Corticosteroid Injections: What are They and How Do They Work?

Summary

Corticosteroid injections are shots that help reduce pain and swelling in joints and soft tissues. They are used for problems like arthritis or tendon irritation. These shots can give fast relief, but they don’t fix the problem for good. Doctors use them carefully because too many can cause side effects, like weakening tendons or making arthritis worse. In some areas, like near the Achilles tendon, they should not be used at all. If used the right way, they can be a helpful part of treatment for joint and soft tissue problems.

Background

Corticosteroid injections, sometimes called “cortisone shots,” are a type of medicine used to reduce inflammation (swelling and irritation) in the body. They are man-made versions of hormones your body naturally produces in the adrenal glands. When injected into a painful or swollen area, corticosteroids help to calm the immune system, relieve pain, and reduce swelling. These shots don’t cure the underlying condition, but they can give fast and often powerful relief from symptoms like pain and stiffness.

When and Where Are Corticosteroid Injections Given?

Doctors often use corticosteroid injections to treat joint pain, bursitis, tendinitis, or arthritis. They are commonly given in joints such as the knee, shoulder, hip, elbow, and even small joints like those in the fingers. Injections can also be used near soft tissues like the spine or plantar fascia in the foot. These shots are often used when other treatments, like physical therapy or oral medications, have not worked well enough. Doctors may also give them to help with inflammatory conditions such as rheumatoid arthritis or certain types of back pain.

What Do Medical Guidelines Say About Results?

Most medical guidelines, including those from the American Academy of Orthopaedic Surgeons (AAOS), agree that corticosteroid injections can provide short-term relief of pain and swelling—especially in joints with osteoarthritis. Many patients feel better within a few days and may see relief that lasts from weeks to several months. However, these benefits are usually temporary, and the shots do not stop disease progression. Also, repeated injections in the same spot may lead to diminishing results over time.

Side Effects and Potential Complications of Corticosteroid Injections

While corticosteroid injections are generally safe, they do carry some risks. Repeated or high-dose injections can lead to weakened tendons and may speed up joint damage, especially in areas already affected by arthritis. For example, corticosteroids should not be injected near the Achilles tendon or the patellar tendon (kneecap tendon), as they can increase the risk of tendon rupture. Other side effects can include skin thinning, temporary increase in blood sugar levels, or joint infection—though the risk of serious problems is low when injections are used carefully and sparingly.

Common Corticosteroids Used for Injections

Triamcinolone acetonide (Kenalog®)

Most commonly used in orthopaedics

Advantages

• Strong anti-inflammatory effect
• Medium-to-long duration (weeks to months)
• Widely available and inexpensive
• Works well for joints, bursae, and tendon sheaths

Disadvantages

• Higher risk of skin thinning or depigmentation if injected too superficially
• Can crystallize → post-injection flare in some patients
• Not ideal for very small or superficial structures unless carefully placed

Best for

• Large and medium joints (knee, shoulder)
• Bursitis
• Tendon sheath injections (with care)

Methylprednisolone acetate (Depo-Medrol®)

Very common alternative to triamcinolone

Advantages

• Good anti-inflammatory effect
• Slightly more soluble than triamcinolone
• Lower risk of crystal-related flare
• Familiar to most clinicians

Disadvantages

• Slightly shorter duration than triamcinolone
• Still carries risk of skin atrophy if superficial

Best for

• Joints and bursae
• Situations where a smoother onset is preferred

Betamethasone (Celestone® Soluspan)

High potency, low volume

Advantages

• Very potent anti-inflammatory effect
• More soluble → less crystal-related irritation
• Smaller injected volume needed
• Lower risk of skin atrophy than triamcinolone

Disadvantages

• Shorter duration than triamcinolone
• More systemic absorption → slightly higher risk of blood sugar spikes
• More expensive

Best for

• Small joints (hand, wrist)
• Tendon sheath injections
• Situations where skin safety matters

Dexamethasone

Highly soluble, short-acting

Advantages

• Minimal crystal formation
• Lowest risk of post-injection flare
• Safer for superficial injections
• Very low risk of skin depigmentation

Disadvantages

• Short duration (days to 1–2 weeks)
• Less effective for chronic conditions
• More systemic absorption relative to duration

Best for

• Superficial structures
• Diagnostic injections
• Patients at higher risk for skin complications

Hydrocortisone

Least potent steroid

Advantages

• Very low risk of tissue damage
• Short-acting and predictable
• Historically well understood

Disadvantages

• Weak anti-inflammatory effect
• Very short duration
• Rarely effective for musculoskeletal injections

Best for

• Rarely used today in orthopaedics
• Occasionally for very mild inflammatory conditions

Edited by Stephen Pinney MD, February 3rd 2026.