Alexander J. Rondon

Increased Complications for Schizophrenia and Bipolar Disorder Patients Undergoing Total Joint Arthroplasty

BACKGROUNDnAlthough it has been shown that anxiety and depression are associated with increased complications after total joint arthroplasty (TJA), the outcomes of TJA in patients with a history of psychosis are unknown. This study evaluated the influence of bipolar and schizophrenic disorders on complications after TJA, particularly aseptic and septic revisions.nnnMETHODSnA retrospective review of 156 TJAs (125 primaries and 31 revisions) was performed at a single institution from 2000 to 2015. Bipolar and schizophrenic patients were identified based on International Classification of Diseases, Ninth Revision codes or by those actively taking anti-psychotic medications, followed by manual chart review to confirm diagnoses. The psychosis patient cohort was matched 3:1 for a variety of factors. Revisions and readmissions were evaluated. Survivorship curves were generated.nnnRESULTSnPatients with schizophrenia or bipolar disorder had an increased odds of developing peri-prosthetic joint infection at 90 days (odds ratio [OR] 3.34, Pxa0= .049), 2 years (OR 3.94, Pxa0= .004), and at any time point (OR 4.32, Pxa0= .002). Psychosis patients had increased odds of aseptic and mechanical revisions at all endpoints, particularly from dislocation. Psychosis patients had a higher number of post-operative emergency department visits (P < .001), and were more likely to be discharged to a rehabilitation facility (P < .001).nnnCONCLUSIONSnPatients with bipolar affective disorder or schizophrenia may have multiple barriers to self-care after TJA, and are at an increased risk for undergoing revision TJA for prosthetic joint infection and mechanical causes. Increased pre-operative education and screening of this patient population may be necessary prior to performing TJA.

Serological Markers of Infection in the Infected Total Knee Arthroplasty

Diagnosis of periprosthetic joint infection (PJI) is challenging as no perfect test for it exists. Often a combination of serological, synovial, microbiological, histological, and radiological investigations is performed that are expensive, invasive, and imperfect. Serum biomarkers are dependable diagnostic tools given the low-risk nature and ease of collecting blood that aid in the diagnosis of PJI. However, it must be noted they are not without limitations. This chapter will focus on current serological markers and their efficacy in diagnosing PJI. Routine workup for PJI involves the measurements of serum white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). The combination of ESR and CRP is very effective to “rule out” PJI. Additional biomarkers such as IL-6, IL-4, TNF-alpha, procalcitonin, and siCAM1 have also shown value in the diagnosis of PJI. Scientific investigation continues to work toward a “gold standard” serum test for the diagnosis of PJI.

Majority of Total Joint Arthroplasties Are Subtherapeutic on Warfarin at Time of Discharge: Another Reason to Avoid Warfarin as a Venous Thromboembolism Prophylaxis?

BACKGROUNDnWarfarin has been used as prophylaxis against venous thromboembolism (VTE) after total joint arthroplasty (TJA) for over 60 years. With trends of shorter hospital stays for TJA patients, it is important to examine how many patients achieve therapeutic international normalized ratio (INR) at time of discharge. We aimed at elucidating the proportion of patients discharged at therapeutic INR and whether this is affected by inpatient specialty anticoagulation management service (AMS) involvement.nnnMETHODSnWe conducted a retrospective review of 2927 primary TJA patients who received warfarin as postoperative VTE chemoprophylaxis from 2011 to 2016. An electronic chart query determined AMS input, length of stay (LOS), INR at discharge, and in-hospital complications. INR results were categorized as subtherapeutic (INR < 2.0), therapeutic (2.0 ≤ INR < 3.0), and supratherapeutic (INR ≥ 3.0). Descriptive statistics, chi-square, and t-tests were performed for analysis.nnnRESULTSnAt discharge, 93.9% of patients had subtherapeutic INR. Average INR was 1.41 with average LOS of 2.53 days. Factors associated with being subtherapeutic included male gender, shorter LOS, fewer comorbidities, reduced in-hospital complications, and higher body mass index. AMS supervised postoperative warfarin dosing in 64.9% of patients. Patients managed by AMS were less likely to be subtherapeutic at discharge compared to those without AMS input; however, the absolute difference in INR may not be clinically significant. There were 19 VTEs, of which 13 had prolonged hospitalization to achieve therapeutic INR.nnnCONCLUSIONnThe majority of patients are discharged at subtherapeutic INR levels despite management by AMS. Patients may not be adequately anticoagulated with warfarin at time of discharge, raising significant patient safety concerns as well as medicolegal implications.

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

BACKGROUNDnTwo-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.nnnMETHODSnA retrospective study of 703 patients with PJI who underwent resection arthroplasty and spacer insertion between January 1999 and June 2015 was performed. Chart review identified intraoperative cultures at the time of spacer, reimplantation, and any subsequent reinfections or surgeries following spacer insertion. After applying the exclusion criteria, a total of 570 patients were included in the analysis. Five definitions of treatment success were assessed: (1) Delphi consensus success, (2) modified Delphi consensus success, (3) microbiological success, (4) implant success, and (5) surgical success.nnnRESULTSnOf the 570 patients with PJIs, 458 were reimplanted at a mean of 4.1 months. Mortality was 13.9% with 6.7% occurring before reimplantation. Treatment success was highly variable depending on the definition used (54.2%-88.9%). In 19.6% of PJI cases, the Delphi consensus definition could not be assessed as reimplantation never occurred. Furthermore, 67.0% of these patients underwent reoperations, which may not be accounted for in the Delphi consensus definition.nnnCONCLUSIONnTreatment success rates vary dramatically depending on the definition used at our institution. We hope these definitions can help bring forth awareness for standardized reporting of outcomes, but further validation and agreement of these definitions among surgeons and infectious disease physicians is crucial.

Determining the Role and Duration of the “Antibiotic Holiday” Period in Periprosthetic Joint Infection

BACKGROUNDnTwo-stage exchange arthroplasty involves resection and reimplantation of new implants at a later stage. An antibiotic-free period is often advocated by surgeons before reimplantation. However, there is no conclusive evidence supporting the utility or duration of this practice. This study evaluated the utility and optimal duration of the antibiotic-free period before reimplantation.nnnMETHODSnElectronic infection databases of 2 institutions were retrospectively reviewed from 2000 to 2014 to identify 785 patients who underwent 2-stage exchange arthroplasty, of which 409 were reimplanted without any surgeries between the first and second stage. Total joint arthroplasties that met the Musculoskeletal Infection Society criteria for periprosthetic joint infection (PJI) and had a minimum of 1-year follow-up were included. The antibiotic holiday period was defined as the time period off antibiotics before reimplantation. Treatment success was defined according to the Delphi consensus criteria. A multivariate analysis and Fisher exact test were performed.nnnRESULTSnThe duration of the antibiotic-free period was not significantly associated with reinfection following reimplantation after controlling for potential confounders, including joint involvement, gender, institution, and comorbidities. However, the duration of spacer implantation was significantly associated with reinfection. Of the patients who failed treatment, 41.5% failed on antibiotics while 58.5% failed during the antibiotic-free period at a mean of 26.1 days.nnnCONCLUSIONnThe duration of an antibiotic-free period does not appear to significantly affect PJI rate after reimplantation. However, many patients fail during the antibiotic-free period. Further prospective studies are needed to determine the optimal timing of reimplantation for 2-stage exchange arthroplasty for PJI treatment.

Two-Stage Exchange Arthroplasty Is a Favorable Treatment Option Upon Diagnosis of a Fungal Periprosthetic Joint Infection

BACKGROUNDnThis study investigated the prevalence of medical comorbidities, risk factors, and treatment outcomes in patients with fungal periprosthetic joint infection (PJI).nnnMETHODSnAll patients with fungal PJI treated from 1999 to 2014 were retrospectively identified at a single institution. Demographic data, comorbidity, and surgical variables were obtained from medical records. Patients were followed up for at least 2 years. PJI was diagnosed using the Musculoskeletal Infection Society criteria. Treatment success was defined using the Delphi consensus criteria. Kaplan-Meier survivorship curves with 95% confidence interval were used for analysis.nnnRESULTSnOverall, fungal PJIs accounted for 2.4% of the PJI treated at our institution. Twenty-seven patients (93.1%) had 2 or more underlying systemic illnesses. Age and revision surgery were significant risk factors for development of fungal PJI after adjusting for confounding variables. Overall treatment success was 55.2% at 1 year and 40.5% at 5 years. When stratified by initial surgical management, treatment success was 57.1% at 1 year and 28.6% at 5 years following irrigation and debridement; 33.3% at 1 year and 5 years following 1-stage revision; and 57.9% at 1 year and 46.3% at 5 years for 2-stage exchange arthroplasty.nnnCONCLUSIONnPatients with fungal PJI have a high prevalence of systemic illness and poor outcome after surgical management. Irrigation and debridement and single-stage revision demonstrate poor longterm outcomes and may have no place as treatment choices for fungal PJI. Moving forward, our efforts should concentrate on optimizing the systemic status of these patients prior to 2-stage exchange arthroplasty.

Inadequate Glycemic Control Is Associated With Increased Surgical Site Infection in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUNDnThe association between inadequate glycemic control and surgical site infection (SSI) following total joint arthroplasty (TJA) remains unclear. The aim of this study is to assess the relationship between perioperative glycemic control and the risk for SSI, mainly periprosthetic joint infection.nnnMETHODSnWe searched OVID-MEDLINE, Embase, and Web of Science from inception up to June 2017. The main independent variable was glycemic control as defined by glycated hemoglobin (HbA1C) or perioperative glucose values. The main outcome was SSI. Publication year, location, study design, sample population (size, age, gender), procedure, glycemic control assessment, infection outcome, results, confounders, and limitations were assessed. Studies included in the meta-analysis had stratified glycemic control using a distinct HbA1C cut-off.nnnRESULTSnSeventeen studies were included in this study. Meta-analysis of 10 studies suggested that elevated HbA1C levels were associated with a higher risk of SSI after TJA (pooled odds ratio 1.49, 95% confidence interval 0.94-2.37, Pxa0= .09) with significant heterogeneity between studies (I2xa0= 81.32%, Pxa0<xa0.0001). In a subgroup analysis of studies considering HbA1C with a cut-off of 7% as uncontrolled, this association was no longer noticed (Pxa0= .50). All 5 studies that specifically assessed for SSI and perioperative hyperglycemia showed a significant association, which was usually attenuated after adjusting for covariates.nnnCONCLUSIONnInadequate glycemic control was associated with increased risk for SSI after TJA. However, the optimal HbA1C threshold remains contentious. Pooled data does not support the conventional 7% cut-off for risk stratification. Future studies should examine new markers for determining adequate glycemic control.

Cefazolin Prophylaxis for Total Joint Arthroplasty: Obese Patients Are Frequently Underdosed and at Increased Risk of Periprosthetic Joint Infection

BACKGROUNDnOne of the most effective prophylactic strategies against periprosthetic joint infection (PJI) is administration of perioperative antibiotics. Many orthopedic surgeons are unaware of the weight-based dosing protocol for cefazolin. This study aimed at elucidating what proportion of patients receiving cefazolin prophylaxis are underdosed and whether this increases the risk of PJI.nnnMETHODSnA retrospective study of 17,393 primary total joint arthroplasties receiving cefazolin as perioperative prophylaxis from 2005 to 2017 was performed. Patients were stratified into 2 groups (underdosed and adequately dosed) based on patient weight and antibiotic dosage. Patients who developed PJI within 1 year following index procedure were identified. A bivariate and multiple logistic regression analyses were performed to control for potential confounders and identify risk factors for PJI.nnnRESULTSnThe majority of patients weighing greater than 120 kg (95.9%, 944/984) were underdosed. Underdosed patients had a higher rate of PJI at 1 year compared with adequately dosed patients (1.51% vs 0.86%, Pxa0= .002). Patients weighing greater than 120 kg had higher 1-year PJI rate than patients weighing less than 120 kg (3.25% vs 0.83%, P < .001). Patients who were underdosed (odds ratio, 1.665; Pxa0= .006) with greater comorbidities (odds ratio, 1.259; P < .001) were more likely to develop PJI at 1 year.nnnCONCLUSIONnCefazolin underdosing is common, especially for patients weighing more than 120 kg. Our study reports that underdosed patients were more likely to develop PJI. Orthopedic surgeons should pay attention to the weight-based dosing of antibiotics in the perioperative period to avoid increasing risk of PJI.

No Difference in Total Episode-of-Care Cost Between Staged and Simultaneous Bilateral Total Joint Arthroplasty

BACKGROUNDnDue to concerns about higher complication rates, surgeons debate whether to perform simultaneous bilateral total joint arthroplasty (BTJA), particularly in the higher-risk Medicare population. Advances in pain management and rehabilitation protocols have called into question older studies that found an overall cost benefit for simultaneous procedures. The purpose of this study was to compare 90-day episode-of-care costs between staged and simultaneous BTJA among Medicare beneficiaries.nnnMETHODSnWe retrospectively reviewed a consecutive series of 319 simultaneous primary TJAs and 168 staged TJAs (336 procedures) at our institution between 2015 and 2016. We recorded demographics, comorbidities, readmission rates, and 90-day episode-of-care costs based upon Centers for Medicare and Medicaid Services claims data. To control for confounding variables, we performed a multivariate regression analysis to identify independent risk factors for increased costs.nnnRESULTSnSimultaneous patients had decreased inpatient facility costs (

Failure after two-stage exchange arthroplasty for treatment of periprosthetic joint infection: the role of antibiotics in the cement spacer

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