Can You Tolerate Repeated Orthopedic Injections?

Many patients with osteoarthritis or chronic joint pain receive orthopedic injections over several years. A common question follows: does the body get used to them, and is it safe to keep repeating them? The answer depends largely on the type of injection, the spacing between treatments and the evolution of the joint itself.

Understanding Orthopedic Injection Tolerance

Tolerance can mean two things. The first is how well the body accepts a product over repeated treatments, without increasing side effects. The second is whether the injection continues to provide the same relief over time. Both are important when planning long-term treatment.

How the Body Responds to Repeated Injections

With corticosteroids, the anti-inflammatory effect usually remains, but repeated injections at short intervals into the same joint may affect cartilage and surrounding tissue. This is why clinicians limit the number of corticosteroid injections per joint each year.

With hyaluronic acid viscosupplements, the body does not develop resistance in the usual sense. The product is gradually broken down and eliminated, which is why repeat courses are needed. Products such as SYNVISC®, MONOVISC®, DUROLANE® and ORTHOVISC® are generally well tolerated over successive treatments.

With combination products such as CINGAL®, spacing follows the precautions for the corticosteroid component.

With PRP, since the product comes from the patient’s own blood, there is no immune tolerance issue, but the response varies from one person to another.

What the Evidence Shows

Studies on repeated viscosupplementation in knee osteoarthritis have reported that repeated courses are well tolerated and that the benefit can be maintained over several cycles in suitable patients. For corticosteroids, studies have suggested that frequent, repeated intra-articular injections may be associated with greater cartilage loss, which supports the practice of spacing them out. Data on repeated PRP injections remain more limited and vary between protocols.

Factors That Influence Tolerance and Effectiveness

• The progression of osteoarthritis: when the joint becomes more damaged, each injection may provide less relief.
• Weight, activity level and muscle strength.
• The accuracy of the injection into the joint space.
• The interval between treatments.
• The patient’s general health and inflammatory conditions.

Our article on how lifestyle influences injection success explains how daily habits affect results.

How to Space Treatments Safely

• Corticosteroids: usually at least three to four months apart, with a limited number per joint each year.
• Viscosupplements: generally every six to twelve months, depending on the product and the duration of relief.
• Combination products: according to the corticosteroid component and the product’s instructions for use.
• PRP: often a series, followed by maintenance spaced several months apart.

Our article on how often you can get an orthopedic injection details these intervals.

Maintaining Efficacy With Repeated Injections

Physiotherapy, strengthening exercises, weight management and regular low-impact activity help each injection last longer. Accurate placement, sometimes under ultrasound guidance, and a product suited to the diagnosis also contribute.

What the Evidence Says About Safety

Viscosupplements have a favourable safety profile over repeated courses; the most common side effects are temporary pain or swelling at the injection site. Corticosteroids require more caution because of their potential effects on cartilage, skin and blood sugar. In Canada, any suspected adverse reaction can be reported to Health Canada through the Canada Vigilance Program. See our article on orthopedic injection side effects.

When to Reassess or Modify Treatment

Treatment should be reassessed when relief becomes noticeably shorter, when symptoms change or when imaging shows significant progression. The clinician may then adjust the interval, change the product or discuss other options, including surgery. Clinics can compare all options in our orthopedic injections category.

References

1. Altman, R., Manjoo, A., Fierlinger, A., Niazi, F., & Nicholls, M. (2018). Efficacy and safety of repeated courses of hyaluronic acid injections for knee osteoarthritis: The AMELIA study. International Journal of Clinical Practice, 72(10), Article e13262. https://doi.org/10.1111/ijcp.13262​
2. Bannuru, R. R., Natov, N. S., Dasi, U. R., Schmid, C. H., & McAlindon, T. E. (2016). Safety of repeated injections of sodium hyaluronate for knee osteoarthritis: A systematic review and retrospective data analysis. The Open Rheumatology Journal, 10, 16–24. https://doi.org/10.2174/1874312901610010016​
3. Gunther, S. F., & Marks, M. R. (2009). Long-term effectiveness of repeat corticosteroid injections for trigger finger. Journal of Hand Surgery (American Volume), 34(6), 1029–1035. https://doi.org/10.1016/j.jhsa.2009.01.015​
4. Testa, G., Giardina, S. M. C., Sessa, A., Costarella, L., Stojanovic, S., & Biazzo, A. (2021). Intra-articular injections for knee osteoarthritis: A review of the literature. Journal of Clinical Medicine, 10(4), Article 685. https://doi.org/10.3390/jcm10040685​​