Knee pain is a common discomfort that can significantly affect your quality of life, limiting daily activities and impacting your overall well-being.
When traditional treatments, such as rest, physiotherapy, and oral painkillers, are not enough to relieve the pain, knee infiltration can be an effective alternative. This minimally invasive procedure involves injecting medication directly into the knee joint to reduce pain and inflammation. In this article, we explain in simple terms what knee infiltration is, the types of infiltrations available, the benefits and risks of the procedure, and the cases in which it is recommended. We will also guide you on what to expect during the procedure and the recovery process.
What is Knee Infiltration?
Knee infiltration is when medication is injected directly into the knee joint. This procedure is performed with a fine needle, and the use of ultrasound guidance is generally not necessary to ensure the accuracy of the injection due to the size and accessibility of this joint. Knee infiltration can be used to treat various conditions that cause pain and inflammation in the joint, such as osteoarthritis, different types of arthritis, and degenerative meniscus or cartilage injuries.
How is Knee Infiltration Performed?
Before performing a knee infiltration, the doctor will assess the cause of the joint pain and inflammation through a thorough examination and appropriate diagnostic tests, such as X-rays and MRI scans. Below are the steps involved in knee infiltration:
- Preparation: The knee area is cleaned and disinfected with an antiseptic. Local anaesthesia may be applied to minimise discomfort during the injection.
- Ultrasound Guidance: To ensure the accuracy of the injection and avoid damaging surrounding structures, the doctor may use an ultrasound to guide the needle to the exact location within the joint. The ultrasound allows real-time visualisation of the needle as it is inserted into the joint. However, as mentioned earlier, the knee is a large and easily accessible joint, so ultrasound is not strictly necessary.
- Injection: A fine needle is inserted into the knee joint, and the medication is injected. You may feel slight pressure or discomfort during the injection, but it should not be painful.
- Dressing: A small dressing or plaster is applied to the puncture site.
Knee infiltration typically takes only a few minutes. The total appointment time, including preparation and recovery, may vary but is generally less than fifteen minutes.
What Types of Medications Are Used in Knee Infiltration?
Knee infiltration is a technique that helps reduce pain and inflammation in the joint. Different medications are used in this treatment, each with specific properties and benefits. The choice of drugs depends on various factors that the doctor will evaluate, such as the cause of the pain, the severity of the inflammation, the patient’s age, and their activity level. Below are some of the most common medications:
- Corticosteroids: Corticosteroids are potent anti-inflammatory drugs that can be used to reduce inflammation and relieve pain in the knee joint. They act quickly, providing significant short-term relief. However, corticosteroids do not repair joint damage or stop the progression of the disease. Additionally, repeated use can have side effects, such as weakening cartilage and tendons, so they should not be used repeatedly and are only recommended for isolated cases.
- Hyaluronic Acid: This is a natural substance found in synovial fluid, which lubricates the joints. In osteoarthritis, the concentration and quality of hyaluronic acid in the synovial fluid decrease, contributing to pain and stiffness. Hyaluronic acid injections, also known as viscosupplementation, replenish the hyaluronic acid in the joint. Their effect is biomechanical, improving lubrication and cushioning, thereby reducing pain. Unlike corticosteroids, hyaluronic acid does not have as significant an anti-inflammatory effect, but its effects are longer-lasting and can improve joint function in the long term.
- Platelet-rich plasma (PRP): PRP is obtained from the patient’s blood through centrifugation. It contains a high concentration of platelets, which release anti-inflammatory factors. PRP injections treat tendon, ligament, and cartilage injuries, stimulating tissue repair and reducing pain. It is a promising treatment, but its long-term benefits are still being researched. In the case of knee osteoarthritis, benefits have been documented and confirmed for at least one year.
- Stem Cells: This experimental treatment is being investigated for osteoarthritis cartilage regeneration. Although initial results are promising, more studies are needed to confirm its long-term efficacy and safety.
How is the Medication for Infiltration Chosen?
The specialist doctor, usually an orthopaedic surgeon or rheumatologist, selects the most appropriate medication for knee infiltration individually, considering various factors. Below are the factors healthcare professionals consider:
- Cause of the Pain: The type of medication is chosen based on the cause of the pain, whether it is osteoarthritis, arthritis, tendinitis, or another condition.
- Severity of Inflammation: Corticosteroids are more effective for acute inflammation, while hyaluronic acid is more suitable for chronic inflammation.
- Overall Joint Condition: The degree of joint damage influences the treatment choice, as no benefits are expected if the joint deterioration is very advanced.
- Patient’s Medical History: Allergies and other medical conditions, such as age and activity level, are considered.
- Patient’s Expectations: The doctor will explain the different treatment options and help you choose the one that best suits your needs and expectations.
What Are the Benefits and Limitations of Knee Infiltration?
Knee infiltration can be an effective therapeutic tool in managing joint pain, but it is essential to have a realistic understanding of its benefits, limitations, and potential risks. It is worth noting that this procedure is not a substitute for a healthy lifestyle and comprehensive treatment.
Below are the main benefits of knee infiltration:
- Rapid Pain Relief: Pain relief is one of the main benefits of knee infiltration. The injected medications act locally in the joint, providing significant relief in a short period, usually within a few days in the case of corticosteroids, while hyaluronic acid and PRP act over a medium-term period. This can allow patients to resume their daily activities with greater comfort and fewer limitations.
- Reduction of Inflammation: Corticosteroid infiltrations are particularly effective in reducing inflammation in the knee joint. The decrease in inflammation contributes to pain relief and improved mobility.
- Improved Mobility: By reducing pain and inflammation, knee infiltration can improve joint mobility and function. This allows patients to perform physical activities more efficiently and enhances their quality of life.
- Minimally Invasive Procedure: It is a minimally invasive procedure performed in the doctor’s office, requiring no hospitalisation or surgical incisions. This means a lower risk of complications compared to surgery.
- Delay or Avoidance of Surgery: In some cases, knee infiltration can help delay or even avoid knee surgery, especially in patients with early-stage osteoarthritis.
Below are the main limitations of knee infiltration:
- Not All Patients Are Candidates: Knee infiltration is unsuitable for all patients. Individuals with active infections in the knee, allergies to the medications used in the infiltration, or blood clotting disorders may not be candidates for this procedure. It is also not used in cases of very advanced osteoarthritis where the expectations of improvement are minimal.
- Results Are Not Permanent: The pain relief provided by knee infiltration is not permanent. The duration of the effect varies depending on the type of medication used and the patient’s condition, but it generally lasts from a few weeks to several months. In some cases, repeated infiltrations may be required to maintain pain relief.
- Does Not Cure the Underlying Condition: Knee infiltration treats the symptoms but does not cure the underlying condition causing the pain. For example, in the case of osteoarthritis, infiltration relieves pain but does not stop the degeneration of cartilage.
Conclusion:
Knee infiltration is a minimally invasive procedure that can significantly relieve knee pain. If you are considering this treatment, speak to your doctor to determine if it suits you. At HM Hospitales, we have a team of orthopaedic surgeons and sports medicine specialists with extensive experience in performing knee infiltrations. Contact us for more information and to schedule an appointment.
Remember: This article is for informational purposes only and does not replace medical consultation. If you have any questions, consult a healthcare professional.
