Joint aspiration is useful for diagnosis and treatment. Treatment may include joint decompression in sepsis and steroid instillation for arthritis.
Equipment includes a culture tube and plain and anticoagulated sterile fluid collection containers.
Skin preparation is surgical with sterile drape.
Anesthetic If the joint is distended, quick placement of the needle into the joint may be least traumatic for the child. In most situations, inject local anesthesia through a #22 needle.
Aspiration Perform aspiration with a #18 or #20 needle. Evacuate the joint completely.
Fluid evaluation Observe the viscosity, turbidity, and color. Consider for gram stain and cultures. Tests commonly ordered include a cell count and differential, sugar, protein, and immunologic tests for arthritis.
Shoulder Approach the shoulder from either an anterior or lateral approach just below the acromial process.
Elbow Aspirate the joint with a posterolateral approach between the radial head and capitellum.
Wrist Aspirate the joint from a dorsal radial approach.
Finger With the digit slightly flexed, approach on either the dorsal ulnar or radial sides.
Hip The hip is more difficult to aspirate due to the deep location. Imaging is helpful. The approach is influenced by the size of the child. In infants and small children, the medial approach is usually best. In most children and adolescents, make an anterolateral approach by directing the needle just proximal to the greater trochanter.
Knee A medial or lateral approach may be used. Direct the needle just inferior to the proximal portion of the patella.
Ankle An anterolateral approach is appropriate.
Toes With the toe slightly flexed, aspirate from a dorsomedial or lateral approach.