Steroid injection therapy, specifically intra-articular corticosteroid injections, is a common treatment for osteoarthritis (OA) of the knee and shoulder. These injections are designed to fight inflammation, relieve pain, and improve joint movement. They’re typically used when conservative options like oral medications and physical therapy fall short.
But like any treatment, steroid injections come with benefits and risks. Understanding both sides is key before making a decision.
How Steroid Injections Work
Mechanism of Action
Corticosteroids mimic hormones naturally produced by the adrenal glands. When injected directly into a joint or muscle, they work by reducing inflammation, redness, and swelling. In osteoarthritis, inflammation is a major cause of pain and joint stiffness, particularly in weight-bearing joints like the knees and complex ones like the shoulders.
Pharmacokinetics and Duration of Action
The effectiveness of a steroid injection depends heavily on the type of corticosteroid used. Here’s the difference:
- Short-acting corticosteroids like dexamethasone sodium phosphate provide quick relief with fewer local side effects.
- Long-acting corticosteroids such as triamcinolone hexacetonide stay longer in the joint, offering extended pain relief but increasing the risk of side effects.
Many doctors use a mix of both short- and long-acting steroids to achieve immediate and prolonged relief.
Biological Impact
Steroid injections reduce synovial blood flow, decrease inflammatory responses, and alter collagen synthesis in the joint. While these effects help alleviate pain, repeated exposure may weaken tendon tissue and cartilage over time. That’s why these injections are best used as short-term support while patients begin long-term solutions like rehab and physical therapy.
When Are Steroid Injections Recommended?
Knee Osteoarthritis
Steroid injections are commonly used for patients with moderate to severe knee OA when:
- Pain interferes with daily activities
- Oral medications and physical therapy haven’t worked
- Surgery isn’t an option due to age or comorbidities
Studies show relief may last up to two weeks, but long-term use has risks, like cartilage degradation, muscle atrophy, or joint instability. That’s why these injections should be used sparingly and in select cases.
Shoulder Osteoarthritis
In patients with shoulder OA, steroid injections help manage:
- Chronic pain in the acromioclavicular (AC) joint
- Limited range of motion
- Pain not relieved by analgesics or physical therapy
While helpful in severe cases, frequent injections can cause joint degeneration. Careful evaluation is necessary to balance short-term relief with long-term joint health.
Pros of Steroid Injections for OA
1. Rapid Pain Relief
Steroids act fast. Some patients notice a reduction in pain within hours or days of the injection. By calming inflammation directly at the joint, steroids make daily tasks like walking, lifting, or even sleeping easier.
2. Anti-Inflammatory Action
Corticosteroids suppress the immune response that drives inflammation. This lowers swelling, redness, and joint warmth—key contributors to OA discomfort.
3. Improved Mobility
With less pain and inflammation, patients often experience better movement in the affected joint. This is particularly important for:
- Starting or resuming physical therapy
- Returning to daily activities
- Preventing stiffness and muscle loss from inactivity
4. Bridge to Rehab
Steroid injections don’t cure OA, but they can buy time. The temporary relief helps patients participate in strengthening and mobility programs that target the root of the problem.
5. Quick and Targeted
Unlike oral medications that affect the whole body, intra-articular injections act right at the problem site. That means stronger effects with fewer systemic complications, at least in the short term.
Cons of Steroid Injections for OA
Temporary Relief Only
Steroid injections are not a cure—they’re a band-aid. Relief typically lasts a few weeks to a couple of months, and symptoms usually return. Relying too much on them can delay more effective long-term care, like exercise or joint replacement surgery.
Local Side Effects
Common localized side effects include:
- Post-injection flare (worsening of pain for a day or two)
- Skin thinning or color changes at the injection site
- Tendon weakening or rupture
- Risk of joint infection
- Accelerated OA progression if overused
Systemic Side Effects
Even though injections are localized, corticosteroids can enter the bloodstream and cause broader side effects, especially with frequent use. These include:
- Increased blood sugar levels (problematic for diabetics)
- Suppressed adrenal gland function
- Higher risk of infections
- Worsened hypertension or ulcers
Mood and Hormonal Effects
Some patients report:
- Mood swings (euphoria, anxiety, or depression)
- Temporary menstrual changes in women
These effects are usually short-lived but should be discussed with your provider if you have a history of hormonal or mental health issues.
Long-Term Joint Damage
Repeated injections over time can degrade cartilage, affect chondrocyte function, and even lead to osteonecrosis (bone death). These are serious and often irreversible complications that underscore the importance of moderation.
Finding the Right Balance
Steroid injections can be incredibly helpful, but only when used wisely. They’re best viewed as a stepping stone, not a destination.
Use Them To:
- Jumpstart physical therapy
- Manage flares of severe pain
- Delay surgery for a short period
Avoid Them If:
- You’ve had multiple injections recently
- Your symptoms are mild and manageable with lifestyle changes
- You’re not planning any follow-up rehab or strengthening work
The Bottom Line
Steroid injections for OA of the knee and shoulder are effective, fast-acting tools for temporary relief. They reduce pain, improve mobility, and help patients participate in physical therapy. However, they’re not without risk, and overuse can cause more harm than good.
Always work with a healthcare provider to determine if a 4-6 month injection interval (or fewer) is right for you. And remember: the goal isn’t just pain relief, it’s lasting joint health.
