Do Positive Cultures at Second Stage Re-Implantation Increase the Risk for Reinfection in Two-Stage Exchange for Periprosthetic Joint Infection?

BackgroundIntraoperative cultures are important in the diagnosis and targeted treatment of periprosthetic joint infection (PJI). Positive cultures at reimplantation during a two-stage exchange are discussed as a risk factor for reinfection. The aim of this study is the investigation of the incidence and risk factors for positive cultures during reimplantation.MethodsWe retrospectively identified 204 patients (111 knees, 93 hips) who were treated between 2012 and 2016 for PJI using a two-stage exchange protocol at a median follow-up of 42 months. PJI was diagnosed using the criteria of the musculoskeletal infection society (MSIS) of 2011. All cultural findings from first and second stage surgery were recorded. The primary endpoint was revision for infection. Risk factors for positive cultures and reinfection were analyzed.ResultsDuring reimplantation 25% (51/204) of patients had at least one positive culture, in 19.1% (39/204) only a single culture. Patients with culture-negative infections had a higher risk for positive cultures at reimplantation (HR 2.946 (95% CI 1.247-6.961), P = .014) and patients with infected total hip arthroplasty (THA) (HR 3.547 (95% CI 1.7-7.4), P = .001). Patients with positive cultures during reimplantation had a higher risk for reinfection (HR 2.27 (95% CI 1.181-4.363), P = .014) as well as patients with a single positive culture (HR 2.421 (95% CI 1.139-5.143), P = .021).ConclusionAs positive cultures are common and increase reinfection risk irrespective of their numbers, longer antibiotic therapy following reimplantation can be an option. Single positive cultures in reimplantation surgery should not be considered contamination.     

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.     

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.     

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

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

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.     

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.     

Does Symptomatic Benign Prostatic Hyperplasia Increase the Risk of Periprosthetic Joint Infection After Primary Total Joint Arthroplasty?

BackgroundPeriprosthetic joint infection (PJI) is among the leading causes of failure in total joint arthroplasty. A recently proposed risk factor for PJI is symptomatic benign prostatic hyperplasia (sBPH). This study aims to determine if sBPH is associated with PJI following primary total hip arthroplasty (THA) and total knee arthroplasty (TKA).MethodsUsing the Mariner all-payer claims database, 1745 patients with sBPH undergoing primary THA were propensity-matched with 3490 controls, and 3053 patients with sBPH undergoing primary TKA were propensity-matched with 6106 controls. Additionally, the same 1745 patients with sBPH undergoing THA were compared to 317,360 prematched controls, and the same 3053 patients with sBPH undergoing TKA were compared to 557,730 prematched controls. Univariate analysis was conducted using chi-squared or ANOVA where appropriate.ResultsAt two years postoperatively, patients with sBPH were not at significantly increased risk for PJI following primary THA (1.54% vs 1.43%; P = .745) and TKA (1.99% vs 2.14%; P = .642) relative to postmatch controls. Compared to matched controls, THA patients with sBPH had an increased 90-day incidence of anemia (P < .001), blood transfusion (P < .001), and urinary tract infection (UTI; P < .001). Total knee arthroplasty patients with sBPH had an increased 90-day incidence of anemia (P < .001), blood transfusion (P < .001), cellulitis (P = .023), renal failure (P = .030), heart failure (P = .029), and UTI (P < .001) relative to matched controls.ConclusionIn primary THA and TKA, sBPH does not appear to be an independent risk factor for PJI within two years postoperatively. However, clinicians should be cognizant of the significantly increased risk for postoperative UTI in this patient population.     

10-Year Cumulative Incidence and Indications for Revision Total Knee Arthroplasty Among Patients Who Have Sickle Cell Disease

BackgroundLiterature regarding total knee arthroplasty (TKA) outcomes in sickle cell disease (SCD) is limited. Moreover, 10-year survivorship of SCD implants is unknown. This study aimed to observe 10-year cumulative incidence and indications for revision TKA in patients who did and did not have SCD.MethodsPatients who underwent primary TKA were identified using a large national database. The SCD patients were matched by age, sex, and a comorbidity index to a control cohort in a 1:4 ratio. The 10-year cumulative incidence rates were determined using Kaplan–Meier survival analyses. Multivariable analyses were conducted using Cox proportional hazard modeling. Chi-squared analyses were conducted to compare indications for revision between cohorts. In total, 1,010 SCD patients were identified, 100,000 patients included in the unmatched control, and 4,020 patients included in the matched control.ResultsCompared to the unmatched control cohort, SCD patients exhibited higher 10-year all-cause revision (HR: 1.86; P < .001) with higher proportions of revisions for periprosthetic joint infection (PJI) (P < .001), aseptic loosening (P < .001), and hematoma (P < .001). Compared to the matched control, SCD patients had higher 10-year all-cause revision (Hazard Ratio (HR): 1.39; P = .034) with a higher proportion of revisions for PJI (P = .044), aseptic loosening (P = .003), and hematoma (P = .019).ConclusionIndependent of other comorbidities, SCD patients are more likely to undergo revisions for PJI, aseptic loosening, and hematoma compared to patients who do not have SCD. Due to the high-risk of these complications, perioperative and postoperative surgical optimization should be enforced in SCD patients.     

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.     

Outcome and Predictors of Septic Failure Following Total Joint Arthroplasty for Prior Septic Arthritis of Hip and Knee Joint

BackgroundArthroplasty patients with prior septic arthritis are at a high risk of developing periprosthetic joint infection (PJI). The aims of this study are to investigate the outcome and predictors of septic failure following total joint arthroplasty (TJA) for prior septic arthritis. In addition, the optimal timing of TJA is also discussed.MethodsA retrospective review of 105 TJA patients with prior septic arthritis between January 2000 and December 2019 was performed. Patient-specific and surgery-related factors, organism profiles, and other relevant variables were recorded.ResultsAt a mean follow-up of 10.3 years, the PJI rate was 16.2%. The adjusted Cox proportional hazards model showed that male gender (HR, 9.95; P < .01), end-stage renal disease (HR, 37.34; P < .01), debridement surgery ≥3 times (HR,4.75; P = .04) and polymicrobial infection in primary septic arthritis (HR, 10.02; P = .02) were independent risk factors for PJI. Neither the types of initial debridement, nor one-stage vs two-stage arthroplasty was related to the risk of PJI. While delaying the timing of TJA did not correlate with a reduction of PJI rate, there was a higher risk of PJI re-infection by the same microorganisms isolated in prior septic arthritis if TJA was performed within 6 months after septic arthritis.ConclusionsOur study demonstrated that male gender, end-stage renal disease (ESRD), multiple debridement surgeries and polymicrobial septic arthritis predisposed septic failure of TJA following prior septic arthritis. Surgeons should counsel patients with the potential complications, and be cognizant about the risk factors pertaining to septic failure when considering TJA.     

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

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

Extended Oral Antibiotic Prophylaxis After Aseptic Revision Total Hip Arthroplasty: Does It Decrease Infection Risk?

BackgroundExtended oral antibiotic prophylaxis (EOA) has been shown to reduce infection after high-risk primary total hip arthroplasties (THAs) and reimplantations. However, data are limited regarding EOA after aseptic revision THAs. This study evaluated the impact of EOA on infection-related outcomes after aseptic revision THAs.MethodsWe retrospectively identified 1,107 aseptic revision THAs performed between 2014 and 2019. Patients who received EOA >24 hours perioperatively (n = 370) were compared to those who did not (n = 737) using an inverse probability of treatment weighting model. Their mean age was 65 years (range, 19-98 years), mean body mass index was 30 kg/m² (range, 16-72), and 54% were women. Outcomes included cumulative probabilities of any infection, periprosthetic joint infection (PJI), and re-revision or reoperation for infection. Mean follow-up was 4 years (range, 2-8 years).ResultsThe cumulative probability of any infection after aseptic revision THA was 2.3% at 90 days, 2.7% at 1 year, and 3.5% at 5 years. The cumulative probability of PJI was 1.7% at 90 days, 2.1% at 1 year, and 2.8% at 5 years. There was a trend toward an increased risk of any infection (hazards ratio [HR] = 2.6; P = .058), PJI (HR = 2.6; P = .085), and re-revision (HR = 6.5; P = .077) or reoperation (HR = 2.3; P = .095) for infection in patients who did not have EOA at the final clinical follow-up.ConclusionsEOA after aseptic revision THA was not associated with a statistically significant decreased risk of any infection, PJI, or re-revision or reoperation for infection at all time points.Level of EvidenceLevel III.     

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.     

Randomized Trial of Static and Articulating Spacers for Treatment of the Infected Total Hip Arthroplasty

BackgroundThe purpose of this randomized clinical trial is to compare perioperative and postoperative variables between static and articulating spacers for the treatment of chronic periprosthetic joint infection (PJI) complicating total hip arthroplasty (THA).MethodsFifty-two patients undergoing resection arthroplasty as part of a 2-stage exchange for PJI at 3 centers were randomized to either a static (n = 23) or articulating spacer (n = 29). The primary endpoint was operative time of the second-stage reimplantation and power analysis determined that 22 patients per cohort were necessary to detect a 20-minute difference. Seven patients were lost to follow-up, 4 were never reimplanted, and one died before discharge after reimplantation. Forty patients were followed for a mean 3.2 years (range 2.0-7.1).ResultsThere were no differences in operative time at second-stage reimplantation (143 minutes static vs 145 minutes articulating, P = .499). Length of hospital stay was longer in the static cohort after stage 1 (8.6 vs 5.4 days, P = .006) and stage 2 (6.3 vs 3.6 days, P < .001). Although it did not reach statistical significance with the numbers available for study, nearly twice as many patients in the static cohort were discharged to an extended care facility after stage 1 (65% vs 30%, P = .056).ConclusionThis randomized trial demonstrated that the outcomes of static and articulating spacers are similar in the treatment of THA PJI undergoing 2-stage exchange arthroplasty. The significantly longer length of hospital stay associated with the use of static spacers may have important economic implications for the health care system.     

Time to Reimplantation: Waiting Longer Confers No Added Benefit

Background

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

Hospital Costs for Unsuccessful Two-Stage Revisions for Periprosthetic Joint Infection

BackgroundAlthough 2-stage exchange arthroplasty is the preferred surgical treatment for periprosthetic joint infection (PJI) in the United States, little is known about the risk of complications between stages, mortality, and the economic burden of unsuccessful 2-stage procedures.MethodsThe 2015-2019 Medicare 100% inpatient sample was used to identify 2-stage PJI revisions in total hip and knee arthroplasty patients using procedural codes. We used the Fine and Gray sub-distribution adaptation of the conventional Kaplan-Meier method to estimate the probability of completing the second stage of the 2-stage PJI infection treatment, accounting for death as a competing risk. Hospital costs were estimated from the hospital charges using “cost-to-charge” ratios from Centers for Medicare and Medicaid Services.ResultsA total of 5094 total hip arthroplasty and 13,062 total knee arthroplasty patients had an index revision for PJI during the study period. In the first 12 months following the first-stage explantation, the likelihood of completing a second-stage PJI revision was 43.1% (95% confidence interval [CI] 41.7-44.5) for hips and 47.9% (95% CI 47.0-48.8) for knees. Following explantation, 1-year patient survival rates for hip and knee patients were 87.4% (95% CI 85.8-88.9) and 91.4% (95% CI 90.6-92.2), respectively. The median additional cost for hospitalizations between stages was $23,582 and $20,965 per patient for hips and knees, respectively. Hospital volume, Northeast or Midwest region, and younger age were associated with reduced PJI costs (P < .05).ConclusionAlthough viewed as the most preferred, the 2-stage revision strategy for PJI had less than a 50% chance of successful completion within the first year, and was associated with high mortality rates and substantial costs for treatment failure.     

Revision Surgery for Instability After Total Hip Arthroplasty: Does Timing Matter?

BackgroundInstability is a common reason for revision surgery after total hip arthroplasty (THA). Recent studies suggest that revisions performed in the early postoperative period are associated with higher complication rates. The purpose of this study is to assess the effect of timing of revision for instability on subsequent complication rates.MethodsThe Medicare Part A claims database was queried from 2010 to 2017 to identify revision THAs for instability. Patients were divided based on time between index and revision surgeries: <1, 1-2, 2-3, 3-6, 6-9, 9-12, and >12 months. Complication rates were compared between groups using multivariate analyses to adjust for demographics and comorbidities.ResultsOf 445,499 THAs identified, 9298 (2.1%) underwent revision for instability. Revision THA within 3 months had the highest rate of periprosthetic joint infection (PJI): 14.7% at <1 month, 12.7% at 1-2 months, and 10.6% at 2-3 months vs 6.9% at >12 months (P < .001). Adjusting for confounding factors, PJI risk remained elevated at earlier periods: <1 month (adjusted odds ratio [aOR]: 1.84, 95% confidence interval [CI]: 1.51-2.23, P < .001), 1-2 months (aOR: 1.45, 95% CI: 1.16-1.82, P = .001), 2-3 months (aOR: 1.35, 95% CI: 1.02-1.78, P = .036). However, revisions performed within 9 months of index surgery had lower rates of subsequent instability than revisions performed >12 months (aOR: 0.67-0.85, P < .050), which may be due to lower rates of acetabular revision and higher rates of head-liner exchange in this later group.ConclusionWhen dislocation occurs in the early postoperative period, delaying revision surgery beyond 3 months from the index procedure may be warranted to reduce risk of PJI.     

Does Metabolic Syndrome Impact the Risk of Reoperation,Revision, or Complication After Primary Total Knee Arthroplasty?

BackgroundMetabolic syndrome (MetS) is an increasingly frequent condition characterized by insulin resistance, abdominal obesity, hypertension, and dyslipidemia. This study evaluated implant survivorship, complications, and clinical outcomes of primary TKAs performed in patients who have MetS.MethodsUtilizing our institutional total joint registry, 2,063 primary TKAs were performed in patients with a diagnosis of MetS according to the World Health Organization criteria. MetS patients were matched 1:1 based on age, sex, and surgical year to those who did not have the condition. The World Health Organization’s body mass index (BMI) classification was utilized to evaluate the effect of obesity within MetS patients. Kaplan–Meier methods were utilized to determine implant survivorship. Clinical outcomes were assessed with Knee Society scores. The mean follow-up was 5 years.ResultsMetS and non-MetS patients did not have significant differences in 5-year implant survivorship free from any reoperation (P = .7), any revision (P = .2), and reoperation for periprosthetic joint infection (PJI; P = .2). When stratifying, patients with MetS and BMI >40 had significantly decreased 5-year survivorship free from any revision (95 versus 98%, respectively; hazard ratio = 2.1, P = .005) and reoperation for PJI (97 versus 99%, respectively; hazard ratio = 2.2, P = .02). Both MetS and non-MetS groups experienced significant improvements in Knee Society Scores (77 versus 78, respectively; P < .001) that were not significantly different (P = .3).ConclusionMetS did not significantly increase the risk of any reoperation after TKA; however, MetS patients with BMI >40 had a two-fold risk of any revision and reoperation for PJI. These results suggest that obesity is an important condition within MetS criteria and remains an independent risk factor.Level of EvidenceLevel 3, Case-control study.     

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.     

Debridement,Antibiotics, and Implant Retention in Periprosthetic Joint Infection: What Predicts Success or Failure?

BackgroundDebridement, antibiotics and implant retention (DAIR) is the treatment of choice for acute postoperative and acute hematogenous periprosthetic joint infection (PJI). There is limited literature on predictive prognostic factors for DAIR. We aim to report the outcomes of DAIR and investigate the predictive prognostic factors.MethodsWe retrospectively reviewed 106 DAIRs. Failure was defined as requiring removal of TKA implants. Predictive factors that may influence success of DAIR treatment such as age, gender, body mass index, ethnicity, American Society of Anesthesiologists score, comorbidities, preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein, symptom duration, time between total knee arthroplasty and DAIR, cultures, rifampicin use, polyethylene liner change, and antibiotic duration were analyzed.ResultsThe success rate of DAIR was 69.8% (74/106 patients). For successes, mean time from DAIR-to-mortality was longer than failures (61.6 ± 42.7 vs 9.75 ± 9.60 months, P = .0150). Methicillin-susceptible Staphylococcus aureus PJI (odds ratio [OR] 3.64, confidence interval [CI] 1.30-10.2, P = .0140) was a significant predictor for failure of DAIR. Higher preoperative ESR correlated to failure (OR 1.02, CI 1.01-1.04, P = .008). In successes, mean ESR was 75.4 (66.1-84.6), whereas mean ESR in failures was 116 (88.3-143) (P = .011). An ESR > 107.5 predicted failure with a sensitivity of 51.5 and specificity of 85.2. ESR > 107.5 correlated to failure (OR 6.60, CI 2.29-19.0, P < .001). Repeat DAIRs were strongly correlated to failure (OR 5.27, CI 1.99-13.9, P < .01).ConclusionDAIR failure is associated with earlier time to mortality. Repeat DAIRs, elevated ESR > 107.5, and S aureus PJI are associated with treatment failure and 2-stage revision is recommended.