 5-10 MHz probe • Anterior transverse scan A (top)= prior to aspiration B (bottom) = following aspiration > = tip of the needle, f = femur. Filippucci E, Iagnocco A, Meenagh G, Riente L, Delle Sedie A, Valesini G, Grassi W.
Position & Prep • Knee extended or slightly bent • Controversial: Studies show bent has a lower yield of fluid in small effusions but is more comfortable. • Can use medial or lateral approach • Suggest lateral with smaller effusions • Prep skin povidone-iodine or Choroprep
Identify LandmarkLateral Approach Insert needle 1 cm above and 1 cm lateral to the superior lateral aspect of the patella. The needle is tilted beneath the patella at a 45-degree angle.
Aspiration • Inserted needle through stretched skin. Stretching the skin can reduce discomfort • Some administer lidocaine into the skin. • The needle is directed at a 45-degree angle distally and 45 degrees into the knee, tilted below the patella • Compression applied over the joint space or "milking" of the bursae, on the patellar side opposite the needle insertion site, may facilitate aspiration. Roberts & Hedges. Clinical Procedures in Emergency Med. 4th Ed Saunders 2004
You now have the Fluid Sample.What labs do you Order?
Examination of Synovial Fluid NormalNoninflammatoryInflammatorySeptic RA = rheumatoid arthritis; SLE = systemic lupus erythematosus
What is your interpretation of the fluid? • Normal • Noninflammatory • Inflammatory • Septic
So, you have determined your patient has Inflammatory Arthritis What information would help you decide which Inflammatory Arthritis your pt has: • Gout? • Pseudogout? • Spondyloarthropathies? • RA? • Lyme disease? • SLE? Number of joints involved Crystals or no crystals
Classification of Arthritis by Number of Affected Joints EMERGENCY MEDICINE: A Comprehensive Study Guide, 6th ed, The McGraw-Hill Companies, Inc.
Lyme Disease • The arthritic manifestations occur in the weeks, months, or years following the primary, stage I infection • Typically, a monarticular or migratory oligoarticular • Large joints are most often affected • Arthrocentesis • inflammatory synovial fluid, usually with negative cultures • History of • endemic area exposure • history of tick bite or erythema chronicum migrans (ECM) rash is helpful but often absent • Show characteristic stage II and stage III findings—such as fatigue, neurologic abnormalities, and/or cardiac conduction disturbances • May require laboratory confirmation • Treatment is administered for 3 to 4 weeks. Rx: doxycycline, penicillin G, amoxicillin, or ceftriaxone.
Rheumatoid Arthritis • Symmetric, polyarticular involvement. • Sparing of the distal interphalangeal (DIP) joints. • Stiffness of the joints after inactivity (morning stiffness). • Multisystem involvement is characteristic • depression, fatigue, and generalized myalgias. • pericarditis, myocarditis, pleural effusion, pneumonitis, • Arthrocentesis of synovial fluid - inflammatory profile. • Treatment: • Salicylates or other NSAIDs • Immobilization providing added relief from joint movement pain. • Corticosteroids may be utilized for brief periods • Long-term therapy using agents such as antimalarials, gold, and methotrexate.
Ankylosing Spondylitis Seronegative spondyloarthropathies • Ankylosing Spondylitis • Similar to RA • morning stiffness and multisystem involvement with constitutional symptoms such as malaise, weakness, and fatigue. • Usually younger than age 40 • Treatment consists of pain control with short-term and long-term management with NSAIDs.
Crystal-Induced Synovitis: Gout & Pseudogout • Gout & Pseudogout • Middle-aged and elderly adults. • Both often follows trauma, surgery, a significant illness, or change in medications affecting uric acid levels. • Pseudogout • Positive birefingence crystals: Calcium pyrophosphate -- rhomboid shape • Acute treatment: same as Gout. • Gout • Negative birefringence:Uric acid crystals -- needle-shaped and blue • 30 % have normal uric acid levels during an acute gout attack • Treatment: nonsteroidal anti-inflammatory drugs (NSAIDs) or Colchicine or indomethacin • Once the symptoms of an acute resolved, elimination of gout-inducing agents (diuretics, aspirin, or cyclosporine) and treatment with allopurinol or probenecid
Your Diagnosis? Acute Rheumatoid Arthritis What is your Treatment Plan
