Prevention of Periprosthetic Joint Infections of the Hip and Knee

Povidone-iodine showers went out of favor with the realization that chlorhexidine gluconate acts longer on the skin surface.^53,54 Preoperative showers involve rinsing with liquid chlorhexidine soap 24 to 48 hours before surgery. However, chlorhexidine binds preferentially to the cotton in washcloths instead of the skin. Edmiston and colleagues^54,55 found that 4% chlorhexidine liquid soaps achieve much lower skin chlorhexidine concentrations than 2% polyester cloths do. Use of these “chlorhexidine wipes” the night before and the day of surgery has decreased PJI after TKA from 2.2% to 0.6%.^56,57

Intraoperative Risk Prevention

Preparation

Which preoperative antibiotic to use is one of the first operative considerations in PJI prophylaxis (Table 2). Cefazolin is recommended as a first-line agent for its excellent soft-tissue penetration, long half-life, and activity against gram-positive bacteria such as skin flora.⁵⁸ Clindamycin may be considered for patients allergic to β-lactam antibiotics. Vancomycin may be considered for adjunctive use with cephalosporins in cases of known MRSA colonization. Vancomycin infusion should be started earlier than infusion with other antibiotics, as vancomycin must be infused slowly and takes longer to become therapeutic.

Antibiotic dosing should be based on local antibiograms, adjusted dosing weight, or BMI.⁵⁹ For revision arthroplasty, preoperative prophylaxis should not be stopped out of fear of affecting operative cultures.⁶⁰ Some surgeons pause antibiotic use if a preoperative joint aspirate has not been obtained. Infusion within 1 hour of incision is part of the pay-for-performance guidelines established by the US Centers for Medicare & Medicaid Services.⁶¹ An antibiotic should be redosed if the operation will take longer than 2 half-lives of the drug.⁵⁹ Surgeons should consider administering a dose every 4 hours or whenever blood loss exceeds 1000 mL.⁶² Engesæter and colleagues⁶³ found that antibiotic prophylaxis was most effective given 4 times perioperatively (1 time before surgery, 3 times after surgery). Postoperative antibiotics should not be administered longer than 24 hours, as prolonged dosing confers no benefit.⁵⁸ Operating room conditions must be optimized for prophylaxis. More people and operating room traffic in nonsterile corridors increase contamination of instruments open to air.⁶⁴ Laminar airflow systems are commonly used. Although there is little dispute that laminar flow decreases the bacterial load of air, there are mixed results regarding its benefit in preventing PJI.^65-68 Skin preparation may address patient risk factors. Hair clipping is preferred to shaving, which may cause microabrasions and increased susceptibility to skin flora.69 Patients should be prepared with antiseptic solution. One randomized controlled trial found that 2% chlorhexidine gluconate mixed with 70% isopropyl alcohol was superior to 10% povidone-iodine in preventing SSIs.⁷⁰ However, a recent cohort study showed a lower rate of superficial wound infections when 1% povidone-iodine (vs 0.5% chlorhexidine) was used with alcohol.⁷¹ This finding may indicate the need for alcohol preparation, higher concentrations of chlorhexidine, or both.

Proper scrubbing and protective gear are needed to reduce surgeon risk factors. Hand washing is a routine part of any surgery. Alcohol-based hand scrubs are as effective as hand scrubbing.65 They reduce local skin flora by 95% immediately and by 99% with repeated applications.⁷² Lidwell and colleagues⁷³ found a 75% reduction in infection when body exhaust suits were used in combination with laminar flow in a multicenter randomized controlled trial of 8052 patients. Sterile draping with impermeable drapes should be done over properly prepared skin. Ioban drapes (3M) are often used as a protective barrier. Interestingly, a Cochrane review found no benefit in using plastic adhesives impregnated with iodine over sterilely prepared skin.⁷⁴