Arthrocentesis – What is it and How can it Help?
Arthritic conditions and chronic joint pain are more prevalent today than they were 20 years ago. As our diet changes to accommodate more processed foods our bodies are not able to withstand the damaging effects of free radicals, injury and disease.
One diagnostic tool in the physician’s arsenal of tools is an arthrocentesis. An arthrocentesis, or more commonly called joint aspiration, should be performed in the doctor’s office and under sterile conditions. The area is prepared with antibacterial soap and draped so the area in which the doctor is working remains sterile. This prevents infection and secondary problems.
The goal of an arthrocentesis is usually to withdraw synovial fluid from the joint. This fluid is then sent to the lab for analysis. Synovial fluid is normally found in the joints and is a lubricant. When there is too much fluid it can cause the joint to swell. In an inflammatory response the synovial fluid can increase in amount and get thicker. Under these circumstances the goals of an arthrocentesis would be to evaluate the fluid and relieve pressure in the joint.
The joint fluid removed during an arthrocentesis is sent to the lab and tested for the white cell count, crystals, protein, glucose and cultured for infection. Sometimes just the removal of the white cells during arthrocentesis will decrease the damage done to the joint since they are the source of enzymes that are destructive.
Before the arthrocentesis the doctor will determine if he will also inject the joint with cortisone at the same time as the fluid is being aspirated. The injection of cortisone will give immediate pain relief to the joint. There are potential side effects to injections with cortisone. These are rare but they do happen. If the cortisone doesn’t remain localized or the injections are received too frequently the patient can also experience increase in blood sugar if they are diabetic. It is also possible to see the effects of steroid use throughout the rest of the system such as puffy face, weight gain and easy bruising.
The arthrocentesis is actually relatively simple. The skin is sterilized with a solution – usually Betadine – and then anesthetized with either a small injection or topical solution. A needle is inserted into the joint and fluid is pulled out from the joint. If a medication is going to be injected the syringe is changed leaving the needle in place. After the needle is removed a bandaid or small dressing is placed over the entry point.
Complications from arthrocentesis are very uncommon. Possible bruising, skin pigmentation changes at the area the needle was placed and minor bleeding into the joint happen occasionally. A very rare side effect is an infection in the joint following the needle aspiration – called septic arthritis. If cortisone related medication is injected into the joint other uncommon side effects are also possible – crystal formation in the joint, inflammation of the joint, and shrinkage of the skin at the injection site.
Arthrocentesis is done as a diagnostic tool – to evaluate the fluid – or a therapeutic tool – to drain the excess fluid, decrease the pain and increase the mobility. Although joint injections are given to treat inflammatory conditions such as gout, rheumatoid arthritis, bursitis and tendonitis, cortisone injections are rarely helpful in osteoarthritis.
More commonly an arthrocentesis is performed on the knee, elbow, shoulder, hand, wrist or thumb. When an arthrocentesis is necessary on a hip joint it is done using the guidance of fluoroscopy in the radiology department. The lumbar spine can also be injected but only by an experienced rheumatologist, radiologist or orthopedist.
After the arthrocentesis it is important to keep the area clean and dry and the bandage on as long as the doctor orders. The area can be tender or sore but you should call the doctor is the area gets red, swelling or bleeding around the injection site, you get a fever or you have increased pain in the joint.