Date Published: August 23, 2017
Author(s): Gabriele Falzarano, Antonio Piscopo, Predrag Grubor, Giuseppe Rollo, Antonio Medici, Valerio Pipola, Michele Bisaccia, Auro Caraffa, Elizabeth Mary Barron, Francesco Nobile, Raffaele Cioffi, Luigi Meccariello.
Orthopedic implants have become essential components of modern medicine. The risk of infection of total hip arthroplasty (THA) is 1.5%−2%. Are the C-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), and procalcitonin (PCT) good markers for THA infection screenings? From February 2009 to December 2012 at our Department of Orthopedics and Traumatology, 1248 patients were treated with THA. No prosthesis was cemented. All patients received antibiotic prophylaxis. All patients were discharged approximately 7.4 days after surgery with this clinical and radiographic follow-up program at 15 days and 1, 3, 6, 12, 24, and 36 months after surgery. Blood samples to determine ESR, CRP, and PCT values were taken at 1 hour before surgery and 15 days and 1, 3, 6, 12, 24, and 36 months after surgery. During follow-ups there were 22 cases of THA infections; according the Widmer classification, infections are hematogenous ones in 16 cases, late chronic ones in 5 cases, and early postoperative ones in 1 case. In all cases the three markers were considered positive; in 6 cases there were no radiological signs of septic loosening. ESR, CRP, and PCT proved to have a greater diagnostic accuracy than X-rays in predicting late chronic and early postoperative infections. These markers are valuable support for the surgeon in monitoring the prosthetic implant lifespan.
The number of primary total hip arthroplasties (THAs) performed in the United States each year continues to increase, as does the incidence of septic complications. The changing profile of antibiotic resistant bacteria has made the prevention and the treatment of primary THA infections increasingly complex . The incidence of PJI (prosthetic joint infections) varies depending on the joint involved; the rate of arthroplasties becoming infected is as follows: 1.7% of primary and 3.2% of nonprimary hip arthroplasties . A correct and early diagnosis is essential in order to provide the most appropriate therapy. If a correct and timely microbiological diagnosis of infections is done within 4 weeks, it could be possible to follow a conservative approach on the prosthesis, since microorganisms are not yet organized in biofilms. A delayed diagnosis (>4 weeks) of early and late infections involves the necessity of prosthesis removal  due to the production of a structurated and mature microbial biofilm. Biofilm is an aggregate of microcolony of microbial cells adherent to a living or nonliving surface embedded in an extracellular polymeric matrix. Biofilm renders bacteria highly tolerant to antibiotics and host defenses .
From January 2009 to December 2012 a cohort of 1248 patients, who had undergone single hip arthroplasty at Department of Orthopedics and Traumatology of the “G. Rummo” Hospital of Benevento, the Sacred Heart Hospital Fatebenefratelli (Benevento, Italy), and the Clinical Center of Banja Luka (BIH), had been prospectively followed to detect the onset of prosthesis infection.
There were 387 complications not related to the THA system (Table 3). The most common complication during the 36-month period was the infection of the urinary tract in 168 patients (13.46%). 4 of them died during follow-up (Table 3). The ESR, CRP, and procalcitonin trends, shown in Figures 1, 2, and 3, are on average not dissimilar to the limits of the work. 1.76% of the patients (n = 22) had a PTA infection.
The total hip arthroplasty infections represent a serious problem given the increasing number of implants performed each year for both arthritis and hip fractures. Early detection of infection is the main objective orthopedists need in order to adopt an appropriate treatment procedure.