Unexpected Positive Intraoperative Cultures in Aseptic Revision Arthroplasty

Unexpected positive intraoperative cultures (UPIC) in presumed aseptic revision arthroplasty can be difficult to interpret. The purpose of this retrospective study was to compare the incidence of subsequent periprosthetic joint infection (PJI) in patients who received antibiotic therapy according to an institutional protocol with those who did not and whether they meet Musculoskeletal Infection Society (MSIS) criteria for PJI. In patients who were treated with antibiotic according to institutional criteria, the incidence of PJI after revision was higher in those who did not meet MSIS criteria (22%) than in those that met MSIS criteria (14%; P > 0.71). UPIC in aseptic revision arthroplasty are not uncommon. PJI cannot be excluded in patients that do not meet MSIS definition.     

Reduced Infection Rate After Aseptic Revision Total Knee Arthroplasty With Extended Oral Antibiotic Protocol

BackgroundThe optimal postoperative antibiotic duration has not been determined for aseptic revision total knee arthroplasty (R-TKA) where the risk of periprosthetic joint infection (PJI) is 3%-7.5%. This study compared PJI rates in aseptic R-TKA performed with extended oral antibiotic prophylaxis (EOAP) to published rates.MethodsAseptic R-TKAs consecutively performed between 2013 and 2017 at a tertiary care referral center in the American Midwest were retrospectively reviewed. All patients were administered intravenous antibiotics while hospitalized and discharged on 7-day oral antibiotic prophylaxis. Infection rates and antibiotic-related complications were assessed.ResultsSixty-seven percent of the 176 analysis patients were female, with an average age of 64 years and body mass index of 35 kg/m². Instability and aseptic loosening comprised 86% of revision diagnoses. Overall, 87.5% of intraoperative cultures were negative, and the remainder were single positive cultures considered contaminants. PJI rates were 0% at 90 days, 1.8% (95% confidence interval 0.4%-5.3%) at 1 year, and 2.2% (95% confidence interval 0.6%-5.7%) at mean follow-up of approximately 3 years (range, 7-65 months).ConclusionEOAP after aseptic R-TKA resulted in a PJI rate equivalent to primary TKA, representing a 2- to-4-fold decrease compared with published aseptic R-TKA infection rates. Further study on the benefits and costs of EOAP after aseptic R-TKA is encouraged.     

Removed Antibiotic-Impregnated Cement Spacers in Two-Stage Revision Joint Arthroplasty Do Not Show Biofilm Formation In Vivo

Use of antibiotic-impregnated spacers is common in the two-stage approach to treatment of periprosthetic joint infection despite the lack of information regarding in vivo performance of these implants. Antibiotic elution levels likely often fall below the minimal inhibitory concentration need to inhibit bacterial growth, raising concern that the spacers themselves may provide a potential attachment site for biofilm formation. Advanced microscopy was used in this study to evaluate the surface characteristics of antibiotic-eluting spacers collected at the time of prosthesis reimplantation from 6 patients undergoing two-stage treatment for an infected total joint arthroplasty. Scanning electron microscopy and confocal scanning microscopy of the removed spacers revealed modest fibrous matrix formation and inflammatory cells with no biofilm or bacteria detected. This study supports the continued use of antibiotic spacers in the treatment of periprosthetic joint infection.     

Extended Antibiotic Prophylaxis Confers No Benefit Following Aseptic Revision Total Hip Arthroplasty: A Matched Case-Controlled Study

BackgroundAdministration of perioperative antibiotic prophylaxis is one of the most important practices for prevention of periprosthetic joint infection (PJI) in patients undergoing total hip arthroplasty (THA). It is common to continue perioperative antibiotic prophylaxis for 48 hours or longer in patients undergoing revision arthroplasty, until results of intraoperative culture samples become available. However, the utility of this practice remains unclear. We examined whether extended antibiotic prophylaxis following aseptic revision THA reduces the risk of subsequent PJI.MethodsWe retrospectively reviewed records of patients undergoing aseptic revision THA between January 2000 and December 2015. At our institution, some surgeons administer prophylactic antibiotics to revision patients for only 24 hours while others prefer to extend until intraoperative culture results become available. We matched 209 patients undergoing revision THA who received extended antibiotic prophylaxis (>24 hours) in a 1:1 ratio with 209 patients receiving standard antibiotic prophylaxis (≤24 hours). The matching criteria were age, sex, body mass index, Charlson comorbidity index, and operative time.ResultsThe incidence of subsequent PJI was 4.8% in patients receiving extended antibiotic prophylaxis vs 2.4% in patients receiving standard. After adjusting for all cofounders and using multivariate logistic regression, the administration of extended prophylactic antibiotics did not reduce the incidence of subsequent infection. When stratified by postoperative antibiotic regimens, the 2 groups had similar infection-free implant survival rate (95.2% in extended and 97.6% in standard).ConclusionIt appears that extending perioperative prophylactic antibiotics until intraoperative culture results become available in patients undergoing revision THA for aseptic failures does not provide any additional benefit in terms of reducing the risk of subsequent PJI.     

Unexpected Positive Cultures in Patients Who Have a History of Septic Revision in the Same Joint

BackgroundThe prevalence of unexpected positive cultures (UPC) in an aseptic revision surgery of the joint with a prior septic revision in the same joint remains unknown. The purpose of this study was to determine the prevalence of UPC in that specific group. As secondary outcomes, we explored risk factors for UPC.MethodsThis retrospective study includes patients who had an aseptic revision total hip/knee arthroplasty procedure with a prior septic revision in the same joint. Patients who had less than 3 microbiology samples, without joint aspiration or with aseptic revision surgery performed <3 weeks after a septic revision were excluded. The UPC was defined as a single positive culture in a revision that the surgeon had classified as aseptic according to the 2018 International Consensus Meeting. After excluding 47, a total of 92 patients were analyzed, who had a mean age of 70 years (range, 38 to 87). There were 66 (71.7%) hips and 26 (28.3%) knees. The mean time between revisions was 83 months (range, 31 to 212).ResultsWe identified 11 (12%) UPC and in 3 cases there was a concordance of the bacteria compared to the previous septic surgery. There were no differences for UPC between hips/knees (P = .282), diabetes (P = .701), immunosuppression (P = .252), previous 1-stage or 2-stages (P = .316), causes for the aseptic revision (P = .429) and time after the septic revision (P = .773).ConclusionThe prevalence of UPC in this specific group was similar to those reported in the literature for aseptic revisions. More studies are needed to better interpret the results.     

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.     

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.     

Septic Revision Total Knee Arthroplasty Is Associated With Significantly Higher Mortality Than Aseptic Revisions: Long-Term Single-Center Study (1254 Patients)

BackgroundThe aim of this study is to examine the differences in long-term mortality rates between septic and aseptic revision total knee arthroplasty (rTKA) in a single specialist center over 17-year period.MethodsRetrospective consecutive study of all patients who underwent rTKA at our tertiary center between 2003 and 2019 was carried out. Revisions were classified as septic or aseptic. We identified patients’ age, gender, American Society of Anesthesiologists grade, and body mass index. The primary outcome measure was all-cause mortality at 5 years, 10 years, and over the whole study period of 17 years. Death was identified through both local hospital electronic databases and linked data from the National Joint Registry/NHS Personal Demographic Service. Kaplan-Meier survival curves were used to estimate time to death.ResultsIn total, 1298 consecutive knee revisions were performed on 1254 patients (44 bilateral revisions) with 985 aseptic revisions in 945 patients (75.4%) and 313 septic revisions in 309 patients (24.6%). Average age was 70.6 years (range 27-95) with 720 females (57.4%). Septic revisions had higher mortality rates; patients’ survivorship for septic vs aseptic revisions was 77.6% vs 89.5% at 5 years, 68.7% vs 80.2% at 10 years, and 66.1% vs 75.0% at 17 years; these differences were all statistically significant (P < .0001). The unadjusted 10-year risk ratio of death after septic revision was 1.59 (95% confidence interval 1.29-1.96) compared to aseptic revisions.ConclusionrTKA performed for infection is associated with significantly higher long-term mortality at all time points compared with aseptic revision surgery.Level of EvidenceLevel IV.     

The Influence of Spacer Design on the Rate of Complications in Two-Stage Revision Hip Arthroplasty

BackgroundAntibiotic cement spacers are used during 2-stage revision total hip arthroplasty for prosthetic joint infection. Complications including dislocation and periprosthetic fracture have been reported but a large cohort comparing spacer design features is lacking. We aimed to determine if spacer design is associated with perioperative complications.MethodsWe performed a retrospective review of antibiotic cement spacers implanted between 2004 and 2014. Radiographic assessment included leg length, offset, and bone loss (Paprosky classification). Clinical outcomes included dislocation, periprosthetic fracture, spacer fracture, infection cure, and overall reoperation rate. Univariate analysis, Student’s t-test, chi-squared test, or Kruskal-Wallis test was employed (P < .05).ResultsOne hundred eighty-five patients were treated: 42% were female and mean age was 64 years (range 24-93, standard deviation 13.6). Spacer types were (1) molded (53%), (2) antibiotic-coated prosthesis (30%), (3) handmade (12%); and (4) prefabricated (4%). Cemented acetabular liners were used in 3% (6/185). There was no loss to follow-up during the interstage period. Spacer complications occurred in 26% (48/185). Dislocation occurred in 9% (17/185) and was associated with reduced femoral offset of >5 mm (P = .033) and increased bone loss (P = .01). Spacer fracture occurred in 8% (14/185); 12% (12/97) molded versus 8% (2/23) handmade (P = .02). Periprosthetic femur fracture was associated with increased offset >5 mm (P = .01) and extended trochanteric osteotomy (P = .001).ConclusionDuring 2-stage total hip arthroplasty, antibiotic-loaded cement spacers had an overall complication rate of 26%. Spacer design, acetabular and femoral bone loss, and offset restoration were significantly associated with perioperative complications. We recommend the optimization of antibiotic-loaded cement spacer placement to minimize potential complications by focusing on restoration of leg-length and offset, ensuring adequate femoral fixation and paying attention to selection of an appropriate head/neck ratio.     

The 2018 International Consensus Meeting Minor Criteria for Chronic Hip and Knee Periprosthetic Joint Infection: Validation From a Single Center

BackgroundRecently, a revised definition of the minor criteria scoring system for diagnosing periprosthetic joint infection (PJI) was developed by the second International Consensus Meeting on musculoskeletal infection. The new system combines preoperative and intraoperative findings, reportedly achieving high sensitivity and specificity. We aimed to validate the modified scoring system at a high-volume center.MethodsWe retrospectively reviewed patients who underwent a revision total hip or knee arthroplasty at our institution from May 2015 to August 2018. Serum C-reactive protein, synovial white blood cell count and polymorphonuclear percentage, leukocyte esterase test, alpha-defensin, microbiological and histologic results, and documented existence of sinus tract and intraoperative purulence were available for all patients. Cases with at least 1 major criterion were considered as infected. Using the new minor criteria, a score of ≥6 reflects PJI, while a score <3 can be considered as noninfected. Sensitivity, specificity, mean accuracy (ACC), positive predictive value (PPV), and negative predictive value (NPV) were analyzed.ResultsA total of 345 cases were included. A cutoff score of ≥6 points had the following diagnostic performance: area under the curve (AUC) = 0.90; ACC = 0.88; sensitivity = 0.96; specificity = 0.84; PPV = 0.70; NPV = 0.98. Diagnostic performance was better for the hip (AUC = 0.92; ACC = 0.90; sensitivity = 0.96; specificity = 0.86; PPV = 0.81; NPV = 0.98) than the knee (AUC = 0.89; ACC = 0.85; sensitivity = 0.95; specificity = 0.83; PPV = 0.59; NPV = 0.98).ConclusionThe modified scoring system proposed by the 2018 International Consensus Meeting in diagnosing PJI showed high sensitivity and a good performance, especially as rule-out diagnostic criteria. The cutoff level seems to be different between the hip and knee. Further validation studies considering the acknowledged limitations are recommended.     

Selected Heat-Sensitive Antibiotics Are Not Inactivated During Polymethylmethacrylate Curing and Can Be Used in Cement Spacers for Periprosthetic Joint Infection

Background

Antibiotic use in polymethylmethacrylate (PMMA) spacers has historically been limited to those which are “heat-stable” and thus retain their antimicrobial properties after exposure to the high temperatures which occur during PMMA curing.

The Fate and Relevance of the Patella in Two-Stage Revision Total Knee Arthroplasty for Periprosthetic Joint Infection

BackgroundIt remains unclear whether reimplantation of a patellar component during a two-stage revision for periprosthetic total knee arthroplasty infection (PJI) affects patient reported outcome measures (PROMs) or implant survivorship. The purpose of this study was to evaluate whether patellar resurfacing during reimplantation confers a functional benefit or increases implant survivorship after two-stage treatment for PJI.MethodsTwo-stage revisions for knee PJI performed by three surgeons at a single tertiary care center were reviewed retrospectively. All original patellar components and cement were removed during resection and the patella was resurfaced whenever feasible during reimplantation. PROMs, implant survivorship, and radiographic measurements (patellar tilt and displacement) were compared between knees reimplanted with a patellar component versus those without a patellar component.ResultsA total of 103 patients met the inclusion criteria. Forty-three patients (41.7%) underwent reimplantation with, and 60 patients (58.3%) without a patellar component. At a mean follow-up of 33.5 months, there were no significant differences in patient demographics or PROMs between groups (P ≥ .156). No significant differences were found in the estimated Kaplan-Meier all-cause, aseptic, or septic survivorship between groups (P ≥ .342) at a maximum of 75 months follow-up. There was no significant difference in the change (pre-resection to post-reimplant) of patellar tilt (P = .504) or displacement (P = .097) between the groups.ConclusionPatellar resurfacing during knee reimplantation does not appear to meaningfully impact postoperative PROMs or survivorship. Given the risk of potential extensor mechanism complications with patellar resurfacing, surgeons may choose to leave the patella without an implant during total knee reimplantation and expect similar clinical outcomes.Level of EvidenceLevel III.     

The Utility of Frozen Section Histology in Diagnosing Periprosthetic Joint Infection in Revision Total Joint Arthroplasty

BackgroundSurgeons utilize a combination of preoperative tests and intraoperative findings to diagnose periprosthetic joint infection (PJI); however, there is currently no reliable diagnostic marker that can be used in isolation. The purpose of our study is to evaluate the utility of frozen section histology in diagnosis of PJI.MethodsRetrospective analysis of 614 patients undergoing revision total joint arthroplasty with frozen section histology from a single institution was performed. Discriminatory value of frozen section histology was assessed using univariate analysis and evaluation of area under the curve (AUC) of a receiver operating characteristic curve comparing frozen section histology results to the 2018 International Consensus Meeting (ICM) PJI criteria modified to exclude the histology component.ResultsThe sensitivity of the frozen section histology was 53.6% and the specificity was 95.2%. There was 99.2% concordance between the permanent section and frozen section results. The receiver operating characteristic curve for frozen section yielded an AUC of 0.744 (95% confidence interval 0.627-0.860) and the modified ICM score yielded an AUC of 0.912 (95% confidence interval 0.836-0.988) when compared to the full score. The addition of frozen section histology changed the decision to infected in 20% of “inconclusive” cases but less than 1% of total cases.ConclusionIn comparison to the modified ICM criteria, intraoperative frozen section histology has poor sensitivity, strong specificity, and acceptable overall discrimination for diagnosing PJI. This test appears to be of particular value for patients deemed “inconclusive” for infection using the remaining ICM criteria.     

Revision Total Hip and Knee Arthroplasties After Solid Organ Transplant

Background

As solid organ transplant (SOT) patients' survival improves, the number undergoing total hip (THA) and total knee arthroplasty (TKA) is increasing. Accordingly, the number of revision procedures in this higher-risk group is also increasing. The goals of this study were to identify the most common failure mechanisms, associated complications, clinical outcomes, and patient survivorship of SOT patients after revision THA or TKA.

Impact of COVID-19 Protocols on Primary and Revision Total Hip Arthroplasty

BackgroundSurgical site infection (SSI) after total hip arthroplasty (THA) is associated with increased morbidity, mortality, and healthcare expenditures. Our institution intensified hygiene standards during the COVID-19 pandemic; hospital staff exercised greater hand hygiene, glove use, and mask compliance. We examined the effect of these factors on SSI rates for primary THA (pTHA) and revision THA (rTHA).MethodsA retrospective review was performed identifying THA from January 2019 to June 2021 at a single institution. Baseline characteristics and outcomes were compared before (January 2019 to February 2020) and during (May 2020 to June 2021) the COVID-19 pandemic and during the first (May 2020 to November 2020) and second (December 2020 to June 2021) periods of the pandemic. Cohorts were compared using the Chi-squared test and independent samples t-test.ResultsA total of 2,682 pTHA (prepandemic: 1,549 [57.8%]; pandemic: 1,133 [42.2%]) and 402 rTHA (prepandemic: 216 [53.7%]; Pandemic: 186 [46.2%]) were included. For primary and revision cases, superficial and deep SSI rates were similar before and during COVID-19. During COVID-19, the incidence of all (?0.43%, P = .029) and deep (?0.36%, P = .049) SSIs decreased between the first and second periods for rTHA. pTHA patients had longer operative times (P < .001) and shorter length of stay (P = .006) during COVID-19. Revision cases had longer operative times (P = .004) and length of stay (P = .046). Both pTHA and rTHA were discharged to skilled nursing facilities less frequently during COVID-19.ConclusionDuring COVID-19, operative times were longer in both pTHA and rTHA and patients were less likely to be discharged to a skilled nursing facility. Although intensified hygienic standards may lower SSI rates, infection rates did not significantly differ after our hospital implemented personal protective guidelines and a mask mandate.     

Evidence-Based Hospital Procedural Volumes as Predictors of Outcomes After Revision Hip Arthroplasty

BackgroundThe aim of this study is to define the evidence-based institutional volume-outcome relationship in revision hip arthroplasty. We hypothesized that high-volume centers would be associated with superior outcomes, and that stratum-specific likelihood ratio (SSLR) analysis would delineate concrete volume thresholds for optimizing outcomes.MethodsThe Nationwide Readmission Database was queried from 2011 to 2016 for patients undergoing revision hip arthroplasty. SSLR analysis was used to determine hospital volume cutoffs specific for outcomes of interest. Volume categories were confirmed with multivariate regression.ResultsSSLR analysis produced distinct hospital volume cutoffs for all outcomes. Each subsequent volume threshold diminished patients’ risk for adverse outcomes. Tertiles were identified for 90-day infection (≤6, 7-51, ≥52 cases per year). Quartiles were found for 90-day readmission (≤5, 6-15, 16-79, ≥80), 90-day prosthesis-related complication (≤5, 6-16, 17-65, ≥66), 90-day dislocation (≤5, 6-19, 20-79, ≥80), and non-home discharge (≤5, 6-15, 16-40, and ≥41). Quintiles were generated for extended length of stay >2 days (≤2, 3-10, 11-20, 21-30, ≥31). Heptiles were produced for medical complications within 90 days (≤2, 3-8, 9-16, 17-51, 52-89, ≥90).ConclusionThis is the first known study to define evidence-based thresholds for the impact of hospital volume on revision joint arthroplasty. This supports the notion that institutional volume functions as a surrogate for protocolized interdisciplinary coordination of care and surgical experience, and that high-volume centers offer enhanced outcomes for complex cases. Additional studies should investigate the potential role for incentivization of such institutions, as they offer optimal outcomes for revision hip arthroplasty.     

Aseptic Reoperations Within 1 Year of Primary Total Knee Arthroplasty Markedly Increase the Risk of Later Periprosthetic Joint Infection

BackgroundDespite the high rate of success of primary total knee arthroplasty (TKA), some patients are candidates for early aseptic reoperation. The goal of this study is to evaluate the risk of subsequent periprosthetic joint infection (PJI) in patients treated with an aseptic reoperation within 1 year of primary TKA.MethodsA retrospective review of our total joint registry compared 249 primary TKAs requiring an aseptic reoperation within 1 year following index arthroplasty to a control group of 17,867 TKAs not requiring reoperation within 1 year. Patients were divided into groups based on time from index TKA: (1) 90 days or less (114 TKAs) and (2) 91 to 365 days (135 TKAs). Mean age was 68 years with 57% female. Mean follow-up was 7 years.ResultsAt 2 years postoperatively, patients undergoing an aseptic reoperation within 90 days subsequently had a 9% PJI rate, while patients undergoing an aseptic reoperation between 91 and 365 days subsequently had a 3% PJI rate. The control group had a 0.4% PJI rate. Compared to the control group, patients undergoing an aseptic reoperation within 90 days had an elevated risk of PJI (hazard ratio, 9; P < .0001), as did patients who had a reoperation between 91 and 365 days (hazard ratio, 4; P < .0001).ConclusionAseptic reoperation within 1 year of primary TKA was associated with a notably increased risk of subsequent PJI.     

Knee Arthroscopy After Total Knee Arthroplasty: Not a Benign Procedure

BackgroundOutcomes of knee arthroscopy (KA) after total knee arthroplasty (TKA) have been limited to small case series with short-term follow-up. The purpose of this study is to report the outcomes of patients who undergo a KA after a TKA using a large longitudinal database.MethodsThe PearlDiver Medicare database was queried for patients who underwent a KA procedure after a TKA on the ipsilateral extremity. A randomly selected control group was created by matching controls to cases in a 3:1 ratio based on age, gender, year of procedure, and Elixhauser Comorbidity Index. Revision for infection and all-cause revision were used as end points.ResultsA total of192 TKA patients who underwent a subsequent KA (TKA + KA group) were compared to 571 TKA patients who did not have a subsequent KA (TKA − KA group). The incidence of revision for infection was 6.3% in the TKA + KA group compared to 2.2% in the TKA − KA group (odds ratio, 2.87; P = .009). The incidence of all-cause revision was 18.8% in the TKA + KA group compared to 5.1% in the TKA − KA group (odds ratio, 4.34; P < .001).ConclusionKA after TKA was associated with increased infection-related and all-cause revision. The association between KA and subsequent infection requires further investigation.     

Patients With Infected Total Hip Arthroplasty Undergoing 2-Stage Exchange Arthroplasty Experience Massive Blood Loss

Background

Two-stage exchange arthroplasty is the preferred treatment for chronic periprosthetic joint infection following total hip arthroplasty (THA). These patients are at high risk of substantial blood loss and perioperative blood transfusion. Our study aimed at determining risk factors for blood transfusion during a 2-stage exchange for infected THA.

High Rate of Positive Cultures in Patients Referred With Antibiotic Spacers as Part of 2-Stage Exchange

Background

Two-stage exchange for periprosthetic joint infection (PJI) in total knee arthroplasty (TKA) remains the gold standard treatment in North America. Occasionally, patients with knee PJI are referred for definitive management after resection and antibiotic spacer placement. Currently, little literature exists to suggest how these patients should be managed. The purpose of this study is to report the clinical outcomes of these patients.