Most cortisone reactions settle, but some need quick care

A short rise in soreness should begin to ease

The needle area may stay tender, and the knee may feel fuller than usual. Flushing, thinner skin, or a color change near the needle spot can also occur.

Ask how the knee may feel that evening and during the next few days. Get clear limits for walking, driving, work, and using a cold pack.

A knee that slowly settles is different from one that worsens each day. Call when pain, heat, or swelling grows instead of easing.

Cortisone can raise blood sugar for a time

Medicine placed in the knee can still affect the rest of your body. Cortisone may cause flushing, higher blood pressure, or a brief rise in blood sugar.

If you have diabetes, bring recent readings to the visit. Ask when to check again, what reading needs a call, and whom to contact.

Don’t change diabetes medicine before speaking with the person who manages it. The rise often passes, but the safe limit is different for each person.

Growing heat and swelling need prompt care

Infection after a needle treatment is uncommon, but it can become serious. A knee that grows hotter, larger, and more painful isn’t a usual reaction.

Fever or feeling ill adds to the concern. Get medical help promptly instead of waiting for the next office visit.

An online answer can’t tell infection from a short reaction in your knee. An exam can show whether care needs to begin quickly.

Repeated cortisone deserves a fresh decision

One long trial found more cartilage loss with repeated cortisone and no added pain relief. Another long trial found no extra joint-space loss and better soreness.

These results don’t show that one shot will damage your knee. They do show why another shot should not be automatic.

Ask how much the last one helped and how long that relief lasted. Diabetes, planned replacement surgery, and how well you walk can change the decision.

Sources

1. A 2024 AJR review of corticosteroid injection side effects lists local effects (post-injection flare, skin hypopigmentation and atrophy, infection, tendon rupture, accelerated osteoarthritis progression, osseous injury) and systemic effects (adrenal suppression, facial flushing, hypertension, hyperglycaemia, osteoporosis), and calls for targeted pre-injection counselling for specific populations.

   Kamel SI, et al. — Local and Systemic Side Effects of Corticosteroid Injections for Musculoskeletal Indications.. AJR Am J Roentgenol, 2024. DOI: 10.2214/AJR.23.30458.

2. A review of systemic absorption after locally injected glucocorticoid found substantial individual variability, and established that both intra-articular and epidural injections can produce systemic effects lasting WEEKS - while noting there are no guidelines addressing systemic absorption or overall systemic risk.

   Stout A, et al. — Systemic Absorption and Side Effects of Locally Injected Glucocorticoids.. PM R, 2019. DOI: 10.1002/pmrj.12042.

3. A JBJS Reviews synthesis notes that although severe complications of corticosteroid injection - infection, tendon rupture, osteonecrosis - are rare, less severe skin reactions and flare responses are not, and that effects on blood glucose matter particularly for patients with diabetes.

   Honcharuk E, et al. — Complications Associated with Intra-Articular and Extra-Articular Corticosteroid Injections.. JBJS Rev, 2016. DOI: 10.2106/JBJS.RVW.16.00004.

4. A review of ten studies found single local corticosteroid injections caused a significant but TRANSIENT rise in blood glucose in patients with diabetes, with no adverse reactions or complications reported, and concluded such injections are most likely safe in people whose diabetes is well controlled.

   Waterbrook AL, et al. — Blood Glucose Levels After Local Musculoskeletal Steroid Injections in Patients With Diabetes Mellitus: A Clinical Review.. Sports Health, 2017. DOI: 10.1177/1941738117702585.

5. A Danish register study of all intra-articular procedures performed on Funen over eight years measured the frequency of septic arthritis within 14 days of a glucocorticoid injection as LOW, under a local protocol using a non-touch sterile technique with patients advised to seek care on suspicion of infection.

   Petersen SK, et al. — Low frequency of septic arthritis after arthrocentesis and intra-articular glucocorticoid injection.. Scand J Rheumatol, 2019. DOI: 10.1080/03009742.2019.1584329.

6. A 2017 MMWR outbreak report describes 41 cases of septic arthritis following intra-articular injections given during 250 patient visits at a single New Jersey outpatient practice, 30 (73%) of whom needed surgery; recovered organisms were oral flora and the investigation found multiple breaches of infection-prevention practice.

   Ross K, et al. — Outbreak of Septic Arthritis Associated with Intra-Articular Injections at an Outpatient Practice - New Jersey, 2017.. MMWR Morb Mortal Wkly Rep, 2017. DOI: 10.15585/mmwr.mm6629a3.

7. A 2019 Radiology review catalogued four adverse joint findings structurally observed after intra-articular corticosteroid injection of the hip and knee: accelerated osteoarthritis progression, subchondral insufficiency fracture, complications of osteonecrosis, and rapid joint destruction including bone loss.

   Kompel AJ, et al. — Intra-articular Corticosteroid Injections in the Hip and Knee: Perhaps Not as Safe as We Thought?. Radiology, 2019. DOI: 10.1148/radiol.2019190341.

8. In the Osteoarthritis Initiative cohort (684 propensity-matched participants), knees whose owners started intra-articular corticosteroids had radiographic OA worsening at 21.7 per 100 person-years versus 7.1 in comparators; the hazard ratio for Kellgren-Lawrence worsening was 3.02 for initiation, higher still for continuous use.

   Zeng C, et al. — Intra-articular corticosteroids and the risk of knee osteoarthritis progression: results from the Osteoarthritis Initiative.. Osteoarthritis Cartilage, 2019. DOI: 10.1016/j.joca.2019.01.007.

9. In a 2-year double-blind RCT of 140 patients with symptomatic knee OA and ultrasound synovitis, 40 mg intra-articular triamcinolone every 12 weeks produced significantly greater cartilage volume loss than saline (index compartment cartilage thickness change -0.21 mm vs -0.10 mm; between-group difference -0.11 mm, 95% CI -0.20 to -0.03) with no significant difference in knee pain.

   McAlindon TE, et al. — Effect of Intra-articular Triamcinolone vs Saline on Knee Cartilage Volume and Pain in Patients With Knee Osteoarthritis: A Randomized Clinical Trial.. JAMA, 2017. DOI: 10.1001/jama.2017.5283.

10. A 2-year double-blind RCT of triamcinolone every 3 months versus saline found NO difference in joint space loss between groups and significantly improved pain and stiffness with repeated steroid injections, and the authors concluded that long-term intra-articular steroid injection is safe for the anatomical structure of the knee.

    Raynauld JP, et al. — Safety and efficacy of long-term intraarticular steroid injections in osteoarthritis of the knee: a randomized, double-blind, placebo-controlled trial.. Arthritis Rheum, 2003. DOI: 10.1002/art.10777.

11. A meta-analysis estimated the incidence of rapidly progressive osteoarthritis after hip corticosteroid injection at 6% (95% CI 3-9%) among the 10 studies designed to detect it, while noting definitions varied widely, many cases were not severe, selection bias is likely, and 17 of 27 studies - including every study cited in the AAOS recommendation - could not have detected the outcome at all.

    Sabatini FM, et al. — Incidence of Rapidly Progressive Osteoarthritis Following Intra-articular Hip Corticosteroid Injection: A Systematic Review and Meta-Analysis.. Arthroplast Today, 2023. DOI: 10.1016/j.artd.2023.101242.

12. In a controlled cohort of 1,471 patients injected in the hip, 106 (7.2%) developed rapidly progressive idiopathic arthritis; compared with controls they were older, had narrower joint spaces and higher Croft scores before injection - so pre-injection joint severity, not the injectate or the anaesthetic, marked the at-risk group.

    Boutin RD, et al. — Rapidly progressive idiopathic arthritis of the hip: incidence and risk factors in a controlled cohort study of 1471 patients after intra-articular corticosteroid injection.. Skeletal Radiol, 2021. DOI: 10.1007/s00256-021-03815-7.