Outcome of group B streptococcal prosthetic hip infections compared to that of other bacterial infections

BackgroundOutcome of streptococcal prosthetic hip infection is often thought to be better than that caused by other pathogens. That supposition was not confirmed in our experience with group B streptococcal prosthetic joint infection.ObjectiveWe compared outcomes of group B streptococcal and other-pathogen prosthetic hip infections.MethodsOne hundred and thirty nine patients, 24 with group B streptococcal and 115 other-pathogen prosthetic hip infections, were included. The primary outcome was the time from surgical treatment to treatment failure, defined as relapse, infection- or treatment-related death. Secondary outcomes were the times from surgical treatment to relapse or any event (event-free survival). The cumulative incidence estimator was used to model primary and secondary outcomes. Multivariable regression analysis was used to determine a set of independent predictors of treatment failure.ResultsWith a median follow-up of 22 months, treatment failed more frequently in patients with group B streptococcal prosthetic hip infections (hazard ratio, 4.88 [95% CI, 1.4–17], P = .012). Multivariable analysis retained the American Society of Anesthesiologist score and group B streptococcal infection as independent risk factors of treatment failure; event-free survival was lower for these patients (hazard ratio, 2.64 [95% CI, 1.2–6], P = .02).ConclusionDespite high antibiotic susceptibility, outcomes of group B streptococcal and other-pathogen prosthetic hip infection differ.     

Differing Microorganism Profile in Early and Late Prosthetic Joint Infections Following Primary Total Knee Arthroplasty — Implications for Empiric Antibiotic Treatment

BackgroundProsthetic joint infection (PJI) is the leading cause of revision following total knee arthroplasty (TKA). Prior to microorganism identification, the choice of the correct empiric antibiotics is critical to treatment success. This study aims to 1) compare the microorganism and resistance profile in early and late PJIs; 2) recommend appropriate empiric antibiotics.MethodsA multicentre retrospective review was performed over a 15-year period. First episode PJIs were classified by both the Tsukayama Classification and Auckland Classification. For each PJI case, the causative organism and antibiotic sensitivity were recorded.ResultsOf eligible patients, 232 culture-positive PJI cases were included. Using either classification system, early PJIs (<4 weeks or <1 year since primary) were significantly more likely to be resistant and polymicrobial. The predominant organisms were coagulase-negative Staphylococci in early PJIs while Staphylococcus aureus was the most common in late PJIs. The distribution of gram-negative cases was higher in early Class-A than late Class-C PJIs (25% versus 6%, P = .004). Vancomycin provided significantly superior coverage when compared to Flucloxacillin for early infections, and addition of a gram-negative agent achieved coverage over 90% using both classification systems.ConclusionBased on the microbiological pattern in Tsukayama criteria, Vancomycin with the consideration of Gram-negative agent should be considered for Class-A infections given the high proportion of resistant and polymicrobial cases. For Class-C infections, Cephazolin or Flucloxacillin is likely sufficient. We recommend antibiotics to be withheld in Class-B infections until cultures and sensitivities are known.     

Reporting Outcomes of Treatment for Periprosthetic Joint Infection of the Knee and Hip Together With a Minimum 1-Year Follow-Up is Reliable

BackgroundAlthough there is an increasing trend toward reporting the outcome of hip and knee arthroplasty separately, it remains unknown whether joint-specific reporting is necessary for periprosthetic joint infection (PJI) as sample sizes are already low, given its relatively rare occurrence. The aim of this study is to compare treatment outcomes of PJI occurring after knee and hip arthroplasty. Furthermore, we aim to establish the necessary follow-up time for an accurate reporting of PJI treatment outcomes.MethodsA retrospective study of 792 cases of hip and knee PJI treated with irrigation and debridement or two-stage exchange arthroplasty from 2000 to 2017 was performed. Treatment failure was defined based on the Delphi method–based criteria. The Kaplan-Meier survivorship curves were generated, and a log-rank test was used to evaluate differences in survivorship. A multivariate Cox proportional hazards regression and a sensitivity analysis using propensity matching were performed. A two-piecewise linear regression model was used to examine the threshold effect of time after treatment on survival rates.ResultsThere were no significant differences between hip and knee PJIs in overall survivorship (P = .71), or when stratified by irrigation and debridement (P = .39), or two-stage exchange arthroplasty (P = .59). There was also no difference by joint in the multivariate or sensitivity analysis. Survival rates had the most dramatic rates of decrease in the initial months after treatment of PJI but began to plateau after 1.09 years.ConclusionThis study reveals no difference in treatment outcomes between knee and hip PJIs. In addition, given the difficulty with obtaining follow-up, we suggest that one-year follow-up is sufficient for an accurate reporting of treatment failure.     

Synchronous Periprosthetic Joint Infections: High Mortality,Reinfection, and Reoperation

BackgroundSynchronous periprosthetic joint infections (PJIs) are a catastrophic complication with potentially high mortality. We aimed to report mortality, risk of reinfection, revision, reoperation, and implant survivorship after synchronous PJIs.MethodsWe identified 34 patients treated for PJI in more than one joint within a single 90-day period from 1990 to 2018. PJIs involved bilateral knee arthroplasty (27), bilateral hip arthroplasty (4), 1 knee arthroplasty and 1 elbow arthroplasty (1), 1 knee arthroplasty and 1 shoulder arthroplasty (1), and bilateral hip and knee arthroplasty (1). Irrigation and debridement with component retention was performed in 23 patients, implant resection in 10 patients, and a combination of irrigation and debridement with component retention and implant resection in 1 patient. A competing risk model was used to analyze implant survivorship, and Kaplan-Meier survival was used for patient mortality. Mean follow-up was 6 years.ResultsMortality was high at 18% at 30 days and 27% at 1 year. The 1-year cumulative incidence of any reinfection was 13% and 27% at 5 years. The 1-year cumulative incidence of any revision or implant removal was 6% and 20% at 5 years. The 1-year cumulative incidence of unplanned reoperation was 25% and 35% at 5 years. Rheumatoid arthritis was associated with increased risk of mortality (HR 7, P < .01), as was liver disease (HR 4, P = .02).ConclusionIn the largest series to date, patients with synchronous PJIs had a high 30-day mortality rate of 18%, and one-fourth underwent unplanned reoperation within the first year.     

Less Than 1-Year Quiescent Period After Septic Arthritis of the Hip is Associated With High Risk of Periprosthetic Joint Infection Following Total Hip Arthroplasty

BackgroundApproximately 20,000 patients are diagnosed with septic arthritis annually, with 15% specifically affecting the hip joint. These cases exacerbate arthritic changes, often warranting a total hip arthroplasty (THA). Given their prior history of infection, these patients are predisposed to subsequent periprosthetic joint infections (PJIs). Multiple studies suggest delaying THA after a native septic hip, but no study utilizing a large cohort examined the specific timing to mitigate post-THA PJI risk within a short (<1 year) quiescent period after septic arthritis. We sought to compare patients who were diagnosed with septic hip arthritis at time intervals (0-6, or 6-12 months) prior to an ipsilateral primary THA to a cohort of THA patients who never had a septic hip history. Specifically, we assessed: from 90 days to 2 years (1) revisions due to PJI and (2) associated risk factors for PJI at 2-years.MethodsA national, all-payer database was queried to identify all patients who underwent a primary THA between 2010 and 2021 and patients who had prior ipsilateral septic hip arthritis were characterized using International Classification of Disease and Current Practice Terminology codes (n = 1,052). A randomized sample of patients who never had a history of septic arthritis prior to undergoing THA was used as a nonseptic group comparison (n = 5,000). The incidences of PJI at 90 days through two years were then identified and compared using bivariate chi-square analyses. Risk factors for post-THA PJIs were then analyzed using multivariate regression models.ResultsThe septic arthritis cohorts were more likely to require revisions due to PJIs, as compared to the non-septic group at 90 days, 1 year, and 2 years (all P < .0001). Patients who were diagnosed with septic arthritis between 0 and 6 months prior to THA were at greater PJI risk at both one-year (odds ratio (OR) of 43.1 versus 29.6, P < .0001) and two years (OR of 38.3 versus 22.1, P < .0001) compared to patients who had diagnoses between 6 and 12 months. Diabetes mellitus, obesity, and tobacco use were associated risk factors for PJIs at 2 years in the septic hip cohort in comparison to the cohort without a septic hip history.ConclusionLess than a 1-year quiescent period after septic arthritis is associated with a 38 times increased risk and a 22 times risk for post-THA PJI, at 0 and 6 months and 6 and 12 months, respectively. Though patients who undergo THA greater than 6 months after their septic arthritis treatment have a decreased risk compared to those between 0 and 6 months the risks are still high. Orthopaedic surgeons should be aware of the increased risks of PJIs when considering performing a THA in patients with a history of septic arthritis.     

Effective Treatment of Single-Stage Revision Using Intra-Articular Antibiotic Infusion for Polymicrobial Periprosthetic Joint Infection

BackgroundThe treatment of polymicrobial periprosthetic joint infection (PJI) confronted distinct challenges. No reports have assessed the efficacy of local antibiotic delivery combined with 1-stage exchange in polymicrobial PJI.MethodsBetween January 2013 and December 2018, we retrospectively analyzed the data of 126 patients, including 19 polymicrobial PJIs and 107 monomicrobial PJIs, who underwent single-stage revision using intra-articular antibiotic infusion. The risk factors, microbiology, infection control rate, and clinical outcomes were compared between the 2 groups.ResultsHigher body mass index, presence of a sinus tract, and prior revisions were the risk factors for polymicrobial PJI. Isolation of Staphylococcus epidermidis, Streptococcus, Enterococcus, and Gram-negative pathogens was highly associated with polymicrobial PJI. Of the 19 polymicrobial PJIs, only 2 patients occurred infection recurrence, which is similar with the result of 6 of 107 patients in the monomicrobial PJI (P = .225). The Harris Hip Score of the polymicrobial group showed no difference from that of the monomicrobial group (78 vs 80; P = .181). Nevertheless, the polymicrobial group exhibited inferior Hospital for Special Surgery knee score relative to the monomicrobial group (77 vs 79; P = .017).ConclusionWith rational and targeted use of antibiotics, single-stage revision can effectively control polymicrobial infections, and achieve favorable outcomes similar to that in monomicrobial patients. However, this regimen is still needed to be further confirmed, especially in the infections with different microbial species simultaneously. Additionally, obese patients with a sinus tract and those who had prior revisions had a greater risk of polymicrobial PJI.     

Perioperative Chlorhexidine Gluconate Wash During Joint Arthroplasty Has Equivalent Periprosthetic Joint Infection Rates in Comparison to Betadine Wash

BackgroundDilute betadine wash has been used for the prevention of prosthetic joint infection (PJI). Appropriateness for this purpose has recently come into question as the Food and Drug Administration determined that several commercial products did not pass the standards of proper sterility. The goal of this study is to determine if change in our institution’s perioperative infection protocol to sterile chlorhexidine gluconate wash affected rates of PJI.MethodsThis is a retrospective study of prospectively collected data for patients who underwent unilateral primary total knee arthroplasty and total hip arthroplasty. Chart review was performed to determine 90-day and 1-year readmissions and the development of PJI as per the diagnostic criteria of the Musculoskeletal Infection Society.ResultsA total of 2386 consecutive patients were included in this study. There were no significant demographic differences between the 2 groups. There was no statistically significant difference in the rate of PJI requiring a return trip to the operating room between the 2 cohorts: 4 in chlorhexidine vs 7 in betadine at 3 months (P = .61); and 9 in chlorhexidine and 14 in betadine at 1 year (P = .48, respectively). There was also no difference in the rate of wound complications between the betadine and chlorhexidine use (P = .93).ConclusionWhen comparing patients who received a betadine wash intraoperatively to those who received a chlorhexidine gluconate wash, there were no statistically significant differences in the rate of postoperative PJIs or return trips to the operating room. Although chlorhexidine gluconate and betadine have equal efficacy in the prevention of PJI, betadine is a far less expensive alternative if their sterility concerns are unwarrantedLevel of EvidenceTherapeutic Level III.     

Closed incision negative pressure therapy decreases complications after periprosthetic fracture surgery around the hip and knee

IntroductionPeriprosthetic fractures (PPFXs) are becoming increasingly common following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Patients sustaining PPFXs face considerable perioperative morbidity, with relatively increased rates of surgical site infection. We sought to evaluate the efficacy of closed-incision negative-pressure wound therapy (ciNPT) in decreasing perioperative wound complications following lower extremity periprosthetic fracture surgery.MethodsWe performed a retrospective review of 69 consecutive patients who underwent surgery to address lower extremity periprosthetic fractures around hip or knee implants performed over a 6.5-year period. The population was divided into two groups based on the surgical dressing used at the conclusion of the procedure: (1) a sterile, antimicrobial hydrofiber dressing, or (2) ciNPT. There were no baseline demographic differences between the two groups. Rates of wound complications, surgical site infection, and reoperation related to the surgical site were compared between groups. Continuous variables were analyzed using a student’s t-test, and categorical variables using either chi-square or fisher’s exact test.ResultsPatients treated with ciNPT developed fewer wound complications (4% vs. 35%; p = 0.002), fewer deep infections (0% vs. 25%; p = 0.004), and underwent fewer reoperations related to the surgical site (4% vs. 25%; p = 0.021) compared to patients treated with standard of care.ConclusionsOur findings suggest that ciNPT may reduce wound complications, SSIs, and reoperations in patients undergoing lower extremity periprosthetic fracture surgery. This is the first study to investigate ciNPT as a treatment for periprosthetic fracture surgery, and has the potential to change the postoperative management of these patients.     

Incomplete Administration of Intravenous Vancomycin Prophylaxis is Common and Associated With Increased Infectious Complications After Primary Total Hip and Knee Arthroplasty

BackgroundVancomycin is often used as antimicrobial prophylaxis in patients undergoing total hip or knee arthroplasty. Vancomycin requires longer infusion times to avoid associated side effects. We hypothesized that vancomycin infusion is often started too late and that delayed infusion may predispose patients to increased rates of surgical site infections and prosthetic joint infections.MethodsWe reviewed clinical data for all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients at our institution between 2013 and 2020 who received intravenous vancomycin as primary perioperative gram-positive antibiotic prophylaxis. We calculated duration of infusion before incision or tourniquet inflation, with a cutoff of 30 minutes defining adequate administration. Patients were divided into two groups: 1) appropriate administration and 2) incomplete administration. Surgical factors and quality outcomes were compared between groups.ResultsWe reviewed 1047 primary THA and TKA patients (524 THAs and 523 TKAs). The indication for intravenous vancomycin usage was allergy (61%), methicillin-resistant staphylococcus aureus colonization (17%), both allergy and colonization (14%), and other (8%). 50.4% of patients began infusion >30 minutes preoperatively (group A), and 49.6% began infusion <30 minutes preoperatively (group B). Group B had significantly higher rates of readmissions for infectious causes (3.6 vs 1.3%, P = .017). This included a statistically significant increase in confirmed prosthetic joint infections (2.2% vs 0.6%, P = .023). Regression analysis confirmed <30 minutes of vancomycin infusion as an independent risk factor for PJI when controlling for comorbidities (OR 5.22, P = .012).ConclusionLate infusion of vancomycin is common and associated with increased rates of infectious causes for readmission and PJI. Preoperative protocols should be created to ensure appropriate vancomycin administration when indicated.     

Outcome of Debridement,Antibiotics, and Implant Retention With Modular Component Exchange in Acute Culture-Negative Periprosthetic Joint Infections

BackgroundModular component exchange and culture-directed antibiotic treatment is routinely employed for acute periprosthetic joint infection (PJI). However, as many as 7%-23% of PJIs have been reported to yield negative culture results. The efficacy of debridement, antibiotics, and implant retention (DAIR) with modular component exchange in the setting of acute culture negative PJI remains largely unknown. The aim of our study is to evaluate the outcomes of DAIR with modular component exchange in acute culture-positive and culture-negative PJI.MethodsA total of 149 consecutive patients with primary total joint replacements (90 total knee arthroplasties and 59 total hip arthroplasties) who underwent DAIR with modular component exchange for acute PJI with at least 3 years of follow-up were evaluated: (1) 46 culture-negative PJI patients and (2) 103 culture-positive PJI patients. Reinfection and aseptic revision rates along with complication rates were compared.ResultsThe reinfection rate for DAIR in acute culture-negative PJI was 13.0% compared to 19.4% in culture-positive PJI (P = .48). Mean survival time from reinfection between culture-negative (7.7 ± 0.4 years) and culture-positive (7.4 ± 0.3 years) PJI groups did not differ significantly (P = .40). Aseptic revision rates were 8.7% and 4.9% (P = .46), respectively, with loosening being the primary reason for implant failure in both cohorts.ConclusionsDespite lack of an identifying organism to guide postoperative antibiotic therapy, DAIR with modular component exchange for acute culture-negative PJI was associated with similar reinfection rates compared to acute culture-positive PJI, suggesting that culture negativity may not be a contraindication to DAIR in patients with acute PJI.     

Septic Failure After One-Stage Exchange for Prosthetic Joint Infection of the Hip: Microbiological Implications

BackgroundThe microbiological implications of septic failure after 1-stage exchange for prosthetic joint infection (PJI) of the hip remain unclear.MethodsInformation was gathered on comorbidities, previous procedures, preoperative and postoperative microbiology results, methods of detection, and antibiotic resistance patterns, for all patients, who developed septic failure after 1-stage exchange for PJI of the hip performed at our institution during 2001-2017.ResultsSeventy-seven patients were identified. Septic failure was diagnosed a mean of 1.7 (standard deviation 2.3, range 0-11.8) years later. Although the spectrum of microorganisms was similar to preoperative, in the majority of patients (55%), the initial microorganism(s) was (were) replaced by (a) totally different microorganism(s). Overall, there was a decrease in the number of polymicrobial PJIs. The number of patients with high virulent microorganisms decreased significantly from 52 to 36 (P = .034). The number of PJIs due to gram-negative pathogens remained similar (11 vs 14, P = .491). The number of rifampicin-resistant staphylococci, fluoroquinolone-resistant streptococci, enterococci, and fungi changed from 8 to 15, 0 to 2, 7 to 3, and 1 to 2, respectively, but these changes did not reach statistical significance.ConclusionThe majority of reinfections is caused by different infecting bacteria, hence it is essential to perform a new diagnostic workup and not base treatment decisions (solely) on historical cultures. We were furthermore unable to irrefutably prove that, from a microbiological point of view, septic failure after 1-stage exchange comes with increased challenges. Given the time interval to failure, we propose that a longer follow-up of these patients is needed, than previously suggested.     

Persistent Fistula for Treatment of a Failed Periprosthetic Joint Infection: Relic From the Past or a Viable Salvage Procedure?

BackgroundNew treatment algorithms for periprosthetic joint infections (PJIs) show high success rates in achieving permanent infection eradication with some degree of failure. Different salvage procedures are described, but there is no evidence for persistent fistula (PF). The purpose of this study was to analyze PF as a salvage procedure in patients with therapy-resistant PJIs.MethodsThis retrospective analysis included all patients treated with PF (2005-2018) in a maximum care center with PJI (knee or hip). The baseline parameters (age, sex, BMI) and other data (number of surgeries, pathogen spectrum, American Society of Anesthesiologists classification) were recorded. The function was documented using the Harris Hip Score, the Knee Society Score, and the quality of life using the SF-36 Health Survey.ResultsA total of 159 patients were included (80 ± 12 years) and subdivided into four groups: hip (n = 66), knee (n = 13), Girdlestone resection arthroplasty (n = 50), knee arthrodesis (n = 27). Patients stayed 111 ± 87 days in the hospital, underwent six operations and three revisions after establishing PF. The mean American Society of Anesthesiologists score was 2.7. The BMI was 31 ± 3 kg/m² (P = .1). The follow-up was 2.8 ± 0.5 years including 27 patients. The Harris Hip Score and Knee Society Score were 38 and 34, respectively. SF-36 showed no significant difference.ConclusionThe study showed poor outcomes regarding quality of life and the function of the infected joint. Therefore, the indication for establishing a PF in the treatment of PJI must be assessed very critically. PF is only an option for multimorbid patients with a limited life expectancy.     

Success Rates of Debridement,Antibiotics, and Implant Retention in 230 Infected Total Knee Arthroplasties: Implications for Classification of Periprosthetic Joint Infection

BackgroundProsthetic joint infection (PJI) is the most common cause of failure following total knee arthroplasty (TKA). This study aimed to determine the success of debridement, antibiotics, and implant retention (DAIR) in a large cohort of TKA PJIs and assess the utility of current classification systems in predicting DAIR outcomes in early postoperative, late hematogenous, and chronic PJIs.MethodsIn a multicenter review over 15 years, 230 patients underwent DAIR for first episode PJI following primary TKA. Patient demographics, disease and surgical factors, treatment regime, and outcomes were identified. Univariate and multivariate survival analyses were performed to identify factors associated with successful DAIR. Continuous variables with predictive value were further analyzed using receiver operating characteristic curves. The ability to predict DAIR outcomes of multiple classification systems was also assessed.ResultsPatients were followed for an average of 6.9 years. The overall success rate of DAIR was 53.9%. On receiver operating characteristic analysis, 3 months (area under the curve = 0.63) and 1-year age (area under the curve = 0.66) of implant cut-offs was similarly predictive of outcomes. On multivariate survival analysis, DAIR was successful in 64% of “early” PJIs (implant <1 year) vs 38% of “late hematogenous” PJIs (implant >1 year; odds ratio [OR] 1.78, P = .01). For late PJIs (implant >1 year), Staphylococcus aureus (OR 4.70, P < .001) and gram-negative infections (OR 2.56, P = .031) were risk factors for DAIR failure.ConclusionDAIR has a high failure rate in all PJIs occurring more than a year post primary TKA, particularly when caused by S aureus or gram-negative bacteria. The age of implant is an important predictor of DAIR outcomes.     

Do local antibiotics reduce periprosthetic joint infections? A retrospective review of 744 cases

Periprosthetic joint infections (PJI) are uncommon but not rare and have significant morbidity and financial implications. Local antibiotics have been used successfully in other areas of orthopedics to reduce postoperative infections, but this method has not been proven in total joint arthroplasty (TJA). Beginning January 1, 2014, our primary investigators began using surgical site lavage with providone-iodine solution and administering 2 g of vancomcyin powder in the surgical wound prior to capsule closure for all primary and revision total hip and knee arthroplasties. We performed a retrospective chart review of patients two years prior to this date and two years after to compare occurrence of PJI. The groups were broken down into patients who received local antibiotics versus those who did not. The groups were further broken down by type of surgery performed; primary or revision total hip or knee arthroplasty. Administration of local antibiotics was preventative for PJI only in the primary total knee arthroplasty group (aOR = 0.28, 0.09–0.89). Administration of local antibiotics trended towards a preventative effect for PJI in the other groups but was not statistically significant. Patients receiving local antibiotics had similar blood urea nitrogen and creatinine levels postoperatively compared to the no antibiotics group indicating minimal systemic effects of local vancomycin powder. While the use of local antibiotics may prevent PJI, more data is required especially in the revision arthroplasty groups.     

Individuals with high bone mass have an increased prevalence of radiographic knee osteoarthritis

We previously reported an association between high bone mass (HBM) and a bone-forming phenotype of radiographic hip osteoarthritis (OA). As knee and hip OA have distinct risk factors, in this study we aimed to determine (i) whether HBM is also associated with knee OA, and (ii) whether the HBM knee OA phenotype demonstrates a similar pattern of radiographic features to that observed at the hip.HBM cases (defined by DXA BMD Z-scores) from the UK-based HBM study were compared with unaffected family controls and general population controls from the Chingford and Hertfordshire cohort studies. A single blinded observer graded AP weight-bearing knee radiographs for features of OA (Kellgren–Lawrence score, osteophytes, joint space narrowing (JSN), sclerosis) using an atlas. Analyses used logistic regression, adjusting a priori for age and gender, and additionally for BMI as a potential mediator of the HBM–OA association, using Stata v12.609 HBM knees in 311 cases (mean age 60.8 years, 74% female) and 1937 control knees in 991 controls (63.4 years, 81% female) were analysed. The prevalence of radiographic knee OA, defined as Kellgren–Lawrence grade ≥ 2, was increased in cases (31.5% vs. 20.9%), with age and gender adjusted OR [95% CI] 2.38 [1.81, 3.14], p < 0.001. The association between HBM and osteophytosis was stronger than that for JSN, both before and after adjustment for BMI which attenuated the ORs for knee OA and osteophytes in cases vs. controls by approximately 50%.Our findings support a positive association between HBM and knee OA. This association was strongest for osteophytes, suggesting HBM confers a general predisposition to a subtype of OA characterised by increased bone formation.     

Microbiology and clinical characteristics of industrial oil burns

IntroductionInfections complicating burns generally transition from Gram-positive to Gram-negatives over the first couple weeks, but this depends on multiple factors. The microbiology of infections complicating crude oil (CO) and hydraulic fracturing (FRAC) burns is unknown.MethodsWe performed a retrospective study of patients with industrial thermal burns hospitalized >2 days with ≥1 day in the ICU between 4/2011–11/2016. Burns were oil-related (ORB; CO or FRAC) or non-oil related (NORB). Epidemiology and microbiology during the first 15 hospital days was compared.Results149 patients were included, with 11 FRAC and 24 CO. CO burns were more severely burned than those with FRAC and NORB (p < 0.05). Mortality was 17% and 18% for CO and FRAC burns compared to 3% in NORB (p < 0.01). More cultures were obtained from ORB than NORB (p < 0.05). ORB were associated with Stenotrophomonas maltophilia and FRAC associated with Serratia marcescens and Candida glabrata. Patients with FRAC, CO and NORB had a median of 13, 3.5, and 4 days to first positive culture respectively (p = 0.03).ConclusionORB were associated with more severe burns and unique microbiology. FRAC burns had longer to initial positive culture, potentially suggesting our current methodology is inadequate to diagnose infections associated with FRAC.     

Effect of Antibiotic-Impregnated Bone Cement in Primary Total Knee Arthroplasty

BackgroundThe purpose of this study is to evaluate the effect of commercially available antibiotic-impregnated bone cement (AIBC) on (1) prosthetic joint infections (PJIs) and (2) surgical site infections (SSIs) after primary total knee arthroplasty (TKA).MethodsA review of primary TKAs between 2014 and 2017 from an institutional database was conducted. This identified 12,541 cases which were separated into AIBC (n = 4337) and non-AIBC (8,164) cohorts. Medical records were reviewed for PJIs and SSIs (mean 2-year postoperative period). Infection rates between the cohorts were compared with univariate analyses followed by subanalysis of high risk patients (defined as having 2 or more of the following characteristics: >65 years, body mass index >40, or Charlson Comorbidity Index score >3). To control for confounders, multivariate analyses were performed with regression models adjusted for age, gender, body mass index, comorbidities, year, operative times, and lengths of stay.ResultsOn univariate analysis, PJI rates were higher in the AIBC cohort (1.0%) compared to the non-AIBC cohort (0.5%, P < .001). Subanalysis of the high risk patients also showed that PJI rates were higher in the AIBC cohort (1.9% vs 0.6%, P < .01). After adjusting for potential confounders, no significant associations between PJIs and AIBC use were found (odds ratio 1.4, 95% confidence interval 0.9-2.3, P = .133). Similarly, no significant differences in SSI rates were observed between the AIBC (2.9%) and non-AIBC cohorts (2.4%, P = .060) and no significant associations between SSIs and AIBC were found with multivariate analysis (odds ratio 1.0, 95% confidence interval CI 0.8-1.3, P = .948).ConclusionThis study found that there was no clinically or statistically significant decrease in infection rates with AIBC in primary TKAs.     

The KHOALA cohort of knee and hip osteoarthritis in France

ObjectivesThis study aimed to describe the prevalence of symptomatic knee and hip osteoarthritis (OA) and its course over time, as well as identify prognostic factors of OA course and determinants of costs and access to care in France in a patient cohort.MethodsSubjects aged 40 to 75 years, with uni- or bilateral symptomatic hip and/or knee OA (ACR criteria), Kellgren and Lawrence (KL) stage 2 or greater, were recruited from a French national prevalence survey for the multicenter KHOALA cohort study. Data collected at baseline included sociodemographic and clinical data; WOMAC, IKS and Harris scores for pain and function; MAQ score for physical activity; functional comorbidity index; GHQ28 score for psychological status; and SF-36 (generic) and OAKHQOL (specific) scores for quality of life. Blood and urine samples were collected.ResultsEight hundred and seventy-eight subjects were included, 222 with OA of the hip (mean age 61.2 ± 8.8 years), 607 knee (mean age 62.0 ± 8.5 years) and 49 both hip and knee (mean age 64.9 ± 7.9 years). Mean body mass index was 26.9 ± 4.5 for hip OA and 30.3 ± 6.3 for knee OA. Hip and knee OA patients had 1.99 and 2.06 comorbidities, on average, respectively. Disease severity on X-rays for KL stages 2, 3 and 4 for hip OA was 69.8, 26.1 and 4.1%, respectively, and for knee OA, 44.5, 30.3, and 25.2%. As compared with population norms, age- and sex-standardized SF-36 scores were greatly decreased for both knee and hip OA in all dimensions, particularly physical and emotional dimensions.PerspectivesPatients will be followed up annually, alternately by mail and clinical visit. This cohort of representative patients with knee and hip OA will be an opportunity for future collaborative research.     

Changing antibiotic prophylaxis for primary joint arthroplasty affects postoperative complication rates and bacterial spectrum

BackgroundThe reduction of Clostridium difficile associated diarrhoea (CDAD) is a national priority. As part of the C. difficile improvement plan in our Trust, antibiotic prophylaxis for primary arthroplasty was changed from cefuroxime to gentamicin. Gentamicin was chosen following a review of the sensitivity profiles of all the organisms isolated from infected primary arthoplasties.MethodsFrom January 2002 to September 2007, 6094 patients (Group 1) undergoing primary hip and knee arthroplasty received three doses of Cefuroxime as prophylaxis; while from October 2007 to February 2009, 2101 patients (Group 2) received single dose Gentamicin (4.5 mg/kg). We studied the rate of CDAD as well as several other postoperative complications, including rate of return to theatre (RTT), before and after the change.FindingsThere was an insignificant fall in CDAD from 0.18% to 0% (p = 0.08) in Group 2, however there was a statistically significant increase in pneumonia (0.67–1.33%, p < 0.01), acute renal failure (ARF) requiring HDU admission (0.07–0.33%, p < 0.01) and RTT (1.08–1.95%, p < 0.01) in this group. RTT for proven infection increased from 0.66% to 1.52% (p < 0.01).ConclusionsWe conclude that Gentamicin 4.5 mg/kg alone should not be used as prophylaxis for primary joint arthroplasty as it does not reduce CDAD significantly but increases the risk of other postoperative complications. We have changed our prophylaxis to low dose gentamicin (3 mg/kg) combined with Teicoplanin 400 mg given once.     

Efficacy of knee joint aspiration in patients with acute ACL injury in the emergency department

PurposeTo evaluate the influence of joint aspiration on the sensitivity of physical examination for diagnosing acute anterior cruciate ligament (ACL) lesion in the second outpatient-department (OPD) follow-up referred from emergency department (ED).MethodsThis retrospective study included sixty patients underwent ACL reconstruction with initial visit at ED. They were divided into two groups based on the presence or absence of joint aspiration at ED. All participants were referred to second OPD follow-up within 7–14 days after the injury. Clinical manifestation (including visual analogue scale (VAS) for pain, range of motion (ROM), and severity of knee effusion) and physical examination (Lachman test and pivot shift test) were checked in ED and the second OPD follow-up.ResultsThe group of patients with joint aspiration (G1) showed substantial decreases in mean values of VAS for pain (p = 0.005), ROM (p = 0.001), and effusion level (p < 0.001), even higher VAS and effusion level and lower ROM at the initial visit of ED than the other group (G2). The sensitivity of positive Lachman and pivot shift test was significantly (p < 0.05) increased following knee joint aspiration. Positive Lachman test was recorded at 76.5% in the second follow-up in G1, which was significantly (p = 0.047) higher than that (47.6%) in G2. The percentage of positive pivot shift test was recorded at 76.5% in the second follow-up in G1, which as significantly (p < 0.001) higher than that (31.0%) in G2.ConclusionsKnee joint aspiration in acute ACL injury with suspected hemarthrosis could be considered as a diagnostic procedure. Joint aspiration in early medical attendance might be able to lower pain scores or raise the sensitivity of physical examination for diagnosing acute ACL injury at follow up visit in orthopedic outpatient department.Level of evidenceRetrospective cohort study III.