What is the procedure for intra-articular knee injection?

From the Guidelines

Knee injections should be performed using the superolateral approach, which has been shown to have the highest pooled accuracy rate of 91% in patients with different arthropathies, as recommended by the EULAR guidelines 1. The procedure begins with proper patient positioning, usually sitting with the knee flexed at 90 degrees, in a professional clean quiet private well-lightened room, with equipment for aseptic procedures and resuscitation equipment close by 1.

• The patient must be fully informed of the nature of the procedure, the injectable and potential benefits and risks, and informed consent should be obtained and documented according to local habits 1.
• The injection site should be cleaned with an antiseptic solution like chlorhexidine or povidone-iodine, and the entry point marked.
• Local anesthetic (1% lidocaine) may be administered using a 25-gauge needle to reduce discomfort.
• The injection is then performed using a larger needle (typically 18-22 gauge) attached to a syringe containing the medication, which might include corticosteroids (such as methylprednisolone 40-80mg or triamcinolone 20-40mg), as supported by the AAOS clinical practice guideline summary 1.
• The needle is inserted perpendicular to the skin until reaching the joint space, often confirmed by aspiration of synovial fluid.
• After injection, the needle is removed, pressure is applied briefly, and a bandage is placed.
• Patients should be advised to rest the joint for 24-48 hours and monitor for signs of infection or allergic reaction. The use of imaging guidance, such as ultrasound, may be used to improve accuracy, although clinical outcomes are similar to those of landmark-guided intra-articular therapies 1.
• The choice of medication for the injection depends on the condition being treated, with corticosteroids being a commonly used option, as supported by the AAOS clinical practice guideline summary 1.

From the FDA Drug Label

For treatment of joints, the usual intra-articular injection technique should be followed If an excessive amount of synovial fluid is present in the joint, some, but not all, should be aspirated to aid in the relief of pain and to prevent undue dilution of the steroid. With intra-articular administration, prior use of a local anesthetic may often be desirable Care should be taken with this kind of injection, particularly in the deltoid region, to avoid injecting the suspension into the tissues surrounding the site, since this may lead to tissue atrophy.

The procedure for a knee injection involves following the usual intra-articular injection technique.

• Aspirate some of the synovial fluid if it is excessive to aid in pain relief and prevent dilution of the steroid.
• Consider using a local anesthetic before the injection.
• Take care to inject the suspension into the joint space, avoiding the surrounding tissues to prevent tissue atrophy 2.

From the Research

Procedure for Knee Injection

The procedure for knee injection involves the use of ultrasound guidance to improve the accuracy of needle placement and reduce procedural pain 3, 4. The following steps are involved in the procedure:

• Preparation of the patient and the injection site
• Use of ultrasound guidance to locate the target intra-articular joint space
• Insertion of the needle into the joint space under ultrasound guidance
• Injection of the corticosteroid or hyaluronic acid into the joint space

Types of Injections

There are two main types of injections used in the treatment of knee osteoarthritis:

• Corticosteroid injections: These injections are commonly used to reduce inflammation and relieve pain in the knee joint 4, 5
• Hyaluronic acid injections: These injections are used to improve joint lubrication and reduce pain and stiffness in the knee joint 6, 7

Efficacy of Injections

The efficacy of knee injections has been studied in several clinical trials. The results of these studies suggest that:

• Ultrasound-guided injections are more accurate and effective than landmark-guided injections 3
• Hyaluronic acid injections are effective in reducing pain and improving function in patients with knee osteoarthritis 7
• Corticosteroid injections are effective in reducing inflammation and relieving pain in the knee joint, but the optimal dose and frequency of injections are still debated 4, 5

Safety of Injections

The safety of knee injections has also been studied in several clinical trials. The results of these studies suggest that:

• Ultrasound-guided injections are safer than landmark-guided injections, with a lower risk of procedural pain and complications 4
• Hyaluronic acid injections are generally well-tolerated, with few side effects reported 6, 7
• Corticosteroid injections can have side effects, including an increase in blood glucose, adrenal suppression, and detrimental effects on cartilage and bone density 4