How Long to Wait for Hip Replacement After Cortisone Injections?

Most orthopedic surgeons recommend waiting at least three months between a cortisone injection into the hip and a total hip replacement. Research consistently shows that operating sooner raises the risk of a serious post-surgical infection called periprosthetic joint infection, or PJI. But the three-month figure is a floor, not a guarantee of safety, and factors like how many injections you’ve had and your overall health can shift the timeline considerably.

What the Evidence Says About the Three-Month Window

The three-month recommendation comes from multiple large studies and meta-analyses looking at infection rates after hip replacement in patients who previously received a cortisone shot directly into the joint. One key study found that people who had hip replacement within three months of a cortisone injection had an infection rate of about 2.4%, with roughly double the odds of infection compared to patients who hadn’t received a recent injection. Between three and six months after an injection, and between six and twelve months, the infection rates were not significantly different from patients who never had an injection at all.¹

A 2023 meta-analysis pooling data from studies on both hip and knee replacements confirmed this pattern, finding a clearly elevated risk of PJI when surgery happened within three months of an injection. The authors concluded that surgeons should avoid performing hip replacement during that window.² A separate meta-analysis published the same year, focusing specifically on the timing question, reached the same conclusion about the zero-to-three-month period being the danger zone.³

Some researchers have found that the risk may linger slightly beyond three months. One large study reported that cortisone injection within four months of surgery was associated with a higher rate of PJI at six-month follow-up compared to patients with no recent injection. When the shot was given within one month of surgery, the odds of infection were nearly twice as high; at four months out, the elevated risk had mostly faded.⁴ So while three months is the most commonly cited minimum, the risk doesn’t vanish like flipping a switch at that point. It’s more of a gradient that tapers over weeks.

Not every study has found a dramatic signal, though. One retrospective look at nearly 500 hips that went on to replacement after cortisone injection, with a mean of four months between the last injection and surgery, reported zero cases of PJI over a minimum two-year follow-up. About 200 of those hips had their last injection less than three months before surgery.⁵ This is a reminder that the absolute risk is still relatively low even for patients who don’t wait the full three months. The concern is that even a small increase in infection risk matters when the infection in question can mean additional surgery, prolonged antibiotics, and sometimes removal and reimplantation of the prosthesis.

Why Multiple Injections Raise the Stakes

Timing isn’t the only variable. How many injections you’ve received before surgery matters too, and it may matter more than most patients realize. One study comparing patients who had a single cortisone injection before hip replacement to those who had multiple injections found an infection rate of 2.0% in the single-injection group versus 6.6% in the multiple-injection group. That’s more than a threefold increase in odds.⁶

A dose-dependent relationship shows up in the data as well. Each additional cortisone injection given in the three months before hip replacement increased the odds of PJI, with the risk climbing steadily from about 1.5 times higher after one shot to more than 3.5 times higher after several.⁴ Another study found that receiving more than two cortisone injections within two years before hip replacement was linked to higher odds of infection within the first 90 days after surgery.⁷

The practical takeaway is that if you know hip replacement is on your horizon, limiting the number of cortisone injections you receive before surgery is just as important as waiting the right amount of time after the last one. Some patients end up in a cycle of repeated injections over months or years while delaying the decision to have surgery. Data suggest that patients who receive injections end up waiting several months longer before proceeding to hip replacement compared to those who don’t, which can mean more injections in the meantime.⁸ If you and your surgeon are already discussing replacement, it’s worth having a frank conversation about whether another injection is worth the incremental risk.

How Cortisone Affects the Body’s Defenses

The connection between cortisone injections and surgical infection risk isn’t just a statistical quirk. There’s a biological explanation. Corticosteroids are powerful anti-inflammatory agents, and their effectiveness at calming joint pain comes from the same property that makes them risky before surgery: they suppress the immune system.

When cortisone is injected into a joint, it doesn’t stay entirely local. Research on the systemic effects of peripheral cortisone injections shows that immune cells involved in fighting infections are suppressed for about 48 hours after the shot, and key signaling molecules that coordinate the immune response are dampened for over 96 hours. The body’s broader hormonal stress-response system can remain suppressed for two to four weeks or even longer.⁹ This temporary immune suppression means the body is less equipped to fight off bacteria that might be introduced during a major surgical procedure.

Beyond the immune effects, corticosteroids can also affect the cartilage and tissue in the joint itself. Studies have found that the common steroid drugs used in hip injections display dose-dependent harmful effects on cartilage cells. At low doses, some recovery and even cell growth has been observed, but at higher doses, the drugs are associated with cartilage damage and cell death.¹⁰ While this is more relevant to patients who are trying to preserve their joint than to someone about to have it replaced, it does mean that the tissue the surgeon works with during hip replacement can be in worse shape after multiple high-dose injections, potentially complicating the procedure.

How Well Cortisone Shots Work for Hip Arthritis Pain

If you’re reading this, there’s a good chance you’re weighing the tradeoff between managing your hip pain now and keeping your options open for surgery later. So it helps to know what cortisone shots actually deliver.

A randomized, double-blind trial comparing cortisone injection to a placebo injection in patients with hip osteoarthritis found striking short-term results. Patients who received cortisone saw their pain scores drop by about half at two months, compared to virtually no change in the placebo group. At three months, nearly 60% of patients in the cortisone group were still reporting meaningful pain relief, versus fewer than 10% of those who got a placebo.¹¹ That makes cortisone injections a genuinely effective bridge for people who need temporary relief, whether they’re waiting for surgery, trying to delay it, or aren’t sure they want it.

The flip side is that the relief is temporary. For most people, the benefits of a single hip injection fade within a few months. That’s what creates the temptation to repeat injections, and where the cumulative risk before surgery starts to build. If a single cortisone shot gives you three months of meaningful relief and you still aren’t ready for surgery, having one more shot and then scheduling your replacement at least three months after that last injection is a reasonable approach. The trap is getting four or five injections over a couple of years without a clear surgical plan, each one adding to the infection risk if and when surgery happens.

Personal Risk Factors That Can Shift the Calculus

The three-month waiting period is a general guideline, and your surgeon may adjust it based on your individual risk profile. Certain health conditions are independently associated with higher rates of PJI after joint replacement, and if you already carry one or more of these risk factors, the added risk from a recent cortisone injection becomes more concerning.

A systematic review of patient-related risk factors for PJI found that obesity is among the strongest predictors. Patients with a body mass index of 40 or higher had roughly 3.7 times the risk of PJI compared to non-obese patients. Diabetes, rheumatoid arthritis, depression, ongoing steroid use for other conditions, and previous surgery on the same joint were all associated with elevated risk as well.¹²

If you have several of these risk factors, your surgeon might recommend waiting longer than three months after a cortisone injection, or might skip cortisone altogether and manage your pain with other strategies. Conversely, a patient with no major risk factors who had a single injection three months ago is in a very different risk category than someone with diabetes and obesity who has had multiple injections over the past year. This is one of those situations where a blanket number gives you a starting point, but the real answer depends on who you are.

Hips and Knees Are Not the Same

If you’ve heard conflicting information about whether cortisone injections before joint replacement are risky, part of the confusion may come from lumping hip and knee replacements together. The evidence suggests that the hip is more sensitive to this problem than the knee.

A systematic review and meta-analysis that separated results by joint found that cortisone injection within 12 months before hip replacement was associated with significantly higher odds of PJI. For knee replacements, the same analysis did not find a statistically significant increase.¹³ The reasons for the difference aren’t entirely clear, but the hip joint sits deeper in the body than the knee, and the surgical approach involves more soft tissue dissection, which may make the joint more vulnerable to infection when the local immune environment has been altered by steroids.

This matters because much of the older literature on cortisone injections before joint replacement studied knees and hips together, and guidelines based on knee data may not be cautious enough for hips. If your surgeon seems more concerned about the timing of your hip injection than your friend’s surgeon was about their knee injection, that difference in approach is supported by the evidence.

What About Hyaluronic Acid Injections

Cortisone isn’t the only substance injected into arthritic hips. Hyaluronic acid, sometimes marketed as a “gel” or “viscosupplementation” injection, is an alternative that patients sometimes assume carries no surgical risk because it isn’t a steroid. That assumption is wrong.

A retrospective study of 565 patients found that hyaluronic acid injection within six months of hip replacement was associated with increased rates of PJI. The authors recommended avoiding hip replacement within six months of a hyaluronic acid injection.¹⁴ That’s actually a longer recommended waiting period than for cortisone. The mechanism is different since hyaluronic acid doesn’t suppress the immune system the way corticosteroids do, but the introduction of any substance into the joint creates a potential path for bacteria and may alter the local tissue environment in ways that matter during surgery.

If you’re considering an injection of any kind and hip replacement is a possibility in the next year, mention that to the doctor administering the injection. The waiting periods differ depending on the substance used, and factoring in surgical timing before the injection happens is much easier than trying to work backward after the fact.

When a Diagnostic Injection Actually Helps Surgical Planning

Not every cortisone injection before hip replacement is purely for pain management. Sometimes doctors inject the hip with a local anesthetic, often combined with a small amount of steroid, as a diagnostic tool. The idea is simple: if numbing the hip joint significantly reduces your pain, it confirms that the hip joint itself is the problem and not your back, your sacroiliac joint, or something else that can mimic hip arthritis.

This approach has real predictive value. One study looking at patients who had a diagnostic injection and then went on to hip replacement found that among those who had a good response to the injection, 93% had a good surgical outcome, with significant improvements in pain and function scores a year after surgery.¹⁵ In other words, the injection served double duty: it confirmed the diagnosis and predicted that surgery would help.

If your surgeon suggests a diagnostic injection before committing to hip replacement, the timing concern still applies, but the injection may use a lower steroid dose or none at all if the primary purpose is diagnostic rather than therapeutic. Ask about what’s being injected and in what dose. A pure local anesthetic injection without cortisone carries a different risk profile than a full therapeutic steroid dose, and your surgeon can factor that into the surgical scheduling.

An Earlier Study That Highlights the Worst-Case Scenario

One of the earlier studies on this topic looked specifically at the outcomes of patients who had hip replacement after previous steroid injections and compared them with a matched group who hadn’t been injected. In the injection group, five hips required revision surgery, four of those for deep infection. The matched control group had none. Six additional patients in the injection group were investigated for possible infection due to persistent hip problems, compared to just one in the control group.¹⁶ While this was a smaller study, it underscores what’s at stake. A deep infection after hip replacement isn’t a minor complication treatable with a course of antibiotics. It can mean additional surgeries, months of intravenous antibiotics, and sometimes removal of the entire prosthesis followed by a long wait before a new one can be implanted.

That severity is the reason the three-month guideline exists despite the fact that the absolute risk of infection remains relatively low even with a recent injection. The consequence of getting it wrong is serious enough that both surgeons and patients benefit from building in a comfortable buffer. If you’re in significant pain and three months feels like an eternity, that’s an honest conversation to have with your surgeon, who can weigh your specific infection risk against the cost of waiting. But in most cases, those three months are a small price for reducing the chance of a complication that could derail your recovery for a year or more.