What is the proper technique for administering a left lateral knee injection?

Proper Technique for Left Lateral Knee Injection

The optimal technique for left lateral knee injection involves using the lateral midpatellar approach, which has a 93% accuracy rate for intra-articular placement compared to other approaches. 1

Patient Positioning and Setup

• Position the patient supine with the knee slightly flexed (20-30 degrees) using a small rolled towel under the knee
• Ensure a professional, clean, quiet, private, well-lit room 2
• Have the patient on an examination table that can be adjusted to a comfortable height for the provider
• Prepare equipment for aseptic procedure and have resuscitation equipment nearby 2

Equipment Needed

• Sterile gloves
• Skin antiseptic (alcohol, iodine disinfectant, or chlorhexidine)
• Sterile drape
• 21-gauge, 2-inch (5.1 cm) needle
• Syringe with medication
• Local anesthetic (optional)
• Bandage

Injection Site and Technique

Lateral Midpatellar Approach (Recommended)

1. Identify the injection site at the lateral border of the patella, at the midpoint between the superior and inferior poles of the patella
2. Prepare the skin with antiseptic solution using aseptic technique 2
3. Consider using local anesthetic (patients should be offered local anesthetic with explanation of pros and cons) 2
4. Insert the needle horizontally from the lateral side, aiming toward the intercondylar notch
5. Advance the needle until you feel decreased resistance as you enter the joint space
6. If synovial fluid is present, aspiration helps confirm intra-articular placement 3
7. Inject the medication slowly
8. Apply gentle pressure and a bandage after removing the needle

Alternative Approaches (Less Accurate)

• Anterolateral approach: 71% accuracy rate 1
• Anteromedial approach: 75% accuracy rate 1

Medication Considerations

• Corticosteroid injections are strongly recommended for knee OA 2
• Triamcinolone acetonide 10 mg is non-inferior to 40 mg for pain relief and has potentially fewer side effects 4
• For diabetic patients, advise about the risk of transient increased glycemia following injection, particularly from days 1-3 2

Post-Injection Care

• Avoid overuse of the injected joint for 24 hours following injection, but immobilization is discouraged 2
• Inform patients that some mild pain may be experienced when injecting into normal tissue 2
• Monitor for potential adverse effects, particularly in diabetic patients

Important Considerations

• Ultrasound guidance may improve accuracy but is not required for knee injections (unlike hip injections, where it is strongly recommended) 2
• Aseptic technique should always be used to minimize the risk of infection 2
• Intra-articular injections may be performed at least 3 months prior to joint replacement surgery 2
• Clinical evidence of joint effusion and successful aspiration of synovial fluid at the time of injection are associated with better outcomes 3

Common Pitfalls to Avoid

• Injecting into the anterior fat pad or subsynovial tissues rather than the joint space
• Using inadequate aseptic technique
• Failing to aspirate effusion if present (which can both confirm needle placement and improve outcomes)
• Not considering patient-specific factors such as diabetes or anticoagulation status

The lateral midpatellar approach provides the highest accuracy rate for knee injections and should be the preferred technique for left lateral knee injection to ensure optimal medication delivery and therapeutic benefit.