Infection after prosthesis implantation is one of the most serious complications that can occur. It can significantly impair the function of the implanted joint and often requires complex and lengthy treatment measures. In this blog, we examine the causes, symptoms, diagnosis, and treatment approaches for infections after prosthesis implantation.

Periprosthetic infection after hip replacement and knee replacement

Causes of prosthetic infection

An infection of a prosthesis can occur through various mechanisms. Mainly, the infection occurs through:

1. Intraoperative contamination: bacteria enter the body during surgery.
2. Hematogenous spread: Bacteria from other infected body regions reach the prosthesis via the bloodstream.
3. Per continuitatem: spread of bacteria from adjacent infected tissues.

The most common pathogens are highly virulent bacteria such as Staphylococcus aureus and gram-negative bacteria, but also low-virulence germs like Staphylococcus epidermidis can cause infections.

Symptoms of prosthesis infection

The symptoms can vary depending on the type of infection. The most common signs include:

• Early infection (within the first 4 weeks after surgery): pain, redness, swelling, and increased temperature in the area of the implanted joint.
• Late infection (more than 4 weeks after surgery): Chronic pain that often increases slowly, as well as a gradual loosening of the prosthesis.
• Acute hematogenous infection: sudden pain, swelling, and systemic signs such as fever.

Diagnostics

The diagnosis of a prosthetic infection involves several steps:

1. Clinical examination: Assessment of symptoms and patient history.
2. Imaging: X-rays and, if necessary, MRI or CT to detect changes in the joint.
3. Laboratory tests: determination of inflammatory parameters in the blood (CRP, ESR, leukocyte count).
4. Joint aspiration: collection and analysis of joint fluid for microbiological examination.

Therapy approaches

The treatment of an infected prosthesis depends on the timing of the infection and the patient's overall health:

1. Early infection: In cases of early infection, the prosthesis can often be retained. This requires thorough joint cleaning (debridement) and intensive antibiotic therapy.
2. Late infection: As a rule, a two-stage revision of the prosthesis is necessary. Here, the infected prosthesis is removed and, after a phase of intensive antibiotic therapy, replaced with a new prosthesis.
3. One-stage revision: In some cases, an immediate exchange of the prosthesis can be performed in a single operation. This enables faster patient mobilization.

Preventive measures

Prevention of prosthetic infections begins before surgery:

• Strict hygiene measures in the OR: reduction of intraoperative contamination risks.
• Optimization of patient health: treatment of existing infections and improvement of immune status before surgery.
• Antibiotic prophylaxis: Administration of antibiotics before, during, and after surgery to minimize the risk of infection.

Long-term effects and follow-up care

A prosthesis infection can have long-term consequences, including:

• Limited joint function: repeated surgeries can impair the stability and function of the joint.
• Chronic pain: Persistent discomfort despite successful treatment of the infection.
• Increased risk of recurrent infections: patients with a history of prosthetic infections have a higher risk of future infections.

Aftercare includes regular check-ups and close collaboration with various medical disciplines to detect and treat a recurrent infection early.

Conclusion

An infection after prosthesis implantation is a serious complication that requires rapid and comprehensive medical intervention. Through preventive measures, early diagnosis, and appropriate therapeutic approaches, the risk can be minimized and the quality of life of patients improved. Those affected should be treated in specialized centers and by endoprosthetic specialists to ensure the best possible care.