Periprosthetic (Knee) Joint Infection: Symptoms, Causes, Prevention & Treatment

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Introduction

Periprosthetic knee joint infection (PJI) is a challenging complication that can occur after knee replacement surgery. This infection affects the area around the knee implant, causing pain, inflammation, and sometimes more severe systemic symptoms. Early detection and treatment are crucial for preserving joint function and patient health.

In this overview, we will explore the symptoms of PJI, such as persistent pain, swelling, and drainage, as well as common causes, including bacterial contamination during surgery and weakened immune responses. We’ll also cover preventive measures, like pre-surgical sterilization protocols and lifestyle factors, alongside the latest treatment options, including antibiotics, surgical interventions, and innovative techniques. Together, these topics provide a comprehensive look into understanding, managing, and preventing periprosthetic knee joint infections.

Knee replacement infection symptoms

Symptoms of infection following knee replacement surgery, or periprosthetic knee joint infection (PJI), can vary but commonly include:

Persistent Pain: Ongoing or worsening pain in the knee joint that doesn’t improve over time.
Swelling and Redness: Increased swelling around the knee, along with redness or warmth, can indicate infection.
Drainage: Fluid or pus draining from the incision site or around the joint may signal infection.
Fever and Chills: Elevated body temperature, chills, and general malaise may accompany more severe infections.
Stiffness or Limited Mobility: Difficulty moving the joint or stiffness that persists or worsens post-surgery.
Weakness or Instability: An infected knee replacement can cause the joint to feel unstable or weak.

Causes of Knee replacement infection

Infections following knee replacement surgery, or periprosthetic joint infections (PJI), can result from several factors. Common causes include:

Bacterial Contamination During Surgery: Despite sterile techniques, bacteria can enter the surgical site during the procedure. This can happen from the patient’s skin, surgical instruments, or even the air in the operating room.
Weak Immune System: Patients with compromised immune systems, such as diabetes, rheumatoid arthritis, or undergoing immunosuppressive therapy, are at higher risk of developing infections post-surgery.
Pre-existing Infections: Any existing infection in the body, such as urinary tract infections or skin infections, can spread to the surgical site, increasing the risk of PJI.
Obesity and Malnutrition: Obesity can impact wound healing, and poor nutrition can impair immune function, making infections more likely.
Poor Wound Healing: Factors like smoking, certain medications, and chronic conditions can slow down wound healing, increasing the risk of infection around the implant site.
Late-onset Infection from Bloodstream Contamination: Bacteria can enter the bloodstream from dental procedures, other surgeries, or infections elsewhere in the body and eventually infect the knee replacement even months or years after surgery.

Risk Factors for Knee Joint Infection

Several risk factors can increase the likelihood of infection following knee replacement surgery, often involving patient health, lifestyle, and surgical factors. These include:

Underlying Health Conditions: Chronic conditions like diabetes, rheumatoid arthritis, and liver disease can compromise immune function, making it harder for the body to fight off infections.
Obesity: Excess body weight increases stress on the joint and can lead to delayed wound healing, both of which raise the risk of infection.
Smoking: Smoking impairs blood flow and oxygenation to tissues, slowing down healing and increasing susceptibility to infections.
Poor Nutrition: Malnutrition weakens the immune system and impacts the body’s ability to heal properly, heightening infection risks post-surgery.
Previous Joint Infections: A history of infections around the joint or previous knee surgeries increases the likelihood of a new infection.
Advanced Age: Older adults often have weaker immune systems, reduced skin integrity, and other age-related health concerns, which can make them more vulnerable.
Immunosuppressive Medications: Drugs that suppress the immune system, such as corticosteroids or immunosuppressants used in autoimmune diseases, increase infection risk.
Multiple Surgeries on the Joint: Patients who have undergone multiple surgeries on the same knee joint are at higher risk due to repeated tissue exposure and increased potential for bacterial contamination.
Extended Surgery Duration: Longer surgery times increase the risk of bacterial exposure and contamination, particularly in complex or revision procedures.
Poor Postoperative Wound Care: Inadequate care or hygiene after surgery can allow bacteria to enter the wound, increasing the risk of infection.

Treatment for knee joint infection

Treating a knee joint or periprosthetic joint infection (PJI) requires a combination of antimicrobial therapy and, often, surgical intervention. The treatment approach depends on the infection’s severity, timing, and patient health. Key treatment options include:

Antibiotic Therapy: Initially, intravenous (IV) antibiotics are often used to control bacterial growth and target specific pathogens identified through culture tests. Oral antibiotics may follow IV treatment; patients might need prolonged antibiotic courses to fully eliminate the infection.
Debridement and Irrigation: In this procedure, the infected tissue around the knee implant is surgically removed, and the area is thoroughly cleaned (irrigated) to remove bacteria. This is often effective for early-stage infections.
Two-Stage Revision Surgery: For severe infections, a two-stage approach is commonly used. First, the infected implant is removed, and a temporary antibiotic-laden spacer is placed to deliver local antibiotics. Once the infection is under control, a second surgery replaces the spacer with a new knee implant.
One-Stage Revision Surgery: In select cases, a single surgery replaces the infected implant with a new one. This method is less common but may be effective for patients with specific types of infection and good overall health.
Joint Fusion or Amputation: As a last resort, if the infection cannot be controlled or if multiple revision surgeries have failed, joint fusion or amputation may be considered to prevent the infection from spreading further and causing additional health complications.

Prevention of knee joint infections

Preventing knee joint infections, particularly periprosthetic joint infections (PJI) after knee replacement surgery, involves a series of preoperative, intraoperative, and postoperative strategies:

Preoperative Health Optimization: Patients are encouraged to manage chronic conditions, like diabetes, which can weaken immune responses, as well as reduce risk factors like smoking and obesity that affect wound healing.
Antibiotic Prophylaxis: Administering antibiotics before and after surgery is a standard preventive measure to help minimize bacterial contamination and lower the risk of infection.
Enhanced Sterile Techniques: Rigorous sterilization of surgical instruments, operating room equipment, and the surgical area on the patient’s body is crucial. Surgeons and staff follow strict sterilization and hygiene protocols to reduce bacterial exposure.
Preoperative Screening and Skin Preparation: Screening for potential sources of infection, like urinary tract infections or skin infections, helps address these issues before surgery. Special antiseptic solutions are often used on the skin around the knee area to reduce bacterial counts.
Limiting Operating Room Traffic: Keeping unnecessary personnel out of the operating room helps reduce airborne contamination during surgery, which has been linked to lower infection rates.
Postoperative Wound Care: Proper care and monitoring of the incision site post-surgery help detect early signs of infection. Patients are advised to keep the wound clean, follow hygiene protocols, and avoid exposing it to potential contaminants.
Dental and Infection Precautions: Patients are advised to follow strict dental hygiene and may require antibiotics before dental procedures, as bacteria from the mouth can enter the bloodstream and potentially infect the knee implant.

Conclusion:

In conclusion, periprosthetic knee joint infections are serious complications following knee replacement surgery that demand prompt diagnosis and a strategic treatment approach. Early detection of symptoms, along with appropriate treatment, can prevent further complications and preserve joint function. Preventive measures before, during, and after surgery are essential to minimize infection risks and improve patient outcomes.

Typically, managing these infections falls under the Orthopedic Department, with specialized teams trained to treat and prevent complex joint infections. For comprehensive care and expertise, Rungta Hospital stands out as an excellent facility for treating knee replacement infections, offering advanced diagnostics, skilled orthopedic care, and cutting-edge treatment protocols to support recovery and joint health.