What Is Arthrocentesis?

Knee joint cavity paracentesis is often used to check the nature of the fluid in the joint cavity, or to inject the medicine into the joint cavity after pumping fluid.

Knee arthrocentesis

Right!

Knee joint cavity paracentesis is often used to check the nature of the fluid in the joint cavity, or to inject the medicine into the joint cavity after pumping fluid.

1. The patient lies supine on the operating table with both lower limbs straight.

2. The puncture site is routinely disinfected. The doctor wears sterile gloves, spreads a sterile hole towel, and uses 2% lidocaine as a local anesthetic.

3 Use 7-9 injection needles, usually in

1. The puncture instruments and surgical operations need to be sterilized strictly to prevent secondary infection of the sterile joint cavity exudate.

2. Be gentle and avoid injury

Sacral puncture

Location: The junction of the outer upper edge of the patella and the lateral femoral muscle. Press the depression of the lateral femoral muscle and stick the nails to penetrate 0.5-1cm.

Advantages: less nerve distribution, less sensitive, thin tissue, and good feel. The patient cooperates easily.

There are fewer synovial membranes in the joints and it is not easy to cause pain. The puncture site has less tissue and the needle can easily reach the joint cavity. Close to the sacral sac, the liquid in the sacral sac can be squeezed down, so that the liquid is drawn thoroughly, and the needle can be moved directly to extract the liquid from the sacral sac.

Puncture of the lower sacrum

Positioning: The knees are bent at 90 degrees, and the lower edge of the patella and the lateral side of the sacral ligament is 1 cm (lateral knee, a small depression can be seen).

Method: After the nail is set to be good, disinfect the affected area. The 10-gauge needle is parallel to the tibial plateau at a 45-degree angle inward, and the needle is fully inserted.

Advantages: better positioning, no pain after joint injection. The patient cooperates easily.

The injection of sodium hyaluronate through the lateral joint cavity of the patellofemoral joint can avoid the pain caused by the injection of the drug into the submental fat pad and affect the efficacy of the drug.

The needle is inserted from the outside of the sacrum, and the needle can also be inserted from the medial margin. If the hyperplasia of the synovium is severe and the subcutaneous fat pad is too thick, it is not easy to insert the needle, but it is easy to repeatedly stimulate the synovium and fat pad to cause pain.

Patient seat with sagging knees

The central point of the sacrum is used as the horizontal and vertical lines, and the first and second quadrants are each made a bisector angle of 45 degrees. The intersection of the bisector and the outer edge of the sacrum is the point of needle insertion.

Conventional knee puncture site: The patient is supine with the knee straight, the intersection of the upper edge of the patella and the medial and lateral edges of the patella is two points, diagonal to the center of the patellofemoral joint, and puncture at 45 °. The knee joint is slightly flexed about 30 °, and the needle is inserted vertically from the medial or lateral joint space below the sacrum.

[1] For patients with a large amount of fluid in the joint, use the outer upper edge of the sacrum to inject a needle, and then inject sodium hyaluronate by the way. Because when there is a large amount of fluid in the joint, the fluid is mostly in the epicondyle and the patellofemoral joint space is relatively large. The needle can be easily inserted into the outer upper edge of the patella and the fluid can also be drawn out. For patients without joint effusion, needle insertion at the outer upper edge of the patella is not easy.

[2] For patients without joint effusion, the position of the lower patella (lateral knee eye) puncture must be established (90 degrees of knee flexion, the lower edge of the patella, 1 cm outside the sacral ligament). The tibial plateau is parallel, at a 45-degree angle inward, and the needle is fully pierced. There is a sense of emptiness. Sometimes the joint fluid will be withdrawn when it is withdrawn. At this time, you can safely inject it. The injection is relatively easy, so there is no problem. If the injection is more laborious and the patient feels pain and swelling, you can insert the needle further inside and move it left and right. The injection is easier, and the patient can re-inject without discomfort. As long as the skilled operation, correct positioning and timely adjustment, patients rarely have discomfort after injection.