Diagnostic Taps : Arthrocentesis

Within the normal joint space there is usually a small amount of fluid (synovial fluid). The fluid is typically clear and stringy. It has the consistency of "oil," and serves to lubricate the joint. When there is an infection, inflammation, or trauma to the joint, the fluid will take on characteristic changes.

The evaluation of a hot, painful, swollen, and difficult to move joint often depends on arthrocentesis for diagnosis. The fluid is studied to rule out the presence of a serious bacterial infection known as septic arthritis. Inflammatory conditions such as rheumatoid arthritis and gout will also cause certain changes in the joint fluid and indicate the appropriate diagnosis to the doctor.

Arthrocentesis can be performed on almost any joint, but, most commonly, it is performed on the knee. The site is cleansed, and a local anesthetic is used. A needle is inserted into the joint space, and fluid is withdrawn. At this time, a long lasting anesthetic or a steroid medication may be injected into the joint space. Cultures will be done on the fluid and treatment will be based on the results of fluid analysis. Rheumatologists, Orthopaedic Surgeons and qualified Emergency Physicians can perform this diagnostic procedure.

***** REMEMBER *****

1. There is a very small risk of infection with this procedure. If bleeding continues from the tap site, it can be controlled by compressive dressing (Ace wrap), and immobilization of the knee in extension (splint).

2. Bleeding within the joint or nerve injury are exceedingly rare. Any risks that accompany this procedure are outweighed by the benefits. A delay in the treatment of septic arthritis often results in permanent joint dysfunction.

MEDICAL TESTS

Abdominal Ultrasound
Abdominal X-Ray
Allergy Testing
Amniocentesis
Amylase Blood Test
Angiodynography
Angiogram
Arterial Blood Gases
Arthrocentesis
Arthrogram
Barium Enema
Blood Chemistry
Blood Coagulation Test
Blood Cultures
Blood Glucose Test
Blood Test Smac 25
Bone Marrow Biopsy Aspiration
Cardiac Catheterization Angioplasty
Cardiac Enzymes
Cholesterol Blood Test
Complete Blood Count
CT Scanning Back
CT Scanning Chest Abdomen
Drug Levels
Glucose Tolerance Test
Hepatitis Blood Test
HIV Blood Test
Kidney Biopsy
Kidney Blood Test
Lipoproteins
Liver Biopsy
Liver Blood Test
Lymph Node Biopsy
Mononucleosis Test
Paracentesis
Peritoneal Lavage
Pregnancy Blood Test
Prostate Specific Antigen
Skin Biopsy
Spine X-Rays
Thyroid Biopsy
Thyroid Blood Test
Toxicology