Unusual Presentation of Hip Pain in a Pregnant Woman Due to Bilateral Cervical Neck Stress Fractures: A Case Report.

CASE: We present an unusual case of bilateral femoral neck fatigue fractures in a 28-year-old pregnant woman at the 18th week of gestation successfully treated through operative intervention involving consecutive total hip arthroplasty and internal fixation within the same procedure, resulting in favorable clinical outcomes. CONCLUSION: Current clinical practices suggest that a restricted use of plain radiographs, even those involving the pelvis in pregnant women carries a minimal risk to the fetus and is not contraindicated. Magnetic resonance imaging proved valuable for differential diagnosis, contrasting with sonography.

The Microbiome of Osteoarthritic Hip and Knee Joints: A Prospective Multicenter Investigation.

BACKGROUND: Recent advances in high-throughput DNA sequencing technologies have made it possible to characterize the microbial profile in anatomical sites previously assumed to be sterile. We used this approach to explore the microbial composition within joints of osteoarthritic patients. METHODS: This prospective multicenter study recruited 113 patients undergoing hip or knee arthroplasty between 2017 and 2019. Demographics and prior intra-articular injections were noted. Matched synovial fluid, tissue, and swab specimens were obtained and shipped to a centralized laboratory for testing. Following DNA extraction, microbial 16S-rRNA sequencing was performed. RESULTS: Comparisons of paired specimens indicated that each was a comparable measure for microbiological sampling of the joint. Swab specimens were modestly different in bacterial composition from synovial fluid and tissue. The 5 most abundant genera were Escherichia, Cutibacterium, Staphylococcus, Acinetobacter, and Pseudomonas. Although sample size varied, the hospital of origin explained a significant portion (18.5%) of the variance in the microbial composition of the joint, and corticosteroid injection within 6 months before arthroplasty was associated with elevated abundance of several lineages. CONCLUSIONS: The findings revealed that prior intra-articular injection and the operative hospital environment may influence the microbial composition of the joint. Furthermore, the most common species observed in this study were not among the most common in previous skin microbiome studies, suggesting that the microbial profiles detected are not likely explained solely by skin contamination. Further research is needed to determine the relationship between the hospital and a "closed" microbiome environment. These findings contribute to establishing the baseline microbial signal and identifying contributing variables in the osteoarthritic joint, which will be valuable as a comparator in the contexts of infection and long-term arthroplasty success. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Using machine learning to predict venous thromboembolism and major bleeding events following total joint arthroplasty.

Venous thromboembolism (VTE) and major bleeding (MBE) are feared complications that are influenced by numerous host and surgical related factors. Using machine learning on contemporary data, our aim was to develop and validate a practical, easy-to-use algorithm to predict risk for VTE and MBE following total joint arthroplasty (TJA). This was a single institutional study of 35,963 primary and revision total hip (THA) and knee arthroplasty (TKA) patients operated between 2009 and 2020. Fifty-six variables related to demographics, comorbidities, operative factors as well as chemoprophylaxis were included in the analysis. The cohort was divided to training (70%) and test (30%) sets. Four machine learning models were developed for each of the outcomes assessed (VTE and MBE). Models were created for all VTE grouped together as well as for pulmonary emboli (PE) and deep vein thrombosis (DVT) individually to examine the need for distinct algorithms. For each outcome, the model that best performed using repeated cross validation was chosen for algorithm development, and predicted versus observed incidences were evaluated. Of the 35,963 patients included, 308 (0.86%) developed VTE (170 PE's, 176 DVT's) and 293 (0.81%) developed MBE. Separate models were created for PE and DVT as they were found to outperform the prediction of VTE. Gradient boosting trees had the highest performance for both PE (AUC-ROC 0.774 [SD 0.055]) and DVT (AUC-ROC 0.759 [SD 0.039]). For MBE, least absolute shrinkage and selection operator (Lasso) analysis had the highest AUC (AUC-ROC 0.803 [SD 0.035]). An algorithm that provides the probability for PE, DVT and MBE for each specific patient was created. All 3 algorithms had good discriminatory capability and cross-validation showed similar probabilities comparing predicted and observed failures indicating high accuracy of the model. We successfully developed and validated an easy-to-use algorithm that accurately predicts VTE and MBE following TJA. This tool can be used in every-day clinical decision making and patient counseling.

Increased postoperative glycemic variability is associated with increased mortality in diabetic patients undergoing hip arthroplasty for hip fracture.

BACKGROUND: Increased glycemic variability (GV) during hospitalization has been associated with increased rates of surgical site and periprosthetic joint infections (PJI) following elective total joint arthroplasty. Uncertainty exists surrounding GV as a predictor for complications in urgent arthroplasty cases following hip fractures. In this study, we evaluated the association between GV and postoperative complications in diabetic patients undergoing total hip arthroplasty (THA) and hemiarthroplasty (HA) for hip fractures. METHODS: We analyzed data on 2421 consecutive patients who underwent THA or HA at our institution from 2011 to 2020. Patients with a known diagnosis of diabetes mellitus who had a minimum of three postoperative glucose values taken within the first week after surgery were included. GV was assessed using a coefficient of variation. Outcomes included short- and long-term mortality, reoperations, prosthetic joint infection (PJI) requiring revision and readmissions for any cause. RESULTS: The final cohort consisted of 482 patients (294 females, 188 males). Higher GV was associated with an increased 90-day mortality (p = 0.017). GV was not associated with 30-day mortality (p = 0.45), readmissions of any cause at 30 or 90 days (p = 0.99, p = 0.91, respectively), reoperation of any cause (p = 0.91) or PJI requiring revision surgery (p = 0.42). CONCLUSIONS: Higher GV in the postoperative period is associated with increased rates of mortality in diabetic patients following THA and HA for hip fractures. Efforts should be made to monitor and control glucose variability in the postoperative period.

The Use of Cement and Tourniquet During Total Knee Arthroplasty Does Not Increase the Risk of Venous Thromboembolism Postoperatively.

Background: Venous thromboembolism (VTE) is a severe complication of total knee arthroplasty (TKA). Cementation and the use of tourniquet during TKA have both been hypothesized to be risk factors of VTE. The purpose of our study was to determine if either of these surgical factors increases the risk of VTE in patients undergoing TKA. Methods: A single-institution, retrospective study was conducted, consisting of 16,972 patients undergoing a primary or revision TKA from 2008 to 2020. Of the total, 1020 patients were excluded from the tourniquet analysis as tourniquet data were unavailable. Clinical records were consulted to identify demographics, surgical variables, and outcomes. Queries of clinical notes and phone-call logs were conducted to capture VTE events following discharge. Statistical analysis consisted of univariate analysis, regression analysis, and propensity score matching. Results: Compared to patients who did not receive tourniquet, the patients with tourniquet did not demonstrate a significantly higher rate of VTE in the univariate analysis (1.00 vs 1.31, P = .132). Propensity score analysis also showed no difference between the 2 cohorts (1.10 vs 0.85, P = .306). Cemented patients similarly did not demonstrate an increased risk of VTE in either the univariate (1.26 vs 1.22, P = .895) or propensity score analysis (1.42 vs 1.26, P = .710) compared to cementless patients. Regression analysis, looking at the interaction between cement and tourniquet with VTE risk as the dependent variable, revealed neither to be risk factors for VTE (odds ratio 1.38, 95% confidence interval 0.63-3.08, P = .426). Conclusions: In our cohort, neither tourniquet nor cement was a significant risk factor for VTE following TKA.

Excessive Sagittal Slope of the Tibia Component during Kinematic Alignment-Safety and Functionality at a Minimum 2-Year Follow-Up.

The aim of this study was to assess the safety and functional outcomes of excessive sagittal alignment in the unrestricted kinematic alignment technique for total knee arthroplasty (TKA). A retrospective, single-center study was conducted between 2018 and 2020, including patients undergoing primary TKA with a minimum 2-year follow-up. EOS imaging conducted before and after surgery was reviewed for overall alignment, and a number of measurements were taken, including sagittal tibial slope and other tibia and femur component positioning. Patients were interviewed and asked to fill out several questionnaires including a visual analog scale, the Oxford Knee Score, and the Knee Injury and Osteoarthritis Outcome Score. Overall, 225 patients (66.7%) had a sagittal tibial slope angle above 5° (excessive) and 112 (33.3%) patients had an angle under 5° (moderate). A significant improvement in pain and function scores was observed in both groups following the surgery (p < 0.001). There were no significant differences between the moderate and excessive groups in the average VAS, OKS or the various subtypes of the KOOS score. However, there was a slight but significant difference in the number of patients achieving MCID in KOOS symptoms. There were no cases of early failure or loosening. Unrestricted KA and the excessive sagittal alignment of the tibial component seem to be reliable and safe in terms of restoring daily function and alleviating pain after a minimum of 2 years following the surgery.

Minimum 2-Year Radiographic and Clinical Outcomes of Unrestricted Kinematic Alignment Total Knee Arthroplasty in Patients with Excessive Varus of the Tibia Component.

Kinematic alignment (KA) total knee arthroplasty (TKA) has gained much attention in recent years. However, debate remains on whether restrictions should be made on the tibia cut. The purpose of this study was to assess the safety and functional outcomes of excessive varus cuts. A single-center, retrospective analysis of consecutive patients undergoing TKA between 2018 and 2020 who had a minimum 2-year follow-up was conducted. EOS™ imaging conducted before and after surgery was analyzed for overall alignment, as well as for tibia and femur component positioning on the coronal planes. Patients were interviewed and asked to fill several questionnaires, including the visual analog score, Oxford knee score, and knee injury and osteoarthritis outcome score. Overall, 243 patients (71.9%) had a coronal tibial plate angle under 5° (moderate) and 95 patients (28.1%) had an angle above 5° (excessive). There were no significant differences between the moderate and excessive groups in patient-reported outcomes, nor were there differences in the number of patients achieving the minimal clinical difference. There were no cases of catastrophic failure or loosening. Unrestricted KA and excessive varus of the tibial component appears to be safe and efficient in relieving pain and restoring function for a minimum of 2 years following surgery.

Minimum 2-Year Radiographic and Clinical Outcomes of Kinematic Alignment Total Knee Arthroplasty in the Valgus Knee.

Kinematic alignment (KA) total knee arthroplasty (TKA) has gained popularity in the past decade, but outcomes of KA-TKA in the valgus knee have never been specifically evaluated. In this retrospective single institution study, we analyzed patient reported outcomes and radiographic measurements at minimum 2 years following KA-TKA for valgus knees (n = 51) and compared the results to KA-TKA performed for non-valgus knees (n = 275). The same approach, technique, and implants were used in both groups without the need to release soft tissues or use constrained implants. Surgery duration was similar between groups (p = 0.353). Lateral distal femoral angle was lower in the valgus group postoperatively (p = 0.036). In both groups significant improvement was seen in relieving pain and improving function, while average scores were superior in the non-valgus group for visual analog score (p = 0.005), oxford knee score (p = 0.013), and knee injury and osteoarthritis outcome score (p = 0.009). However, these differences did not translate to statistically significant differences in minimal clinical important difference achievement rates. In conclusion, KA-TKA is efficient in relieving pain and improving function, as reported in subjective questionnaires, and holds advantage in patients with valgus alignment by avoiding soft tissue releases and use of constrained implants. Future studies should examine whether bone loss occurs in the lateral distal femur.

Serum Glucose Variability Increases the Risk of Complications Following Aseptic Revision Hip and Knee Arthroplasty.

BACKGROUND: Increased serum glucose variability has been proposed as a risk factor for perioperative morbidity and mortality. Given the greater surgical complexity and complication risk of revision total joint arthroplasty (TJA), previous findings may not be generalizable to the revision population. The purpose of this study was to investigate the association between glucose variability and postoperative complications following aseptic revision TJA. METHODS: We identified 1,983 patients who underwent an aseptic revision TJA (636 total knee arthroplasties [TKAs] and 1,347 total hip arthroplasties [THAs]) from 2001 to 2019. Patients with ≥2 postoperative glucose values per day or ≥3 values during hospitalization were included in this study. Glucose variability was assessed using the coefficient of variation (COV). Outcomes included length of hospital stay, 90-day complications, mortality, and periprosthetic joint infection (PJI) as defined by the 2018 International Consensus Meeting criteria. Multivariate regression was used to determine the association between glucose variability and each end point, using COV as continuous and categorical variables (that is, COV tertiles). RESULTS: Patients with high glycemic variability were at 1.7 times greater risk for 90-day complications (odds ratio [OR], 1.664 [95% confidence interval (CI), 1.266 to 2.188]; p < 0.001) and 2 times greater risk for PJI at a minimum 1-year follow-up (OR, 1.984 [95% CI, 1.270 to 3.100]; p = 0.003). The risk of 90-day complications increased by 2.2% (OR, 1.022 [95% CI, 1.012 to 1.032]; p < 0.001) and the risk of PJI increased by 1.8% (OR, 1.018 [95% CI, 1.003 to 1.034]; p = 0.013) for every percentage-point increase in COV. Patients with higher glucose variability also had a longer length of stay (beta, 1.028 days [95% CI, 0.590 to 1.466 days]; p < 0.001). These associations were independent of age, sex, body mass index, Charlson Comorbidity Index, involved joint, operative time, history of diabetes, and mean glucose levels. CONCLUSIONS: Higher glucose variability was associated with an increased risk of medical complications and PJI following aseptic revision TJA. Patients undergoing these complex procedures should have glucose levels monitored closely in the perioperative period. Future studies should evaluate the utility of continuous glucose monitoring in this high-risk population. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Aspirin May Be a Suitable Prophylaxis for Patients with a History of Venous Thromboembolism Undergoing Total Joint Arthroplasty.

BACKGROUND: In recent years, aspirin has become a popular agent for venous thromboembolism (VTE) prophylaxis following total joint arthroplasty (TJA). Yet patients with a history of VTE are often given more aggressive prophylactic agents because of their increased baseline risk. The purpose of this study was to assess whether aspirin is an effective prophylactic agent in patients with a history of VTE. METHODS: This was a single-institution, retrospective cohort study. The electronic clinical records of 36,333 patients undergoing TJA between 2008 and 2020 were reviewed. Data on demographic characteristics, comorbidities, intraoperative factors, and postoperative complications were collected. A propensity score-matched analysis was performed, as well as a multivariate regression analysis to account for confounders. RESULTS: Of the 36,333 patients undergoing TJA, 1,087 patients (3.0%) had a history of VTE and were not receiving chronic non-aspirin. The risk for subsequent VTE was significantly higher (p = 0.03) in patients with a history of VTE (1.4%) compared with patients without prior VTE (0.9%). However, the incidence of VTE was not significantly lower (p = 0.208) in patients with a history of VTE who received aspirin (0.4%) compared with patients who received other VTE prophylaxis (1.5%). Propensity score matching showed no difference in VTE rates between the 2 groups (2.2% compared with 0.55%; p = 0.372). In a regression analysis accounting for VTE risk, the administration of aspirin was not associated with an increased risk for subsequent VTE (adjusted odds ratio, 0.32 [95% confidence interval, 0.02 to 1.66]; p = 0.274). CONCLUSIONS: Our findings suggest that, although patients with a history of VTE have an increased baseline risk for subsequent VTE, aspirin may be a suitable VTE prophylaxis in this group of patients. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

An Enhanced Understanding of Culture-Negative Periprosthetic Joint Infection with Next-Generation Sequencing: A Multicenter Study.

BACKGROUND: The challenges of culture-negative periprosthetic joint infection (PJI) have led to the emergence of molecular methods of pathogen identification, including next-generation sequencing (NGS). While its increased sensitivity compared with traditional culture techniques is well documented, it is not fully known which organisms could be expected to be detected with use of NGS. The aim of this study was to describe the NGS profile of culture-negative PJI. METHODS: Patients undergoing revision hip or knee arthroplasty from June 2016 to August 2020 at 14 institutions were prospectively recruited. Patients meeting International Consensus Meeting (ICM) criteria for PJI were included in this study. Intraoperative samples were obtained and concurrently sent for both routine culture and NGS. Patients for whom NGS was positive and standard culture was negative were included in our analysis. RESULTS: The overall cohort included 301 patients who met the ICM criteria for PJI. Of these patients, 85 (28.2%) were culture-negative. A pathogen could be identified by NGS in 56 (65.9%) of these culture-negative patients. Seventeen species were identified as common based on a study-wide incidence threshold of 5%. NGS revealed a polymicrobial infection in 91.1% of culture-negative PJI cases, with the set of common species contributing to 82.4% of polymicrobial profiles. Escherichia coli, Cutibacterium acnes, Staphylococcus epidermidis, and Staphylococcus aureus ranked highest in terms of incidence and study-wide mean relative abundance and were most frequently the dominant organism when occurring in polymicrobial infections. CONCLUSIONS: NGS provides a more comprehensive picture of the microbial profile of infection that is often missed by traditional culture. Examining the profile of PJI in a multicenter cohort using NGS, this study demonstrated that approximately two-thirds of culture-negative PJIs had identifiable opportunistically pathogenic organisms, and furthermore, the majority of infections were polymicrobial. LEVEL OF EVIDENCE: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Synovial C-Reactive Protein is a Useful Adjunct for Diagnosis of Periprosthetic Joint Infection.

BACKGROUND: The diagnostic utility of synovial C-reactive protein (CRP) has been debated for a while. Existing studies are limited by small sample sizes and using outdated criteria for periprosthetic joint infection (PJI). Furthermore, the relationship between synovial and serum CRP has rarely been investigated in the setting of PJI. This study aimed to evaluate the diagnostic utility of synovial CRP and to assess its relationship with serum CRP and other common biomarkers. METHODS: We reviewed 621 patients who underwent evaluation for PJI prior to revision arthroplasty from 2014 to 2021. Biomarkers, including serum CRP and erythrocyte sedimentation rate, synovial CRP, polymorphonuclear leukocyte percentage, white blood cell count, and alpha-defensin, were evaluated using the 2018 International Consensus Meeting criteria. RESULTS: In total, 194 patients had a PJI; 394 were considered aseptic failures and 33 were inconclusive. Synovial CRP showed an area under the curve (AUC) of 0.951 (95% CI, 0.932-0.970) with 74.2% sensitivity and 98.0% specificity, whereas, serum CRP had an AUC of 0.926 (95% CI, 0.903-0.949) with 83.5% sensitivity and 88.3% specificity. There was a good correlation between synovial and serum CRP (R = 0.703; 95% CI, 0.604-0.785). The combination of serum and synovial CRP yielded a significantly higher AUC than that obtained when using serum CRP alone (AUC 0.964 versus 0.926, P = .016). CONCLUSION: Synovial CRP demonstrated excellent accuracy when used to determine the presence of PJI. There was a good correlation between serum and synovial CRP levels in revision arthroplasty patients and the combined use of serum and synovial CRP proved to be more accurate than the serum test alone. These findings support the use of synovial CRP as an adjunct in the workup of PJI.

For Patients With Acute PJI Treated With Debridement, Antibiotics, and Implant Retention, What Factors Are Associated With Systemic Sepsis and Recurrent or Persistent Infection in Septic Patients?

BACKGROUND: Periprosthetic joint infection (PJI) can lead to a severe systemic inflammatory response and may result in systemic sepsis. However, little is known about how often systemic sepsis may occur in patients with PJI, and whether sepsis is associated with a greater likelihood of persistent or recurrent PJI. QUESTIONS/PURPOSES: (1) Among patients who present with acute or acute hematogenous PJI and who were treated with debridement, antibiotics, and implant retention (DAIR), what proportion have sepsis and what factors are associated with a presentation with sepsis? (2) For patients presenting with sepsis, what factors are associated with persistent or recurrent PJI? METHODS: In all, 320 patients who underwent DAIR for the treatment of acute postoperative or acute hematogenous PJI between January 2000 and December 2019 were included in this study. Exclusion criteria were patients with other known sources of infection, such as pneumonia or urinary tract infections, which could contribute to systemic sepsis (6% [18 of 320]), patients with chronic PJI, and those with less than 6 months of follow-up (21% [66 of 320]). Our final cohort consisted of 236 patients presenting with an acute postoperative or acute hematogenous PJI who underwent an irrigation and debridement procedure. Sepsis was defined by the criteria for systemic inflammatory response syndrome (SIRS) or bacteria-positive blood culture results. Inclusion of patients with positive blood culture by organisms that caused their joint infection was important as all patients presented with fulminant acute infection of a prosthetic joint. Data, including vital signs, surgical variables, and treatment outcomes, were collected retrospectively through a chart review of an electronic medical record system. The statistical analysis comparing patients with sepsis versus patients without sepsis consisted of logistic regression to identify factors associated with sepsis. After confirming its ability to identify patients with a higher association with the development of sepsis through area under the curve models, a nomogram was generated to standardize our results from the regression, which was supported by the area under the curve model, to help readers better identify patients who are more likely to develop sepsis. RESULTS: A total of 44% (103 of 236) of patients had infections that met the criteria for sepsis. After controlling for confounding variables, including congestive heart failure, anemia, serum C-reactive protein (CRP), and the male sex, it was revealed that serum CRP (odds ratio 1.07 [95% confidence interval 1.04 to 1.11]; p < 0.001) and male sex (OR 1.96 [95% CI 1.03 to 3.81]; p = 0.04) were associated with the development of systemic sepsis. For patients presenting with sepsis, persistent or recurrent PJI were associated with an increased CRP level (OR 1.06 [95% CI 1.02 to 1.11]; p = 0.01) and number of prior surgical procedures on the joint (OR 2.30 [95% CI 1.21 to 4.89]; p = 0.02). CONCLUSION: Overall, our findings support that patients with systematic sepsis may benefit from two-stage revision rather than DAIR to decrease the bioburden more effectively, especially in those with methicillin-resistant Staphylococcus aureus and polymicrobial infections. High serum CRP levels and a history of prior surgical procedures on the involved joint should trigger prompt, aggressive surgical treatment if the patient's overall clinical status can tolerate such an intervention. LEVEL OF EVIDENCE: Level III, therapeutic study.

Time to Venous Thromboembolism Events Following Total Hip Arthroplasty: A Comparison Between Aspirin and Warfarin.

BACKGROUND: The attitude and approach of orthopedic community for minimizing venous thromboembolism (VTE) has evolved over the last decade with the trend toward use of aspirin (and mechanical modalities) in lieu of aggressive anticoagulation. The optimal length of VTE prophylaxis following total hip arthroplasty (THA) still remains unknown. This study aimed to determine the timing of VTE in patients who received aspirin compared to warfarin, and determine if 30 days of prophylaxis remain adequate. METHODS: This is a retrospective study of 18,003 patients undergoing primary and revision THA at a single institution between January 2008 and August 2020. During this time, our institution underwent a transition from the use of warfarin to aspirin as the main method for VTE prophylaxis. Symptomatic deep vein thrombosis and pulmonary embolism occurring within 90 days of surgery were identified from medical records and phone call logs. Aspirin and warfarin cohorts were matched to account for demographic and comorbidity differences. Timing of pulmonary embolism was determined based on either the date of diagnostic imaging or patient-provider phone calls confirming diagnosis. RESULTS: The cohorts included 46 patients in the warfarin group and 46 in the aspirin group. Time to VTE was significantly shorter in the warfarin group compared to aspirin (P = .021) with a median time to VTE of 3 days (interquartile range 2-14) and 10 days (interquartile range 4-19) respectively. Over 90% of the events occurred within 32 or 30 days of surgery in the warfarin and aspirin groups respectively. CONCLUSION: Based on the findings, a 30-day aspirin prophylaxis remains appropriate for patients undergoing THA.

Aspirin Administered for Venous Thromboembolism Prophylaxis May Protect Against Stiffness Following Total Knee Arthroplasty.

BACKGROUND: Aspirin has become the main agent for venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA). This study assessed whether aspirin is associated with less knee stiffness compared to warfarin and other chemoprophylaxis agents. METHODS: This is a retrospective review of all primary and revision TKAs performed between January 2009 and October 2020 at a high volume institution. Demographics, comorbidity data, and operative variables were extracted from medical records. VTE prophylaxis administered during this time period included aspirin, warfarin, and "others" (factor Xa, unfractionated heparin, low-molecular-weight heparin, fondaparinux, adenosine diphosphate receptor inhibitor, and direct thrombin inhibitor). The primary outcome assessed was manipulation under anesthesia (MUA) performed within 6 months of index surgery. Secondary outcome included major bleeding events. Univariate followed by multivariate regression analyses were performed. RESULTS: A total of 15,903 cases were included in the study, of which 531 (3.3%) patients developed stiffness that required MUA. The rates of MUA were 2.7% (251/9223) for patients receiving aspirin, 4.2% (238/5709) for patients receiving warfarin, and 4.3% (42/971) for all others (P's < .001). Multivariate regression analysis confirmed that aspirin is associated with lower rates of VTE compared to warfarin (adjusted odds ratio 1.423, 95% confidence interval 1.158-1.747, P < .001) and compared to other anticoagulation medications (adjusted odds ratio 1.742, 95% confidence interval 1.122-2.704, P = .013). Major bleeding events were also significantly lower in patients who received aspirin compared to the other 2 groups (P's = .001). CONCLUSION: Aspirin prophylaxis is associated with lower rates of MUA following TKA compared to warfarin and other VTE chemoprophylactic agents when grouped together.

Aspirin Thromboprophylaxis Is Associated With Less Major Bleeding Events Following Total Joint Arthroplasty.

BACKGROUND: There is ongoing debate on what is optimal prophylactic agent to reduce venous thromboembolism (VTE) following total joint arthroplasty (TJA). Although many studies assess the efficacy of these agents in VTE prevention, no attention is given to their adverse effect on major bleeding events (MBEs). This study compared the incidence of MBE in patients receiving aspirin as VTE prophylaxis vs other chemoprophylaxis. METHODS: A single-institution, retrospective study of 35,860 patients undergoing TJA between 2009 and 2020 was conducted. Demographic variables, co-morbidities, type of chemoprophylaxis, and intraoperative factors were collected. MBE was defined using the 2010 criteria for major bleeding in surgical patients presented by the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis. To enhance capture rate, comprehensive queries utilizing MBE keywords were conducted in clinical notes, physician dictations, and phone call logs. Univariate followed by multivariate regression was performed as well as propensity score matched analysis. RESULTS: Overall, 270 patients (0.75%) in this cohort developed MBE. The MBE rate was 0.5% in the aspirin group and 1.2% in the non-aspirin group. After adjusting for confounders, multiple logistic regression and propensity score matched analysis revealed almost 2 times lower odds of MBE in patients who received aspirin. Variables independently associated with increased MBE risk included increasing age, body mass index, American Society of Anesthesiologists score, revision surgery, peptic ulcer disease, coagulopathy, intraoperative blood transfusion, and active smoking. CONCLUSION: Administration of aspirin for VTE prophylaxis, compared to other chemoprophylaxis agents may have an association with lower risk of major bleeding following TJA. Future randomized controlled trials should examine these findings.

Dilute Povidone-Iodine Irrigation Reduces the Rate of Periprosthetic Joint Infection Following Hip and Knee Arthroplasty: An Analysis of 31,331 Cases.

BACKGROUND: Total joint arthroplasty (TJA) surgeons employ various strategies to reduce the risk of periprosthetic joint infection (PJI). Few studies have examined the efficacy of preclosure dilute povidone-iodine irrigation in a large cohort accounting for recent practice changes in TJA. This study compared the risk of PJI in TJA patients with and without dilute povidone-iodine irrigation. METHODS: This is a retrospective study of all consecutive primary TJAs between 2009 and 2019 at a single institution. We included 31,331 cases, of which 8659 were irrigated with dilute povidone-iodine and 22,672 were irrigated with sterile saline prior to closure. The primary endpoint was PJI as defined by 2018 International Consensus Meeting criteria with a minimum follow-up of 1 year. Multivariate logistic regression was used to determine the association between dilute povidone-iodine irrigation and PJI while controlling for demographics, comorbidities, and operative factors. RESULTS: In total, 340 patients (1.09%) developed PJI. Dilute povidone-iodine irrigation was associated with 2.34 times lower rate of PJI (0.6% vs 1.3%). Using multiple regression, dilute povidone-iodine remained significantly associated with a reduction in PJI. The absolute risk reduction was 0.73% and number needed to treat was 137 patients. Female gender, American Society of Anesthesiologists score, operative time, anesthesia type, prophylactic antibiotic type, and tranexamic acid were other significant factors in the regression model. CONCLUSION: The routine use of dilute povidone-iodine could prevent 1 PJI for every 137 TJA patients, regardless of their preoperative risk. These findings support the use of povidone-iodine irrigation as a safe and cost-effective measure to reduce PJI.

Mild radiographic osteoarthritis is associated with increased pain and dissatisfaction following total knee arthroplasty when compared with severe osteoarthritis: a systematic review and meta-analysis.

PURPOSE: The association between severity of radiographic osteoarthritis with patient pain, function, and satisfaction following total knee arthroplasty has been disputed. The discrepancies in current literature prompt us to further examine this association in a systematic review and meta-analysis. METHODS: The OVID-Medline, Embase, and Web of Science databases were searched from their inception up to Mar 2020. The main independent variable was osteoarthritis severity as defined by preoperative radiographs. The outcomes measured were pain, function and satisfaction following total knee arthroplasty. A minimum of three studies assessing the same patient-reported outcome measures were included in the meta-analysis, as well as those separating patients by chronic pain or dissatisfaction. RESULTS: 29 studies were included in this study. Significant heterogeneity was seen between radiographic evaluation and reported outcomes. Patients with only mild radiographic osteoarthritis were more likely to suffer from chronic pain (odds ratio = 2.45, 95% CI = 1.80-3.34, p < 0.001) and dissatisfaction (odds ratio = 2.43, 95% CI = 1.79-3.31, p < 0.001) compared to patients with severe osteoarthritis. A significant association was found between mild radiographic severity and lower total Western Ontario and McMaster Universities Osteoarthritis scores (95% CI = - 0.37-0.06, p = 0.006) as well as Knee Society Scores (CI: - 0.54-0.16, p < 0.001). CONCLUSION: Patients with mild radiographic osteoarthritis are anticipated to gain less from total knee arthroplasty compared to those with severe osteoarthritis. They are also at risk for chronic pain and dissatisfaction and should be consulted about this risk prior to surgery. LEVEL OF EVIDENCE: III.

Commercial Synovial Antibody Testing is No Better Than Traditional Culture in Identification of Pathogen(s) Causing Periprosthetic Joint Infection.

BACKGROUND: Identification of infective organism causing periprosthetic joint infections (PJIs) is crucial to tailor the best combination of surgical and antimicrobial treatment. Traditional culture, with all its limitations, has been utilized for this purpose. A synovial fluid antibody assay against some common pathogens has been introduced by a commercial entity recently. This study aimed to determine if the antibody testing could be used as a proxy to traditional culture, and whether it provided additional information, in the setting of PJI. METHODS: A retrospective study was conducted of patients who underwent revision total hip and knee arthroplasty between January 2019 and 2020. Aspirated synovial fluid was sent for analyses including the commercial antibody testing. All patients had samples harvested for culture per standard of care. Results of the antibody testing and culture, in terms of concordance, were compared. Receiver operating characteristic curve and Youden's criterion were used to compare the 2 methods. RESULTS: A total of 419 patients were included. Using the International Consensus Meeting criteria as reference standard for PJI, antibody testing had a sensitivity and specificity of 40.5% and 93.4%, respectively. There were 59.5% false negative results with antibody testing compared with 50% for culture. Of the 12 patients who had positive results in both tests, 5 (41.7%) had discordant pathogens identified in each test. CONCLUSION: Synovial fluid antibody testing does not provide clinical benefit when compared to traditional cultures for PJI diagnosis. The antibody testing had a low sensitivity and a high rate of discordance with culture, when both tests were positive.