Source

The Norwegian Arthroplasty Register, Department of Orthopaedic Surgery, Haukeland University Hospital, Bergen, Norway. haavard.dale@helse-bergen.no

Abstract

BACKGROUND AND PURPOSE:

The aim of the present study was to assess incidence of and risk factors forinfection after hip arthroplasty in data from 3 national health registries. We investigated differences in risk patterns between surgical site infection (SSI) and revision due to infection after primary total hip arthroplasty (THA) and hemiarthroplasty (HA).

MATERIALS AND METHODS:

This observational study was based on prospective data from 2005-2009 on primary THAs and HAs from the Norwegian Arthroplasty Register (NAR), the Norwegian Hip Fracture Register (NHFR), and the Norwegian Surveillance System for Healthcare-Associated Infections (NOIS). The Norwegian Patient Register (NPR) was used for evaluation of case reporting. Cox regression analyses were performed with revision due to infection as endpoint for data from the NAR and the NHFR, and with SSI as the endpoint for data from the NOIS.

RESULTS:

The 1-year incidence of SSI in the NOIS was 3.0% after THA (167/5,540) and 7.3% after HA (103/1,416). The 1-year incidence of revision due to infection was 0.7% for THAs in the NAR (182/24,512) and 1.5% for HAs in the NHFR (128/8,262). Risk factors for SSI after THA were advanced age, ASA class higher than 2, and short duration of surgery. For THA, the risk factors for revision due to infection were male sex, advanced age, ASA class higher than 1, emergency surgery, uncemented fixation, and a National NosocomialInfection Surveillance (NNIS) risk index of 2 or more. For HAs inserted after fracture, age less than 60 and short duration of surgery were risk factors of revision due to infection.

INTERPRETATION:

The incidences of SSI and revision due to infection after primary hip replacements in Norway are similar to those in other countries. There may be differences in risk pattern between SSI and revision due to infection after arthroplasty. The risk patterns for revision due to infection appear to be different for HA and THA.

Source

Department of Orthopaedic, Joint Replacement and Reconstruction Center, Sir Ganga Ram Hospital, New Delhi, India. roy_sp27@yahoo.com

Source

Department of Orthopaedic Surgery, School of Medicine, Yokohama City University, Yokohama, Japan. yute@yhc.att.ne.jp

Abstract

BACKGROUND AND PURPOSE:

The accurate diagnosis of periprosthetic infection requires assessment of intraoperative tissues. These must be sampled from the appropriate sites. We used (18)F-fluoride positron emission tomography (PET) to identify sites of inflammation in order to improve the sensitivity of histopathology, microbiological culture, and real-time PCR in total hip arthroplasty (THA) patients.

PATIENTS AND METHODS:

23 THA patients (23 hips) scheduled for revision surgery (the revision group) and 17 uninfected THA patients (23 hips; control group) were enrolled. Uptake was classified into major, minor, and no uptake. To evaluate the association between the (18)F-fluoride uptake and intraoperative tissue results in the revision group, we calculated their sensitivity on each of the major, minor, and no-uptake sides.

RESULTS:

17 revision patients showed major uptake and all were diagnosed as having septic loosening from intraoperative tissue results. Minor uptake was observed in the other 6 revision patients and all were diagnosed as having aseptic loosening. Apart from 3 cases that showed minor uptake regions, control subjects showed no uptake. In the revision group, the sensitivities of histopathology, microbiological culture, real-time PCR separately and also in combination were 0.78, 0.58, 0.96, and 0.96, respectively, on the major (18)F-fluoride uptake sides, 0.0, 0.0, 0.1, and 0.1 on the minor-uptake sides, and 0, 0, 0.18, and 0.18 on the no-uptake sides.

INTERPRETATION:

Our findings suggest that preoperative assessment of major uptake of (18)F-fluoride markedly improves the accuracy of tissue sampling, and thus the sensitivity of subsequent tissue examinations. More definitive diagnosis of periprosthetic infection is therefore possible.

Comment on

• Use of a cement-loaded Kuntscher nail in first-stage revision hip arthroplasty for massive femoral bone loss secondary to infection: a report of four cases. [J Orthop Surg (Hong Kong). 2010]

Source

Department of Orthopaedic Surgery, Rothman Institute at Thomas Jefferson University, 925 Chestnut Street, Philadelphia, PA 19107, USA. parvj@aol.com

Abstract

BACKGROUND:

It is believed that some cases of aseptic failure of THA may be attributable to occult infections. However, it is unclear whether preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are more likely elevated in these patients than those without overt infection.

QUESTIONS/PURPOSES:

We asked whether some patients with aseptic THA failures have abnormal serologic indicators of periprosthetic joint infection (PJI) at the time of revision, namely ESR and/or CRP.

METHODS:

Three hundred twenty-three revision THAs for aseptic loosening from 2004 to 2007 were retrospectively evaluated. We categorized all cases into two groups: (1) those with overt PJI (n = 14) plus patients who had a positive intraoperative culture during the index revision (n = 13) and (2) those who did not require rerevision (n = 276) or required surgery for noninfected causes (n = 20). Mean and frequency of abnormal ESR and CRP were compared between the two groups. The minimum followup was 11 months (average, 35 months; range, 11-54 months).

RESULTS:

The mean and frequency of abnormal CRP in first group (n = 27) at 2.1 mg/dL and 48% respectively, were greater than those of the uninfected (n = 296) at 1.2 mg/dL and 27%, respectively. However, there were no differences between two groups regarding mean or frequency of abnormal ESR.

CONCLUSION:

Some patients with presumed aseptic loosening may have abnormal serologic indicators of PJI that either have escaped diagnosis or were not adequately investigated. All patients undergoing revision THA should have ESR and CRP measured preoperatively and those with abnormal CRP should have additional evaluations to rule out or confirm PJI.

Comment in

• Letter to the editor: Aseptic loosening of total hip arthroplasty: infection always should be ruled out. [Clin Orthop Relat Res. 2011]

Source

Orthopaedic Surgery Service, Geneva University Hospitals, Geneva, Switzerland.

Abstract

During a two-stage revision for prosthetic joint infections (PJI), joint aspirations, open tissue sampling and serum inflammatory markers are performed before re-implantation to exclude ongoing silent infection. We investigated the performance of these diagnostic procedures on the risk of recurrence of PJI among asymptomatic patients undergoing a two-stage revision. A total of 62 PJI were found in 58 patients. All patients had intra-operative surgical exploration during re-implantation, and 48 of them had intra-operative microbiological swabs. Additionally, 18 joint aspirations and one open biopsy were performed before second-stage reimplantation. Recurrence or persistence of PJI occurred in 12 cases with a mean delay of 218 days after re-implantation, but only four pre- or intraoperative invasive joint samples had grown a pathogen in cultures. In at least seven recurrent PJIs (58%), patients had a normal C-reactive protein (CRP, < 10 mg/l) level before re-implantation. The sensitivity, specificity, positive predictive and negative predictive values of pre-operative invasive joint aspiration and CRP for the prediction of PJI recurrence was 0.58, 0.88, 0.5, 0.84 and 0.17, 0.81, 0.13, 0.86, respectively. As a conclusion, pre-operative joint aspiration, intraoperative bacterial sampling, surgical exploration and serum inflammatory markers are poor predictors of PJI recurrence. The onset of reinfection usually occurs far later than reimplantation.

Source

Department of Orthopedic Surgery, University of Wisconsin Hospitals and Clinics, 600 Highland Ave, Madison, WI 53792-3228, USA. squire@ortho.wisc.edu

Abstract

OBJECTIVE: The purpose of this article is to illustrate how total knee arthroplasty (TKA) and total hip arthroplasty (THA) aspiration by the radiologist can assist the health care team in determining the presence or absence of periprosthetic joint infection. CONCLUSION: The increasing incidence of periprosthetic TKA and THA infection, as well as the changing role of aspiration for diagnosing periprosthetic joint infection, will likely increase demand for this important procedure in the future.

Source

Department of Orthopaedics, University of British Columbia, 3114-910 West 10th Avenue, Vancouver, BC V5Z 4E3, Canada.

Abstract

BACKGROUND:

Methicillin-resistant hip infections are increasingly common. Reports of the surgical management of these patients using two-stage THA show variable control of infection, but all reports used static spacers.

QUESTIONS/PURPOSES:

We therefore determined (1) the rate of successful control of infection and (2) function in patients with methicillin-resistant infection treated with a two-stage THA using an articulated cement spacer during the first stage.

METHODS:

We retrospectively reviewed 50 patients who had a two-stage revision THA for methicillin-resistant Staphylococcus aureus or methicillin-resistant Staphylococcus epidermidis infection. Twelve patients died, leaving 38 for review. All eligible patients completed quality-of-life outcome questionnaires (WOMAC, SF-12, Oxford-12, UCLA activity score, hip and knee satisfaction score). Minimum followup was 24 months after the second stage (mean, 58 months; range, 24-123 months).

RESULTS:

Of the 38 patients, eight (21%) had recurrence of their infection requiring further revision surgery. Of the remaining 27 patients, the mean WOMAC was 62, mean Oxford-12 60, mean UCLA activity score 4.3, and mean hip and knee satisfaction score 66.

CONCLUSIONS:

We found a treatment failure rate of 21% for patients with methicillin-resistant S. aureus or methicillin-resistant S. epidermidis infection. This is a higher rate than reported for two-stage THA for studies including patients infected with both nonresistant and resistant organisms. The functional scores for patients were also lower than those reported in the literature.

LEVEL OF EVIDENCE:

Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Source

Department of Orthopaedic and Traumatology, Hospital Clínic, University of Barcelona, Barcelona, Spain. gbori@clinic.ub.es

Abstract

The objective of our study was to study which is the most accurate specimen for histological diagnosis of prosthetic joint infections (pseudocapsule or interface membrane). This is a prospective study including hip revision arthroplasties performed from January 2007 to June 2009. Specimens from pseudocapsule and from interface membrane were obtained from each patient. The histology was considered positive for infection when ≥5 neutrophils per high-power field ( × 40) were found. Definitive diagnosis of infection was considered when ≥2 cultures were positive for the same microorganism. According to the definition of infection, patients were classified in two groups: (A) patients with aseptic loosening in whom cultures obtained during surgery were negative and (B) patients with prosthetic joint infection. A total of 69 revisions were included in the study; 57 were classified in group A and 12 in group B. In group B, the percentage of positive interface membrane histology was significantly higher than the percentage of positive pseudocapsule histology (83 vs 42%, P=0.04, Fisher's exact test). The results suggest that periprosthetic interface membrane is the best specimen for the histological diagnosis of prosthetic joint infection.

Source

Department of Orthopaedics, Weston General Hospital, Weston Super Mare, UK. riazhzi@yahoo.co.uk

Abstract

INTRODUCTION:

Infection after joint arthroplasty is a disastrous complication. Implants used in hip arthroplasty increase the risk of infection from organisms of low pathogenicity. Potential reservoirs, that have not been assessed as yet, are the supports used for patient positioning in hip arthroplasty. The purpose of this study was to assess these supports for presence of bacterial pathogens.

SUBJECTS AND METHODS:

We studied 40 supports used in 20 hip arthroplasty procedures. Tryptone soya agar plates were used to sample these supports. All agar plates were incubated at 37 °C for 48 h.

RESULTS:

Of the 20 anterior supports, 17 (85%) showed bacterial colonisation; of the 20 posterior supports, 10 (50%) had bacterial colonisation. Fourteen (52%) supports were contaminated with one organism, 9 (33%) with two organisms, three (11%) with three organisms and one (4%) with four organisms. Coagulase-negative staphylococci were the most common isolated organisms (61%) followed by coryneforms (10%) and bacilli (10%). Anterior supports had two times more colony forming units compared to the posterior supports.

CONCLUSIONS:

This study showed contamination of supports used for positioning patients during hip arthroplasty. It reflects poor cleaning practice and certainly raises the possibility that a high bacterial load on these supports may contribute to higher infection rates in hip arthroplasties. The study raises concerns related to contamination of supports, as there is a potential for cross-infection, wound problems, and deep sepsis around implants which could be disastrous. While colonisation does not equate with infection, we suggest thorough cleaning of the supports before and after every surgical procedure.

Source

Department of Anesthesiology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, USA. Boris.Mraovic@jefferson.edu

Abstract

BACKGROUND:

One of the most serious complications after major orthopedic surgery is deep wound or periprosthetic joint infection. Various risk factors for infection after hip and knee replacement surgery have been reported, including patients' comorbidities and surgical technique factors. We investigated whether hyperglycemia and diabetes mellitus (DM) are associated with infection that requires surgical intervention after total hip and knee arthroplasty.

METHODS:

We reviewed our computerized database for elective primary total hip and knee arthroplasty from 2000 to 2008. Demographic information, past medical history of patients, perioperative biochemistry, and postoperative complications were reviewed. Patients were divided into two groups: infected group (101 patients who had surgical intervention for infection at our institution within 2 years after primary surgery) and noninfected group (1847 patients with no intervention with a minimum of one year follow-up. The data were analyzed using t, chi-squared, and Fisher's exact tests.

RESULTS:

There were significantly more diabetes patients in the infected group compared with the noninfected group (22% versus 9%, p < .001). Infected patients had significantly higher perioperative blood glucose (BG) values: preoperative BG (112 ± 36 versus 105 ± 31 mg/dl, p = .043) and postoperative day (POD) 1 BG (154 ± 37 versus 138 ± 31 mg/dl, p < .001). Postoperative morning hyperglycemia (BG >200 mg/dl) increased the risk for the infection more than two-fold. Non-DM patients were three times more likely to develop the infection if their morning BG was >140 mg/dl on POD 1, p = .001. Male gender, higher body mass index, knee arthroplasty, longer operative time and hospital stay, higher comorbidity index, history of myocardial infarction, congestive heart failure, and renal insufficiency were also associated with the infection.

CONCLUSIONS:

Diabetes mellitus and morning postoperative hyperglycemia were predictors for postoperativeinfection following total joint arthroplasty. Even patients without a diagnosis of DM who developed postoperative hyperglycemia had a significantly increased risk for the infection.

© 2011 Diabetes Technology Society.

Source

Department of Orthopaedics, Sint Maartenskliniek, Nijmegen, the Netherlands.

Abstract

BACKGROUND AND PURPOSE:

Successful treatment of prosthetic hip joint infection (PI) means elimination of infection and restored hip function. However, functional outcome is rarely studied. We analyzed the outcome of the strict use of a treatment algorithm for PI.

PATIENTS AND METHODS:

The study groups included 22 hips with 1-stage exchange for PI (group 1), 22 matched hips revised for aseptic loosening (controls), and 50 hips with 2-stage exchange (group 2). Relapse ofinfection, Harris hip score (HHS), limping, use of crutches, reoperations, complications, and radiographic changes were compared between the groups.

RESULTS:

There was 1 relapse of infection, which occurred in group 2. In group 1, the mean HHS was 84; 4 of 19 patients were limping and 2 required 2 crutches, which was similar to the control results. In group 2, scores were lower and complication rates higher. The use of a Burch-Schneider ring and the presence of a deficient trochanter impaired function. There were no differences in radiographic outcome between the groups.

INTERPRETATION:

With the algorithm used, infection can be cured with high reliability. With a 1-stage procedure, mobility is maintained. After 2-stage procedures, function was impaired due to there being more previous surgery and more serious infection.

Source

Department of Orthopaedic Surgery, Middlemore Hospital, South Auckland Clinical School, University of Auckland, Private Bag, 93311, Auckland, New Zealand.

Abstract

While total hip arthroplasty has progressed to become one of the most successful surgical procedures ever developed, infection remains a serious complication. We have conducted a review of the literature pertaining to management of deep infection in total hip arthroplasty, specifically focusing on clinically relevant articles published in the last five years. A search was conducted using MEDLINE and PubMed, as well as a review of the Cochrane database, using the terms "total hip arthroplasty", "total hip replacement" and "infection". References for all selected articles were cross-checked. While the so-called two-stage revision is generally considered to be the gold standard for management, numerous studies now report outcomes for implant retention and reassessing one-stage revision strategies. There are encouraging reports for complex reconstruction options in patients with associated severe bone stock loss. The duration of antibiotic therapy remains controversial. There is concern about increasing bacterial resistance especially with the widespread use of vancomycin and ertapenem (carbapenem).

Source

Division of Sports Medicine, Department of Orthopedic Surgery, Chang Gung Memorial Hospital at Chia Yi, (6 West Section Chia Pu Road), Chia Yi Hsien, (613), Taiwan.

Abstract

BACKGROUNDS:

A two-stage revision arthroplasty was suggested optimal treatment for deep infections in hip joint. The effect of endoskeleton of cement spacers on the interim function and infection control remains unclear.

METHODS:

From Jan. 2004 to Dec. 2007, we collected a prospective cohort of consecutive 34 patients who treated with two-stage revision total hip arthroplasty for deep infection of hip joint. In group 1, fifteen patients were treated by a novel design augmented with hip compression screw while nineteen patients were treated by traditional design in group 2.

RESULTS:

No fracture of cement spacer occurred in group 1 while 6 cases developed spacer failure in group 2. (p < 0.05) There were significant differences in bodily pain and general health perception between groups (p < 0.05).

CONCLUSIONS:

Patients being treated for deep infection of hip joint using cement spacer augmented with stronger endoskeleton have lower pain levels and better joint function between stages.

Source

Department of Orthopaedic Surgery, NYU Langone Hospital for Joint Diseases, New York, New York, USA. nicholas.ramos@nyumc.org

Abstract

BACKGROUND:

Although the effect of Staphylococcus aureus (SA) decolonization on surgical site infection(SSI) rates has been studied, patient tolerance and acceptance of these regimens has not been assessed. Surgical patients at our hospital's Pre-Admission Testing Clinic (PAT) receive SA reduction protocols instructing the preoperative use of chlorhexidine gluconate (CHG) soap and intranasal mupirocin ointment (MO). Certain insurers do not cover MO costs resulting in out of pocket (OOP) expenses for some patients.

OBJECTIVE:

This study assessed patient attitudes and compliance with our hospital's SA decolonization regimen.

METHODS:

One-hundred-forty-six patients received surveys. Descriptive statistics were used for analysis.

RESULTS:

Of respondents fitting inclusion criteria, 81% followed the MO protocol (MO users) while 89% followed the CHG protocol (CHG users). Fifty-four percent of MO users reported OOP expenses and 13% reported a hard or very hard financial burden. Ninety-three percent of CHG users reported the protocol was easy or very easy to follow.

CONCLUSION:

Eighty-one percent of patients receiving the SA protocol were fully compliant despite cost or difficulty obtaining MO. Given these barriers and some difficulty with CHG application, we hypothesize compliance may be improved if MO is provided to patients without OOP expenses and if the CHG application method is simplified.

Source

Department of Orthopaedic Surgery, Harvard Medical School, Boston, MA, USA. hbedair@gmail.com

Abstract

BACKGROUND:

Synovial fluid white blood cell count is useful for diagnosing periprosthetic infections but the utility of this test in the early postoperative period remains unknown as hemarthrosis and postoperative inflammation may render standard cutoff values inaccurate.

QUESTIONS/PURPOSES:

We evaluated the diagnostic performance of four common laboratory tests, the synovial white blood cell count, differential, C-reactive protein, and erythrocyte sedimentation rate to detectinfection in the first 6 weeks after primary TKA.

METHODS:

We reviewed 11,964 primary TKAs and identified 146 that had a knee aspiration within 6 weeks of surgery. Infection was diagnosed in 19 of the 146 knees by positive cultures or gross purulence. We compared demographic information, time from surgery, and the laboratory test values between infected and noninfected knees to determine if any could identify infection early postoperatively. Receiver operating characteristic curves were constructed to determine optimal cutoff values for each of the test parameters.

RESULTS:

Synovial white blood cell count (92,600 versus 4200 cells/μL), percentage of polymorphonuclear cells (89.6% versus 76.9%), and C-reactive protein (171 versus 88 mg/L) were higher in the infected group. The optimal synovial white blood cell cutoff was 27,800 cells/μL (sensitivity, 84%; specificity, 99%; positive predictive value, 94%; negative predictive value, 98%) for diagnosing infection. The optimal cutoff for the differential was 89% polymorphonuclear cells and for C-reactive protein 95 mg/L.

CONCLUSIONS:

With a cutoff of 27,800 cells/μL, synovial white blood cell count predicted infection within 6 weeks after primary TKA with a positive predicted value of 94% and a negative predictive value of 98%. The use of standard cutoff values for this parameter (~ 3000 cells/μL) would have led to unnecessary reoperations.

LEVEL OF EVIDENCE:

Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Source

Department of Orthopaedics and Rehabilitation, The University of Iowa Hospitals and Clinics, 200 Hawkins Drive, Iowa City, IA 52242, USA.

Abstract

Total hip arthroplasty (THA) with conventional polyethylene bearings is traditionally the standard operative treatment for endstage arthritis of the hip. This design has excellent survivorship in most populations, with a low occurrence of infection and other associated complications. Due to concern over increased wear in younger, more active populations, other bearing surfaces have been evaluated, particularly metal-on-metal with wear rates theorized to be lower than conventional THA. Unique to metal-on-metal THA, however, is the possibility of local soft tissue reactions that can mimic infection, making proper diagnosis and treatment difficult. We present a case series of nine hips in eight patients undergoing revision of metal-on-metal THA for local soft tissue reactions, three of which were also found to be concomitantly infected. The laboratory and hip aspirate data described show significant overlap between the infected and non-infected cases. Care must be taken when evaluating patients with failed metal-on-metal THA as there may be an increased incidence of co-infection in this group of patients.

Source

Hospital for Joint Replacement, Tampere, Finland. esa.jamsen@uta.fi

Source

Department of Orthopaedics, University Medical Center Utrecht, the Netherlands. D.J.F.Moojen@umcutrecht.nl

Abstract

PURPOSE:

We investigated the hypothesis that many total hip arthroplasty revisions that are classified as aseptic are in fact low-grade infections missed with routine diagnostics.

METHODS:

In 7 Dutch hospitals, 176 consecutive patients with the preoperative diagnosis of aseptic loosening of their total hip arthroplasty were enrolled. During surgery, between 14 and 20 tissue samples were obtained for culture, pathology, and broad-range 16S rRNA PCR with reverse line blot hybridization. Patients were classified as either not being infected, suspected of having infection, or infected according to strict, predefined criteria. Each patient had a follow-up visit after 1 year.

RESULTS:

7 patients were classified as infected, 4 of whom were not identified by routine culture. 15 additional patients were suspected of having infection. 20 of these 22 patients received a cemented prosthesis, fixated with antibiotic-loaded bone cement. All 22 patients received prophylactic systemic antibiotics. 7 of them reported complaints one year after surgery, but only one showed signs of early loosening. However, additional surgery was not performed in any of the patients.

INTERPRETATION:

Although the proportions were not as high as previously reported in the literature, between 4% and 13% of patients with the preoperative diagnosis of aseptic loosening were infected. However, as thorough debridement was performed during surgery and prophylactic antibiotics were used, the diagnosis ofinfection did not have any obvious clinical consequences, as most patients performed well at the 1-year follow-up. Whether this observation has implications for long-term implant survival remains to be seen.