Knee Injection
Evidence Grade A: For reduction of pain and swelling in osteoarthritis.
Obtain informed consent from the patient.
Gather appropriate equipment needed for the procedure.
First, draw up 3-5cc of 1 or 2% lidocaine into a 5 or 10cc syringe.
Then draw up the steroid in order to intermix them together (or, into a separate syringe if aspirating an effusion first). You may use this list of four commonly used steroids as a reference.
Position the patient and palpate your landmarks as described below.
There are several options. Here are two common approaches: Supine and Flexion.
Supine
Have the patient lay supine with the knee to be injected slightly flexed to 20 degrees by placing a towel roll underneath.
A superior-lateral approach is commonly performed. Identify important anatomic landmarks by palpating the superior and lateral edges of the patella.
Palpate the soft indentation approximately one finger breadth superior and one finger breadth lateral from the edge of the patella and mark with the end of a pen.
In this image: The extended knee is flexed 20 degrees.
Using a 22-gauge, 1.5-inch needle, direct the needle 45 degrees to the skin and aim 45 degrees distally, tilted toward the undersurface of the patella.
In this image: The physician injects the knee at a 45-degree angle.
Aspirate the space once the needle has been inserted approximately one inch. If there is fluid return, you know you are in the right space.
Grossly examine the fluid. Normal fluid should be clear and straw-colored.
If there is an effusion that you plan to aspirate:
Inject the lidocaine into the subcutaneous tissue as you are entering the joint space.
Aspirate and remove the fluid.
Once the majority of the fluid is removed, unscrew the syringe and attach the steroid-containing syringe. If needed, stabilize the needle hub with a hemostat.
Inject the steroid into the joint space (if appropriate).
Send the fluid for appropriate studies.
To complete the procedure:
Withdraw the needle and apply pressure to the injection site with a sterile gauze pad.
Cleanse the site with a moistened gauze pad and pat dry.
Cover the needle puncture site with a sterile bandage.
Flexion
Have the patient sit on the edge of the exam table with the knee flexed to 90 degrees.
Palpate the lateral joint line and the inferior-lateral aspect of the patella.
Cleanse the skin overlying the area to be injected with povidone-iodine solution or an alcohol swab.
If desired, spray the skin with ethyl chloride or simply hold the skin with tension to decrease pain caused by the injection.
In this image: The knee is flexed to a 90-degree angle.
Using a 22-gauge, 1.5-inch needle, direct the needle 45 degrees to the skin and aim 45 degrees medially, at the level of the joint line.
In this image: The physician injects the knee that is in flexion.
Aspirate the space once the needle has been inserted approximately one inch. If there is fluid return, you know you are in the right space.
Grossly examine the fluid. Normal fluid should be clear and straw-colored.
If there is resistance or you feel bone:
Redirect the needle more inferiorly and beneath the patella.
Inject the steroid-anesthetic mixture into the joint space.
It should flow easily without resistance.
To complete the procedure:
Withdraw the needle and apply pressure to the injection site with a sterile gauze pad.
Cleanse the site with a moistened gauze pad and pat dry.
Cover the needle puncture site with a sterile bandage.