Steroid Injections Overview
Knee pain can be debilitating, affecting everyday activities and overall quality of life. One commonly utilized treatment option for knee pain includes steroid injections, specifically cortisone shots.
Introduction to Steroid Injections
Corticosteroid injections, often referred to as cortisone shots, are used to deliver medication directly to a problem area in the body. These injections are used to reduce inflammation and help manage conditions such as arthritis, tendinitis, or bursitis.
Healthcare providers typically administer these injections for inflammation in joints, tendons, or bursae. Bursae are fluid-filled sacs that provide cushioning around and between joints, tendons, and bones.
Steroid injections, including cortisone shots, are frequently used as a first-line treatment for joint pain. They can effectively reduce inflammation and pain swiftly, providing relief that typically lasts about three months for chronic pain. However, repeated and long-term use of these injections can potentially have side effects on the cartilage in the joint and throughout the body.
Mechanism of Action
Corticosteroid injections work by calming the immune system's response in the specific location of the injection. This action helps manage symptoms or conditions that may hinder day-to-day activities by reducing pain and inflammation.
Though steroid injections like cortisone shots are an effective short-term solution, they are recommended for occasional use only due to potential long-term side effects. For those experiencing knee osteoarthritis, it's important to note that while steroid injections can provide temporary relief, other types of injections lack strong supporting data for their effectiveness in treating this condition [3].
As with any medical treatment, it's essential to discuss the potential risks and benefits with a healthcare provider before deciding on the best course of action. This conversation should include a comprehensive understanding of the different types of steroid injections for knee pain and how each may affect the individual's specific condition.
Types of Steroid Injections
When it comes to alleviating knee discomfort, there are various types of steroid injections available. These injections are used to deliver medication directly to a problem spot in the body to reduce inflammation and help treat conditions like arthritis, tendinitis, or bursitis.
Corticosteroid Injections
Corticosteroid injections, also known as cortisone shots, are commonly used for knee pain. They work by reducing inflammation in joints, tendons, or bursae, the fluid-filled sacs that cushion spaces around and between joints, tendons, and bones. The aim is to calm the immune system's response in the specific location of the injection, which helps manage symptoms or conditions that hinder day-to-day activities.
Intra-articular corticosteroid injections are conditionally recommended by the American College of Rheumatology/Arthritis Foundation (ACR) for patients with knee and/or hip osteoarthritis. Though the benefits of corticosteroid injections may be relatively short-lived (<4 weeks), they have shown good short-term outcomes.
Combined Injections
Combined injections are an option for treating knee pain. These injections can include a mix of corticosteroids and other medications, designed to target multiple areas of inflammation. The specific combination used will depend on the patient's individual needs and the physician's judgement.
Risks and Benefits
While corticosteroid injections can provide relief from knee pain, they also come with potential risks. These can include skin discoloration, fat atrophy at the injection site, elevated blood sugar levels, weakened tendons, and potential negative impact on cartilage.
| Potential Risk |
Description |
| Skin Discoloration |
Can occur weeks or months after the injection, especially in darker-skinned patients. Not harmful but can be permanent, affecting 1.3% to 4% of patients. |
| Fat Atrophy |
Can cause a divot or depression in the skin. Usually returns to normal within 6 months to 2-3 years. Occurs in an estimated 0.6% of injections. |
| Elevated Blood Sugar Levels |
Can impact blood sugar levels, especially in diabetic patients. Patients with diabetes should inform their doctors before the injection and monitor blood sugar levels closely for a day or two post-injection. |
| Weakened Tendons |
Can make tendons more susceptible to tearing. Physicians avoid injecting cortisone directly into or next to a tendon. |
| Negative Impact on Cartilage |
Repeated cortisone injections associated with a 0.11 cm loss of cartilage in the knee. However, the same study did not find an association with increased knee pain. |
Despite these risks, corticosteroid injections remain a valuable tool for managing knee pain. By understanding the potential risks and benefits, patients and healthcare providers can make informed decisions about the best course of treatment.
Hyaluronic Acid Injections
Hyaluronic acid injections are another treatment option for knee pain, particularly in cases of knee osteoarthritis. While the use of these injections is considered unsupported by the latest guidelines, some evidence supports their efficacy for pain reduction and functional improvement in knee osteoarthritis [4].
Efficacy of Hyaluronic Acid
Hyaluronic acid injections, also known as knee gel injections, mimic the normal cushioning fluid inside the joints and have been shown to provide relief from knee pain that can last from 6 to 12 months. These injections are especially beneficial in cases of mild to moderate arthritis.
However, the optimal dosing regimen and type of hyaluronic acid product to use remain unclear [6]. Good outcomes for both pain reduction and functional improvement have been reported, but these are limited to studies that used high molecular weight viscosupplementation with a course of two to four injections per year.
Considerations and Effectiveness
While hyaluronic acid injections can be effective in relieving knee pain, it's important to consider that these injections are generally recommended if other treatments like medication, exercise, or other types of steroid injections for knee pain have not been successful, and knee replacement is not yet necessary.
Viscosupplementation, which involves injecting hyaluronic acid gel into the joint, is another type of knee injection. However, studies show that it isn't very effective for knee osteoarthritis symptoms. Furthermore, insurance companies may require prior authorization for coverage, and the number of injections depends on the brand, with potential repetition every 6 months [3].
Ultimately, while hyaluronic acid injections can be beneficial for some individuals with knee pain, it's important to discuss this treatment option with a healthcare provider to determine whether it's the right choice based on individual needs and circumstances.
Platelet-Rich Plasma (PRP)
Among the various types of steroid injections for knee pain, platelet-rich plasma (PRP) injections have emerged as a potential solution for some patients.
PRP for Knee Pain
PRP injections have shown mixed results for the treatment of knee osteoarthritis. Some studies have demonstrated improvement in pain and function for mild to moderate osteoarthritis, while others showed no difference. Due to their cost, lack of insurance coverage, and mixed efficacy results, experts do not routinely recommend PRP injections [3]. However, PRP injections have been found to be superior to hyaluronic acid injections in reducing pain and improving function in patients with knee osteoarthritis [7].
Autologous conditioned serum (ACS) injections, derived from a patient's own blood and containing anti-inflammatory molecules, have shown benefits in a few small studies for knee osteoarthritis. However, due to limited data, higher cost compared to other injections like PRP, and lack of insurance coverage, experts do not recommend ACS.
Safety and Efficacy
PRP has a good safety profile and may offer advantages over other conservative treatments. PRP injections have also been shown to be effective in comparison to corticosteroid injections for relieving pain and improving the quality of life in patients with knee osteoarthritis. PRP may be particularly beneficial for older patients [8].
However, PRP injections are strongly not recommended for knee osteoarthritis due to concerns about heterogeneity and lack of standardization in available preparations of PRP. As such, while PRP can be beneficial for some patients, it's important to consult with a healthcare professional to determine the most suitable treatment option based on individual health conditions and needs.
Alternative Injections
While corticosteroids and hyaluronic acid injections are commonly administered for knee pain, there are other alternative injections that can also provide relief. These include prolotherapy injections and orthobiologics, including stem cells.
Prolotherapy Injections
Prolotherapy injections, which use concentrated sugar water (dextrose), aim to relieve joint, ligament, and tendon pain. These injections can help reduce pain from osteoarthritis and chronic tendon and ligament injuries. While they are rarely covered by insurance, prolotherapy has shown strong research evidence for helping knee arthritis and tennis elbow [2]. According to the NCBI, periarticular prolotherapy has comparable effects on pain and disability due to knee OA to intra-articular injections, while avoiding risks of complications.
Orthobiologics and Stem Cells
Orthobiologics, a newer category of injectables, show potential in promoting healing in tissue. These injections are made from the patient's own blood or tissue. Although research has not definitively proven their efficacy, they have been used to target arthritic joints and chronic tendon problems in various parts of the body. However, it's important to note that orthobiologics are not FDA-approved for treating arthritis or joint conditions and are not commonly covered by insurance.
One type of orthobiologic injection is the autologous conditioned serum (ACS) injections. Derived from a patient's own blood and containing anti-inflammatory molecules, ACS injections have shown benefits in a few small studies for knee osteoarthritis. However, due to limited data, higher cost compared to other injections like PRP, and lack of insurance coverage, experts do not recommend ACS [3].
Stem cell injections, another form of orthobiologic treatment, involve injecting stem cells into an arthritic knee to encourage damaged cartilage to regrow and heal, and reduce inflammation. Stem cells, obtained from the individual's body typically from bone marrow in the pelvic bone, can help improve function and relieve pain after two to six weeks.
These alternative injections are part of the broader spectrum of options for managing knee pain. It's important that patients discuss these options with their healthcare provider to determine the best approach for their individual needs.
Injection Side Effects
While the types of steroid injections for knee pain can provide significant relief, they may also lead to certain side effects. It's essential to consider these potential side effects, ranging from common immediate reactions to long-term considerations.
Common Side Effects
Cortisone injections for knee pain can lead to a few common side effects. For instance, skin discoloration may occur weeks or months after the injection, especially in darker-skinned patients. This side effect is not harmful but can be permanent, affecting 1.3% to 4% of patients. The occurrence seems to be linked to the type and concentration of corticosteroid medication used.
Another common side effect is fat atrophy at the injection site, which can cause a divot or depression in the skin due to deteriorated fat cells. While the skin's appearance usually returns to normal within 6 months to 2-3 years, this side effect occurs in an estimated 0.6% (6 out of every 1000) injections.
Additionally, cortisone injections for knee pain can elevate blood sugar levels, especially in diabetic patients. Although the injection does not deliver cortisone directly to the bloodstream, it can still impact blood sugar levels. Patients with diabetes should inform their doctors before the injection and monitor blood sugar levels closely for a day or two post-injection.
Long-Term Considerations
Cortisone injections for knee pain may have long-term side effects that require careful consideration. For instance, they may weaken nearby tendons, making them more susceptible to tearing. Due to this risk, physicians avoid injecting cortisone directly into or next to a tendon. Patients can reduce the risk by resting the joint post-injection and gradually increasing activity with recommended stretching and exercises [5].
Furthermore, research indicates that cortisone injections for knee pain could have a negative impact on cartilage. For instance, a study found an association between repeated cortisone injections and a 0.11 cm loss of cartilage in the knee. However, the same study did not find an association with increased knee pain.
Given these potential side effects, patients should discuss the risks and benefits with their healthcare provider before opting for steroid injections for knee pain. It's crucial to make an informed decision that prioritizes long-term knee health and pain management.
References
[1]: https://my.clevelandclinic.org/health/treatments/cortisone-shots-steroid-injections
[2]: https://www.massgeneralbrigham.org/en/about/newsroom/articles/types-of-injections-that-can-help-with-joint-pain
[3]: https://www.goodrx.com/conditions/arthritis/injections-for-knee-pain
[4]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8096293/
[5]: https://www.arthritis-health.com/treatment/injections/cortisone-injection-risks-and-side-effects
[6]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9484571/#:~:text=A%20total%20of%2086%20studies,%2DFunction%2C%20and%20WOMAC%2DTotal.
[7]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9484571/#:~:text=A%20pooled%20estimate%20of%2012,12%20months%20and%2022%20months.
[8]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9484571/#:~:text=Similarly%2C%20in%202019%2C%20another,in%20patients%20with%20knee%20OA.
[9]: https://nyulangone.org/conditions/osteoarthritis-of-the-knee/treatments/therapeutic-injections-for-osteoarthritis-of-the-knee
