[Show abstract][Hide abstract] ABSTRACT: Antibiotic-laden bone cement (ALBC) is used in primary arthroplasties throughout Europe. In North America, ALBC is only FDA approved for revision arthroplasty after periprosthetic joint infection (PJI). No article has evaluated whether infecting microbial profile and resistance has changed with the introduction of ALBC. We hypothesized that prophylactic use of ALBC in primary total knee arthroplasty (TKA) has not had a significant impact on infecting pathogens, and antibiotic resistance profiles. A retrospective cohort analysis was conducted of all PJI patients undergoing primary TKA and total hip arthroplasty (THA) between January 2000 and January 2009. No significant change in the patterns of infecting PJI pathogens, and no notable increase in percentage resistance was found among organisms grown from patients with PJI that had received prophylactic antibiotic-loaded cement in their primary joint arthroplasty. Early findings suggest that routine prophylactic use of ALBC has not led to changes in infecting pathogen profile, nor has led to the emergence of antimicrobial resistance at our institution.
The Journal of arthroplasty 12/2013; · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The use of cementless acetabular components in total hip arthroplasty has gained popularity over the past decade. Most total hip arthroplasties being performed in North America currently use cementless acetabular components. The objective of this systematic review and meta-analysis was to compare the survivorship and revision rate of cemented and cementless acetabular components utilized in total hip arthroplasty.
A primary literature search in PubMed identified 3488 articles, of which 3407 did not meet the inclusion criteria and were excluded. Only English-language articles on either the survivorship or revision rate of primary total hip arthroplasty at a minimum of ten years of follow-up were included. The present study analyzed forty-five articles reporting the long-term outcome of cementless acetabular components, twenty-nine reporting the outcome of cemented acetabular components, and seven comparing cemented and cementless acetabular components. Meta-analysis (with a random-effects model) was performed on the data from the seven comparative studies, and study-level logistic regression analysis (with a quasibinomial model) was performed on the pooled data on the eighty-one included articles to determine a consensus. The studies were weighted according to the number of total hip arthroplasties performed.
The meta-analysis did not reveal any effect of the type of acetabular component fixation on either survivorship or revision rate. The regression analysis revealed the estimated odds ratio for survivorship of a cemented acetabular component to be 1.60 (95% confidence interval, 1.32 to 2.40; p = 0.002) when adjustments for factors including age, sex, and mean duration of follow-up were made.
The preference for cementless acetabular components on the basis of improved survivorship is not supported by the published evidence. Although concerns regarding aseptic loosening of cemented acetabular components may have led North American surgeons toward the nearly exclusive use of cementless acetabular components, the available literature suggests that the fixation of cemented acetabular components is more reliable than that of cementless components beyond the first postoperative decade.
The Journal of Bone and Joint Surgery 01/2013; 95(2):168-74. · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The diagnosis of periprosthetic joint infection poses many challenges, one of which is the difficulty of isolating the infecting organism. Recently, a sophisticated modality (the Ibis Biosciences T5000 biosensor system) has been introduced that uses pan-domain primers in a series of polymerase chain reactions (PCRs) to identify and speciate essentially all bacteria and fungi as well as to identify key antibiotic resistance genes. We investigated the role of the Ibis in identifying infecting organisms in cases of known and suspected periprosthetic joint infection.
Synovial fluid specimens were collected prospectively from eighty-two patients undergoing eighty-seven arthroplasty procedures (sixty-five knee revisions, fifteen hip revisions, and seven primary knee arthroplasties) and were sent for both conventional culture and Ibis analysis. The surgeon's clinical determination of the cause for revision arthroplasty was failure due to infection in twenty-three cases and noninfectious failure in fifty-seven cases.
In the twenty-three cases that were considered on clinical grounds to involve a periprosthetic joint infection, the Ibis detected the same pathogen isolated by conventional culture in seventeen of eighteen cases and also detected one or more organisms in four of the five culture-negative cases. In addition, the Ibis detected organisms in fifty (88%) of the fifty-seven cases in which revision arthroplasty was performed for a presumed noninfectious failure.
The Ibis technology was not only effective at detecting organisms in cases of suspected periprosthetic joint infection in which cultures were negative, but it also suggested that many of the revision arthroplasty cases that have previously been considered to be purely aseptic may have a component of unrecognized, subclinical infection.
Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.
The Journal of Bone and Joint Surgery 12/2012; 94(24):2247-54. · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Periprosthetic joint infection continues to frustrate the medical community. Although the demand for total joint arthroplasty is increasing, the burden of such infections is increasing even more rapidly, and they pose a unique challenge because their accurate diagnosis and eradication can prove elusive. This review describes the current knowledge regarding diagnosis and treatment of periprosthetic joint infection. A number of tools are available to aid in establishing a diagnosis of periprosthetic joint infection. These include the erythrocyte sedimentation rate, serum C-reactive protein concentration, synovial white blood-cell count and differential, imaging studies, tissue specimen culturing, and histological analysis. Multiple definitions of periprosthetic joint infection have been proposed but there is no consensus. Tools under investigation to diagnose such infections include the C-reactive protein concentration in the joint fluid, point-of-care strip tests for the leukocyte esterase concentration in the joint fluid, and other molecular markers of periprosthetic joint infection. Treatment options include irrigation and debridement with prosthesis retention, one-stage prosthesis exchange, two-stage prosthesis exchange with intervening placement of an antibiotic-loaded spacer, and salvage treatments such as joint arthrodesis and amputation. Treatment selection is dependent on multiple factors including the timing of the symptom onset, patient health, the infecting organism, and a history of infection in the joint. Although prosthesis retention has the theoretical advantages of decreased morbidity and improved return to function, two-stage exchange provides a lower rate of recurrent infection. As the burden of periprosthetic joint infection increases, the orthopaedic and medical community should become more familiar with the disease. It is hoped that the tools currently under investigation will aid clinicians in diagnosing periprosthetic joint infection in an accurate and timely fashion to allow appropriate treatment. Given the current knowledge and planned future research, the medical community should be prepared to effectively manage this increasingly prevalent disease.
The Journal of Bone and Joint Surgery 07/2012; 94(14):e104. · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty. Lack of confirmation of an infecting organism poses a challenge with regard to the selection of an appropriate antibiotic agent and surgical treatment. It is unclear whether patients with negative cultures presumed to have infections achieve similar rates of infection-free survival as those with positive cultures.
The purposes of this study were (1) to report the infection control rates using irrigation and débridement and two-stage exchange for treatment of culture-negative PJIs; and (2) to compare infection control rates in culture-negative cases with those in culture-positive cases.
We retrospectively reviewed 55 patients with culture-negative PJI treated between 2000 and 2007. We compared the infection-free survival rate in the culture-negative patients with that of 295 culture-positive cases of PJI.
Overall infection control rate in culture-negative cases was 73% at minimum 1-year followup (mean, 47 months; range, 12-119 months). We found similar infection control rates in culture-negative and culture-positive PJI. Infection-free survival rates in both groups were highest after two-stage exchange arthroplasty and postoperative vancomycin therapy.
Our observations suggest aggressive two-stage exchange arthroplasty and postoperative parenteral vancomycin therapy in patients with culture-negative PJI achieves similar rates of infection-free survival as with patients having culture-positive PJI.
Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
Clinical Orthopaedics and Related Research 06/2012; 470(10):2717-23. · 2.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Serum white blood cell (WBC) count and neutrophil differential are frequently ordered during preoperative workup of suspected cases of periprosthetic joint infection (PJI). However, their roles in diagnosis of PJI have remained unclear despite previous studies. In this study, preoperative serum WBC and neutrophil percentages were retrieved from hospital charts. The diagnostic cutoff point determined by receiver operating characteristic curve analysis was 7800 cells/μL with 55% sensitivity and 66% specificity for WBC count, whereas the cutoff value for neutrophil percentage was 68% with 52% sensitivity and 75% specificity. Our study confirms the long-held belief that serum WBC count and differential has minimal role in routine workup of patients with suspected PJI.
The Journal of arthroplasty 05/2012; 27(8 Suppl):51-4.e1. · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We hypothesized that some aseptic revision total knee arthroplasty failures are indeed caused by occult infection. This prospective study recruited 65 patients undergoing revision total knee arthroplasty. The mean follow-up period was 19 months. Collected synovial fluid was analyzed by Ibis T5000 biosensor (Abbott Molecular Inc, Ill; a multiplex polymerase chain reaction technology). Cases were considered as infected or aseptic based on the surgeon's judgment and Ibis findings. Based on Ibis biosensor, 17 aseptic cases were indeed infected that had been missed. Of these 17 cases, 2 developed infection after the index revision. A considerable number of so-called aseptic failures seem to be occult infections that were not adequately investigated and/or miscategorized as aseptic failure. We recommend that all patients undergoing revision arthroplasty be investigated for periprosthetic joint infection.
The Journal of arthroplasty 03/2012; 27(6):1239-43.e1-2. · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Periprosthetic joint infection (PJI) is a significant and costly challenge to the orthopedic community. The lack of a gold standard for diagnosis remains the biggest obstacle in the detection and subsequent treatment of PJI. Molecular markers in the serum and joint fluid aspirate hold immense promise to enhance the development of a firm diagnostic criterion. The primary goal is one marker with high sensitivity and specificity. Here, we review our current research efforts in the field of molecular markers: C-reactive protein, erythrocyte sedimentation rate, white blood cells, and leukocyte esterase. Each marker has been studied to determine its sensitivity, specificity, and positive and negative predictive values in diagnosing PJI.
The International journal of artificial organs 11/2011; 34(9):847-55. · 1.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: C-reactive protein (CRP) serum assays are a standard element of the diagnostic workup for periprosthetic joint infection (PJI). However, because CRP is a marker for systemic inflammation, this test is not specific to PJI.
Our purpose was to assess whether synovial fluid and serum assays alone could differentiate between infected and uninfected revision knee arthroplasties and to determine which of these methods had the greatest diagnostic accuracy.
We collected synovial fluid specimens from 66 patients undergoing revision total knee arthroplasty. Patients were judged uninfected or infected by standardized criteria. Synovial CRP levels were measured using an individual CRP assay (15 samples; 10 infected, five uninfected) and a multiplex immunoassay platform (59 samples; 25 infected, 34 uninfected). Results from preoperative standard serum CRP assays conducted were also collected (55 samples; 25 infected, 30 uninfected). Sensitivity, specificity, and receiver operating characteristic curve analyses were performed for each assay with a diagnosis of infection based on previously established criteria.
Synovial CRP concentrations differed between infected and uninfected joints in the multiplex and serum analyses. The area under the curve was 0.84 for the individual assay, 0.91 for the multiplex assay, and 0.88 for the serum CRP assay. Sensitivity and specificity were 70.0% and 100.0% for the individual enzyme-linked immunosorbent assay, 84.0% and 97.1% for the multiplex assay, and 76.0% and 93.3% for the serum CRP assay.
An assay measuring CRP in synovial fluid may be more accurate in diagnosing PJI than the standard serum CRP assay. We believe such an assay holds promise as a new diagnostic marker for PJI.
Clinical Orthopaedics and Related Research 07/2011; 470(1):54-60. · 2.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Squeaking is reportedly a complication in patients having ceramic-on-ceramic total hip implants. The etiology remains unknown and multifactorial with recent studies suggesting a relationship between the audible squeak and implant design. When we evaluated our ceramic-on-ceramic cohort, we noticed squeaking primarily in patients receiving an acetabular system designed with an elevated titanium rim. OBJECTIVES/PURPOSES: We therefore (1) determined the incidence of squeaking among four different ceramic-on-ceramic bearing surfaces used for THA at our institution; (2) evaluated the association between different acetabular designs and the incidence of squeaking; and (3) assessed other potential variables associated with squeaking.
We retrospectively reviewed 1507 patients having a ceramic-on-ceramic THA between 2002 and 2009; we separately analyzed those receiving an acetabular system with and without an elevated titanium rim. Data were collected through phone-administered questionnaires and retrospective reviews of patient charts for intraoperative findings, followup reports, demographic information, and radiographic findings.
Squeaking occurred in 92 of the 1507 patients (6%). All 92 patients with squeaking received an elevated rim design (1291 patients) or an incidence of 7% with that design. We found no association between squeaking and any other examined factors.
Our findings complement the theory from in vitro studies suggesting that neck impingement on the elevated titanium rim is the probable cause of the increased frequency of squeaking with this design.
Clinical Orthopaedics and Related Research 06/2011; 469(6):1598-605. · 2.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Despite a battery of tests available for diagnosing periprosthetic joint infection, as yet, no gold standard has been identified. Our purpose was to measure inflammatory proteins in synovial fluid from patients undergoing revision arthroplasty for septic or aseptic failure. We analyzed 74 synovial fluid samples: 31 infected and 43 uninfected, based on clinical and laboratory criteria. Proteomics analysis and receiver operating characteristic curve analyses were conducted on 46 inflammatory proteins for each sample. Of 46 proteins, 5 (interleukin 6, interleukin 8, α(2)-macroglobulin, C-reactive protein, and vascular endothelial growth factor) had an area under the curve greater than 0.90. This prospective study has demonstrated promising results for the use of molecular markers in diagnosis of periprosthetic joint infection. Future studies will focus on designing assays with these proteins in mind.
The Journal of arthroplasty 05/2011; 26(6 Suppl):99-103.e1. · 2.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Periprosthetic joint infection has become the most common cause of failure following total knee arthroplasty. Over the past 4 decades, treatment of this disease has evolved with technological innovations and pathogen profiling. The appropriate treatment selection is dependent on patient immune system quality, timing of symptom onset, and pathogen type. Antibiotic suppression alone is reserved for those cases without drainage, low-virulent antimicrobial-susceptible pathogens, and patients whose level of health increases the risk of surgery past any risk associated with chronic infection. In patients with an acute onset of symptoms and antimicrobial-susceptible pathogens, irrigation and debridement with exchange of modular components is moderately successful and offers the advantage of component retention and maximum knee function. In failed irrigation or chronic periprosthetic joint infection, resection of all components is necessitated. Resection and reimplantation can either be performed in one or two stages. A single-stage exchange has the potential to decrease the number of surgeries and therefore cost. However, the success rate of direct exchange is lower than that of two-stage revision. This has led to two-stage revision, with the placement of an intra-stage antibiotic-loaded spacer, to become the "gold" standard for periprosthetic joint infection eradication. In an immunocompromised patient with an uncontrollable periprosthetic joint infection, salvage procedures are necessitated. Complete eradication of periprosthetic joint infection is achieved by resection of all components without reimplantation through arthrodesis or above-the-knee-amputation. While amputation may be unpopular with patients it provides a greater ability to reconstruct, with an external prosthesis, a functioning joint.