What Happens If You Get an Infection in a Hip Replacement?

An infection in a hip replacement is one of the most serious complications that can follow joint surgery, often requiring additional operations, months of antibiotics, and a recovery that stretches far beyond what most patients anticipated. Though uncommon, occurring in roughly 1 to 2 percent of primary hip replacements, a prosthetic joint infection can mean prolonged hospital stays, significant functional setbacks, and costs several times higher than the original surgery. The bacteria involved tend to form a protective coating on the metal and plastic surfaces of the implant, which makes the infection stubbornly resistant to antibiotics alone and usually demands some form of surgical intervention.

How Common Are Hip Replacement Infections

The overall infection rate after a first-time hip replacement is low but not negligible. One study tracking over 2,000 primary hip replacements found that infection developed within the first year in about 0.4% of cases.¹ That figure, however, reflects a single center with rigorous protocols. Broader population studies generally report rates between 1% and 2%, with the number ticking higher for patients who have additional health conditions or who undergo revision surgery rather than a first-time procedure. In absolute terms, these sound small, but with hundreds of thousands of hip replacements performed each year in the United States alone, even a 1% rate translates into thousands of affected patients annually.

Why Implant Infections Are So Stubborn

The bacteria that cause prosthetic joint infections behave differently from those in a typical wound infection. Once they land on the surface of an implant, they produce what researchers call a biofilm, essentially a slimy, self-made fortress that shields the colony from both antibiotics and the immune system.² This biofilm is a major reason why antibiotics alone rarely cure an established prosthetic infection. The drugs can knock back free-floating bacteria in the surrounding tissue, but the organisms embedded in the biofilm survive and re-seed the infection once treatment stops.³

Staphylococci dominate the microbiology. Coagulase-negative staphylococci (skin bacteria that most people carry harmlessly) are the most frequently isolated organisms, though Staphylococcus aureus is becoming increasingly important.⁴ A concerning proportion of these staphylococci are methicillin-resistant. In one large epidemiological study, roughly 42% of staphylococcal isolates from prosthetic joint infections showed methicillin resistance.⁵ This limits the antibiotics that can be used and underscores why surgery to physically remove or disrupt the biofilm is almost always part of the treatment plan.

When Infections Appear and How They Feel

Prosthetic joint infections are generally grouped by when they show up. Early infections develop within the first few weeks after surgery. Delayed infections surface between about one month and a year. Late infections strike after the first year and are often seeded by bacteria that traveled through the bloodstream from another site, such as a urinary tract infection, a dental abscess, or an infected skin wound. In one treatment series, roughly 29% of infections were early, 41% were delayed, and 30% were late.⁶

Symptoms depend on the timing. An early infection typically brings the classic signs of wound trouble: redness, warmth, swelling around the incision, and sometimes drainage. Fever and worsening pain that had been improving are red flags. Delayed and late infections can be more subtle. Some patients experience a gradual return of hip pain without any visible wound issues, a new limp, or stiffness that they initially attribute to aging or overdoing an activity. Because the symptoms can mimic other problems like implant loosening from normal wear, delayed infections are sometimes missed for weeks or months before the real cause is identified.

Who Is at Higher Risk

Not everyone faces the same odds. A large meta-analysis pooling data from multiple studies identified several patient-related risk factors with strong supporting evidence. Obesity, defined as a body mass index of 30 or above, roughly doubled the risk. Male sex, diabetes, heart disease, and a higher overall illness burden (measured by anesthesia fitness scores) were all independently associated with a greater chance of infection. Operations lasting two hours or more also carried elevated risk.⁷ A separate 15-year population study confirmed that male sex and type 2 diabetes stood out as consistent predictors, and added that being discharged to a rehabilitation facility rather than going home also increased the hazard.⁸

A broader meta-analysis of 40 studies added a few more risk factors to the list: rheumatoid arthritis, chronic lung disease, neurological conditions, opioid use, and iron-deficiency anemia were all associated with modestly elevated risk. Interestingly, patients whose hip replacement was done for osteoarthritis had a somewhat lower infection rate compared with those whose surgery was prompted by other conditions like avascular necrosis or a femoral neck fracture.⁹

How Infections Are Diagnosed

Confirming a prosthetic joint infection is not as straightforward as swabbing a wound and growing bacteria. Most clinicians start with blood tests. C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are widely used as initial screening tools. CRP is generally considered more useful because it normalizes about three weeks after surgery, whereas ESR can remain elevated for up to a year after a hip replacement, making it a less reliable marker in the early postoperative period.¹⁰ Blood tests alone, however, are not enough to rule an infection in or out. Their sensitivity and specificity vary widely across studies, and no single blood marker delivers a definitive answer.

The next step is usually aspirating fluid from the joint with a needle. Testing that fluid for specific markers gives a much clearer picture. A laboratory-based alpha-defensin test on the synovial fluid has emerged as one of the most accurate single tests, with sensitivity and specificity each reported around 97%.¹¹ A systematic review confirmed that synovial fluid tests, including alpha-defensin and leukocyte esterase strip tests, consistently outperformed blood-based markers for diagnosing chronic infections.¹² Culturing the fluid or tissue samples taken during surgery to identify the specific organism remains the gold standard, because knowing which bacterium is responsible shapes the antibiotic strategy.

Treatment Options and How They Escalate

Treatment depends on when the infection is caught, which organism is involved, and how well-fixed the implant still is. There are essentially three tiers, each progressively more invasive.

DAIR (Keeping the Implant)

When an infection is caught early and the implant is still firmly anchored in bone, surgeons may attempt debridement, antibiotics, and implant retention, commonly abbreviated DAIR. The joint is surgically opened, infected and dead tissue is aggressively cleaned out, plastic liner components are swapped, and the patient is placed on a long course of targeted antibiotics. A systematic review found that reported success rates for DAIR range widely, from about 55% to 90%, with an average around 71%.¹³ One study reported an 82% success rate at four years of follow-up, which rose to 89% when a subgroup that received gentamicin beads (associated with worse outcomes in this cohort) was excluded. Obesity and elevated inflammatory markers at the time of surgery increased the risk of DAIR failing.¹⁴

The appeal of DAIR is obvious: you keep your implant and avoid the ordeal of a full revision. But when it fails, patients end up undergoing the more extensive procedures anyway, sometimes in worse condition than if they had gone straight to revision surgery.

Revision Surgery

When the infection is more established or the implant has loosened, the prosthesis needs to come out. This can happen in one operation (one-stage revision) or two (two-stage revision).

In a one-stage revision, the surgeon removes the infected implant, cleans the joint thoroughly, and implants a new prosthesis with antibiotic-loaded cement in the same operation. The advantage is that the patient endures a single major surgery and avoids the weeks or months spent living with a temporary spacer.¹⁵ One-stage revisions are typically reserved for patients with a known, antibiotic-sensitive organism, adequate bone stock, and healthy soft tissues around the hip.

The two-stage revision has long been considered the gold standard, especially in North America. In the first stage, the infected implant is removed and replaced with a temporary antibiotic-loaded cement spacer that delivers high local doses of antibiotics directly into the joint.¹⁶ The patient then receives weeks of intravenous antibiotics. Once blood tests and sometimes repeat joint aspirations suggest the infection has cleared, a second surgery is performed to remove the spacer and implant a new prosthesis. A long-term study using an articulated hip spacer reported a success rate of 89% at ten to fifteen years, rising to 96% when additional surgeries were counted.¹⁷

Salvage Procedures

In cases where infection cannot be controlled, bone quality is too poor for a new implant, or the patient is too medically fragile for further major surgery, a salvage option called resection arthroplasty (sometimes called the Girdlestone procedure) may be performed. The infected implant is removed permanently and no new prosthesis is placed. This relieves pain and eliminates the infection, but it leaves the patient with a shortened leg and a hip that does not function normally, usually requiring a walking aid permanently.¹⁸ In the hip, resection arthroplasty provides more predictable outcomes than the equivalent salvage options for infected knee replacements.¹⁹ Some patients later undergo reconstruction with a new prosthesis if the infection stays clear and their health improves enough to tolerate another operation.

The Role of Antibiotics

Regardless of which surgical approach is used, prolonged antibiotic therapy is part of nearly every treatment plan. The specific drugs depend on the cultured organism, but one antibiotic that comes up frequently in staphylococcal infections is rifampin, valued for its ability to penetrate biofilms. A study at a VA medical center found that among patients treated with curative intent using rifampin-containing regimens, 82% achieved treatment success. Success was markedly higher when the implant was less than two months old (93%) compared with older implants (65%).²⁰ For DAIR cases specifically, one study found that rifampin-based regimens lowered the risk of failure in knee infections, though the same protective effect was not statistically significant for hip infections.²¹ Antibiotic courses typically run for weeks to months, often starting with intravenous delivery before transitioning to oral pills.

Life with a Spacer

Patients undergoing a two-stage revision spend weeks or months living with a cement spacer in their hip before the second surgery. This interval can be one of the most physically and emotionally difficult parts of the entire process. Spacers are designed to deliver antibiotics locally and maintain some joint space, but they are not true prostheses. They do not bear weight as reliably, and they come with their own set of mechanical complications.

A systematic review found that the overall mechanical complication rate for hip spacers averaged about 19%, with dislocation being the most common problem at roughly 11%, followed by spacer fractures and femoral fractures at about 3.5% each.²² Individual series have reported even higher complication rates. One study of 185 patients found spacer complications in 26%, with dislocation linked to changes in the leg’s geometry and fracture rates differing by spacer construction method.²³ These complications can mean additional unplanned surgeries during what is already a prolonged treatment course.

Long-Term Functional Outcomes

Even when the infection is ultimately cured, patients who go through a prosthetic joint infection tend to fare worse in the long run than those whose hip replacement went smoothly. A Swedish study with at least ten years of follow-up found that patients who had experienced a hip infection scored lower on quality-of-life measures, were nearly twice as likely to be living in assisted care, and were three times more likely to rely on a walking aid compared with matched controls who had an uncomplicated hip replacement.²⁴

A systematic review of quality-of-life scores after staged revision for infected hips showed that physical function scores lagged behind population norms by about 15 to 27%, depending on the measurement tool used. Mental health scores, by contrast, were closer to normal, suggesting that while patients adapt psychologically over time, the physical deficit persists.²⁵

The Psychological Toll

The mental health impact of prosthetic joint infections is real and often underappreciated. A study comparing patients who underwent spacer placement for an infected hip replacement against those who had standard revision surgery found that the risk of depressive disorders and stress-related disorders was about 50% higher in the infection group.²⁶ A separate analysis of nearly 14,000 patients found a significant correlation between prosthetic joint infections and the need for postoperative psychological consultation, with women at particularly high risk. The authors argued that psychological support should be routinely offered to patients dealing with a septic complication.²⁷

This is not surprising when you consider what patients go through: a surgery they expected to fix their hip pain leads instead to multiple additional operations, months of IV antibiotics often administered through a line at home, extended inability to work, restricted mobility while living with a spacer, and the constant uncertainty about whether the infection will return.

The Financial Burden

The economic impact is striking. A Canadian study found that managing a prosthetic hip infection cost an average of about $38,000 (Canadian dollars), compared with roughly $6,800 for an uncomplicated primary hip replacement, a roughly fivefold increase. Hospital stays averaged 26.5 days versus 2 days, and readmissions were dramatically more frequent.²⁸ A meta-analysis of revision hip costs found that septic revision hip replacement averaged about $57,000 (USD), which was 87% higher than revision surgery for non-infected reasons. Two-stage septic revisions were especially expensive, averaging over $70,000, compared with roughly $40,000 for one-stage approaches.²⁹ European data showed a similar pattern, with mean direct hospital costs across all types of hip prosthetic joint infection procedures coming in around $29,000, though DAIR procedures that successfully saved the implant were considerably cheaper at roughly $7,000.³⁰

Prevention Strategies

Given how difficult and costly prosthetic joint infections are to treat, prevention is the priority. Expert panels and guideline reviews have identified a handful of measures as the most impactful: properly timed antibiotic prophylaxis before the incision, antiseptic skin preparation of the patient, surgical hand antisepsis, sterile gowns, ultraclean operating theater air, antibiotic-impregnated bone cement, and active surveillance programs that track infection rates over time.³¹ Evidence supports bundling these measures together rather than relying on any single intervention.³² One institution that implemented a comprehensive aseptic protocol saw its infection rate drop to 0.39%, significantly lower than its own historical rate of 2.6%.³³

For patients, the modifiable risk factors worth addressing before surgery include optimizing blood sugar control if you have diabetes, losing weight if you are obese, addressing anemia, and stopping smoking. After surgery, dental infections, urinary tract infections, and skin infections should be treated promptly, since bacteria from these sites can travel through the blood and settle on the prosthesis even years later.

Phage Therapy as an Emerging Approach

One of the more promising experimental strategies for prosthetic joint infections involves bacteriophages, viruses that specifically infect and kill bacteria. The appeal of phages is that they can target biofilm-embedded bacteria, precisely the organisms that conventional antibiotics struggle to reach. Researchers are exploring various ways to deliver them: intravenously, directly into the joint, and even embedded in bone cement or hydrogel coatings on implant surfaces.³⁴

In a recent mouse study modeling a methicillin-resistant Staphylococcus aureus prosthetic joint infection, animals that received both phage therapy delivered into the joint and systemic vancomycin showed significant reductions in bacteria on the prosthesis surface compared with those receiving either vancomycin alone or no treatment.³⁵ Phage therapy is not yet standard care, and human clinical data remain limited. But with antibiotic resistance rising among the staphylococci that dominate prosthetic joint infections, having a fundamentally different weapon in the arsenal is an area of active research that patients may start hearing about in the coming years.

Malpractice Litigation Around Hip Replacement Infections

Infection has historically been one of the leading reasons patients pursue malpractice claims after hip replacement surgery, particularly in the revision setting. An analysis of lawsuits following primary and revision total hip replacements found that dislocation and infection were the most common sources of suits in revision cases.³⁶ Litigation trends have shifted somewhat over time, with newer data showing that ongoing or worsening pain has overtaken infection as the primary cause of litigation in knee arthroplasty cases, though infection remains a significant driver of claims in hip surgery.³⁷ The reality is that most prosthetic joint infections are not the result of negligence. They arise despite proper sterile technique, appropriate prophylactic antibiotics, and correct surgical execution. But the sheer severity of the outcome, and the gap between what patients expected and what they got, makes this a persistently contentious area in orthopedic litigation.