Cortisone shots are a common medical intervention for managing knee pain, especially when inflammation is involved. These injections can provide significant relief for conditions like osteoarthritis, which often causes discomfort and swelling in the knee joint. For many individuals experiencing chronic knee pain, cortisone injections offer a way to alleviate symptoms and improve daily function.
Understanding Cortisone Injections
Cortisone, a synthetic corticosteroid, mimics cortisol, a hormone produced by the adrenal glands. When injected into the knee, it reduces inflammation by suppressing the body’s inflammatory response. This action helps calm nerves and reduce pain and swelling.
Cortisone itself is not a pain reliever like an anesthetic; its primary role is to decrease inflammatory processes contributing to pain. A local anesthetic like lidocaine is often combined with cortisone for immediate relief while the corticosteroid begins its anti-inflammatory work, which can take a few days. The goal of these injections is to target inflammation within the joint space, offering localized relief.
Recommended Frequency and Limits
Medical professionals advise caution regarding the frequency of cortisone injections into the knee. While there is no lifetime limit, doctors recommend no more than three or four injections into a single joint within a year. A waiting period of at least three months between injections in the same knee is suggested to allow the joint to recover. For chronic conditions, some individuals might require multiple injections over time, but these guidelines help balance symptom relief with potential risks.
The rationale behind these limits centers on concerns about the long-term effects of corticosteroids on joint tissues. Frequent injections have been linked to damage to cartilage, the smooth tissue covering the ends of bones in a joint. There is also a risk of weakening tendons around the injection site, making them more susceptible to rupture. Adhering to these guidelines minimizes risks while allowing patients to benefit from the treatment’s anti-inflammatory effects.
Potential Risks and Considerations
While cortisone injections can be effective, they carry side effects and risks that patients should consider. Immediately following an injection, some individuals may experience a temporary increase in pain, swelling, and irritation in the joint, known as a “cortisone flare,” which subsides within one to two days. Other common side effects include bruising, skin discoloration or lightening at the injection site, and facial flushing.
More serious, though rare, complications can occur. These include joint infection, nerve damage, or significant weakening or rupture of nearby tendons. For individuals with diabetes, cortisone injections can temporarily elevate blood sugar levels for several days, requiring careful monitoring. Repeated injections may also contribute to thinning of the skin and soft tissues around the injection site, or in very rare cases, bone death (osteonecrosis) or accelerated progression of osteoarthritis.
When Cortisone Shots May Not Be Ideal
Cortisone injections are not always the appropriate treatment option for knee pain. In cases of severe joint degeneration, where structural damage to the knee is extensive, the injections may offer limited or no benefit. If inflammation is not the primary cause of pain, or if the pain is due to mechanical issues rather than an inflammatory process, cortisone may not be effective.
Certain patient conditions can also make cortisone injections less ideal or contraindicated. Patients with an active infection at the injection site or in the joint should not receive cortisone due to the risk of spreading the infection. Individuals with poorly controlled diabetes may face challenges with temporary blood sugar spikes following the injection. If a patient is scheduled for knee surgery soon, doctors might advise against a recent cortisone injection, as it could increase the risk of postoperative infection or negatively affect wound healing.