High Mortality After Total Knee Arthroplasty Periprosthetic Joint Infection is Related to Preoperative Morbidity and the Disease Process but Not Treatment

BackgroundPeriprosthetic joint infection (PJI) mortality rate is approximately 20%. The etiology for high mortality remains unknown. The objective of this study was to determine whether mortality was associated with preoperative morbidity (frailty), sequalae of treatment, or the PJI disease process itself.MethodsA multicenter observational study was completed comparing 184 patients treated with septic revision total knee arthroplasty (TKA) to a control group of 38 patients treated with aseptic revision TKA. Primary outcomes included time and the cause of death. Secondary outcomes included preoperative comorbidities and Charlson Comorbidity Index (CCMI) measured preoperatively and at various postoperative timepoints.ResultsThe septic revision TKA cohort experienced earlier mortality compared to the aseptic cohort, with a higher mortality rate at 90 days, 1, 2, and 3 years after index revision surgery (P = .01). There was no significant difference for any single cause of death (P > .05 for each). The mean preoperative CCMI was higher (P = .005) in the septic revision TKA cohort. Both septic and aseptic cohorts experienced a significant increase in CCMI from the preoperative to 3 years postoperative (P < .0001 and P = .002) and time of death (P < .0001 both) timepoints. The septic revision TKA cohort had a higher CCMI 3 years postoperatively (P = .001) and at time of death (P = .046), but not one year postoperatively (P = .119).ConclusionCompared to mortality from aseptic revision surgery, septic revision TKA is associated with earlier mortality, but there is no single specific etiology. As quantified by changes in CCMI, PJI mortality was associated with both frailty and the PJI disease process, but not treatment.     

The Impact of Exchanging Cerclage Fixation after Extended Trochanteric Osteotomy in Revision Total Hip Arthroplasty for Periprosthetic Joint Infection

BackgroundAn extended trochanteric osteotomy (ETO) is a powerful tool for femoral component revision. There is limited evidence that directly supports its use in the setting of a periprosthetic joint infection (PJI). Cerclage fixation raises the theoretical concern for persistent infection.MethodsOur institutional database included 76 ETOs for revision hip arthroplasty between January 1, 2008 and December 31, 2019. The cohort was divided based on indication for femoral component revision: PJI versus aseptic revision. The PJI group was subdivided based on second-stage exchange versus retention of initial cerclage fixation. Operative time, estimated blood loss, complications, and rate of repeat revision surgery were evaluated.ResultsForty-nine patients (64%) underwent revision for PJI and 27 patients (36%) underwent aseptic revision. There was no significant difference in operative times (P = .082), postoperative complications (P = .258), or rate of repeat revision surgery (P = .322) between groups. Of the 49 patients in the PJI group, 40 (82%) retained cerclage fixation while 9 (18%) had cerclage exchange. Cerclage exchange did not significantly impact operative time (P = .758), blood loss (P = .498), rate of repeat revision surgery (P = .302), or postoperative complications (P = .253) including infection (P = .639).ConclusionAn ETO remains a powerful tool for femoral component removal, even in the presence of a PJI. A multi-institutional investigation would be required to validate observed trends toward better infection control with cerclage exchange. Cerclage exchange did not appear to increase operative time, blood loss, or postoperative complication rates.     

Higher 2-Year Cumulative Incidence of Mental Health Disorders Following Antibiotic Spacer Placement for Chronic Periprosthetic Joint Infection following Total Joint Arthroplasty

BackgroundThe relationship of chronic periprosthetic joint infection (PJI) treatment on the development and relapse of mood disorders remains largely unreported. This study aims to compare the incidence of different mental health disorders following antibiotic spacer placement for chronic PJI when compared to aseptic revisions and primary procedures.MethodsPatients who underwent antibiotic spacer for septic total hip and knee arthroplasty (PJI THA/TKA) were identified in the PearlDiver Database using Current Procedure Terminology (CPT) codes for hip and knee antibiotic spacers. Patients who underwent aseptic revision and primary-THA/TKA were also identified using CPT codes. The incidences of depressive, anxiety, bipolar, psychotic, and stress disorders were identified within 2 years following the index procedures via Kaplan–Meier Analysis.ResultsThe risk of depressive (hazard ratio (HR): 1.5; P < .001) and stress (HR: 1.5; P < .001) disorders were significantly higher in those who underwent PJI-THA when compared to aseptic revision, with the added risk of bipolar when compared to primary THA. The risk of depressive (HR: 1.6; P < .001), stress (HR: 1.4; P < .001), bipolar (HR: 1.3; P < .001), and psychotic disorders (HR: 1.5; P = .003) were significantly higher in those who underwent PJI-TKA when compared to aseptic revision, with the added risk of anxiety when compared to primary TKA.ConclusionPatients who undergo spacer placement for septic-THA/TKA have a disproportionately higher incidence of mental health disorders within 2 years following surgery when compared those undergoing aseptic revisions and primary procedures. Due to this higher risk, physicians should strongly consider collaborative care with psychiatrists or mental health professionals.Level of EvidenceIII.     

Utilization of Debridement,Antibiotics, and Implant Retention for Infection After Total Joint Arthroplasty Over a Decade in the United States

BackgroundReported clinical outcomes have varied for debridement, antibiotics, and implant retention (DAIR) and little is known regarding trends in utilization. We sought to evaluate the rate of DAIR utilization for total knee arthroplasty (TKA) and total hip arthroplasty (THA) periprosthetic joint infection (PJI) over a decade and clinical factors associated with these trends.MethodsA retrospective study of primary TKAs and THAs was performed using Medicare data from 2005 to 2014 using the PearlDiver database platform. Current Procedural Technology and International Classification of Diseases Ninth Edition codes identified patients who underwent a surgical revision for PJI, whether revision was a DAIR, as well as associated clinical factors including timing from index arthroplasty.ResultsThe proportion of revision TKAs and THAs performed using DAIR was 27% and 12% across all years, respectively. This proportion varied by year for TKAs and THAs with a linear trend toward increasing relative use of DAIR estimated at 1.4% and 0.9% per year (P < .001; P < .001). DAIR for TKA and THA performed within 90 days increased at a faster rate, 3.4% and 2.1% per year (P < .001; P < .001). Trends over time in TKA DAIRs showed an association with Elixhauser Comorbidity Index (ECI), 0-5 group increasing at 2.0% per year (P = .03) and patients >85 years (P = .04).ConclusionThe proportion of revision arthroplasty cases for PJI managed with DAIR has been increasing over time in the United States, with the most substantial increase seen <90 days from index arthroplasty. Age, gender, and ECI had a minimal association with this trend, except in the TKA population >85 years and in those with a very low ECI score.     

Cumulative Intraarticular Injections Are Not a Risk Factor for Periprosthetic Joint Infection Following total Knee Arthroplasty

BackgroundWhile injections within 90 days prior to total knee arthroplasty (TKA) are associated with an increased risk of periprosthetic joint infection (PJI), there is a paucity of literature regarding the impact of cumulative injections on PJI risk. This study was conducted to assess the association between cumulative corticosteroid and hyaluronic acid (HA) injections and PJI risk following TKA.MethodsThis retrospective study using an injection database included patients undergoing TKA with a minimum 1-year follow-up from 2015 to 2020. Patients with injections within 90 days prior to surgery were excluded. The sum of corticosteroid and HA injections within five years prior to TKA was recorded. The primary outcome was PJI within 90 days following TKA. Area under the curve (AUC) values were calculated for a cumulative number of injections.Results648 knees with no injections and 672 knees with injections prior to TKA were included, among whom 243 received corticosteroids, 151 received HA, and 278 received both. No significant differences in early PJI rates existed between patients who received injections (0.60%) or not (0.93%) (P = .541). No significant differences existed in early PJI rates between patients injected with corticosteroids (0.82%), HA (0.66%), or both (0.36%) (P = .832). No cutoff number of injections was predictive for PJI.DiscussionA cumulative amount of steroid or HA injections, if given more than 90 days prior to TKA, does not appear to increase the risk of PJI within 90 days postoperatively. Multiple intraarticular corticosteroid injections and HA injections may be safely administered before TKA, without increased risk for early PJI.     

The Cost-Effectiveness of Silver-Impregnated Occlusive Dressings for Infection Prevention After Total Joint Arthroplasty

BackgroundProsthetic joint infection (PJI) is a catastrophic complication after total joint arthroplasty that exacts a substantial economic burden on the health-care system. This study used break-even analysis to investigate whether the use of silver-impregnated occlusive dressings is a cost-effective measure for preventing PJI after primary total knee arthroplasty (TKA) and total hip arthroplasty (THA).MethodsBaseline infection rates after TKA and THA, the cost of revision arthroplasty for PJI, and the cost of a silver-impregnated occlusive dressing were determined based on institutional data and the existing literature. A break-even analysis was then conducted to calculate the minimal absolute risk reduction needed for cost-effectiveness.ResultsThe use of silver-impregnated occlusive dressings would be economically viable at an infection rate of 1.10%, treatment costs of $25,692 for TKA PJI, and $31,753 for THA PJI and our institutional dressing price of $38.05 if it reduces infection rates after TKA by 0.15% (the number needed to treat [NNT] = 676) and THA by 0.12% (NNT = 835). The absolute risk reduction needed to maintain cost-effectiveness did not change with varying initial infection rates and remained less than 0.40% (NNT = 263) for infection treatment costs as low as $10,000 and less than 0.80% (NNT = 129) for dressing prices as high as $200.ConclusionThe use of silver-impregnated occlusive dressings is a cost-effective measure for infection prophylaxis after TKA and THA.     

Risk of Prosthetic Joint Infection Increases Following Early Aseptic Revision Surgery of Total Hip and Knee Arthroplasty

BackgroundIt is important to identify risk factors for periprosthetic joint infection (PJI) following total joint arthroplasty in order to mitigate the substantial social and economic burden. The objective of this study is to evaluate early aseptic revision surgery as a potential risk factor for PJI following total hip (THA) and total knee arthroplasty (TKA).MethodsPatients who underwent primary THA or TKA with early aseptic revision were identified in 2 national insurance databases. Control groups of patients who did not undergo revision were identified and matched 10:1 to study patients. Rates of PJI at 1 and 2 years postoperatively following revision surgery were calculated and compared to controls using a logistic regression analysis.ResultsIn total, 328 Medicare and 222 Humana patients undergoing aseptic revision THA within 1 year of index THA were found to have significantly increased risk of PJI at 1 year (5.49% vs 0.91%, odds ratio [OR] 5.61, P < .001 for Medicare; 7.21% vs 0.68%, OR 11.34, P < .001 for Humana) and 2 years (5.79% vs 1.10%, OR 4.79, P < .001 for Medicare; 8.11% vs 1.04%, OR 9.05, P < .001 for Humana). Similarly for TKA, 190 Medicare and 226 Humana patients who underwent aseptic revision TKA within 1 year were found to have significantly higher rates of PJI at 1 year (6.48% vs 1.16%, OR 7.69, P < .001 for Medicare; 6.19% vs 1.28%, OR 4.89, P < .001 for Humana) and 2 years (8.42% vs 1.58%, OR 6.57, P < .001 for Medicare; 7.08% vs 1.50%, OR 4.50, P < .001 for Humana).ConclusionEarly aseptic revision surgery following THA and TKA is associated with significantly increased risks of subsequent PJI within 2 years.     

Single-Stage Revision of the Infected Total Knee Arthroplasty Is Associated With Improved Functional Outcomes: A Propensity Score–Matched Cohort Study

BackgroundSingle-stage revision is an alternative to the standard 2-stage revision, potentially minimizing morbidities and improving functional outcomes. This study aimed at comparing single-stage and 2-stage revision total knee arthroplasty (TKA) for chronic periprosthetic joint infection (PJI) with regard to patient-reported outcome measures (PROMs) and complication rates.Methods:A total of 185 consecutive revision TKA patients for chronic PJI with complete preoperative and postoperative PROMs were investigated. A total of 44 patients with single-stage revision TKA were matched to 88 patients following 2-stage revision TKA using propensity score matching, yielding a total of 132 propensity score–matched patients for analysis. Patient demographics and clinical information including reinfection and readmission rates were evaluated.Results:There was no significant difference in preoperative PROMs between propensity score–matched single-stage and 2-stage revision TKA cohorts. Postoperatively, significantly higher PROMs for single-stage revision TKA were observed for Knee disability and Osteoarthritis Outcome Score physical function (62.2 vs 51.9, P < .01), physical function short form 10A (42.8 vs 38.1, P < .01), PROMIS SF Physical (44.8 vs 41.0, P = .01), and PROMIS SF Mental (50.5 vs 47.1, P = .02). There was no difference between propensity score–matched single-stage and 2-stage revision TKA cohorts for clinical outcomes including reinfection rates (25.0% vs 27.2%, P = .78) and 90-day readmission rates (22.7% vs 25.0%, P = .77).ConclusionThis study illustrated that single-stage revision TKA for chronic PJI may be associated with superior patient-reported outcomes compared to 2-stage revision for the infected TKA using a variety of PROMs. Improved PROMs were not accompanied by differences in complication rates between both cohorts, suggesting that single-stage revision TKA may provide an effective alternative to 2-stage revision in patients with chronic TKA PJI.     

Impact of Perioperative Urinary Tract Infection on Surgical Site Infection in Patients Undergoing Primary Hip and Knee Arthroplasty

BackgroundThe literature lacks clear consensus regarding the association between postoperative urinary tract infection (UTI) and surgical site infection (SSI). Additionally, in contrast to preoperative asymptomatic bacteriuria, SSI risk in patients with preoperative UTI has been incompletely studied. Therefore, our goal was to determine the effect of perioperative UTI on SSI in patients undergoing primary hip and knee arthroplasty.MethodsUsing the National Surgical Quality Improvement Program database, all patients undergoing primary hip and knee arthroplasty were identified. Univariate and multivariate regressions, as well as propensity matching, were used to determine the independent risk of preoperative and postoperative UTI on SSI, reported as odds ratios (ORs) with 95% confidence intervals (CIs).ResultsPostoperative UTI significantly increased the risk for superficial wound infection (OR 2.147, 95% CI 1.622-2.842), deep periprosthetic joint infection (PJI) (OR 2.288, 95% CI 1.579-3.316), and all SSIs (superficial and deep) (OR 2.193, 95% CI 1.741-2.763) (all P < .001). Preoperative UTI was not associated with a significantly increased risk of superficial infection (P = .636), PJI (P = .330), or all SSIs (P = .284). Further analysis of UTI present at the time of surgery using propensity matching showed no increased risk of superficial infection (P = 1.000), PJI (P = .624), or SSI (P = .546).ConclusionPostoperative UTI was associated with SSI, reinforcing the need to minimize factors which predispose patients to the risk of UTI after surgery. The lack of association between preoperative UTI and SSI suggests that hip and knee arthroplasty can proceed without delay, although initiating antibiotic treatment is prudent and future prospective investigations are warranted.     

Irrigation,Débridement,and Implant Retention for Recurrence of Periprosthetic Joint Infection Following Two-Stage Revision Total Knee Arthroplasty: A Matched Cohort Study

BackgroundWe investigated clinical/functional outcomes and implant survivorship in patients who underwent 2-stage revision total knee arthroplasty (TKA) after periprosthetic joint infection (PJI), experienced acute PJI recurrence, and underwent irrigation, débridement, and polyethylene exchange (IDPE) with retention of stable implant.MethodsTwenty-four patients (24 knees) were identified who underwent 2-stage revision TKA for PJI, experienced acute PJI recurrence, and then underwent IDPE between 2005 and 2016 (minimum 2-year follow-up). After IDPE, intravenous antibiotics (6 weeks) and oral suppression therapy (minimum 6 months) were administered. Data were compared with 1:2 matched control group that underwent 2-stage revision TKA for chronic PJI and did not receive IDPE.ResultsAverage IDPE group follow-up was 3.8 years (range, 2.4-7.2). Reinfection rate after IDPE was 29% (n = 7): 3 of 7 underwent second IDPE (2 of 3 had no infection recurrence) and 5 (one was patient who had recurrent infection after second IDPE) underwent another 2-stage revision TKA. Control group reinfection rate was 27% (n = 13) (P = .85). For IDPE group, mean time to reinfection after 2-stage revision TKA was 4.6 months (range, 1-8 months) (patients presented with acute symptoms less than 3 weeks duration). At latest follow-up, mean Knee Society Score was 70 (range, 35-85) in IDPE group and 75 (range, 30-85) in control group (P = .53).ConclusionIDPE for acute reinfection following 2-stage revision TKA with well-fixed implants had a 71% success rate. These patients had comparable functional outcome as patients with no IDPE after 2-stage revision TKA. IDPE followed by long-term suppression antibiotic therapy should be considered in patients with acute infection and stable components.     

Dilute Betadine Lavage Reduces the Risk of Acute Postoperative Periprosthetic Joint Infection in Aseptic Revision Total Knee and Hip Arthroplasty: A Randomized Controlled Trial

BackgroundThe purpose of this randomized, controlled trial is to determine whether dilute betadine lavage compared to normal saline lavage reduces the rate of acute postoperative periprosthetic joint infection (PJI) in aseptic revision total knee (TKA) and hip arthroplasty (THA).MethodsA total of 478 patients undergoing aseptic revision TKA and THA were randomized to receive a 3-minute dilute betadine lavage (0.35%) or normal saline lavage before surgical wound closure. Fifteen patients were excluded following randomization (3.1%) and six were lost to follow-up (1.3%), leaving 457 patients available for study. Of them, 234 patients (153 knees, 81 hips) received normal saline lavage and 223 (144 knees, 79 hips) received dilute betadine lavage. The primary outcome was PJI within 90 days of surgery with a secondary assessment of 90-day wound complications. A priori power analysis determined that 285 patients per group were needed to detect a reduction in the rate of PJI from 5% to 1% with 80% power and alpha of 0.05.ResultsThere were eight infections in the saline group and 1 in the betadine group (3.4% vs 0.4%, P = .038). There was no difference in wound complications between groups (1.3% vs 0%, P = .248). There were no differences in any baseline demographics or type of revision procedure between groups, suggesting appropriate randomization.ConclusionDilute betadine lavage before surgical wound closure in aseptic revision TKA and THA appears to be a simple, safe, and effective measure to reduce the risk of acute postoperative PJI.Level of EvidenceLevel I.     

Topical Vancomycin Powder and Dilute Povidone-Iodine Lavage Reduce the Rate of Early Periprosthetic Joint Infection After Primary Total Knee Arthroplasty

BackgroundVancomycin powder and dilute povidone-iodine lavage (VIP) was introduced to reduce the incidence of periprosthetic joint infection (PJI) in high-risk total knee arthroplasty (TKA) patients. We hypothesize that VIP can reduce the incidence of early PJI in all primary TKA patients, regardless of preoperative risk.MethodsAn infection database of primary TKAs performed before a VIP protocol was implemented (January 2012-December 2013), during a time when only high-risk TKAs received VIP (January 2014-December 2015), and when all TKAs received VIP (January 2016-September 2019) at an urban, university-affiliated, not-for-profit orthopedic hospital was retrospectively reviewed to identify patients with PJI. Criteria used for diagnosis of PJI were the National Healthcare Safety Network and Musculoskeletal Infection Society guidelines.ResultsVIP reduced early primary TKA PJI incidence in both the high-risk and all-risk cohorts compared with the pre-VIP cohort by 44.6% and 56.4%, respectively (1.01% vs 0.56% vs 0.44%, P = .0088). In addition, after introducing VIP to all-risk TKA patients, compared with high-risk TKA patients, the relative risk of PJI dropped an additional 21.4%, but this finding did not reach statistical significance (0.56% vs 0.44%, P = .4212). There were no demographic differences between the 3 VIP PJI cohorts.ConclusionVIP is associated with a reduced early PJI incidence after primary TKA, regardless of preoperative risk. With the literature supporting its safety and cost-effectiveness, VIP is a value-based intervention, but given the nature of this historical cohort study, a multicenter randomized controlled trial is underway to definitively confirm its efficacy.     

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.     

Risk of Periprosthetic Joint Infection in Patients With Total Knee Arthroplasty Undergoing Colonoscopy: A Nationwide Propensity Score Matched Study

BackgroundThe post-colonoscopy periprosthetic joint infection (PJI) risk in patients with total prosthetic knee joints has limited research. The present study investigated the PJI risk and determined the risk factors for post-colonoscopy PJI in total knee arthroplasty (TKA) recipients. The hypothesis was that colonoscopy is associated with an increased PJI risk in patients with total prosthetic knee joints. This study can potentially help guide the decision making for prophylactic antibiotic use for colonoscopy.MethodsThis nationwide matched cohort study used claims data from the Health Insurance Review and Assessment Service database and enrolled patients who underwent unilateral TKA between 2008 and 2016. The history of diagnostic colonoscopy was investigated at least 1 year postoperatively. The propensity score was matched between colonoscopy and non-colonoscopy cohorts, and the post-colonoscopy PJI risk was compared. The PJI risk following invasive colonoscopic procedures, including biopsy, polypectomy, and mucosal or submucosal resection, was investigated, and the risk factors for post-colonoscopy PJI were determined.ResultsIn total, 45,612 and 211,841 patients were matched in the colonoscopy and control cohorts, respectively. The colonoscopy cohort had greater 9-month and 1-year PJI risks from the index colonoscopy date than the matched controls (9 months: hazard ratio [HR] 1.836, P = .006; 1 year: HR 1.822, P = .031). Invasive colonoscopic procedures did not increase the PJI risk at any time point post-colonoscopy. The only significant risk factor for PJI was post-traumatic arthritis (adjusted HR 4.034, P = .023).ConclusionColonoscopy was associated with an increased PJI risk in TKA recipients, regardless of concomitant invasive colonoscopic procedures.Level of evidenceIII, Prognostic.     

No Difference in the Rate of Periprosthetic Joint Infection in Patients Undergoing the Posterolateral Compared to the Direct Anterior Approach

BackgroundThere remains inconsistent data about the association of surgical approach and periprosthetic joint infection (PJI). We sought to evaluate the risk of reoperation for superficial infection and PJI after primary total hip arthroplasty (THA) in a multivariate model.MethodsWe reviewed 16,500 primary THAs, collecting data on surgical approach and all reoperations within 1 year for superficial infection (n = 36) or PJI (n = 70). Considering superficial infection and PJI separately, we used Kaplan–Meier survivorship to assess survival free from reoperation and a Cox Proportional Hazards multivariate models to assess risk factors for reoperation.ResultsBetween direct anterior approach (DAA) (N = 3,351) and PLA (N = 13,149) cohorts, rates of superficial infection (0.4 versus 0.2%) and PJI (0.3 versus 0.5%) were low and survivorship free from reoperation for superficial infection (99.6 versus 99.8%) and PJI (99.4 versus 99.7%) were excellent at both 1 and 2 years. The risk of developing superficial infection increased with high body mass index (BMI) (hazard ratio [HR] = 1.1 per unit increase, P = .003), DAA (HR = 2.7, P = .01), and smoking status (HR = 2.9, P = .03). The risk of developing PJI increased with the high BMI (HR = 1.04, P = .03), but not surgical approach (HR = 0.68, P = .3).ConclusionIn this study of 16,500 primary THAs, DAA was independently associated with an elevated risk of superficial infection reoperation compared to the PLA, but there was no association between surgical approach and PJI. An elevated patient BMI was the strongest risk factor for superficial infection and PJI in our cohort.Level of EvidenceIII, retrospective cohort study.     

Trends of Prosthetic Joint Infection Organisms and Recurrence for a Single High-Volume Arthroplasty Surgeon Over 20 Years

BackgroundProsthetic joint infection (PJI) is a morbid complication following total joint arthroplasty (TJA). PJI diagnosis and treatment has changed over time, and patient co-management with a high-volume musculoskeletal infectious disease (MSK ID) specialist has been implemented at our institution in the last decade.MethodsWe retrospectively evaluated all consecutive TJA patients treated for PJI between 1995 and 2018 by a single high-volume revision TJA surgeon. Microbial identities, antibiotic resistance, prior PJI, and MSK ID consultation were investigated.ResultsIn total, 261 PJI patients (median age 66 years, interquartile range 57-75) were treated. One-year and 5-year reinfection rates were 15.8% (95% confidence interval [CI] 11.6-20.7) and 22.1% (95% CI 17.0-27.7), respectively. Microbial identities and antibiotic resistances did not change significantly over time. Despite seeing more prior PJI patients (53.3% vs 37.6%, P = .012), MSK ID-managed patients had similar infection rates as non-MSK ID-managed patients (hazard ratio [HR] 1.02, 95% CI 0.6-1.75, P = .93). Prior PJI was associated with higher reinfection risk (HR 2.39, 95% CI 1.39-4.12, P = .002) overall and in patients without MSK ID consultation, specifically (HR 2.78, 95% CI 1.37-5.65, P = .005). This risk was somewhat lower and did not reach significance in prior PJI patients with MSK ID consultation (HR 1.97, 95% CI 0.87-4.48, P = .106).ConclusionWe noted minimal differences in microbial/antibiotic resistances for PJI over 20 years in a single institution, suggesting current standards of PJI treatment remain encouragingly valid in most cases. MSK ID involvement was not associated with lower reinfection risk overall; however, in patients with prior PJI, the risk of reinfection appeared to be somewhat lower with MSK ID involvement.Level of EvidenceLevel IV–Case Series.     

Treatment Outcomes and Attrition in Gram-Negative Periprosthetic Joint Infection

BackgroundWhile the prevailing belief is that periprosthetic joint infection (PJI) caused by Gram-negative (GN) organisms confers a poorer prognosis than Gram-positive (GP) cases, the current literature is sparse and inconsistent. The purpose of this study is to compare the treatment outcomes for GN PJI vs GP PJI and Gram-mixed (GM) PJI.MethodsA retrospective review of 1189 PJI cases between 2007 and 2017 was performed using our institutional PJI database. Treatment failure defined by international consensus criteria was compared between PJI caused by GN organisms (n = 45), GP organisms (n = 663), and GM (n = 28) cases. Multivariate regression was used to predict time to failure.ResultsGM status, but not GN, had significantly higher rates of treatment failure compared to GP PJI (67.9% vs 33.2% failure; hazards ratio [HR] = 2.243, P = .004) in the multivariate analysis. In a subanalysis of only the 2-stage exchange procedures, both GN and GM cases were significantly less likely to reach reimplantation than GP cases (HR = .344, P < .0001; HR = .404, P = .013).ConclusionAlthough there was no observed difference in the overall international consensus failure rates between GN (31.1% failure) and GP (33.2%) PJI cases, there was significant attrition in the 2-stage exchange GN cohort, and these patients were significantly less likely to reach reimplantation. Our findings corroborate the prevailing notion that GN PJI is associated with poorer overall outcomes vs GP PJI. These data add to the current body of literature, which may currently underestimate the overall failure rates of GN PJI treated via 2-stage exchange and fail to identify pre-reimplantation morbidity.     

Utility of Diagnostic Markers in Late Periprosthetic Joint Infection Workup for Total Knee Arthroplasty Patients Who Received Antibiotics 48 Hours Before Aspiration

BackgroundDiagnosing periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) remains challenging despite recent advancements in testing and evolving criteria over the last decade. Moreover, the effects of antibiotic use on diagnostic markers are not fully understood. Thus, this study sought to determine the influence of antibiotic use within 48 hours before knee aspiration on synovial and serum laboratory values for suspected late PJI.MethodsPatients who underwent a TKA and subsequent knee arthrocentesis for PJI workup at least 6 weeks after their index arthroplasty were reviewed across a single healthcare system from 2013 to 2020. Median synovial white blood cell (WBC) count, synovial polymorphonuclear (PMN) percentage, serum erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), and serum WBC count were compared between immediate antibiotic and nonantibiotic PJI groups. Receiver operating characteristic (ROC) curves and Youden’s index were used to determine test performance and diagnostic cutoffs for the immediate antibiotics group.ResultsThe immediate antibiotics group had significantly more culture-negative PJIs than the no antibiotics group (38.1 versus 16.2%, P = .0124). Synovial WBC count demonstrated excellent discriminatory ability for late PJI in the immediate antibiotics group (area under curve, AUC = 0.97), followed by synovial PMN percentage (AUC = 0.88), serum CRP (AUC = 0.86), and serum ESR (AUC = 0.82).ConclusionAntibiotic use immediately preceding knee aspiration should not preclude the utility of synovial and serum lab values for the diagnosis of late PJI. Instead, these markers should be considered thoroughly during infection workup considering the high rate of culture-negative PJI in these patients.Level of EvidenceLevel III, retrospective comparative study.     

Are We Winning or Losing the Battle With Periprosthetic Joint Infection: Trends in Periprosthetic Joint Infection and Mortality Risk for the Medicare Population

Background

Periprosthetic joint infection (PJI) is a potentially deadly complication of total joint arthroplasty. This study was designed to address how the incidence of PJI and outcome of treatment, including mortality, are changing in the population over time.