by Tanju Tasyurek


Arthrocentesis is an acknowledged, useful procedure to puncture and aspiration of a joint. It is usually performed both as a diagnostic and therapeutic tool for various clinical situations. Arthrocentesis (synovial fluid aspiration) of a joint can be performed either diagnostically (for identification of the etiology of acute arthritis) or therapeutically (for pain relief, drainage of effusion, or injection of medications). Arthrocentesis is required procedure in majority of patients with monoarthritis and is mandatory if an infection is suspected.

Indications of Arthrocentesis

  • Diagnosis of septic or crystal-induced arthritis
  • Evaluation of therapeutic response for septic arthritis
  • Diagnosis of traumatic bony or ligamentous injury
  • Installation of medications for acute or chronic arthritis
  • Relief of the pain of acute hemarthrosis
  • Determination of communication between the laceration and joint space


  • Absolute contraindication to arthrocentesis is an infection in the tissue overlying the site to be punctured. However, inflammation with warmth, swelling, and tenderness may overlie an acutely arthritic joint, and this condition may mimic a soft tissue infection.
  • Coagulopathy is an absolute contraindication. However, few studies are demonstrating whether it is dangerous performing arthrocentesis in patients using anticoagulants. It was found safe even in those who have international normalized ratios as high as 4.5.
  • Prosthetic joints increase the risk for infection. Therefore arthrocentesis should be avoided for these joints. However, if an infected prosthesis is suspected, arthrocentesis should be performed.


  • Sterile gloves and drapes
  • Gauze pads (5), 4 × 4 inches.
  • Skin cleaning agent
  • Local anesthetic such as Lidocaine 1%
  • Various syringes (5 mL, 20 mL, 30 mL, 60 mL)
  • Various size of needles, 18 or 20 G and 25 or 27 G
  • Morbidly obese patients might require a 21-gauge spinal
    needle for arthrocentesis
  • Specimen tubes
  • Bandage

General Arthrocentesis Technique

Arthrocentesis is a relatively simple procedure. Knowledge of anatomic landmarks and patient positioning will aid in the successful completion of joint aspiration. Defining the anatomy is the most important part of the procedure. The clinician should be familiar with the anatomy of the specific joint and landmarks in order to avoid puncture of tendons, blood vessels, and nerves.

The procedure should be explained to the patient and written consent should be taken. To avoid infection, aseptic technique is essential, including the use of sterile gloves and instruments. After skin preparation with antiseptic solutions, the clinician should allow the solution to dry for several minutes because the bactericidal effects of iodine are dependent on both concentration and time. Iodine solution should be removed with an alcohol sponge. This will prevent iodine transfer into the joint space, which can cause an inflammation.

Without anesthesia, arthrocentesis may be quite painful. Entire route of the needle should be anesthesized from skin to joint capsule. 1% or 2 % lidocaine can be used.
Rigid needles are preferred whereas some clinicians can use sturdy catheters. As a general rule, one should try to remove as much fluid or blood as possible.

Arthrocentesis of the hip joint is generally performed by an orthopedic surgeon.
İt may be difficult to aspirate fluid from small joints. If only one drop of fluid is obtained from small joints, it is best to send it for culture.

The common complications of procedure

  • Iatrogenic infection
  • Iatrogenic hemorrhage
  • Pain during the time of the procedure
  • Reaccumulation of the joint fluid

Specific Arthrocentesis Techniques

Landmarks and positioning are important while performing arthrocentesis. For small joints, application of traction is often very helpful in obtaining fluid.

Radiohumeral Joint (Elbow)

Lateral approach

  • The patient sits upright on a stretcher.
  • Bend the patient’s elbow to 90º.
  • Pronate the patient’s forearm and rest it with the palm down on a side table set at the appropriate height for comfort.
  • Identify the olecranon process, lateral epicondyle, and radial head, and find the depression (or bulge, if the effusion is large) in the soft triangle. This site is used for all approaches.
  • Identify the entry site, and mark the site with a plastic needle sheath or a sterile surgical marker.
  • Carefully examine the elbow before arthrocentesis.
  • Olecranon bursitis is located posteriorly over the olecranon and can be confused with the elbow joint.

The alternative is the posterolateral approach can be used. However, there is an increased risk of injury to the radial nerve and triceps tendon. This approach is useful if the bulge of effusion is palpated inferior to the lateral epicondyle. In the posterolateral approach, insert the needle perpendicular to the skin but parallel to the radial shaft. The landmarks can be found easily if the arm is first extended. At this point, the depression can be located. Then flex and pronate the arm for the procedure.

Because of the risk of ulnar nerve and superior ulnar collateral artery injury, the medial approach should not be used.

How to locate the entry site; please watch the video.

Real patient example

Radiocarpal Joint (Wrist)

The wrist joint is anatomically complex. The dorsal site is the preferred site of aspiration of the wrist joint.

The landmark of this joint is the dorsal radial tubercle (Lister’s tubercle). The extensor pollicis longus tendon runs in a groove on the radial side of the tubercle. The tendon can be palpated by active extension of the wrist and thumb.

  • The wrist should be slightly palmar flexed to facilitate the performance of the procedure.
    The positioning of the wrist is approximately 20 to 30 degrees of flexion with accompanying ulnar deviation.
  • Applying traction to the hand might be helpful.
  • Insert the needle dorsally just distal to the radius and just ulnar to the anatomic snuff box.
  • Avoid the associated tendons (extensor carpi radialis brevis and extensor pollicis longus).
  • Direct the needle perpendicular to the skin.
  • If the bone is hit, pull the needle back and redirect it slightly toward the thumb.


Glenohumeral Joint (Shoulder), Anterior Approach

  • First of all arthrocentesis of this joint is moderately difficult.
  • The patient should sit upright with the arm at the side, with the shoulder held in external rotation.
  • To find the landmark clinician should palpate the coracoid process medially and the proximal end of the humerus laterally.
  • The clinician should insert a 20-gauge needle at a point inferior and lateral to the coracoid process and direct it posteriorly toward the glenoid rim.

The below video shows posterior approach.


Knee Joint, Anteromedial Approach

The medial surface of the patella at the middle or superior portion of the patella is the landmark for the knee joint. Knee arthrocentesis may be done via the parapatellar approach (which is generally preferred), suprapatellar approach, or infrapatellar approach.

For the parapatellar approach, identify the midpoint of either the medial or the lateral border of the patella. Insert an 18-gauge needle 3-4 mm below the midpoint of either the medial or the lateral border of the patella. Direct the needle toward the intercondylar notch of the femur by perpendicular to its’ long axis.

For the suprapatellar approach, identify the midpoint of either side of the superomedial or the superolateral border of the patella. Insert an 18-gauge needle through the midpoint of either superior borders. Direct the needle toward the intercondylar notch of the femur.
The needle enters the suprapatellar bursa. Remember that in 10% of the population, the suprapatellar bursa does not communicate with the knee joint.

For the infrapatellar approach, position the patient sitting upright with the knee bent at 90° over the edge of the bed. Identify either side of the inferior border of the patella and the patellar tendon. Insert an 18-gauge needle 5 mm below the inferior border of the patella and just lateral to the edge of the patellar tendon. Be careful not to go through the patellar tendon while inserting the needle.

The video below shows good anatomical landmarking


Tibiotalar Joint (Ankle)

The medial malleolar sulcus is bordered medially by the medial malleolus and laterally by the anterior tibial tendon. The tendon can easily be identified with active dorsiflexion of the foot. The clinician should insert the needle at a point just medial to the anterior tibial tendon and directed into the hollow at the anterior edge of the medial malleolus. The needle must be inserted 2 to 3 cm to penetrate the joint space.

Metatarsophalangeal and Interphalangeal Joints

For the first digit, landmarks are the distal metatarsal head and the proximal base of the first phalanx. For the other toes, the landmarks are the prominences at the proximal interphalangeal and distal interphalangeal joints. The extensor tendon of the great toe can be located by active extension of the toe. The clinician should insert the needle into the skin at a 90-degree angle and enter the dorsomedial aspect of the great toe (MTP) joint, just medial to the extensor tendon.

References and Further Reading