Dr Parvizi is from the Rothman Institute, Philadelphia, Pennsylvania.
Dr Parvizi has no relevant financial relationships to disclose.
Correspondence should be addressed to: Javad Parvizi, MD, Rothman Institute, 925 Chestnut St, 5th Floor, Philadelphia, PA 19107 (email@example.com).
A number of important studies have been conducted that have evaluated the risk factors that predispose patients to periprosthetic joint infection. Although it is difficult to be inclusive of all of these factors, some of the most important factors relate to the immune status of the patients. Patients who are immunocompromised (eg, patients with diabetes, those on steroids and disease-modifying agents, and cancer patients) are at risk for developing infection in general and periprosthetic joint infection in particular. Patients with poor blood supply to the extremity (eg, vascular disease, smokers, and those with venous insufficiency and lymphedema) and those with skin problems (eg, psoriasis, eczema, or ulcers) are also at risk for periprosthetic joint infection.
One of the most important problems predisposing patients to periprosthetic joint infection relates to wound problems postoperatively. Patients with persistent wound drainage and hematoma formation are at particularly high risk for periprosthetic joint infection. Thus, patients with bleeding disorders (eg, platelet dysfunction, liver failure, and renal dysfunction), those placed on anticoagulation (particularly aggressive type), and those with poor healing potential (eg, malnourished, obese, or with previous irradiation) are also at risk of periprosthetic joint infection.
The major challenge is that there is no gold standard for diagnosis. If one were to rely on isolation of an organism from the joint as the gold standard, then accuracy for diagnosis of periprosthetic joint infection would be approximately 80% to 85%. In approximately 5% to 8% of patients with periprosthetic joint infection, an organism cannot be isolated (for various reasons), and in approximately 5% to 10% of patients, an organism may be isolated that does not represent true infection (false positive). Combining all the available diagnostic modalities to reach diagnosis of periprosthetic joint infection provides accuracy that is well below absolute. The other challenge for diagnosis of periprosthetic joint infection relates to a lack of “standard” definition for periprosthetic joint infection. What might be considered as infected by 1 surgeon or 1 institution may not be seen as such by another surgeon or institution. The promise of using molecular diagnostics in the future to meet these challenges is exciting.
On average, 1% to 2% of patients undergoing joint arthroplasty may develop periprosthetic joint infection. The risk for periprosthetic joint infection is higher after total knee arthroplasty compared to total hip arthroplasty (THA) (2%–2.5% vs 1.5%–2%) and also much higher after revision arthroplasty (5%–6%).
The majority of patients with periprosthetic joint infection require surgical intervention. The type of surgery depends on the time of presentation, and also the infecting organism to some extent. It is commonly believed that patients presenting with acute periprosthetic joint infection (within 4 weeks of index arthroplasty) may be candidates for irrigation and debridement of the infected joint and retention of the prosthesis. Recent studies by the Periprosthetic Joint Infection Consortium have demonstrated a high failure of irrigation and debridement, even for acute periprosthetic joint infection cases, especially those infected with methicillin-resistant organisms. Thus, indication for irrigation and debridement is changing. There is little to indicate for 1-stage exchange arthroplasty. I feel an indication for this procedure would be for patients presenting with acute periprosthetic joint infection after uncemented THA. The gold standard for periprosthetic joint infection remains the 2-stage exchange arthroplasty. For patients who have failed reconstructive surgery and continue to be infected, salvage operations in the form of resection arthroplasty or amputation may be required.