Abstract
Periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a devastating complication. It is associated with high morbidity and mortality. It remains, unfortunately, one of the most common modes of failure in TKA. Much attention has been paid to the treatment of PJI once it occurs. Our attention, however, should focus on how to reduce the risk of PJI from developing in the first place. Infection prevention should focus on reducing modifiable risk factors that place patients at increasing risk for developing PJI. These areas include pre-operative patient optimization and intra-operative measures to reduce risk.
Pre-operative Modifiable Risk Factors: There are several patient related factors that have been shown to increase patient's risk of developing PJI. Many of these are modifiable risk factors can and should be optimised prior to surgery. Obesity and in particular Morbid Obesity (BMI >40) has a strong association with increased risk of PJI. Appropriate and healthy weight loss strategies should be instituted prior to elective TKA. Uncontrolled Diabetes (Hgb A1C >8) and poor glycemic control around the time of surgery increases the risk for complications, especially PJI. Malnutrition should be screened for in at-risk patients. Low Albumin levels are a risk factor for PJI and should be corrected. Patients should be required to stop smoking 6 weeks prior to surgery to lower risk. Low Vitamin D levels have been show to increase risk of PJI. Reduction of colonization of patient's nares with methicillin sensitive (MSSA) and resistant (MRSA) staphylococcus should be addressed with a screen and treat program.
Intra-operative Measures to Reduce PJI: During surgery, several steps should be taken to reduce risk of infection. Appropriate dosing and timing of antibiotics is critical and a first generation cephalosporin remains the antibiotic of choice. The use of antibiotic cement remains controversial with regards to its PJI prophylactic effectiveness. The utilization of a dilute betadine lavage has demonstrated decreased rate of PJI. Maintaining normothermia is critical to improve the body's ability to fight infection. An alcohol-based skin preparation can reduce skin flora as a cause of PJI. Appropriate selection of skin incisions and soft tissue handling can reduce wound healing problems and reduce development of PJI. Likewise, the use of occlusive dressing has been shown to promote wound healing and reduce PJI rates.
