Acute Kidney Injury After Total Hip and Knee Arthroplasty. What Is the Culprit?

Background: Acute kidney injury (AKI) is associated with increased complications after total hip arthroplasty (THA) and total knee arthroplasty (TKA). The purpose of this study was to determine the risk factors for AKI after THA and TKA and evaluate if preoperative use of antihypertensive drugs is a risk factor for AKI. Methods: A retrospective review of 7406 primary TKAs and THAs (4532 hips and 2874 knees) from 2013 to 2019 was performed. The following preoperative variables were obtained from medical records: medications, chemistry 7 panel, Elixhauser comorbidities, and demographic factors. AKI was defined as an increase in serum creatinine by 26.4 µmol·L-1. Multivariate analysis was performed to identify the risk factors. Results: The overall incidence of postoperative AKI was 6.2% (n = 459). Risk factors for postoperative AKI were found to be: chronic kidney disease (odds ratio [OR] = 7.09; 95% confidence interval [CI]: 4.8-9.4), diabetes (OR: 5.03; 95% CI: 2.8-6.06), ≥3 antihypertensive drugs (OR: 4.2; 95% CI: 2.1-6.2), preoperative use of an angiotensin receptor blockers or angiotensin-converting enzyme inhibitors (OR: 3.8; 95% CI: 2.2-5.9), perioperative vancomycin (OR: 2.7; 95% CI: 1.8-4.6), and body mass index >40 kg/m2 (OR: 1.9; 95% CI: 1.3-3.06). Conclusions: We have identified several modifiable risk factors for AKI that can be optimized prior to an elective THA or TKA. The use of certain antihypertensive agents namely angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and multidrug antihypertensive regimens were found to significantly increase the risk of AKI. Therefore, perioperative management of patients undergoing joint replacement should include medical comanagement with a focus on careful management of antihypertensives.

Plasma D-Dimer Is Noninferior to Serum C-Reactive Protein in the Diagnosis of Periprosthetic Joint Infection.

BACKGROUND: No single test has demonstrated absolute accuracy in the diagnosis of periprosthetic joint infection (PJI). Serological markers are often used as screening tools in the workup of patients with suspected PJI. This study aimed to determine the diagnostic utility of plasma D-dimer for PJI in a variety of clinical scenarios. METHODS: This prospective study enrolled 502 patients undergoing revision hip or knee arthroplasty. PJI was defined per a modified version of the 2018 International Consensus Meeting (ICM) criteria. Plasma D-dimer, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and fibrinogen were measured preoperatively. Receiver operating characteristic curves were used to assess the utility of each biomarker in the diagnosis of PJI. Pairwise comparison with Bonferroni correction was performed to determine whether the differences in areas under the curve (AUCs) between the markers were significant. RESULTS: Of the 412 patients included, 317 (76.9%) did not have an infection (aseptic group) and 95 (23.1%) had an infection (PJI group). All 4 serological markers, D-dimer (AUC, 0.860; sensitivity, 81.3%; specificity, 81.7%), CRP (AUC, 0.862; sensitivity, 90.4%; specificity, 70.0%), ESR (AUC, 0.833; sensitivity, 73.9%; specificity, 85.2%), and fibrinogen (AUC, 0.798; sensitivity, 74.7%; specificity, 75.4%), demonstrated comparable accuracy for the diagnosis of PJI (all p > 0.05). When examining the performance of the different inflammatory markers in diagnosing infection caused by indolent organisms, D-dimer demonstrated the highest sensitivity at 93.8%. CONCLUSIONS: We found that plasma D-dimer was noninferior to serum CRP and ESR in the diagnosis of PJI and may be a useful adjunct when screening patients undergoing revision total joint arthroplasty. LEVEL OF EVIDENCE: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Implant Removal Due to Infection After Open Reduction and Internal Fixation: Trends and Predictors.

Background: Implant removal due to infection is one of the major causes failure following open reduction and internal fixation (ORIF). The aim of this study was to determine trends and predictors of infection-related implant removal following ORIF of extremities using a nationally representative database. Methods: Nationwide Inpatient Sample data from 2006 to 2017 was used to identify cases of ORIF following upper and lower extremity fractures, as well as cases that underwent infection-related implant removal following ORIF. Multivariate analysis was performed to identify independent predictors of infection-related implant removal, controlling for patient demographics and comorbidities, hospital characteristics, site of fracture, and year. Results: For all ORIF procedures, the highest rate of implant removal due to infection was the phalanges/hand (5.61%), phalanges/foot (5.08%), and the radius/ulna (4.85%). Implant removal rates due to infection decreased in all fractures except radial/ulnar fractures. Tarsal/metatarsal fractures (odds ratio (OR)=1.45, 95% confidence interval (CI): 1.02-2.05), and tibial fractures (OR=1.82, 95% CI: 1.45-2.28) were identified as independent predictors of infection-related implant removal. Male gender (OR=1.67, 95% CI: 1.49-1.87), Obesity (OR=1.85, 95% CI: 1.34-2.54), diabetes mellitus with chronic complications (OR=1.69, 95% CI: 1.13-2.54, P<0.05), deficiency anemia (OR=1.59, 95% CI: 1.14-2.22) were patient factors that were associated with increased infection-related removals. Removal of implant due to infection had a higher total charge associated with the episode of care (mean: $166,041) than non-infection related implant removal (mean: $133,110). Conclusion: Implant removal rates due to infection decreased in all fractures except radial/ulnar fractures. Diabetes, liver disease, and rheumatoid arthritis were important predictors of infection-related implant removal. The study identified some risk factors for implant related infection following ORIF, such as diabetes, obesity, and anemia, that should be studied further to implement strategies to reduce rate of infection following ORIF.

The Delivery of Orthopaedic Care midst COVID-19 and Social Distancing.

In this paper we present the findings of a literature review covering articles published in the last three decades describing the application of telemedicine in orthopaedics. A review of the PubMed Central and Medline provided 75 articles studying the role of telemedicine, the majority directly examining the application of telemedicine in orthopaedic patients. We report the summarized findings of these studies, the financial and HIPAA considerations of using telemedicine, and provide an example of our single urban level-1 trauma center's strategy for incorporating telemedicine into the clinical practice of orthopaedic surgeons during the COVID-19 pandemic.

Is D-dimer a Reliable Serum Marker for Shoulder Periprosthetic Joint Infection?

BACKGROUND: The diagnosis of periprosthetic shoulder infection continues to be difficult to make with confidence. Serum D-dimer has proven to be effective as a screening tool for periprosthetic joint infection in other major joints; however, it has yet to be evaluated for use in periprosthetic shoulder infection. QUESTIONS/PURPOSES: (1) Is D-dimer elevated in patients with probable or definite periprosthetic shoulder infections? (2) What is the diagnostic accuracy of D-dimer for periprosthetic shoulder infections? (3) What are the diagnostic accuracies of serum tests (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], and D-dimer), singly and in combination? METHODS: Between March 2016 and March 2020, 94 patients undergoing revision total shoulder arthroplasty (anatomic or reverse) at a single institution had preoperative serum testing with CRP, ESR, and D-dimer. These 94 patients were a subset of 189 revision shoulder arthroplasties performed at this institution during the study period who met inclusion criteria and consented to participate. Included patients had a mean ± SD age of 69 ± 8 years, and 56% (53 of 94) were men. Patient records were reviewed to classify patients as definitely having infection, probably having infection, possibly having infection, or unlikely to have an infection, according to the International Consensus Meeting (ICM) definition of periprosthetic shoulder infection. Statistical analyses, including a receiver operating characteristic curve analysis, were performed to quantify the diagnostic value of D-dimer for periprosthetic shoulder infection. Based on the ICM definition, 4% (4 of 94), 15% (14 of 94), 14% (13 of 94), and 67% (63 of 94) of patients had definite, probable, possible, or unlikely periprosthetic shoulder infections. RESULTS: D-dimer was elevated in patients with definite or probable infections (median [range] 661 ng/mL [150 to 8205]) compared with those with possible infections or those who were unlikely to have an infection (263 ng/mL [150 to 3060]; median difference 143 ng/mL [95% CI 40 to 503]; p = 0.01). In the receiver operating characteristic curve analysis, D-dimer had an area under the curve of 0.71 (0.50-0.92), demonstrating weak diagnostic value. A D-dimer level of 598 ng/mL provided a sensitivity and specificity of 61% (95% CI 36% to 82%) and 74% (95% CI 62% to 83%), respectively, for diagnosing a definite or probable infection according to the ICM definitions. The specificity of detecting periprosthetic joint infection (88% [95% CI 79% to 94%]) was high when three positive serum markers (ESR, CRP, and D-dimer) were required, at the expense of sensitivity (28% [95% CI 10% to 53%]). CONCLUSION: In periprosthetic shoulder infection, D-dimer is elevated. However, similar to other serum tests, it has limited diagnostic utility in identifying patients with periprosthetic shoulder infection. Further work is needed to understand the process by which D-dimer is associated with active infection. LEVEL OF EVIDENCE: Level III, diagnostic study.

The Expanding Role of Biomarkers in Diagnosing Infection in Total Joint Arthroplasty: A Review of Current Literature.

Consistent diagnosis of periprosthetic infection in total joint arthroplasty continues to elude the orthopedic surgeon because no gold standard test exists. Therefore clinicians must rely on a combination of tests to help aid the diagnosis. The expanding role of biomarkers has shown promising results to more accurately diagnose an infection when combined with clinical suspicion and bacterial culture testing. This paper reviews the diagnostic capabilities of the most current serum and synovial biomarkers as well as next generation sequencing in the setting of periprosthetic joint infection. Future research and high-powered studies will be necessary to determine sensitivity and specificity of each biomarker.

What Is the Effect on Kinesio Taping on Pain and Gait in Patients With Patellofemoral Pain Syndrome?

Introduction Patellofemoral pain syndrome (PFPS) is one of the leading causes of anterior knee pain treated by orthopedists and physical therapists. This syndrome predominantly affects young, active individuals, and remains a challenging syndrome to manage due to the lack of quantitative diagnostic criteria to monitor during treatment. The etiology of this syndrome is believed to be multifactorial, with the gait and movement patterns of a patient potentially contributing to pain due to increased stress on the knee. In this study, we investigated the gait of participants with PFPS using the GaitRite system (CIR Systems Inc., Clifton, NJ) before and after the application of Kinesio Tape in order to assess the impact of Kinesio Tape on cadence, stance time, and pain. Methods A convenience sample of 10 participants were recruited for this study, with five participants without PFPS serving as controls, and five with PFPS in the Kinesio Tape group. Participants in the Kinesio Tape groups served as their own internal control, ambulating both before and after taping. All participants ambulated across the GaitRite carpet three times and completed a visual analogue scale pain score for each trip. Results The results of our study found there to be no significant difference in the cadence for gait between the participants without PFPS and participants with PFPS (105.2 seconds vs. 105.1 seconds, p = 0.272), or in the stance time between the control and PFPS group (1.43 seconds vs. 1.44, p = 0.907). Similarly, no significant difference was found in participants with PFPS before and after Kinesio Taping in the cadence and stance times (105.1 seconds vs. 107.4 seconds, p =0.288, and 1.44 vs. 1.40, p = 0.272). There was a significant difference in pain in PFPS participants before and after taping, with a 112.5% reduction in pain reported after taping (3.4 vs. 1.6, p < 0.05). Discussion and conclusion This study is one of the first studies to utilize the GaitRite system in order to analyze the impact of Kinesio Tape on gait in participants with PFPS. While our study failed to demonstrate a significant difference in the gait of participants with PFPS in comparison to those without PFPS, we did demonstrate a significant reduction in pain after the application of Kinesio Tape. These results suggest other variables addressed by the Kinesio Tape may be causing the pain associated with PFPS.

Persistent Wound Drainage among Total Joint Arthroplasty Patients Receiving Aspirin vs Coumadin.

BACKGROUND: Persistent wound drainage (PWD) is one of the major risk factors for periprosthetic joint infections (PJI), arguably the most dreaded complications after a total hip and knee arthroplasty (THA and TKA). The aim of this study is to identify the rates of PWD among THA and TKA patients who received aspirin (ASA) or Coumadin for postoperative venous thromboembolism (VTE) prophylaxis. METHODS: Retrospective review of 5516 primary THA and TKA was performed. Patients with PWD were identified. Chi-square test was used to compare the incidences of PWD, 30-day VTE, and PJI at 6 months between the ASA and Coumadin groups. Multivariate regression model was used to identify independent risk factors for PWD using Charlson and Elixhauser comorbidity indexes. RESULTS: The prevalence of PWD was 6.4% (353/5516). Patients receiving ASA had lower incidence of PWD (3.2% vs 8.5%, P < .0001) while having comparable rates of 30-day VTE (1.3% vs 1.4%, P = .722) and PJI at 6 months (1.8% vs 1.4%, P = .233) compared to those receiving Coumadin. Risk factors for PWD were diabetes (odds ratio [OR], 19.3; 95% confidence interval [CI], 11.8-23.2), rheumatoid arthritis (OR, 15.3; 95% CI, 10.8-17.2), morbid obesity (OR, 13.2; 95% CI, 9.7-17.5), chronic alcohol use (OR, 3.5; 95% CI, 1.8-5.5), hypothyroidism (OR, 1.9; 95% CI, 1.1-3.2), and Coumadin (OR, 1.7; 95% CI, 1.2-2.2). CONCLUSION: Use of ASA is associated with significantly lower rates of PWD after THA and TKA when compared to Coumadin while being equally efficacious at preventing VTE. Coumadin was found to be an independent risk factor for PWD.

The risk factors and an evidence-based protocol for the management of persistent wound drainage after total hip and knee arthroplasty.

BACKGROUND: Persistent wound drainage (PWD) is one of the major risk factors for periprosthetic joint infections (PJIs), arguably the most dreaded complication after total joint arthroplasty (TJA). The aim of this study was to identify the risk factors for PWD and provide a stepwise management protocol for it. METHODS: A retrospective review of 4873 TJAs was performed. After determining patients with PWD, a logistic regression model was designed to identify the risk factors using Charlson and Elixhauser comorbidity indexes. Finally, the protocol that was instituted for the management of PWD and its success rate was presented. RESULTS: The prevalence of PWD was 6.2% (302 of 4873). Of these, 196 did not require any surgical interventions, and drainage stopped with local wound care. 106 patients required surgical intervention, of which, 64 underwent superficial irrigation and debridement and 42 underwent deep irrigation and debridement with modular components exchange. Patients with PWD had significantly higher rates of PJI (odds ratio [OR]: 16.9; 95% confidence interval [CI]: 9.1-31.6). Risks factors were diabetes (OR: 21.2; 95% CI: 12.8-25.1), morbid obesity (OR: 17.3; 95% CI: 14.7-21.5), rheumatoid arthritis (OR: 14.2; 95% CI: 11.7-16.5), chronic alcohol use (OR: 4.3; 95% CI: 2.3-6.1), hypothyroidism (OR: 2.8; 95% CI: 1.3-4.2), and female gender (OR: 1.9; 95% CI: 1.1-2.2). CONCLUSIONS: Several modifiable risk factors of PWD were identified. Surgeons must be cognizant of these comorbidities and optimize patients' general health before an elective TJA. Our results demonstrated that PWD ceased in about 65% of the patients with local wound care measures alone. Patients with PWD were at substantially higher risk for PJI.

Clinical and Pathophysiologic Significance of MRI Identified Bone Marrow Lesions Associated with Knee Osteoarthritis.

Knee osteoarthritis (OA) affects the joint beyond just the articular cartilage. Specifically, magnetic resonance imaging-identified bone marrow lesions (BML) in the subchondral bone have both clinical and pathophysiological significance. Compared to joint space narrowing on traditional radiographs, the presence of BMLs has been better correlated with severity of clinical symptoms as well as clinical deterioration. Presence of a BML increases the likelihood for progression to a total knee arthroplasty by up to nine fold. Histochemical analysis of BMLs has shown increased levels of tumor necrosis factor-alpha, matrix metalloproteinases and substance P, thought to stimulate pain receptors in osteoarthritis. LEVEL OF EVIDENCE: V.

Arthroscopic-Assisted Reduction of Tibial Plateau Fractures.

Arthroscopic reduction of tibial plateau fractures have been gaining in popularity. Advantages include accurate diagnosis and treatment of joint pathology, minimally invasive soft tissue dissection, quicker recovery of joint motion, and anatomic reduction of joint surface. Success depends on accurate fracture selection. With arthroscopic-assisted reduction of tibial plateau fractures, patient set-up is similar to standard knee arthroscopy, but the C-arm is used to aid with fracture reduction and fixation. Outcomes are comparable or even improved when compared with standard procedures, and morbidity with arthroscopic reduction can often be lower with decreased rates of infection, wound complications, and thromboembolism.

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

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

The Leukocyte Esterase Test for Periprosthetic Joint Infection Is Not Affected by Prior Antibiotic Administration.

BACKGROUND: It has been demonstrated that administration of antibiotics prior to performing diagnostic testing for periprosthetic joint infection can interfere with the accuracy of the standard diagnostic tests. Therefore, the purpose of this study was to evaluate the effects of antibiotic administration prior to performing the synovial leukocyte esterase strip test for periprosthetic joint infection. METHODS: We identified 121 patients who underwent revision hip or knee arthroplasty for a Musculoskeletal Infection Society (MSIS)-confirmed periprosthetic joint infection. All patients also had a leukocyte esterase strip test performed. Patients in one group (32%) took antibiotics prior to the diagnostic workup, whereas patients in another group (68%) did not receive antibiotics within 2 weeks of the diagnostic workup. The leukocyte esterase strip test, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP), synovial white blood-cell (WBC) count, and polymorphonuclear neutrophil (PMN) percentage were collected and were compared between the 2 groups. RESULTS: The median serum ESR (85 compared with 67 mm/hr for patients who did not and did receive antibiotics; p = 0.009), CRP (16.5 compared with 12.9 mg/L; p = 0.032), synovial WBC count (45,675 compared with 9,650 cells/µL; p < 0.0001), and PMN percentage (93% compared with 88%; p = 0.004) were all significantly lower for patients receiving antibiotics. Furthermore, the administration of antibiotics resulted in a significant decrease in the sensitivity of all tests, except leukocyte esterase: ESR (79.5% in the antibiotics cohort compared with 92.7% in the no-antibiotics cohort [relative risk (RR) for false-negative results, 2.8; p = 0.04]), CRP (64.2% compared with 81.8% [RR, 1.9; p = 0.03]), WBC count (69.3% compared with 93.4% [RR, 5.0; p = 0.001]), PMN percentage (74.4% compared with 91.5% [RR, 3.0; p = 0.01]), and leukocyte esterase (78% compared with 83% [RR, 1.6; p = 0.17]). The rate of negative cultures was higher in the antibiotics group at 30.7% compared with the no-antibiotics group at 12.1% (p = 0.015). CONCLUSIONS: This current study and previous studies have demonstrated that the administration of premature antibiotics can compromise the results of standard diagnostic tests for periprosthetic joint infection, causing significant increases in false-negative results. However, in this study, the leukocyte esterase strip test maintained its performance even in the setting of antibiotic administration. Antibiotic administration prior to diagnostic workups for periprosthetic joint infection stands to interfere with diagnosis. The leukocyte esterase strip test can be used as a reliable diagnostic marker for diagnosing periprosthetic joint infection even when prior antibiotics are administered. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Acetabular Labral Tears Are Common in Asymptomatic Contralateral Hips With Femoroacetabular Impingement.

BACKGROUND: The number of patients undergoing hip arthroscopy for labral tears has increased, but labral tears are sometimes seen in asymptomatic patients with femoroacetabular impingement (FAI). The frequency of this finding, however, has not been well characterized nor is the proportion of patients with previously asymptomatic labral tears who may later become symptomatic. QUESTIONS/PURPOSES: The purpose of this study was to determine (1) the prevalence of labral tears and other intraarticular pathology in the asymptomatic contralateral hip of patients undergoing surgery for symptomatic FAI; (2) the likelihood that the asymptomatic hip had become symptomatic at latest followup; and (3) any association between MRI findings and age, sex, and body mass index (BMI) in both symptomatic and asymptomatic sides. METHODS: This study included patients who were diagnosed with unilateral symptomatic FAI between 2013 and 2015 and who had an available MRI of both hips. The study included 100 patients (47 females, 53 males) with a mean age of 33 years (range, 17-57 years). Patients with a symptomatic contralateral hip (n = 56) or an unsuitable MRI for review based on both reviewers' consensus (n = 344) were excluded. The MRI of both hips was independently evaluated by two orthopaedic surgeons and interobserver reliability tested. The interobserver reliability for the two surgeons' MRI ratings was almost perfect (κ ≥ 0.85). The presence of a labral tear, an acetabular chondral lesion, subchondral acetabular cysts, and fibrocystic changes in the femoral head-neck junction was documented for both hips. At latest followup, asymptomatic hips were investigated for any symptomatic labral tears or surgical procedures resulting from FAI. RESULTS: A labral tear was recorded in 97 (97%) and 96 (96%) of symptomatic hips, respectively, for each surgeon's evaluation. A labral tear was also detected in 41 (41%) and 43 (43%) of asymptomatic hips. In addition, an acetabular chondral lesion was detected in 32 (32%) and 35 (35%) of the symptomatic hips and 15 (15%) and 17 (17%) of the asymptomatic hips. At latest followup, nine of the patients were diagnosed with symptomatic labral tears in the contralateral asymptomatic hip and were treated. None of the radiologic parameters examined demonstrated an association with patient age, sex, or BMI in either symptomatic or asymptomatic hips. CONCLUSIONS: Labral tears and acetabular chondral lesions are common in the asymptomatic contralateral hip of patients undergoing surgery for FAI. The incidence of a symptomatic labral tear in these asymptomatic hips was 9% during 2 years of followup. We suggest that the decision to perform chondral or labral surgery in patients with FAI should be made with caution considering the relatively high prevalence of labral tears in asymptomatic hips and the low chance of development of symptoms. LEVEL OF EVIDENCE: Level IV, case-series study.

What are the incidence and risk factors of in-hospital mortality after venous thromboembolism events in total hip and knee arthroplasty patients?

BACKGROUND: Pulmonary embolism and deep vein thrombosis, together referred to as venous thromboembolism (VTE), are serious and potentially preventable complications after total hip arthroplasty and total knee arthroplasty. The aim of this study was to investigate the incidence of mortality after VTE events and assess the risk factors that are associated with it. METHODS: The Nationwide Inpatient Sample was used to estimate the total number of total hip arthroplasty, total knee arthroplasty, VTE events, and mortality using the International Classification of Diseases, Ninth Revision procedure codes from 2003 to 2012. Patients' demographics, Elixhauser, and Charlson comorbidity indices were used to identify the risk factors associated with in-hospital VTEs and mortality. RESULTS: A total of 1,805,621 THAs and TKAs were included. The overall rate of VTE was 0.93%. The in-hospital mortality rate among patients with VTEs was 7.1% vs 0.30% in patients without VTEs (P-value < .0001). The risk factors for mortality after VTE events in descending order were as follows: hypercoagulable state (odds ratio [OR]: 5.3, 95% confidence interval [CI]: 3.6-5.8), metastatic cancer (OR: 5.2, 95% CI: 3.3-5.6), myocardial infarction (OR: 4.2, 95% CI: 2.3-4.7), peripheral vascular disease (OR: 3.6, 95% CI: 3.2-4.0), cardiac arrhythmias (OR: 3.2, 95% CI: 1.6-4.3), advanced age (OR: 3.1, 95% CI: 2.3-3.7), electrolyte disorders (OR: 3.1, 95% CI: 2.2-3.6), pulmonary circulation disorders (OR: 2.9, 95% CI: 2.6-3.3), depression (OR: 2.8, 95% CI: 1.6-3.4), complicated diabetes (OR: 2.7, 95% CI: 2.1-3.2), weight loss (OR: 2.6, 95% CI: 2.2-3.3), renal failure (OR: 2.6, 95% CI: 1.7-3.5), chronic pulmonary disease (OR: 2.5, 95% CI: 1.3-3.1), valvular disease (OR: 2.4, 95% CI: 1.8-2.7), liver disease (OR: 1.7, 95% CI: 1.2-1.9), and obesity (OR: 1.6, 95% CI: 1.5-1.9). CONCLUSIONS: In-hospital VTE has a significant in-hospital mortality rate. Several of the identified risk factors in this study are modifiable preoperatively. We strongly urge the orthopaedic community to be cognizant of these risk factors and emphasize on optimizing patients' comorbidities before an elective arthroplasty.

Development and Evaluation of a Preoperative Risk Calculator for Periprosthetic Joint Infection Following Total Joint Arthroplasty.

BACKGROUND: Preoperative identification of patients at risk for periprosthetic joint infection (PJI) following total hip arthroplasty (THA) or total knee arthroplasty (TKA) is important for patient optimization and targeted prevention. The purpose of this study was to create a preoperative PJI risk calculator for assessing a patient's individual risk of developing (1) any PJI, (2) PJI caused by Staphylococcus aureus, and (3) PJI caused by antibiotic-resistant organisms. METHODS: A retrospective review was performed of 27,717 patients (12,086 TKAs and 31,167 THAs), including 1,035 with confirmed PJI, who were treated at a single institution from 2000 to 2014. A total of 42 risk factors, including patient characteristics and surgical variables, were evaluated with a multivariate analysis in which coefficients were scaled to produce integer scores. External validation was performed with use of data on 29,252 patients who had undergone total joint arthroplasty (TJA) at an independent institution. RESULTS: Of the 42 risk factors studied, 25 were found not to be significant risk factors for PJI. The most influential of the remaining 17 included a previous open surgical procedure, drug abuse, a revision procedure, and human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS). The areas under the curves were 0.83 and 0.84 for any PJI, 0.86 and 0.83 for antibiotic-resistant PJI, and 0.86 and 0.73 for S. aureus PJI in the internal and external validation models, respectively. The rates of PJI were 0.56% and 0.61% in the lowest decile of risk scores and 15.85% and 20.63% in the highest decile. CONCLUSIONS: In this large-cohort study, we were able to identify and validate risk factors and their relative weights for predicting PJI. Factors such as prior surgical procedures and high-risk comorbidities should be considered when determining whether TJA is indicated and when counseling patients. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.