Prevention of Periprosthetic Joint Infections of the Hip and Knee

Immunocompromising Medications

Immunocompromising medications are modifiable and should be adjusted before surgery. Stopping any disease-modifying antirheumatic drug (DMARD) more than 4 weeks before surgery is not recommended.²⁷

Corticosteroid use can lead to immunosuppression and increased protein catabolism, which impairs soft-tissue healing. To avoid flares or adrenal insufficiency, however, chronic corticosteroid users should continue their regular doses perioperatively.²⁸ On the day of surgery, they should also receive a stress dose of hydrocortisone 50 to 75 mg (for primary arthroplasty) or 100 to 150 mg (for revision arthroplasty), followed by expeditious tapering over 1 to 2 days.²⁹ DMARDs are increasingly used by rheumatologists. One of the most effective DMARDs is methotrexate. Despite its immunocompromising activity, methotrexate should be continued perioperatively, as stopping for even 2 days may increase flare-related complications.³⁰ Hydroxychloroquine can be continued perioperatively and has even been shown, by Johnson and Charnley,³¹ to prevent deep vein thromboses. Sulfasalazine can also be continued perioperatively—but with caution, as it may elevate international normalized ratio (INR) levels in patients receiving warfarin.²⁹ Most other DMARDs should be temporarily discontinued. Leflunomide and interleukin 1 antagonists, such as anakinra, should be stopped 1 to 2 days before surgery and restarted 10 to 14 days after surgery.²⁹ Rituximab should be stopped 1 week before surgery and restarted 10 to 14 days after surgery. Tumor necrosis factor α inhibitors should be discontinued for 2 half-lives before and after surgery.³² Etanercept has a half-life of 3 to 5 days; infliximab, 8 to 10 days; and adalimumab, 10 to 13 days. Most surgeons schedule surgery for the end of a dosing cycle and discontinue these biologic agents for another 10 to 14 days after surgery.

Metabolic Factors

Obese patients are susceptible to longer surgeries, more extensive dissection, poorly vascularized subcutaneous tissue, and higher requirements of weight-adjusted antibiotic dosing.¹³ Body mass index (BMI) of 40 kg/m² or more (morbid obesity) and BMI over 50 kg/m² have been associated with 9 times and 21.3 times increased risk of PJI, respectively.^13,14 Delaying surgery with dietary consultation has been suggested,^33,34 and bariatric surgery before TKA may decrease infection rates by 3.5 times.³⁵

Nutritional markers are considered before arthroplasty. According to most laboratories, a serum transferrin level under 200 mg/dL, albumin level under 3.5 g/dL, and total lymphocyte count under 1500 cells/mm³ indicate malnourishment, which can increase the incidence of wound complications by 5 to 7 times.³⁶ Patients should also have sufficient protein, vitamin, and mineral supplementation, particularly vitamins A and C, zinc, and copper.³⁷Smokers who cease smoking at least 4 to 6 weeks before surgery lower their wound complication rate by up to 26%.^38,39 When nicotine leaves the bloodstream, vasodilation occurs, oxygenation improves, and the immune system recovers.³⁹ Studies have found more SSIs in patients who abuse alcohol,40 and numerous authors have confirmed this finding in the arthroplasty population.^24,41,42 Alcohol inhibits platelet function and may predispose to a postoperative hematoma. In contrast to smoking cessation evidence, evidence regarding alcohol interventions in preventing postoperative infections is less conclusive.^43,44

MRSA Colonization

Methicillin-resistant Staphylococcus aureus (MRSA) is a particularly difficult bacterium to eradicate in PJI. As the mean cost of treating a single case of MRSA-related prosthetic infection is $107,264 vs $68,053 for susceptible strains,45,46 many infection-containment strategies focus on addressing benign MRSA colonization before surgery.

MRSA is present in the nares of 25 million people in the United States. Nasal colonization increases the risk of bacteremia 4-fold⁴⁷ and SSI 2- to 9-fold.^48,49 Nasal swabs are analyzed with either a rapid polymerase chain reaction (PCR) test, which provides results in 2 hours, or a bacterial culture, which provides results in 1 to 4 days. The PCR test is more expensive.

Eradication of MRSA colonization is increasingly prevalent. Several Scandinavian countries have instituted strict practices by which patients are denied elective surgery until negative nasal swabs are obtained.⁴⁹ Nasal decontamination is one method of colonization reduction. Topical mupirocin, which yields eradication in 91% of nasal carriers immediately after treatment and in 87% after 4 weeks,⁵⁰ is effective in reducing SSI rates only when used in conjunction with a body wash, which is used to clean the axilla and groin.⁵¹ There is no consensus on optimal timing, but Bode and colleagues⁵² found a significant decrease in deep SSIs when decontamination occurred just 24 hours before surgery.