What are Knee Joint Injections?
Knee joint injections explained by Denver, Golden, Aurora, Boulder, Broomfield, Jefferson, and Littleton Colorado’s top pain doctors
Knee joint injections are commonly administered in order to manage both stiffness and knee pain that develops as a result of inflammation. Acute and chronic knee pain typically causes mobility problems that hinder daily activities and leads to a decrease in the quality of life. These types of symptoms can eventually begin to affect an individual’s health and emotional well-being.
Several types of knee joint injections have been established that demonstrate the effectiveness of this type of pain management. The injection that will be administered depends on the cause of the knee pain. Corticosteroid injections are most commonly utilized for inflammation and additional injections include:
- A platelet rich plasma (PRP) injection, which involves injecting a patient’s own blood plasma that has been fortified with platelets in order to promote healing
- A hyaluronic acid injection may also be administered as a means of lubricating and cushioning the knee joint
Physicians perform various types of knee injections based on the cause and severity of the pain. The knee joint is comprised of four bones called the tibia, femur, patella, and fibula that work in unison to promote movement. There are also additional muscles that play a role in knee extension and flexion such as the hamstrings and quadriceps. The hamstrings provide support for the back of the knee while the quadriceps provide support for the front of the knee.
Cartilage and ligaments also help stabilize the knee joint. More specifically, the posterior cruciate ligament (PCL) and the anterior cruciate ligament (ACL) are two cruciate ligaments that are located near the center of the knee which promote its rotation. Cartilage known as the lateral and medial meniscus provides cushion for the femur and tibia and prevents them from rubbing together. Furthermore, ligaments in the lateral and medial regions of the knee provide additional support.
An injury or irritation of any of these anatomical structures can manifest itself as inflammation or throbbing pain. For instance, rapidly twisting the knee while playing sports or engaging in other activities, may cause a tendon to become injured. Similarly, the gradual degeneration of cartilage may cause pain and inflammation. Assessing an individual’s medical history and performing imaging screening of the knee helps physicians identify the underlying problem in order to make an accurate diagnosis and recommend the appropriate knee joint injection.
How is a Knee Joint Injection Performed?
Preparation for the procedure involves sterilizing the injection site to prevent the development of an infection. A local anesthetic is administered to the skin after it has been sterilized and then a long-lasting steroid is injected directly into the knee joint.
In preparation for a platelet rich plasma injection, blood is drawn from the patient. The sample is placed in a centrifuge that separates the plasma from the blood. The isolated plasma, which contains a higher concentration of platelets, is then injected directly into the knee. A special real-time, imaging technique called fluoroscopy is used during this injection to ensure that the needle is inserted into the right location.
Corticosteroid injections are a common form of knee pain management that have been widely studied in order to evaluate their effectiveness. For example, a systematic review of more than 20 randomized controlled trials demonstrated that corticosteroid injections for knee pain provide short-term pain relief.
Research regarding hyaluronic acid injections for troubled knee joints has also demonstrated positive results. More specifically, a recent study reported that hyaluronic acid injections result in consistently positive therapeutic outcomes for patients who are suffering from osteoarthritis-induced knee pain.
Additionally, a study published in the journal of Knee Surgery, Sports Traumatology, and Arthroscopy describes platelet rich plasma injections as a successful treatment approach for knee pain. According to the researchers, statistical analysis was conducted on patients who received platelet rich plasma injections for knee pain. By the end of the study, a significant improvement in symptoms was observed in patients who the platelet rich plasma injections were administered to in comparison to the placebo group.
Knee joint injectionsare safe and non-invasive, but may still pose a few rare side effects and risks such as facial flushing, bruising, an allergic reaction, an infection, nerve damage, and bleeding.
Conditions Related To Knee Joint Injections
The prevalence of knee pain in the United States is quite high, with the majority of the cases being attributed to osteoarthritis. This condition develops when the gradual wear and tear or degeneration of cartilage causes pain and inflammation. Furthermore, reports from the Centers for Disease Control and Prevention indicate that approximately 50% of adults 65 years of age or older have arthritis.
Knee joint injections are not a cure or prevention for osteoarthritis, but physicians generally recommend them along with additional methods as a means of managing the pain that is associated with arthritis. However, in addition to treating osteoarthritis-induced pain, knee joint injections have demonstrated the ability to reduce pain that is caused by gout, bursitis, cartilage tears, and tendonitis.
Knee joint injectionsare a conventional treatment option for knee pain. This well-established procedure does not require surgery and has repeatedly been shown to be a safe and effective method through clinical trials. Patients who undergo successful knee joint injections are typically able to quickly return to their normal daily routines, especially because this procedure can be performed in an outpatient setting.
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- Sampson, S, Reed N, Silvers H, Meng M, Mandelbaum B. Injection of platelet-rich plasma in patients with primary and secondary knee osteoarthritis: a pilot study. Am J Phys Med Rehabil. 2010;89(12):961-969.