Knee Joint Injection
|Knee Joint Injection|
|Injectate Options||Steroid, hyaluronic acid, PRP, dextrose|
|Steroid||0.5-2mL of steroid (e.g. 20-40mg triamcinolone)|
|Local||5-10mL of 1% lidocaine or 0.25% to 0.5% bupivacaine|
Infection, uncontrolled coagulopathy, joint prosthesis, poor response to previous injections. Allergy to eggs or feathers is a relative contraindication to hyaluronic acid.
A variety of options exist for injectates - steroid, visco-supplementation, platelet rich plasma, stem cells, and dextrose prolotherapy.
- Protective gloves and use sterile technique.
- Position: Lie supine with the knee slightly flexed, supported underneath with a rolled towel or cushion.
- Palpate and identify the borders of the patella and mark the entry site
- Clean the skin
- Draw up the injectate mixture.
- Optional infiltration of skin with 3-5mL local anaesthetic with 27-30g needle.
- Use a 20-27 gauge 1 inch needle on a 10 ml syringe to enter the joint.
- Lateral: Enter the skin 1 cm superior and 1 cm lateral to the superior lateral aspect of the patella; direct the needle at a 45° angle, tilting below the patella, and aim toward the middle of the medial side of the joint
- Medial: Enter the medial aspect of the knee at the middle of the patella, aiming toward the lateral midpole.
- Anterior: The patient's knee should be flexed 90°; keeping the needle parallel to the tibial plateau, enter just medial or lateral to the patellar tendon
- May feel a "pop" when penetrating the joint capsule. Flow of the injection should not meet resistance.
- Change the path of the needle slightly if injecting the medication is difficult; the needle may be within a fat pad or thick synovium.
- Redirect or withdraw the needle if severe pain occurs; the needle may be hitting the cartilaginous surface.
- Apply a bandage after withdrawing the needle.
Repetitive intra-articular corticosteroid injections may cause accelerated cartilage loss. McAlindon evaluated triamcinolone vs saline repeated every 12 weeks for 2 years in 141 patients with knee osteoarthritis. The steroid group had greater cartilage loss (-0.21 mm vs -0.10mm), and no significant difference in pain. There was a small increase in HbA1c levels in the steroid group. The steroid group had 5 complications, and the saline group had 3.
Other complications include bleeding, infection (1:10,000), postinjection flare (1%-2%), no response, non-sustained response, temporary glucose elevated. Allergic reactions are rare.
Specific to hyaluronic acid is that it can more frequently cause pain and can cause a large joint effusion, rash, and itching.
Rest the knee, avoid strenuous activity for 48 hours, shower/bathe as normal. Post-injection flares can be treated with ice and NSAIDs. Safety netting for injection.