1.5-Stage Exchange Arthroplasty for Total Knee Arthroplasty Periprosthetic Joint Infections

BackgroundPeriprosthetic joint infection (PJI) in total knee arthroplasty (TKA) is a challenging problem. The purpose of this study was to outline a novel technique to treat TKA PJI. We define 1.5-stage exchange arthroplasty as placing an articulating spacer with the intent to last for a prolonged time.MethodsA retrospective review was performed from 2007 to 2019 to evaluate patients treated with 1.5-stage exchange arthroplasty for TKA PJI. Inclusion criteria included: articulating knee spacer(s) remaining in situ for 12 months and the patient deferring a second-stage reimplantation because the patient had acceptable function with the spacer (28 knees) or not being a surgical candidate (three knees). Thirty-one knees were included with a mean age of 63 years, mean BMI 34.4 kg/m², 12 were female, with a mean clinical follow-up of 2.7 years. Cobalt-chrome femoral and polyethylene tibial components were used. We evaluated progression to second-stage reimplantation, reinfection, and radiographic outcomes.ResultsAt a mean follow-up of 2.7 years, 25 initial spacers were in situ (81%). Five knees retained their spacer(s) for some time (mean 1.5 years) and then underwent a second-stage reimplantation; one of the five had progressive radiolucent lines but no evidence of component migration. Three knees (10%) had PJI reoccurrence. Four had progressive radiolucent lines, but there was no evidence of component migration in any knees.Conclusions1.5-stage exchange arthroplasty may be a reasonable method to treat TKA PJI. At a mean follow-up of 2.7 years, there was an acceptable rate of infection recurrence and implant durability.     

Nephrotoxicity After the Treatment of Periprosthetic Joint Infection With Antibiotic-Loaded Cement Spacers

Background

Treatment of periprosthetic joint infections commonly involves insertion of an antibiotic-loaded cement spacer (ACS). The risk for acute kidney injury (AKI) related to use of antibiotic spacers has not been well defined. We aimed to identify the incidence of and risk factors for AKI after placement of an ACS.

Outcomes and Risk Factors Associated With 2-Stage Reimplantation Requiring an Interim Spacer Exchange for Periprosthetic Joint Infection

BackgroundPatients undergoing a 2-stage revision for periprosthetic joint infection (PJI) often require a repeat spacer in the interim due to persistent infection. This study aims to report outcomes for patients with repeat spacer exchange and to identify risk factors associated with interim spacer exchange in 2-stage revision arthroplasty.MethodsA total of 256 consecutive 2-stage revisions for chronic infection of total hip arthroplasty and total knee arthroplasty with reimplantation and minimum 2-year follow-up were investigated. An interim spacer exchange was performed in 49 patients (exchange cohort), and these patients were propensity score matched to 196 patients (nonexchange cohort). Multivariate analysis was performed to analyze risk factors for failure of interim spacer exchange.ResultsPatients in the propensity score–matched exchange cohort demonstrated a significantly increased reinfection risk compared to patients without interim spacer exchange (24% vs 15%, P = .03). Patients in the propensity score–matched exchange cohort showed significantly lower postoperative scores for 3 patient-reported outcome measures (PROMs): hip disability and osteoarthritis outcome score physical function (46.0 vs 54.9, P = .01); knee disability and osteoarthritis outcome score physical function (43.1 vs 51.7, P < .01); and patient-reported outcomes measurement information system physical function short form (41.6 vs 47.0, P = .03). Multivariate analysis demonstrated Charles Comorbidity Index (odds ratio, 1.56; P = .01) and the presence of Enterococcus species (odds ratio, 1.43; P = .03) as independent risk factors associated with 2-stage reimplantation requiring an interim spacer exchange for periprosthetic joint infection.ConclusionThis study demonstrates that patients with spacer exchange had a significantly higher risk of reinfection at 2 years of follow-up. Additionally, patients with spacer exchange demonstrated lower postoperative PROM scores and diminished improvement in multiple PROM scores after reimplantation, indicating that an interim spacer exchange in 2-stage revision is associated with worse patient outcomes.     

Two-Stage Revision Total Hip Arthroplasty With a Specific Articulating Antibiotic Spacer Design: Reliable Periprosthetic Joint Infection Eradication and Functional Improvement

Background

Two-stage revision utilizing spacers loaded with high-dose antibiotic cement prior to reimplantation remains the gold standard for treatment of periprosthetic joint infections (PJI) in total hip arthroplasty (THA) in North America, but there is a paucity of data on mid-term outcomes. We sought to analyze the survivorship free of infection, clinical outcomes, and complications of a specific articulating spacer utilized during 2-stage revision.

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.     

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.     

Hypoalbuminemia Predicts Failure of Two-Stage Exchange for Chronic Periprosthetic Joint Infection of the Hip and Knee

BackgroundNutritionally compromized patients, with preoperative serum albumin (SAB) < 3.5g/dL, are at higher risk for periprosthetic joint infection (PJI) in total joint arthroplasty. The relationship between nutritional and PJI treatment success is unknown. The purpose of this study was to examine the relationship between preresection nutrition and success after first-stage resection in planned two-stage exchange for PJI.MethodsA retrospective review was performed on 418 patients who had first-stage resection of a planned two-stage exchange for chronic hip or knee PJI between 2014 and 2018. A total of 157 patients (58 hips and 99 knees) were included who completed first stage, had available preop SAB and had a 2-year follow-up. Failure was defined as persistent infection or repeat surgery for infection after resection. Demographic and surgical data were abstracted and analyzed.ResultsAmong knee patients with preop SAB >3.5 g/dL, the failure rate was 32% (15 of 47) versus a 48% (25 of 40) failure rate when SAB <3.5 g/dL (P = .10). Similarly, the failure rate among hip patients with preop SAB >3.5 g/dL versus 12.5% (3 of 24) versus 44% (15 of 34) for hip patients with SAB <3.5 g/dL (P = .01). Multivariable regression results indicated that patients with SAB< 3.5 g/dL (P = .0143) and Musculoskeletal Infection Society host type C (P = .0316) were at an increased risk of failure.ConclusionLow preoperative SAB and Musculoskeletal Infection Societyhost type-C are independent risk factors for failure following first-stage resection in planned two-stage exchange for PJI. Efforts to nutritionally optimize PJI patients, when possible, may improve the outcome of two-stage exchange.     

The Utility of Serum d-Dimer for the Diagnosis of Periprosthetic Joint Infection in Revision Total Hip and Knee Arthroplasty

BackgroundThere is scarce and contradicting evidence supporting the use of serum d-dimer for the diagnosis of periprosthetic joint infection in revision total hip (THA) and knee (TKA) arthroplasty. Therefore, the purpose of this study is to test the accuracy of serum d-dimer against the 2013 International Consensus Meeting (ICM) criteria.MethodsA retrospective review was performed on a consecutive series of 172 revision THA/TKA surgeries performed by 3 fellowship-trained surgeons at a single institution (August 2017 to May 2019) and that had d-dimer performed during their preoperative workup. Of this cohort, 111 (42 THAs/69 TKAs) cases had complete 2013 ICM criteria tests and were included in the final analysis. Septic and aseptic revisions were categorized per 2013 ICM criteria (“gold standard”) and compared against serum d-dimer using an established threshold (850 ng/mL). Sensitivity, specificity, likelihood ratios, and positive/negative predictive values were determined. Independent t-tests, Fisher’s exact tests, chi-squared tests, and receiver operating characteristic curve analysis were performed.ResultsThere was no statistically significant difference in baseline demographics between septic and aseptic cases per 2013 ICM criteria. When compared to ICM criteria, d-dimer demonstrated high sensitivity (95.9%) and negative predictive value (90.9%) but low specificity (32.3%), positive predictive value (52.8%), and overall, poor accuracy (61%) to diagnose periprosthetic joint infection. Positive likelihood ratio was 1.42 while negative likelihood ratio was 0.13. The area under the curve (AUC) was 0.742.ConclusionSerum d-dimer has poor accuracy to discriminate between septic and aseptic cases using a described threshold in the setting of revision THA and TKA.     

Repeat 2-Stage Revision for Recurrent Infection of Total Hip Arthroplasty

Eleven patients who developed reinfection after 2-stage revision for infected total hip arthroplasty (THA) were treated with a repeat 2-stage rerevision. Of the 11 rerevisions, 4 were successful, with no recurrent infection at mean follow-up of 44 months. Reinfection occurred in 7 patients of whom 6 involved either a significantly compromised host or poor local wound status. Clinical symptoms of infection were controlled in 4 of the 7 reinfected cases with antibiotic therapy in 2, irrigation and debridement in 1, and a third 2-stage revision THA in 1. Repeat 2-stage treatment of infected THA is associated with a high failure rate. However, successful results can be achieved particularly if the host is not immunocompromised and healthy soft tissue coverage is present.     

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.     

Cement Loaded With High-Dose Gentamicin and Clindamycin Reduces the Risk of Subsequent Infection After One-Stage Hip or Knee Arthroplasty Exchange for Periprosthetic Infection: A Preliminary Study

BackgroundThe use of antibiotic-loaded acrylic cement for treating periprosthetic joint infections remains controversial. We hypothesized that the raw rate of surgical site infection (SSI) is lower after using cement loaded with high-dose gentamicin and clindamycin than after using cement loaded with standard-dose gentamicin for implant fixation during 1-stage hip and knee revision arthroplasty for infection.MethodsOne hundred seventy-one continuous patients operated by 2 experienced surgeons during a 2-year period were included in the study. All patients were followed for 24 months. The primary endpoint was the raw rate of SSI after 2 years of follow-up time.ResultsThe raw rate of SSI after 2 years of follow-up time was significantly lower in the study group (13%) than in the control group (26%) (P = .03) with an odds ratio of 0.42 (P = .03). These SSIs were new infections rather than a recurrence/persistence of the initial infection.ConclusionThe cement used in the study group significantly reduced the risk of SSI relative to the cement used in the control group. Routine use of this high-dose dual antibiotic-loaded cement can be considered during 1-stage knee or hip revision arthroplasty for infection.     

Mortality During Total Knee Periprosthetic Joint Infection

Background

Periprosthetic joint infections (PJIs) are fraught with multiple complications including poor patient-reported outcomes, disability, reinfection, disarticulation, and even death. We sought to perform a systematic review asking the question: (1) What is the mortality rate of a PJI of the knee undergoing 2-stage revision for infection? (2) Has this rate improved over time? (3) How does this compare to a normal cohort of individuals?

Defining Treatment Success After 2-Stage Exchange Arthroplasty for Periprosthetic Joint Infection

Background

Two-stage exchange arthroplasty remains the preferred surgical treatment method for patients with chronic periprosthetic joint infection (PJI). The success of this procedure is not known exactly as various definitions of success have been used. This study aimed at analyzing the difference in outcome following 2-stage exchange arthroplasty using different definitions for success.

Two-Stage Exchange Arthroplasty for Periprosthetic Joint Infection Following Total Hip or Knee Arthroplasty Is Associated With High Attrition Rate and Mortality

BackgroundWe sought to determine the ultimate fate of patients undergoing resection arthroplasty as a first stage in the process of 2-stage exchange and evaluate risk factors for modes of failure.MethodsA retrospective case study was performed including all patients with minimum 2-year follow-up who underwent first-stage resection of a hip or knee periprosthetic joint infection from 2008 to 2015. Patient demographics, laboratory, and health status variables were collected. The primary outcome analyzed was defined as failure to achieve an infection-free 2-stage revision. Univariate pairwise comparison followed by multivariate regression analysis was used to determine risk factors for failure outcomes.ResultsEighty-nine patients underwent resection arthroplasty in a planned 2-stage exchange protocol (27 hips, 62 knees). Mean age was 64 years (range, 43-84), 56.2% were males, and mean follow-up was 56.3 months. Also, 68.5% (61/89) of patients underwent second-stage revision. Of the 61 patients who complete a 2-stage protocol, 14.8% (9/61) of patients failed with diagnosis of repeat or recurrent infection. Mortality rate was 23.6%. Multivariate analysis identified risk factors for failure to achieve an infection-free 2-stage revision as polymicrobial infection (P < .004; adjusted odds ratio [AOR], 7.8; 95% confidence interval [CI], 2.1-29.0), McPherson extremity grade 3 (P < .024; AOR, 4.1; 95% CI, 1.2-14.3), and history of prior resection (P < .013; AOR, 4.7; 95% CI, 1.4-16.4).ConclusionPatients undergoing resection arthroplasty for periprosthetic joint infection are at high risk of death (24%) and failure to complete the 2-stage protocol (32%). Those who complete the 2-stage protocol have a 15% rate of reinfection at 4.5-year follow-up.     

Two-Stage Revision for Prosthetic Joint Infection: Outcome and Role of Reimplantation Microbiology in 107 Cases

Two-stage revision is widely used for the treatment of prosthetic joint infections. However, the duration of antibiotic treatment between stages and role of reimplantation microbiology are controversial. The purpose of this study was to evaluate the outcome and influence of the reimplantation microbiology of two-staged revisions with 6 weeks of antibiotic treatment. We retrospectively reviewed 107 patients treated with two-stage revision between 2001 and 2009. The overall treatment success rate was 94.4%. The reimplantation cultures were positive in 5/97 (5.2%) cases, and only one of them failed. Therefore, we achieved excellent results with a 6-week course of antibiotics between stages in two-stage revision. Positive reimplantation cultures do not seem to be associated with worse outcomes.     

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.     

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.     

Acute Renal Failure After the First Stage of a 2-Stage Exchange for Periprosthetic Joint Infection

BackgroundTwo-stage exchange using antibiotic-loaded spacers is a common approach in treating periprosthetic joint infections. Acute kidney injury (AKIN) can be a systemic complication of this procedure. This study investigates the prevalence of AKIN and identifies potential risk factors.MethodsThis is a single-center retrospective analysis of patients undergoing 2-stage exchange using a spacer in 285 patients treated between 2010 and 2017. Risk factors were evaluated using parametric and nonparametric analyses and a multivariate, binary logistic regression model.ResultsThirty-three percent of patients (95/285) developed an AKIN postoperatively. Twenty-four percent (23/95) of these patients had an acute on chronic kidney failure with a previously impaired renal function.In multivariate analysis, a higher age (hazard ratio [HR], 1.034; 95% confidence interval [CI], 1-1.068; P = .046) and a higher baseline creatinine level (HR, 1.94; 95% CI, 1.237-3.052; P = .004) were risk factors for AKIN. Treatment with vancomycin in the spacer or systemically was not associated with AKIN while a high vancomycin blood level (HR, 1.91; 95% CI, 0.913-3.992; P = .086) and fungal infections were (HR, 3.482; 95% CI, 0.968-12.521; P = .056).Furthermore, in univariate analysis, a higher median Charlson comorbidity index (4 vs 3, P = .007), a lower preoperative hemoglobin (10.9 vs 11.7 g/dL, P = .008), and a higher number of blood transfusions (1 vs 0, P = .004) were associated with AKIN.ConclusionAKIN is common in patients undergoing 2-stage exchange. Associated patient factors, particularly in patients with chronic renal dysfunction, should be optimized. The general use of glycopeptide antibiotics was no risk factor for AKIN.     

Gastrocnemius Muscle Flaps for Soft Tissue Coverage in Periprosthetic Knee Joint Infection

BackgroundSoft tissue deficiency in total knee arthroplasty infection is a potentially devastating complication. Gastrocnemius muscle flaps can be used to address this problem. We aim at reporting survival rates of these reconstructions and identify risk factors for failure.MethodsA retrospective evaluation of all flaps performed at a single center between 2006 and 2019 was performed. Clinical and microbiological results were assessed in 43 cases after a median follow-up period of 53 months (25%-75% interquartile range 18-79). Function was assessed using the Oxford Knee Score. We analyzed the infection-free survival and identified risk factors using survival comparison and (non-)parametric testing.ResultsInfection-free survival was 71% at 2 years and 63% at 5 years. The rate of subsequent amputation was 16% with a mortality rate of 26% during follow-up. Four patients did not undergo reimplantation and 11 patients received an arthrodesis implant. There were no failures of the flap itself. The Charlson Comorbidity index was the only relevant risk factor for reinfection. Coagulase-negative staphylococci were most common organisms identified. Postoperative function was limited with a mean Oxford Knee Score of 20.ConclusionGastrocnemius flap coverage is a valid option for soft tissue reconstruction in periprosthetic infections to retain a functioning limb despite a high complication rate and the risk of subsequent amputation.     

High Rate of Intramedullary Canal Culture Positivity in Total Knee Arthroplasty Resection for Prosthetic Joint Infection

BackgroundPeriprosthetic infection is a devastating complication following total knee arthroplasty. A 2-stage protocol often includes an interim antibiotic spacer with intramedullary (IM) dowels. However, the necessity of IM dowels has recently been challenged. Specifically, the data supporting bacterial colonization of the IM canal are limited and controversial. The purpose of this study was to identify the rate of positive IM cultures during resection arthroplasty in periprosthetic knee infection.MethodsA total of 66 IM diaphyseal cultures were taken during resection arthroplasty from 34 patients diagnosed with periprosthetic knee infection. These IM cultures were taken from the femoral and tibial canals using separate sterile instruments. All patients had infected primary total knee arthroplasty implants at the time of resection.ResultsThirty one percent (n = 21) of IM canal cultures in this study were positive from either the tibial or the femoral diaphysis at the time of resection arthroplasty. There were 18 of 21 (86%) of the positive IM canal cultures with concordant intraoperative joint cultures where the IM cultures matched the intraarticular cultures.ConclusionWith a 31% positive IM canal culture rate, this study confirms the logic of using IM dowels with an antibiotic spacer to treat periprosthetic knee infection. Since the failure of a 2-stage reimplantation is catastrophic, any attempt to provide additional local antibiotic delivery seems warranted. Since nearly one-third of our patients had positive IM cultures, this simple addition to an antibiotic spacer has the potential to improve 2-stage results. Claims supporting the elimination of IM dowels during resection arthroplasty seem ill-advised.