Cementless two-staged total hip arthroplasty for deep periprosthetic infection

Pasteurella multocida From a Cat Scratch as a Cause of Recurrent Prosthetic Joint Infection After Previously Successful Single-Stage Exchange Arthroplasty

We report a case of a 74-year-old female with a history of a prosthetic joint infection that was successfully treated with a single-stage exchange arthroplasty, off antibiotics, and without symptoms for 20 months. She presented 1 week after a cat scratch with acute knee pain, and aspiration grew Pasteurella multocida. She was successfully treated with surgical debridement and a prolonged course of antibiotics. Debate remains in the literature regarding whether recurrent infections represent a previously undetected organism or a new infection. Our report provides convincing evidence that, at least in some circumstances, the infection is new. Furthermore, this is the first case described of P. multocida resulting in a recurrent prosthetic joint infection after a previously successful exchange arthroplasty due to a different causative organism.

Against the Norm: Do Not Rely on Serum C-Reactive Protein and White Blood Cell Count Only When Assessing Eradication of Periprosthetic Joint Infection

Introduction: Periprosthetic joint infections (PJI) following primary arthroplasty continue to be a serious complication, despite advances in diagnostics and treatment. Two-stage revision arthroplasty has been commonly used as the gold standard for the treatment of PJI. However, much discussion persists regarding the interim of the two-stage procedure and the optimal timing of reimplantation. Serology markers have been proposed as defining parameters for a successful reimplantation. The objective of this matched-pair analysis was to assess the role of serum C-reactive protein (CRP) and white blood cell count (WBC) in determining infection eradication and proper timing of reimplantation. We investigated the delta (∆) change in CRP and WBC values prior to both stages of two-stage revision arthroplasty as a useful marker of infection eradication. Methods: We analyzed 39 patients and 39 controls, matched by propensity score matching (BMI, age, ASA-classification), with a minimum follow-up of 24 months and treated with a two-stage revision THA or TKA in our institution. Data of serum CRP and WBC values were gathered at two selected time points: prior to the explantation of the implant (preexplantation) and following the completion of antibiotic treatment regimen, both systemic and with a drug-eluting cement spacer (prereimplantation). Patient records were reviewed electronically for preexisting comorbidities, overall health status, synovial fluid cultures, inflammatory serologies, revision surgeries, and recurrent or persistent infection based on the modified Musculoskeletal Infection Society criteria. Patient demographics, ∆CRP, ∆WBC, and time interval to reimplantation were statistically analyzed using receiver operator curves (ROC), Pearson’s correlation coefficient, Levene’s test, and Student’s t-test. Results: Infection-free patients exhibited higher mean CRP and WBC than did patients who were reinfected at both time points. When comparing preexplantation with prereimplantation values, the median ∆CRP was 9.48 mg/L (interquartile range (IQR) 2.3−36.6 mg/L) for patients who did not develop a reinfection versus 2.74 mg/L (IQR 1.4−14.2 mg/L) for patients who developed reinfection (p = 0.069). The median ∆WBC was 1.5 × 109/L (IQR 0.6−4.0 × 109/L) for patients who remained infection-free versus 1.2 × 109/L (IQR 0.8−2.2 109/L) for patients who developed reinfection (p = 0.072). Analysis of areas under the curve (AUC) using ROC demonstrated poor prediction of persistent infection by ∆CRP (AUC = 0.654) and ∆WBC (AUC = 0.573). Although a highly significant correlation was found between the interim interval and infection persistence (r = 0.655, p < 0.01), analysis using ROC failed to result in a specific threshold time to reimplantation above which patients are at significantly higher risk for reinfection (AUC = 0.507). Conclusion: No association could be determined between the delta change in serum CRP and WBC before and after two-stage revision arthroplasty for PJI and reinfection risk. Even though inflammatory serologies demonstrate a downtrending pattern prior to reimplantation, the role of CRP and WBC in determining the optimal timing of reimplantation seems to be dispensable. Planning a second-stage reimplantation requires assessing multiple variables rather than relying on specific numeric changes in these inflammatory marker values.

Successive new-pathogen prosthetic joint reinfections: Observational cohort study on 61 patients

OBJECTIVES

s (PJI) treatment failure may be due to relapsing infection (same microorganism) or new-pathogen reinfection (npPJI). The aim was to describe npPJI epidemiological, clinical and microbiological characteristics, their treatments and outcomes, and identify their risk factors.

METHODS

This observational, single-center, cohort study was conducted in a French Referral Center for Bone-and-Joint Infections between September 2004 and December 2015. Patients treated for at least two successive hip or knee PJIs in the same joint with a different pathogen were identified in the prospective database. We compared each patient's first PJI and subsequent npPJI(s) to analyze the type and microbiological characteristics of npPJIs. To search for npPJI risk factors, we compared those cases to a random selection of 122 "unique-episode" PJIs treated during the study period.

RESULTS

Among 990 PJIs, 79 (8%) npPJIs occurring in 61 patients were included. New-pathogen prosthetic joint infections (npPJIs) s developed more frequently in knee (14%) than hip prostheses (5%). Median interval from the first PJI to the npPJI was 26 months. New-pathogen prosthetic joint infections (npPJIs) s more frequently spread hematogenously (60% vs 33%) and were predominantly caused by Staphylococcus (36%) or Streptococcus (33%) species. Multivariate analysis identified two risk factors: chronic dermatitis (odds ratio: 6.23; P<0.05) and cardiovascular diseases (odds ratio: 2.71; P<0.01). A curative strategy was applied to 70%: DAIR (29%), one-stage (28%), two-stage exchange arthroplasty (7%) or other strategies (7%). The others received prolonged suppressive antibiotic therapy (29%).

CONCLUSIONS

New-pathogen prosthetic joint infections (npPJIs) s are complex infections requiring management by multidisciplinary teams that should be adapted to each clinical situation.

Two-Stage Reimplantation of a Prosthetic Hip Infection: Systematic Review of Long-Term Reinfection and Pathogen Outcomes

BACKGROUND

Although two-stage exchange for chronic periprosthetic hip infections remains an effective option for infection eradication, long-term outcome reporting remains scarce. Compiling outcomes data for this standard of care is necessary to characterize long-term reinfection risk and identify bacteria associated with reinfection. The purpose of our study was to perform a systematic review to determine the long-term risk of reinfection after two-stage reimplantation. The second purpose was to identify the proportion of reinfections caused by the same or different organism(s) relative to the index infection.

METHODS

We performed a systematic review of two-stage reimplantation randomized control trials, cohort studies, and case series for the treatment of periprosthetic joint infections, yielding 320 unique citations for abstract review, of which 138 were reviewed in full. We collected reinfection data including the timing of reinfection after successful reimplantation and the bacteria identified at reinfection. Meeting inclusion criteria were 28 studies with 2047 patients and 2055 hips that completed both reimplantation stages with just seven studies having greater than 24 month follow-up.

RESULTS

Studies with longer average follow-up reported significantly higher all-time reinfection rates (P = .042). Among studies with at least 5 years of follow-up, the risk of reinfection was 10.25% (8.21-12.47). Among studies with minimum follow-up of at least 24 months, the 24-month rate of reinfection was 4.58% (2.17-7.66), which increased to 7.34% (4.44-10.82) by final follow-up. Only 12 studies reported index and recurrent pathogen data. In those studies, 3.00% (1.19-5.38) of all hips which completed both reimplantation stages were reinfected by a new pathogen, and 1.70% (0.52-3.35) of patients became reinfected by recurrent pathogens.

CONCLUSION

While the majority of two stage reimplantation literature follows patients for two years, there is significant risk of reinfection into the long term. Further studies with detailed outcomes and long-term follow-up are needed to identify factors associated with late infections.

Successful Two-Stage Exchange Arthroplasty for Periprosthetic Infection Following Total Knee Arthroplasty: The Impact of Timing on Eradication of Infection

Background: Periprosthetic joint infection (PJI) represents a serious complication following total knee arthroplasty. In the setting of chronic infections, the two-staged approach has traditionally been the preferred treatment method. The aim of this study was to determine the optimal period of rest between the first and second stage. Furthermore, we analyzed potentially outcome-relevant parameters, such as general and local conditions and the presence of difficult-to-treat or unidentified microorganisms, with regard to their impact on successful treatment of PJI. Patients and Methods: We performed a retrospective analysis of prospectively collected data for all patients treated for PJI at our institution. Seventy-seven patients who had undergone two-stage revision arthroplasty for PJI of the knee were included into the study. Antibiotic-loaded cement spacers were used for all patients. Results: After a median follow-up time of 24.5 months, infection had reoccurred in 14 (18.7%) patients. A prolonged spacer-retention period of more than 83 days was related to a significantly higher proportion of reinfections. Furthermore, significant compromising local conditions of the prosthetic tissue and surrounding skin, as well as repeated spacer-exchanges between first- and second-stage surgery, negatively influenced the outcome. Neither the patients' age nor gender exerted a significant influence on the outcome regarding reinfection rates for patients' age or gender. Conclusions: We observed the best outcome regarding infection control in patients who had undergone second-stage surgery within 12 weeks after first-stage surgery. Nearly 90% of these patients stayed free from infection until the final follow-up. An increased number of performed spacer-exchanges and a bad local extremity grade also had a negative impact on the outcome.

Contemporary 2-Stage Treatment of Periprosthetic Hip Infection with Evidence-Based Standardized Protocols Yields Excellent Results: Caveats and Recommendations

BACKGROUND

This study quantified the effectiveness of contemporary and evidence-based standardized 2-stage treatment for periprosthetic hip infection. Findings illustrate potential limitations of criticisms of 2-stage protocols and potential consequences of adopting single-stage protocols before definitive data are available.

METHODS

Fifty-four consecutive hips treated with 2-stage resection and reimplantation were retrospectively reviewed. Standardized protocols were adhered to including implant resection, meticulous surgical debridement, antibiotic spacer, 6-week intravenous antibiotics, a 2-week drug holiday, and laboratory assessment of infection eradication before reimplantation. After reimplantation, patients were placed on prophylactic intravenous antibiotics until discharge and discharged on oral antibiotics for a minimum of 7 days until intraoperative cultures were final. Successful treatment was defined per Delphi-based International Multidisciplinary Consensus.

RESULTS

The overall treatment success rate was 95.7% (44 of 46 cases) with mean infection-free survivorship of 67.2 (range, 23.8-106.4) months. Success rates were 100% for early and acute hematogenous infections regardless of host type and 100% for chronic infections in uncompromised hosts. 95% (19/20) of chronic infections in compromised hosts and 83.3% (5/6) of chronic infections in significantly compromised hosts were successfully treated. About 4% of primary hips and 20% of revision hips required repeat debridement and spacer exchange after initial resection. No patients died because of treatment.

CONCLUSION

Details from this consecutive series of patients undergoing 2-stage treatment for hip infection suggest that some criticisms of 2-stage treatment as well as some arguments in support of single-stage treatment may be overstated. Promotion and uncritical adoption of single-stage treatment protocols are discouraged until further and more definitive data exist.

Positive Alpha-defensin at Reimplantation of a Two-stage Revision Arthroplasty Is Not Associated with Infection at 1 Year

BACKGROUND

Diagnosing periprosthetic joint infection (PJI) represents a challenge that relies on multiple clinical and laboratory criteria that may not be consistently present. The synovial alpha-defensin-1 (AD-1) test has been shown to correlate accurately with the Musculoskeletal Infection Society (MSIS) criteria for the diagnosis of PJI, however, its association with persistent PJI has not been elucidated in the setting of patients receiving antibiotic spacers during second-stage reimplantation. Applying a Delphi-based consensus to define successful eradication of PJI offers an opportunity to test the utility of AD-1 in this setting.

QUESTIONS/PURPOSES

(1) Can the AD-1 test determine whether infection has been controlled using the Delphi criteria for persistent PJI as a surrogate for infection eradication during two-stage revision for PJI treatment with a spacer? (2) How does the performance of the AD-1 test compare with the MSIS criteria?

METHODS

This was a multicenter analysis of retrospectively collected data on patients who underwent a two-stage revision arthroplasty between May 2014 and July 2016. We included patients who had a previously confirmed PJI and received a cement spacer, underwent the second stage, had MSIS criteria data and a synovial fluid AD-1 test, and had a minimum followup of 1 year. We were unable to determine for all study sites how many patients had the test but did not meet all the criteria and so could not be studied; however, we were able to identify 69 patients (43 knees, 26 hips) who met all criteria. During the period in question, indications for use of AD-1 varied by surgeon; however, during that time, in general if a surgeon ordered it as part of the initial workup, the test would have been repeated before the second-stage reimplantation procedure. To assess the validity of AD-1 against persistence of PJI criteria at 1 year, the following were calculated using the Delphi criteria for persistent PJI as the gold standard: sensitivity, specificity, positive and negative predictive values, accuracy, and area under the curve (AUC) with 95% confidence intervals (CIs). Concordance index (c-index) and its Wald 95% CI with receiver operating characteristic (ROC) curve were calculated in relation to Delphi criteria for persistent PJI using AD-1 and then MSIS criteria. The two c-indices of AD-1 and MSIS were compared using the DeLong nonparametric approach.

RESULTS

The AD-1 test showed poor sensitivity (7%; 95% CI, 0.2-34), and poor overall accuracy (73%; 95% CI, 60-83; AUC = 0.5; 95% CI, 0.3-0.6) in detecting infection eradication at 1 year. The c-index for AD-1 versus Delphi criteria for persistent PJI was 0.519 (95% CI, 0.44-0.60), and the c-index for MSIS criteria versus Delphi criteria for persistent PJI was 0.518 (95% CI, 0.49-0.54), suggesting the weak diagnostic abilities of these models. The contrast estimate between MSIS criteria and AD-1 were not different from one another at -0.001 (95% CI%, -0.09 to 0.09; p = 0.99).

CONCLUSIONS

We found that a positive synovial fluid AD-1 test correlated poorly with the presence of persistent infection 1 year after two-stage revision arthroplasty for PJI. For this reason, we recommend against the routine use of AD-1 in patients with cement spacers, until or unless future studies demonstrate that the test is more effective than we found it to be.

LEVEL OF EVIDENCE

Level IV, diagnostic study.

Outcome of Irrigation and Debridement after Failed Two-Stage Reimplantation for Periprosthetic Joint Infection

Introduction

Two-stage revision is the gold standard for the treatment of deep implant infection after knee or hip arthroplasty. Irrigation and debridement may be a treatment option for failed 2-stage revisions in cases where a reinfection occurs within 30 days or the symptoms exist not longer than 3 weeks and is appealing because of its low morbidity. We determined the incidence of recurrent infections following irrigation and debridement for failed two-stage revision hip and knee arthroplasty.

Methods

We performed a single center retrospective review of periprosthetic hip and knee infections treated with a two-stage procedure from 2002 to 2010. All patients that subsequently underwent irrigation and debridement for a subsequent infection were selected for the current study.

Results

440 two-stage revisions were performed between 2002 and 2010. Fifty-one two-stage revisions failed (11.6%). Nineteen failed two-stage revisions were treated with irrigation and debridement; 12 (63.2%) patients remained free of infection at follow-up (mean follow-up: 39 months; range, 24-90 months), infection persisted in 6 patients (31.6%), and 1 patient died (5.3%).

Conclusions

Success rates of irrigation and debridement for failed two-stage procedures are similar to the success rates of irrigation and debridement in primary implant infections. According to the current paper, irrigation and debridement are an acceptable treatment for acute reinfections after failed two-stage revision if performed within the first 30 postoperative days after failed two-stage procedure or if symptoms are present for less than 3 weeks in the presence of a susceptible organism.

Time to Reimplantation: Waiting Longer Confers No Added Benefit

BACKGROUND

While the preferred surgical treatment for chronic periprosthetic joint infection (PJI) in North America is a 2-stage exchange arthroplasty, the optimal time between first-stage and reimplantation surgery remains unknown. This study was conceived to examine the association between time to reimplantation and treatment failure.

METHODS

Using an institutional database, we identified PJI cases treated with 2-stage exchange arthroplasty between 2000 and 2016. Musculoskeletal Infection Society criteria were used to define PJI, and treatment failure was defined using Delphi criteria. The interstage interval between first-stage and reimplantation surgery for each case was collected, alongside demographics, patient-related and organism-specific data. Multivariate logistic regression analyses were used to examine association with treatment failure.

RESULTS

Our final analysis consisted of 282 patients with an average time to reimplantation of 100.2 days (range, 20-648). Sixty-three patients (22.3%) failed at 1 year based on Delphi criteria. Time to reimplantation was not significantly associated with failure in both univariate (P = .598) and multivariate (P = .397) models. However, patients reimplanted at >26 weeks were twice as likely to fail in comparison to those reimplanted within <26 weeks (43.8% vs 21.1%), and this finding reached marginal significance (P = .057). Patients who failed had significantly more comorbidities (P = .008). Charlson comorbidity index was the only variable significantly associated with treatment failure in regression analysis (odds ratio, 1.40; 95% confidence interval, 1.06-1.86; P = .019).

CONCLUSION

The length of the interstage interval was not a statistically significant predictor of failure in patients undergoing 2-stage exchange arthroplasty for PJI.

Histopathology in Periprosthetic Joint Infection: When Will the Morphomolecular Diagnosis Be a Reality?

The presence of a polymorphonuclear neutrophil infiltrate in periprosthetic tissues has been shown to correlate closely with the diagnosis of septic implant failure. The histological criterion considered by the Musculoskeletal Infection Society to be diagnostic of periprosthetic joint infection is “greater than five neutrophils per high-power field in five high-power fields observed from histologic analysis of periprosthetic tissue at ×400 magnification.” Surgeons and pathologists should be aware of the qualifications introduced by different authors during the last years in the histological techniques, samples for histological study, cutoffs used for the diagnosis of infection, and types of patients studied. Recently, immunohistochemistry and histochemistry studies have appeared which suggest that the cutoff point of five polymorphonuclear neutrophils in five high-power fields is too high for the diagnosis of many periprosthetic joint infections. Therefore, morphomolecular techniques could help in the future to achieve a more reliable histological diagnosis of periprosthetic joint infection.

Late Reinfection May Recur More Than 5 Years After Reimplantation of THA and TKA: Analysis of Pathogen Factors

BACKGROUND

Two-stage reimplantation has consistently yielded high rates of success for patients with chronic prosthetic joint infection, although results more than 5 years after reimplantation are not commonly reported. Numerous factors may contribute to the risk of reinfection, although these factors-as well as the at-risk period after reimplantation-are not well characterized.

QUESTIONS/PURPOSES

(1) What is the risk of reinfection after reimplantation for prosthetic joint infection at a minimum of 5 years? (2) Is the bacteriology of the index infection associated with late reinfection? (3) Is the presence of bacteria at the time of reimplantation associated with late reinfection?

METHODS

Between 1995 and 2010, we performed 97 two-stage revisions in 93 patients for prosthetic joint infection of the hip or knee, and all are included in this retrospective study. During that time, the indications for this procedure generally were (1) infections occurring more than 3 months after the index arthroplasty; and (2) more acute infections associated with prosthetic loosening or resistant organisms. One patient (1%) was lost to followup; all others have a minimum of 5 years of followup (mean, 11 years; range, 5-20 years) and all living patients have been seen within the last 2 years. Patients were considered free from infection if they did not have pain at rest or constitutional symptoms such as fever, chills, or malaise. The patients' bacteriology and resistance patterns of these organisms were observed with respect to recurrence of infection. Odds ratios and Fisher's exact test were performed to analyze the data. The incidence of reinfection was determined using cumulative incidence methods that considered death as a competing event.

RESULTS

Reinfection occurred in 12 of the 97 joints resulting in implant revision. The estimated 10-year cumulative incidence of infection was 14% (95% confidence interval [CI], 7%-23%) and incidence of infection from the same organism was 5% (95% CI, 1%-11%). Five occurred early or within 2 years and three were resistant pathogens (methicillin-resistant Staphylococcus aureus, methicillin-resistant Staphylococcus epidermidis, or vancomycin-resistant Enterococcus). Seven late hematogenous infections occurred and all were > 4 years after reimplantation and involved nonresistant organisms. Three of the five (60%) early infections were caused by resistant bacteria, whereas all seven late infections were caused by different organisms or a combination of different organisms than were isolated in the original infection. The early reinfections were more often caused by resistant organisms, whereas late infections involved different organisms than were isolated in the original infection and none involved resistant organisms. With the numbers available, we found no difference between patients in whom bacteria were detected at the time of reimplantation and those in whom cultures were negative in terms of the risk of reinfection 5 years after reimplantation (18.6% [18 of 97] versus 81.4% [79 of 97], odds ratio 1.56 [95% CI, 0.38-6.44]; p = 0.54); however, with only 93 patients, we may have been underpowered to make this analysis.

CONCLUSIONS

In our study, resistant organisms were more often associated with early reinfection, whereas late failures were more commonly associated with new pathogens. We believe the most important finding in our study is that substantial risk of late infection remains even among patients who seemed free from infection 2 years after reimplantation for prosthetic joint infections of the hip or knee. This highlights the importance of educating our patients about the ongoing risk of prosthetic joint infection.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Comparison of the efficacy of static versus articular spacers in two-stage revision surgery for the treatment of infection following total knee arthroplasty: a meta-analysis

Background

The aim of this study was to compare the outcomes of static versus articular spacers in two-stage reimplantation for the treatment of infected total knee arthroplasty (TKA).

Methods

The literature regarding the articulating and static spacers for treating infected TKA were searched in PubMed, Embase, Cochrane Library, Chinese Periodical Full-Text Database of CNKI, and Wanfang database. Data were extracted according to the inclusion and exclusion criteria and analyzed by Review Manager 5.3.

Results

Ten studies were included to this meta-analysis (nine retrospective studies, one prospective study) according to the principle of PICOS. There was no significant difference regarding the eradication rate (P = 0.28) and the American Knee Society knee score (KSS) pain score (P = 0.11) between the articulating and static spacers in the two-stage revision surgery. There was no significant difference regarding quadriceps femoroplasty and tibial tubercle osteotomy between the two groups (P = 0.50). The knee range of motion (ROM), Hospital for Special Surgery (HSS) score, and KSS function score in the articulating group were significantly higher than those in the static group (P < 0.00001).

Conclusion

Articulating spacers can provide better ROM and knee function scores after revision surgery when compared to static spacer while not compromising the infection eradication rate, soft tissue contracture during exclusion period, and knee pain scores.

Single-stage Acetabular Revision During Two-stage THA Revision for Infection is Effective in Selected Patients

BACKGROUND

The treatment of periprosthetic infections of hip arthroplasties typically involves use of either a single- or two-stage (with implantation of a temporary spacer) revision surgery. In patients with severe acetabular bone deficiencies, either already present or after component removal, spacers cannot be safely implanted. In such hips where it is impossible to use spacers and yet a two-stage revision of the prosthetic stem is recommended, we have combined a two-stage revision of the stem with a single revision of the cup. To our knowledge, this approach has not been reported before.

QUESTIONS/PURPOSES

(1) What proportion of patients treated with single-stage acetabular reconstruction as part of a two-stage revision for an infected THA remain free from infection at 2 or more years? (2) What are the Harris hip scores after the first stage and at 2 years or more after the definitive reimplantation?

METHODS

Between June 2009 and June 2014, we treated all patients undergoing surgical treatment for an infected THA using a single-stage acetabular revision as part of a two-stage THA exchange if the acetabular defect classification was Paprosky Types 2B, 2C, 3A, 3B, or pelvic discontinuity and a two-stage procedure was preferred for the femur. The procedure included removal of all components, joint débridement, definitive acetabular reconstruction (with a cage to bridge the defect, and a cemented socket), and a temporary cemented femoral component at the first stage; the second stage consisted of repeat joint and femoral débridement and exchange of the femoral component to a cementless device. During the period noted, 35 patients met those definitions and were treated with this approach. No patients were lost to followup before 2 years; mean followup was 42 months (range, 24-84 months). The clinical evaluation was performed with the Harris hip scores and resolution of infection was assessed by the absence of clinical signs of infection and a C-reactive protein level less than 10 mg/L. All patients were assessed before surgery, between stages, every 3 months during the first year after surgery, every 6 months during the second year postoperative, and at latest followup, and were retrospectively drawn from a longitudinally maintained institutional database.

RESULTS

Thirty-four of 35 patients (97.2%; 95% CI, 85.4%-99.5%) appeared free of infection by criteria of Masri et al. and Zimmerli et al. at latest followup. The Harris hip score was 61 ± 13 points after the first operation and 82 ± 16 points 2 years after the second operation.

CONCLUSIONS

This technique is a promising treatment option for periprosthetic infections of the hip in which substantial acetabular defects exclude implantation of a normal spacer and a two-stage revision of the femoral component is favored.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Periprosthetic Infection Recurrence After 2-Stage Exchange Arthroplasty: Failure or Fate?

BACKGROUND

Two-stage exchange arthroplasty remains the preferred method for treating a chronic periprosthetic joint infection (PJI) in North America. However, infection recurrence may occur. Previously, recurrent infections have been classified as persistent (same isolated pathogen) or new (different pathogen identified). We sought to determine (1) recurrence rates among patients with chronic hip and knee PJI, treated with 2-stage exchange arthroplasty; (2) risk factors for infection recurrence; and (3) risk factors for developing persistent vs new infection.

METHODS

We retrospectively reviewed clinical characteristics of patients with chronic hip and knee PJI, treated with 2-stage revision between January 1998 and March 2014. Minimum follow-up was 24 months. Two multivariate logistic regression models were constructed to determine independent predictors for infection recurrence and persistence.

RESULTS

In total, 548 patients were identified (283 men, 265 women). Forty-eight had a recurrent infection (8.76%). Men had 54.8% lower odds of PJI recurrence than women (odds ratio [OR] = 0.452; 95% confidence interval [CI], 0.235-0.869). Patients with heart disease had 109% higher odds of infection recurrence than patients without heart disease (OR = 2.09; 95% CI, 1.097-3.081). The risk of infection recurrence was 119% higher in patients with psychiatric disorders than in patients without psychiatric disorders (OR = 2.19; 95% CI, 1.011-4.761). Patients with recurrent knee PJI had 84.6% lower odds of persistent infection (OR = 0.154; 95% CI, 0.034-0.696) compared to hip PJI. Patients with heart disease had 5-fold increased odds for persistent PJI (OR = 5.068; 95% CI, 1.38-22.56).

CONCLUSION

Female gender, heart disease, and psychiatric disorders increase the risk of hip and knee PJI recurrence. Patients with PJI of the hip and with heart disease are at higher risk of infection persistence.

Are Frozen Sections and MSIS Criteria Reliable at the Time of Reimplantation of Two-stage Revision Arthroplasty?

BACKGROUND

Frozen section histology is widely used to aid in the diagnosis of periprosthetic joint infection at the second stage of revision arthroplasty, although there are limited data regarding its utility. Moreover, there is no definitive method to assess control of infection at the time of reimplantation. Because failure of a two-stage revision can have serious consequences, it is important to identify the cases that might fail and defer reimplantation if necessary. Thus, a reliable test providing information about the control of infection and risk of subsequent failure is necessary.

QUESTIONS/PURPOSES

(1) At second-stage reimplantation surgery, what is the diagnostic accuracy of frozen sections as compared with the Musculoskeletal Infection Society (MSIS) as the gold standard? (2) What are the diagnostic accuracy parameters for the MSIS criteria and frozen sections in predicting failure of reimplantation? (3) Do positive MSIS criteria or frozen section at the time of reimplantation increase the risk of subsequent failure?

METHODS

A total of 97 patients undergoing the second stage of revision total hip arthroplasty or total knee arthroplasty in 2013 for a diagnosis of periprosthetic joint infection (PJI) were considered eligible for the study. Of these, 11 had incomplete MSIS criteria and seven lacked 1-year followup, leaving 79 patients (38 knees and 41 hips) available for analysis. At the time of reimplantation, frozen section results were compared with modified MSIS criteria as the gold standard in detecting infection. Subsequently, success or failure of reimplantation was defined by (1) control of infection, as characterized by a healed wound without fistula, drainage, or pain; (2) no subsequent surgical intervention for infection after reimplantation surgery; and (3) no occurrence of PJI-related mortality; and diagnostic parameters in predicting treatment failure were calculated for both the modified MSIS criteria and frozen sections.

RESULTS

At the time of second-stage reimplantation surgery, frozen section is useful in ruling in infection, where the specificity is 94% (95% confidence interval [CI], 89%-99%); however, there is less utility in ruling out infection, because sensitivity is only 50% (CI, 13%-88%). Both the MSIS criteria and frozen sections have high specificity for ruling in failure of reimplantation (MSIS criteria specificity: 96% [CI, 91%-100%]; frozen section: 95% [CI, 88%-100%]), but screening capabilities are limited (MSIS sensitivity: 26% [CI, 9%-44%]; frozen section: 22% [CI, 9%-29%]). Positive MSIS criteria at the time of reimplantation were a risk factor for subsequent failure (hazard ratio [HR], 5.22 [1.64-16.62], p = 0.005), whereas positive frozen section was not (HR, 1.16 [0.15-8.86], p = 0.883).

CONCLUSIONS

On the basis of our results, both frozen section and MSIS are recommended at the time of the second stage of revision arthroplasty. Both frozen section and modified MSIS criteria had limited screening capabilities to identify failure, although both demonstrated high specificity. MSIS criteria should be evaluated at the second stage of revision arthroplasty because performing reimplantation in a joint that is positive for infection significantly increases the risk for subsequent failure.

LEVEL OF EVIDENCE

Level III, diagnostic study.

The Transfemoral Approach for Removal of Well-Fixed Femoral Stems in 2-Stage Septic Hip Revision

BACKGROUND

The value of a transfemoral approach for removal of well-fixed infected hip arthroplasties in 2-stage revision is unclear, especially whether cerclages for closure of the flap in the first step lead to higher reinfection rates and whether reopening of the flap for reimplantation of a hip arthroplasty leads to a lower union rate of the bony flap.

METHODS

Seventy-six septic 2-stage revisions via a transfemoral approach with cerclages for closure of the flap in the first step and reopening of the flap for reimplantation were followed prospectively for a mean period of 51.2 ± 23.2 (24-118) months.

RESULTS

The union rate of the bony flap after reimplantation was 98.7%, and no recurrence of reinfection was recorded in 93.4% of all cases. Subsidence of the stem occurred at a rate of 6.6%, dislocation at a rate of 6.6%, and there was no aseptic loosening of the implants. The Harris Hip Score was 62.2 ± 12.6 points with the spacer and 86.6 ± 15.5 points 2 years after reimplantation. Nine fractures (11.8%) of the flap occurred during the operation because of osteolytic or osteoporotic weakness of the flap itself, but these all healed without further intervention.

CONCLUSION

The transfemoral approach is a safe method for septic revision of well-fixed hip prostheses, and the use of cerclage wires for closing the osteotomy flap in the first stage does not appear to lead to a higher reinfection rate. Similarly, the reopening of the flap does not appear to decrease the union rate of the flap.

Limitations of Gram staining for the diagnosis of infections following total hip or knee arthroplasty

The diagnosis of prosthetic joint infection (PJI) following total joint arthroplasty is difficult for clinicians to make decisions due to the similar symptoms presented by aseptic loosening and infection. Gram staining (GS) is a widely used test but its value remains controversial due to conflicting results in the diagnosis of PJI. The aim of the present study was therefore to evaluate the value of GS in the diagnosis of PJI. Searches using MEDLINE, EMBASE and OVID databases were conducted for data published between January 1990 and December 2013. Meta-analysis was used to pool the sensitivity, specificity, diagnostic odd ratios (DORs), area under the receiver-operating characteristic curve (AUC), positive-likelihood ratios (PLRs), negative-likelihood ratios (NLRs) and post-test probability. The heterogeneity and publication bias were assessed, and subgroup and meta-regression analyses were conducted. A total of 18 studies, including a total of 4,647 patients, were selected for analysis. The pooled sensitivity and specificity values for the diagnosis of PJI were 0.19 and 1.00, respectively. The AUC, PLR and NLR were 0.89, 41.6 and 0.82, respectively. Subgroup analyses indicated that the sensitivity/specificity for total hip arthroplasty was 0.14/0.99, whereas that for total knee arthroplasty was 0.14/1.00. Synovial fluid best reflected accurate GS-based diagnoses, with the highest DOR of 242, whereas tissue had the highest AUC of 0.96 (95% CI, 0.94-0.97). GS had a poor clinically acceptable diagnostic value for detecting PJI. These data do not support the routine use of GS, without additional proof of infection, for diagnosing PJI; instead, GS could be used as an adjuvant tool to support the results of other investigations.

Morbid obesity: a significant risk factor for failure of two-stage revision total hip arthroplasty for infection

BACKGROUND

Morbid obesity (BMI [body mass index], ≥40 kg/m2) is associated with a higher risk of complications, including infection and implant failure, following primary total hip arthroplasty. The purpose of this study was to compare the results of two-stage revision total hip arthroplasty for infection in a morbidly obese patient cohort (BMI, ≥40 kg/m2) and nonobese patients (BMI, <30 kg/m2).

METHODS

Using an institutional total joint registry, we reviewed the medical records of 653 patients treated with two-stage revision total hip arthroplasty for periprosthetic joint infection over a twenty-year period (1987 to 2007). Patients were stratified according to preoperative BMI. Thirty-three patients (fourteen male and nineteen female) with a BMI of ≥40 kg/m2 were identified. These patients were matched 1:2 with a cohort of sixty-six patients (twenty-eight male and thirty-eight female) of the same sex and similar age (91% within two years) who were not obese (BMI, <30 kg/m2). All patients had a minimum of five years of clinical follow-up (mean, 8.1 years in the morbidly obese group and 10.3 years in the nonobese group).

RESULTS

Compared with nonobese patients, morbidly obese patients had significantly greater rates of reinfection (18% compared with 2%, p<0.005), revision (42% compared with 11%, p<0.001) and reoperation for any reason (61% compared with 12%, p<0.001). Prior to surgery, the mean Harris Hip Score had been 50.6 in the morbidly obese group and 48.8 in the nonobese group, and these scores improved significantly in both groups postoperatively (p<0.01).

CONCLUSIONS

Morbidly obese patients have markedly elevated risks of reinfection, reoperation, and component resection as well as poorer intermediate-term clinical outcome scores compared with nonobese patients following revision total hip arthroplasty for periprosthetic joint infection.

Extensively coated non-modular stem used in two-stage revision for infected total hip arthroplasty: mid-term to long-term follow-up

OBJECTIVE

To determine the rate of curing the infection and mid- to long-term outcomes of using extensively coated non-modular stems in two-stage revision for infected total hip arthroplasty (THA).

METHODS

The clinical data of 33 patients (33 hips) in whom extensively coated non-modular stems had been used in two-stage revision THA for deep infection were retrospectively analyzed. All operations received two-stage reimplantation, which included resection arthroplasty, thorough debridement, insertion of a hand-molded antibiotic-impregnated cement spacer with stainless steel reinforcement, a course of intravenous antibiotics, and delayed reimplantation. Microorganism-specific antibiotics had been chosen according to the results of microbiological studies performed postoperatively. All patients received i.v. antimicrobial therapy for 4 weeks and oral antibiotics to which their organisms were sensitive for a further 6 weeks. Harris hip score (HHS) and plain X-ray films were used to perform clinical and radiological evaluations.

RESULTS

During follow-up for a minimum of 5 years, no reinfection or loosening were found. Cultures of samples taken during the second stage were all negative for infection. The mean HHS improved from 42 preoperative to 89 at the final follow-up. All granular bones had fused well with the host bones by 12 months after the surgery.

CONCLUSION

Using extensively coated non-modular stems combined with intramedullary allografts in two-stage revision for treating infected THAs can achieve satisfactory outcomes.

Two-stage hip revision arthroplasty with a hexagonal modular cementless stem in cases of periprosthetic infection

Background

Two-stage revision arthroplasty is today regarded as the gold standard treatment method for deep prosthetic joint infection. The aim of the present study was to evaluate clinical and functional outcomes with the Modular Universal Tumor And Revision System (MUTARS) RS stem in patients undergoing two-stage revisions.

Methods

The functional and clinical outcomes for 43 patients who had undergone two-stage revision procedures for PJI were analyzed in a retrospective study. The minimum follow-up period was 24 months. Shorter follow-up periods were only observed when there were complications such as loosening or recurrent infection. The mean follow-up period was 3.86 years (range 7 months to 11.6 years).

Results

The success rate with infection control for PJI was 93%. Reinfection occurred in four cases (7%). The risk of reinfection after MRSA infection was 20.5 times greater (P >0.01) than with sensitive or unknown bacteria. Two aseptic loosening occurred after 7 and 20 months. The average Harris Hip Score was 80 (range 62–93).

Conclusion

This retrospective study showed a 93% rate of eradication using specific antibiotic therapy. With the modular MUTARS RS stem, there was a low rate of aseptic loosening of 4.6%. MRSA infection was identified as a risk factor for reinfection. The two-stage procedure with modular cementless implants used is therefore appropriate for treating periprosthetic infections associated with hip endoprostheses.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-398) contains supplementary material, which is available to authorized users.

A multidisciplinary team approach to two-stage revision for the infected hip replacement

We report the five year outcomes of a two-stage approach for infected total hip replacement. This is a single-surgeon experience at a tertiary centre where the more straightforward cases are treated using single-stage exchange. This study highlights the vital role of the multidisciplinary team in managing these cases.

A total of 125 patients (51 male, 74 female) with a mean age of 68 years (42 to 78) were reviewed prospectively. Functional status was assessed using the Harris hip score (HHS). The mean HHS improved from 38 (6 to 78.5) pre-operatively to 81.2 (33 to 98) post-operatively. Staphylococcus species were isolated in 85 patients (68%).

The rate of control of infection was 96% at five years. In all, 19 patients died during the period of the study. This represented a one year mortality of 0.8% and an overall mortality of 15.2% at five years. No patients were lost to follow-up.

We report excellent control of infection in a series of complex patients and infections using a two-stage revision protocol supported by a multidisciplinary approach. The reason for the high rate of mortality in these patients is not known.

Cite this article: Bone Joint J 2014;96-B:1312–18

Mid term results with the curved modular tapered, fluted titanium Revitan stem in revision hip replacement

We report our experience of revision total hip replacement (THR) using the Revitan curved modular titanium fluted revision stem in patients with a full spectrum of proximal femoral defects. A total of 112 patients (116 revisions) with a mean age of 73.4 years (39 to 90) were included in the study. The mean follow-up was 7.5 years (5.3 to 9.1). A total of 12 patients (12 hips) died but their data were included in the survival analysis, and four patients (4 hips) were lost to follow-up. The clinical outcome, proximal bone regeneration and subsidence were assessed for 101 hips. The mean Harris Hip Score was 88.2 (45.8 to 100) after five years and there was an increase of the mean Barnett and Nordin-Score, a measure of the proximal bone regeneration, of 20.8 (-3.1 to 52.7). Five stems had to be revised (4.3%), three (2.9%) showed subsidence, five (4.3%) a dislocation and two of 85 aseptic revisions (2.3%) a periprosthetic infection. At the latest follow-up, the survival with revision of the stem as the endpoint was 95.7% (95% confidence interval 91.9% to 99.4%) and with aseptic loosening as the endpoint, was 100%. Peri-prosthetic fractures were not observed. We report excellent results with respect to subsidence, the risk of fracture, and loosening after femoral revision using a modular curved revision stem with distal cone-in-cone fixation. A successful outcome depends on careful pre-operative planning and the use of a transfemoral approach when the anatomy is distorted or a fracture is imminent, or residual cement or a partially-secured existing stem cannot be removed. The shortest appropriate stem should, in our opinion, be used and secured with > 3 cm fixation at the femoral isthmus, and distal interlocking screws should be used for additional stability when this goal cannot be realised.

Routine one-stage exchange for chronic infection after total hip replacement

PURPOSE

We hypothesized that a routine one-stage exchange for treatment of chronically infected total hip replacement (THR) will lead to (1) a higher rate of infection recurrence and (2) a poorer hip outcome than the published rates after two-stage exchange.

METHODS

Sixty-five cases have been treated consecutively with one-stage exchange. All patients have been followed for a period of three to six years or until death or infection recurrence.

RESULTS

The five-year rate for infection recurrence was 16%. The five-year survival rate for recurrence of the index infection was 8%. Forty-two percent of the hips had a good or excellent PMA score, and 46% a good or excellent OH score.

CONCLUSIONS

Routine one-stage exchange was not associated with a higher recurrence rate and a poorer hip function than previously published series of two-stage exchange. Therefore, there is little support to choose two-stage exchange as the routine treatment for management of chronically infected THR.

Two-stage revision of hip prosthesis infection using a hip spacer with stabilising proximal cementation

Two-stage revision hip arthroplasty for infection using an antibiotic-loaded cement spacer has been used frequently with good results. However, spacer instability is also frequent. Proximal cementation of the spacer could avoid spacer dislocation. We retrospectively assessed 35 patients in whom a 2-stage revision hip arthroplasty for infection was carried out using an antibiotic-loaded cement spacer with gentamicin (Spacer-G) in which the spacer was proximally cemented in 16 patients. The mean follow-up was 32 months. We assessed spacer stability and infection elimination. There were 8 spacer dislocations (22.9%), 5 in hips without proximal cementation and 2 in hips with proximal cementation (p>0.05). There was no fracture in any hip. Reinfection occurred in 5 hips (14.3%), in 3 with the same microorganism, while 2 had a different microorganism. Our results indicate that the proximal cementation of the spacer prevents its dislocation. Infection was eliminated in 86% of the hips.

Partial two-stage exchange for infected total hip arthroplasty: a preliminary report

BACKGROUND

One common approach to the infected total hip arthroplasty (THA) calls for a staged revision, including removal of all components. However, removal of well-fixed femoral components can result in bone loss and compromised fixation; it is not known whether it is effective to leave a well-fixed femoral component in situ, remove only the acetabular component, débride thoroughly, place a spacer, and delay reimplantation.

QUESTIONS/PURPOSES

The purposes of this study were to determine (1) the frequency of infection recurrence; (2) the frequency of death; and (3) the Harris hip scores of patients treated with a "two-stage partial exchange" approach.

METHODS

A retrospective analysis from 2000 through January 2011 revealed 19 patients with infected THA treated with partial two-stage exchange including complete acetabular component removal, aggressive soft tissue débridement, retention of the well-fixed femoral stem, placement of an antibiotic-laden cement femoral head on the trunnion of the retained stem, postoperative course of antibiotics, and delayed reimplantation. Indications for this treatment included those patients whose femoral component was determined to be well fixed and its removal would result in significant femoral bone loss and compromise of future fixation. During the study period, this represented 7% (19 of 262) of the patients whom we treated for a chronically infected THA. Minimum followup was 2 years (mean, 4 years; range, 2-11 years). None of the 19 patients in this series were lost to followup. We defined failure as recurrence of infection in the same hip or the use of long-term suppressive antibiotics.

RESULTS

Two patients (11%), both with prior failure of two-staged treatment of infection, failed secondary to recurrence of infection at an average of 3.3 years. There were no patient deaths within 90 days. The mean Harris hip score was 68 (range, 31-100; best score is 100).

CONCLUSIONS

Insofar as 89% of patients in this series were clinically free of infection at a minimum of 2 years, we believe partial two-stage exchange may represent an acceptable option for patients with infected THA when femoral component removal would result in significant bone loss and compromise of reconstruction. Further study is required on this approach.

One-stage exchange arthroplasty for chronic periprosthetic hip infection: results of a large prospective cohort study

BACKGROUND

Exchange arthroplasty of one or two stages is required for the treatment of chronic periprosthetic joint infections. Two-stage exchange is costly and has high morbidity with limited patient mobility between procedures. One-stage exchange has been promoted by several European teams as the preferred alternative. The aim of this study was to prospectively analyze the outcome of patients with a periprosthetic hip infection treated with one-stage exchange arthroplasty.

METHODS

We performed a prospective cohort study in a French referral center for osteoarticular infections including all periprosthetic hip infections treated with one-stage exchange arthroplasty from November 2002 to March 2010. Direct exchange was performed in chronic periprosthetic hip infection with no or minor bone loss and preoperative identification of a microorganism from joint fluid aspirate. No antibiotic-loaded bone cement was used. Antibiotic therapy was administered for twelve weeks: intravenously for four to six weeks, followed by an oral regimen for six to eight weeks. Follow-up was a minimum of two years. The following events were noted: relapse, new infection, joint revision for mechanical reasons, and periprosthetic hip infection-related and unrelated deaths.

RESULTS

One hundred and fifty-seven patients with periprosthetic hip infections with a median infection duration of 258 days (interquartile range, 120 to 551 days) prior to our index surgical procedure for infection were included. Periprosthetic hip infection occurred in ninety-nine cases of primary hip arthroplasty, twenty-seven cases of revision arthroplasty, and thirty-one cases in which the periprosthetic hip infection had been treated previously. A difficult-to-treat organism was isolated in fifty-nine cases (38%). After a median follow-up of 41.6 months (interquartile range, 28.1 to 66.9 months), two relapses, six new infections, nine revisions for mechanical reasons, two related deaths, and nineteen unrelated deaths occurred.

CONCLUSIONS

One-stage exchange arthroplasty is an effective surgical procedure in patients with periprosthetic hip infection who have good bone quality. Precise identification of the microorganism(s) and prolonged administration of appropriate intravenous antibiotic therapy are key factors for successful treatment.

Recurrent periprosthetic joint infection: persistent or new infection?

It is unclear if recurrent periprosthetic joint infection (PJI) is a result of failed pathogen eradication. This study addresses this issue. We identified 92 patients from three institutions who failed two-stage exchange. Cultured organisms at each stage of treatment were compared to determine whether these were persistent or new infections. Only twenty-nine of the 92 patients (31.5%) had identical organisms at treatment failure. Of the failures associated with Staphylococcus as the original infecting organism, 37% (25 of 67) failed due to the same organism compared to only 16% (four of 25) caused by other organisms. Positive cultures at reimplantation and poor health status were associated with higher rates of recurrent infection due to new organisms. Successful management of PJI with a two-stage exchange must stress minimization of comorbid risk factors that may contribute to the low success rate of PJI treatment and recurrence of infection.

Economical analysis on prophylaxis, diagnosis, and treatment of periprosthetic infections

The economic burden of periprosthetic infections is enormous, but the number of economic studies dealing with this issue is very scarce. This review tries to know the economic literature existing, assess the value of current data, and recognize the less costly and more effective procedures for prevention, diagnosis and treatment of periprosthetic infections. Forty five studies meeting the inclusion criteria and adhering to the quality criteria used were carefully analyzed to extract the economic data of relevance in evaluating the magnitude of problem and the more cost-effective solutions. However, because the heterogeneity and the low-quality of most of these studies meta-analytical technique has not been possible. Instead, the studies have been reviewed descriptively. Optimizing the antibiotic use in the prevention and treatment of periprosthetic infection, combined with systemic and behavioral changes in the operating room; detecting and treating the high-risk groups; a quick, simple, reliable, safe, and cost-effective diagnosis, and the rationale management of the instituted infection, specifically using the different procedures according to each particular case, could allow to improve outcomes and produce the highest quality of life for patients and the lowest economic impact. Nevertheless, the cost effectiveness of different interventions to prevent and to treat the periprosthetic infection remains unclear.

A two stage re-implantation protocol for the treatment of deep periprosthetic hip infection. Mid to long-term results

Deep periprosthetic hip infection is a devastating complication. Goal of treatment is infection eradication and durable functional reconstruction. Two-stage re-implantation is the standard of treatment. From January 1998 to December 2004 we treated 38 patients with an infected THA. There were 24 females and 14 males, with a mean age of 67 years (61-75). The infection occurred 13 months to 15 years (mean: 7.2 years) after the index operation. The mean follow-up was 11.6 years (7 to 14). 35 patients were available for review. Almost one third of the patients had been treated before with antibiotics. In 5 cases more than one pathogen were present. In 3 cases, it was not possible to isolate a causative organism. In 15 cases (43%), a resistant pathogen was isolated. We used a two stage re- implantation protocol. Spacer was not used in any of the cases. Femoral revision was performed with uncemented implants, 21 of distal (wagner type) fixation and 14 of modular type with proximal fixation. 24 press fit shells (17 oTMT cups) and 11 Muller rings were used. In 33 cases (94%) eradication of infection was achieved. The mean HHS improved from a mean of 38.2 preoperatively to a mean of 88.6 at final follow-up (p<0.001). There was no case of implant loosening or migration. Chronic late infection can be managed successfully with a two stage re-implantation protocol, without interim spacer, including neglected cases, previous long term antibiotics and cases with resistant pathogens.

Peri-prosthetic hip infections: in favour of one-stage

Although it does offer certain obvious advantages, the one-staged revision approach in infected THA remains rare in the field of orthopaedics. Besides the reduced number of surgical interventions for patients, it is associated with a decreased inpatient hospital stay and quicker mobilisation. Furthermore, it might be the more cost-effective approach and enables a reduced duration of post-operative systemic antibiotics, usually less than 14 days in our setting. Technically speaking, the presence of a positive culture of a pre-operative aspiration and respective antibiogram are mandatory requirements. A general cemented implant fixation using topical antibiotics is the treatment of choice for single-staged procedures. The key to surgical success is based on the well-defined and detailed intra-hospital infrastructure, including a meticulous pre-operative hip aspiration regime, pre-operative planning and an aggressive intra-operative surgical approach.

Comparison of bulb syringe, pressurized pulsatile, and hydrosurgery debridement methods for removing bacteria from fracture implants

Surgical-site infection is a common form of noscomial infection that can occur in fractures following internal fixation. Treatment of these infections has traditionally included preserving stable implants via debridement and antibiotic administration while the fracture is healing. Recent evidence indicated that this algorithm results in less-than-optimal rates of fracture union and infection eradication.The premise for this study is that bacterial removal from fracture implants using the Versajet Hydrosurgery System (Smith & Nephew, Memphis, Tennessee) method is better compared with the bulb syringe and pressurized pulsatile lavage methods. Thirty-two stainless steel, 4-hole, nonlocking, 3.5-mm fracture plates were incubated with Staphylococus aureus and divided into 4 groups. Eight plates in each group underwent irrigation with 1 L of saline using a bulb syringe lavage, pressurized pulsatile lavage, or the Versajet Hydrosurgery System method. Eight plates underwent no irrigation method and served as a control group. The residual bacterial loads following irrigation were quantitatively cultured. Each of the experimental groups had significantly reduced levels of bacteria adherent to the plate following irrigation compared with the control group (P=.0002). Furthermore, the Versajet Hydrosurgery System was most the effective at bacterial removal, followed by the pressurized pulsatile and bulb syringe lavage techniques (P=.0002 to P=.0012, respectively).Novel approaches to eradicate bacteria from implants, such as hydrosurgery technology, while maintaining rigid stability of healing fracture, may improve clinical outcomes.

Repeat 2-stage exchange for infected total hip arthroplasty: a viable option?

We investigated whether performing a repeat 2-stage exchange eradicates infection in patients who previously underwent 2-stage treatment for an infected total hip arthroplasty. We identified 15 patients who had failed a 2-stage total hip arthroplasty and underwent a planned repeat 2-stage between 2000 and 2009. Of the 15 patients, 8 were treated with a complete 2-stage procedure, whereas the remaining 7 patients were treated only with a first-stage resection of the infected implant. Of the 8 patients who underwent complete 2-stage exchange, 1 died because of in-hospital complications, and 1 had a recurrent infection. Repeat infection is highly associated with resistant organisms, obesity, and poor patient health. Of the 7 patients who underwent resection without reimplantation, 3 had a recurrent infection. Our data suggest that if infection can be adequately controlled after repeat resection of the joint prosthesis, reimplantation is a reasonable option.

Treatment of early postoperative infections after THA: a decision analysis

BACKGROUND

The treatment for an early postoperative periprosthetic infection after cementless THA that results in the highest quality of life after the control of infection is unknown. Although common treatments include irrigation and débridement with component retention, a one-stage exchange, or a two-stage exchange, it is unclear whether any of these provides a higher quality of life after the control of infection.

QUESTIONS/PURPOSES

We projected, through decision-analysis modeling, the possible estimated final health states defined as health-related quality of life based on quality-of-life studies of an early postoperative periprosthetic infection after cementless THA treated by irrigation and débridement, one-stage exchange, or two-stage exchange.

METHODS

Publications addressing early postoperative infections after THA were analyzed for the estimated rate of infection control and quality-of-life measures after a specific treatment. Decision analysis was used to model the different treatments and describe which, if any, treatment results in the greatest quality of life after early THA infection.

RESULTS

In the model, a one-stage exchange was the treatment for early THA infection that maximized quality-of-life outcomes if the probability of controlling the infection exceeded 66% with this procedure. If the probability of infection control of a one-stage exchange was less than 66% or that of irrigation and débridement was greater than 60%, then irrigation and débridement appeared to result in the greatest quality-of-life outcome.

CONCLUSIONS

A decision analysis using estimates of infection control rate and quality-of-life outcomes after different treatments for an early postoperative infection after THA showed possible outcomes for each treatment.

LEVEL OF EVIDENCE

Level II, economic and decision analyses. See Guidelines for Authors for a complete description of levels of evidence.

Sufficient release of antibiotic by a spacer 6 weeks after implantation in two-stage revision of infected hip prostheses

BACKGROUND

Although antibiotic-loaded spacers are commonly used to treat periprosthetic infections, it is unclear whether spacers continue to release bactericidal levels of antibiotic 6 weeks after implantation.

QUESTIONS/PURPOSES

We asked whether an antibiotic can be detected in the tissue surrounding the spacer 6 weeks after implantation and whether the concentration is higher than the minimal inhibition concentration (MIC) previously determined for pathogens that are responsible for most periprosthetic infections.

METHODS

We removed 14 spacers used in two-stage septic revisions of infected hip prostheses 6 weeks after the primary implantations and determined the concentration of the antibiotics in the membrane formed between the spacer and the neighboring bone on the acetabular and the femoral sides. In seven cases Copal cement with gentamicin and clindamycin were used, and in seven other cases vancomycin was added to the Copal cement. Concentrations of the spacer antibiotics in the neighboring tissue were determined by tandem mass spectroscopy.

RESULTS

All three antibiotics were detected in concentrations higher than their MIC. There were no differences between the groups regardless whether vancomycin was added to the cement, or whether the cement was applied with the acetabular cup spacer or with the stem spacer.

CONCLUSIONS

We concluded that, using the spacer technique described in this study, 6 weeks after spacer implantation, the concentrations of antibiotic are sufficient to treat a periprosthetic infection.

[Hip joint infections - Results of a questionnaire among 28 university orthopedic departments]

BACKGROUND

Despite numerous prophylactic measures infections still remain a hazardous complication in orthopedic surgery.

MATERIAL AND METHODS

A questionnaire about hip joint infections was sent to all university orthopedic departments in Germany and Austria. The questionnaire included 33 questions with respect to demographic data, causative organisms, diagnostic measures, treatment options for early and late infections, antibiotic therapy and prosthesis reimplantation.

RESULTS

The participation rate was 70%. The most frequent primary surgical indication was primary total hip replacement and Staphylococcus aureus and S. epidermidis were the most common pathogens identified. All departments performed a joint aspiration for diagnosis confirmation but for other diagnostic measures a great discrepancy could be observed. In the treatment of early infections removable components were always exchanged, whereas a local antibiotic therapy was not always employed. With regard to late infections a two-stage protocol was more frequently used than a one-stage treatment, whereby the implantation of a cement spacer was more commonly performed than a resection arthroplasty. The time between stages varied between 6 and 12 weeks and systemic antibiotics were administered for a mean time of 6 weeks. For prosthesis reimplantion cementless components were mostly used but no clear tendency could be determined for systemic antibiotic therapy.

CONCLUSION

Treatment of hip joint infections among German and Austrian university orthopedic departments is only partly carried out in a similar manner.

Comparison of one and two-stage revision of total hip arthroplasty complicated by infection: a Markov expected-utility decision analysis

BACKGROUND

Two-stage revisions of total hip arthroplasties complicated by chronic infection result in reinfection rates that are lower than those following single-stage revisions but may also result in increased surgical morbidity. Using a decision analysis, we compared single-stage and two-stage revisions to determine which treatment modality resulted in greater quality-adjusted life years (QALYs).

METHODS

A review of the literature on the treatment of patients with an infection at the site of a total hip arthroplasty provided probabilities; utility values for common postoperative health states were determined in a previously published study. With these data, we conducted a Markov cohort simulation decision analysis. Sensitivity analysis validated the model, and comparisons were made in terms of QALYs.

RESULTS

The twelve-month model favored direct-exchange revision over the two-stage approach, regardless of whether surgeon or patient-derived utilities were used (0.945 versus 0.896 and 0.897 versus 0.861 QALYs for the patient and surgeon models, respectively). Similar results were observed in a lifetime model with a ten-year life expectancy (7.853 versus 7.771, and 7.438 versus 7.362 QALYs, respectively). The findings were found to be robust in sensitivity analyses in which clinically relevant ranges of input variables were used.

CONCLUSIONS

This analysis favored the direct-exchange arthroplasty over the two-stage approach. This study should be considered hypothesis-generating for future randomized controlled trials in which, ideally, health end points will be considered in addition to the eradication of infection.

Cementless revision for infected total hip replacements

Our aim was to determine the success rate of repeated debridement and two-stage cementless revision arthroplasty according to the type of infected total hip replacement (THR). We enrolled 294 patients (294 hips) with an infected THR in the study. There were 222 men and 72 women with a mean age of 55.1 years (24.0 to 78.0). The rate of control of infection after the initial treatment and after repeated debridement and two-stage revisions was determined. The clinical (Harris hip score) and radiological results were evaluated. The mean follow-up was 10.4 years (5.0 to 14.0). The eventual rate of control of infection was 100.0% for early superficial post-operative infection, 98.4% for early deep post-operative infection, 98.5% for late chronic infection and 91.0% for acute haematogenous infection. Overall, 288 patients (98%) maintained a functioning THR at the latest follow-up. All the allografts appeared to be united and there were no failures. These techniques effectively controlled infection and maintained a functional THR with firm fixation in most patients. Repeated debridement and two-stage or repeated two-stage revisions further improved the rate of control of infection after the initial treatment and increased the likelihood of maintaining a functional THR.

Vastus lateralis muscle flap for infected hips after resection arthroplasty

We evaluated the potential of a vastus lateralis muscle flap in controlling infection after resection arthroplasty of the hip. We retrospectively reviewed 119 patients with 120 chronic infections after resection arthroplasty treated with this procedure. The flap was fixed with Mitek anchors in the acetabular cavity. The mean duration of infection after resection before the muscle flap procedure was 6.5 months (2 to 13). The patients had previously undergone a mean of 4.9 operations (2 to 25). In all patients the infected cavity was the origin of the persistent infection. The mean follow-up was for 2.6 years (1.0 to 4.7). No patient had recurrent infection post-operatively and all had an improvement in the pain and better quality of life.

Infection in total hip replacement: meta-analysis

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).

Two-stage treatment protocol for isolated septic acetabular cup loosening

The aim of this study was to evaluate the treatment of isolated septic acetabular cup loosening without involvement of the prosthesis stem by insertion of an antibiotic-loaded spacer head and stem retention. Between 1999 and 2008, 13 patients (5 men, 8 women, mean age 69 years) were treated according to this regimen. S. epidermidis and S. aureus were the two most commonly identified pathogens. In 12 cases the polymethylmethacrylate spacers were impregnated with 0.5 g gentamicin + 2 g vancomycin per 40 g bone cement, except in one patient with vancomycin allergy, in whom 0.5 g gentamicin + 0.4 g teicoplanin were used. The spacers acted as hemiarthroplasties. The mean spacer head implantation time was 88 (35-270) days. At a mean follow-up of 55 (12-83) months, infection eradication was achieved in 11 out of 12 cases (91.6%). Complications included a draining sinus, and one spacer and one definitive prosthesis dislocation. One patient died after reimplantation due to cardiopulmonary decompensation.

Cementless two-staged total hip arthroplasty with a short term interval period for chronic deep periprosthetic infection. Technique and long-term results

BACKGROUND

The two-staged exchange with delayed reimplantation is the most reliable method to treat a deep periprosthetic infection after a total hip arthroplasty (THR). Nether uniform recommendations for the technique of cementless reimplantation, nor long term clinical and radiological results are reported.

MATERIALS AND METHODS

Our protocol is performed under short term antibiosis with cementless primary porous hip implants to treat chronic deep periprosthetic infections following THR. A retrospective study was performed to evaluate the clinical and radiological long term outcome and the rate of persistent infection of 14 patients.

RESULTS

In a five year minimum follow up persistent infection was observed twice in a two-staged revision THR. A dislocation of the hip components was observed in three cases, and could be surgically treated in twice and by wearing a hip-brace in one case. We could not find a loosening of THR components. Three patients had a good or excellent, 11 patients a fair or bad functional outcome. There was a significant correlation between functional outcome and length of interval of prosthesis exand reimplantation.

CONCLUSION

Patients have an increased comfort resulting from a short, CRP depending time interval between ex- and reimplantation. Functional outcome is the better the shorter the interval is. The reinfection rate is comparable to those of cemented revision THR's with a long term interval. We could observe advantages in a reduced amount of bone loss and better osseous integration of the uncemented implants, compared to cemented implants reviewing literature. Alterations of acetabular bone stock and soft tissue are responsible for a high rate of instability of the THR. An inaccurate gait pattern is caused by gluteal weakness in the majority of patients. Repeated surgical intervention and duration of immobilization have to be minimalized.

Poor performance of microbiological sampling in the prediction of recurrent arthroplasty infection

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.

[Early-onset infection after hemiarthroplasty of the hip: an algorithm for surgical therapy]

BACKGROUND

In a retrospective study, we compared the results of different surgical therapies in 30 patients who had an early-onset infection after implantation of a hip hemiarthroplasty.

MATERIAL AND METHODS

Patients were divided into two groups: In group 1 (n=16, deep infection), we changed the polyethylene inlay as well as the femoral head. In group 2 (n=14, deep infection), an acetabular component was also implanted.

RESULTS

In group 1, successful treatment was achieved in 37.5% of patients 6 months after the last operation, compared with 71.4% in group 2 (p=0.019). All patients were supported with antibiotics. In group 1, three patients died from septic multiorgan failure. Two patients in group 1 and one patient in group 2 received a Girdlestone operation.

CONCLUSIONS

These results suggest that aggressive surgical treatment with soft tissue revision, lavage, and implantation of an acetabular component in combination with antibiotics is a useful technique for treating early-onset infection.

Revision of late periprosthetic infections of total hip endoprostheses: pros and cons of different concepts

Many concepts have been devised for the treatment of late periprosthetic infections of total hip prostheses. A two-stage revision with a temporary antibiotic-impregnated cement spacer and a cemented prosthesis appears to be the most preferred procedure although, in recent times, there seems to be a trend towards cementless implants and a shorter period of antibiotic treatment. Because of the differences in procedure, not only between studies but also within studies, it cannot be decided which period of parenteral antibiotic treatment and which spacer period is the most suitable. The fact that comparable rates of success can be achieved with different treatment regimens emphasises the importance of surgical removal of all foreign materials and the radical debridement of all infected and ischaemic tissues and the contribution of these crucial procedures to the successful treatment of late periprosthetic infections.