The Otto Aufranc Award: Modifiable versus nonmodifiable risk factors for infection after hip arthroplasty

Is Preoperative Weight Reduction in Patients Who Have Body Mass Index ≥ 40 Associated With Lower Complication Rates After Primary Total Hip Arthroplasty?

BACKGROUND

Given the heightened risk of postoperative complications associated with obesity, delaying total hip arthroplasty (THA) in patients who have a body mass index (BMI) > 40 to maximize preoperative weight loss has been advocated by professional societies and orthopaedic surgeons. While the benefits of this strategy are not well-understood, previous studies have suggested that a 5% reduction in weight or BMI may be associated with reduced complications after THA.

METHODS

We identified 613 patients who underwent primary THA in a single institution during a 7-year period and who had a BMI >40 recorded from 9 to 12 months prior to surgery. Subjects were stratified into 3 cohorts based on whether their baseline BMI decreased by >5% (147 patients, 24%), was unchanged ( ± 5%) (336 patients, 55%), or increased by >5% (130 patients, 21%) on the day of surgery. The frequency of 90-days Hip Society and Centers for Medicare & Medicaid Services complications was compared between these cohorts. There were significant baseline differences between the cohorts with respect to baseline American Society of Anesthesiologists class (P < .001) and hemoglobin A1C (P = .011), which were accounted for in a multivariate regression analysis.

RESULTS

In univariate analysis, there was a lower incidence of readmission (P = .025) and total complications (P = .005) in the increased BMI cohort. The overall complication rate was 18.4% in the decreased BMI cohort, 17.6% in the unchanged cohort, and 6.2% in the increased cohort. However, multivariable regression analysis controlling for potential confounders did not find that preoperative change in BMI was associated with differences in 90-days complications between cohorts (P > .05).

CONCLUSIONS

Patients who have a BMI >40 and achieved a clinically significant (>5%) BMI reduction prior to THA did not have a lower risk of 90-days complications or readmissions. Thus, delaying THA in these patients to encourage weight loss may result in restricting access to a beneficial surgery without an appreciable safety benefit.

Smoking is not closely related to revision for periprosthetic joint infection after primary total knee and hip arthroplasty

BACKGROUND

The influence of smoking on the risk of periprosthetic joint infection (PJI) remains unclear. The objective was to explore the impact of smoking on PJI after primary total knee (TKA) and hip (THA) arthroplasty.

HYPOTHESIS

Current smoking patients should have an increased risk of PIJ compared with nonsmoking patients.

PATIENTS AND METHODS

A prospective registry-based observational cohort study was performed. A total of 4591 patients who underwent primary TKA (3076 patients) or THA (1515) were included. According to the smoking status at the time of arthroplasty, patients were classified as nonsmokers (3031 patients), ex-smokers (688), and smokers (872). Multivariate analysis included smoking status, age, gender, education level, body mass index, American Society of Anesthesiologists class, diagnosis (osteoarthritis, rheumatism), diabetes, chronic obstructive pulmonary disease, perioperative blood transfusion, site of arthroplasty (knee, hip), length of operation, and length of stay.

RESULTS

There were PJI after 59 (1.9%) TKA and 27 (1.8%) THA (p=0.840). There were PJI in 47 (1.6%) nonsmokers, 12 (1.7%) ex-smokers, and 17 (1.9%) smokers (p=0.413). There were wound complications (delayed wound healing and superficial wound infection) in 34 (0.7%) nonsmokers, 9 (1.3%) in ex-smokers, and 17 (1.9%) in smokers (p=0.045). In multivariate analysis, only the female gender was a significant predictor of PJI (OR 1.3, 95% CI 1.1-2.4 [p=0.039]). Specifically, the categories of ex-smokers (OR 0.8, 95% CI 0.2-1.7 [p=0.241]) and smokers (OR 1.1, 95% CI 0.6-1.5 [p=0.052]) were not significant predictors. The 4-year arthroplasty survival with PJI as the endpoint was 99.1% (95% CI: 99.0-99.7) for nonsmokers, 99.0% (95% CI: 98.8-99.2) for ex-smokers, and 98.7% (95% CI: 98.2-99.0) for smokers was not significantly different between smoking status groups (p=0.318).

DISCUSSION

Smoking was not identified as a significant predictor for PJI following primary TKA or THA.

LEVEL OF EVIDENCE

III, prospective cohort study.

Greater Risk of Periprosthetic Joint Infection Associated with Prolonged Operative Time in Primary Total Knee Arthroplasty: Meta-Analysis of 427,361 Patients

Background/Objectives: Periprosthetic joint infection (PJI) is a severe complication in total knee arthroplasty (TKA) with catastrophic outcomes. The relationship between prolonged operative times and PJI remains debated. This meta-analysis investigated the link between prolonged operative times and the risk of PJI in primary TKA. Methods: A comprehensive search of the MEDLINE/PubMed, Cochrane Library, and EMBASE databases was conducted to identify studies comparing the incidence of PJI in TKAs with prolonged versus short operative times, as well as those comparing operative times in TKAs with and without PJI. Pooled standardized mean differences (SMD) in operative times between groups with and without PJI or surgical site infections (SSI), including superficial SSIs and PJIs, were analyzed. Additionally, the pooled odds ratios (OR) for PJI in TKAs with operative times exceeding 90 or 120 min were examined. Results: Seventeen studies involving 427,361 patients were included. Significant differences in pooled mean operative times between the infected and non-infected TKA groups were observed (PJI, pooled SMD = 0.38, p < 0.01; SSI, pooled SMD = 0.72, p < 0.01). A higher risk of PJI was noted in surgeries lasting over 90 or 120 min compared to those of shorter duration (90 min, pooled OR = 1.50, p < 0.01; 120 min, pooled OR = 1.56, p < 0.01). Conclusions: An association between prolonged operative time and increased risk of PJI in primary TKA has been established. Strategies for infection prevention should encompass thorough preoperative planning aimed at minimizing factors that contribute to prolonged operative times.

The Effect of American Society of Anesthesiologists Score and Operative Time on Surgical Site Infection Rates in Major Abdominal Surgeries

BACKGROUND

The objective of this study was to evaluate the influence of two crucial variables, the American Society of Anesthesiologists (ASA) score and operative time, on the occurrence of surgical site infections (SSIs) in the context of major abdominal surgical procedures.

METHODOLOGY

A cross-sectional research study involved patients undergoing various gastrointestinal surgical procedures. Surgical details, procedure duration, and ASA score were meticulously documented. Patients were observed for surgical site infections (SSIs) during their inpatient stay until discharge. Following their discharge, patients were monitored in the outpatient department for a minimum of 30 days post-surgery, and those who underwent mesh procedures were observed for one year.

RESULTS

In the overall study population, surgical site infections were identified in 42 cases, constituting 6.7%. There was a significant association between ASA grade and the incidence of surgical site infections (p=0.001), indicating a higher prevalence of infections in cases with elevated ASA grades. Furthermore, a statistically significant association exists between the average duration of surgery and the occurrence of surgical site infections (p=0.001). The mean surgery duration for cases with infections is reported as 206.33 min, with a standard deviation of 103.73, while for cases without infections, the mean duration is 99.72 min, with a standard deviation of 79.71. In the multivariate analysis, it was found that an ASA score of 3 or higher and operative time exceeding 90 min were identified as independent factors for predicting the likelihood of surgical site infections.

CONCLUSION

 The significant associations identified between the American Society of Anesthesiologists (ASA) grade, average surgery duration, and SSIs underscore the importance of comprehensive preoperative assessment and procedural management in infection prevention.

Intraarticular vancomycin decreased the risk of acute postoperative periprosthetic joint infection without increasing complication in primary total joint arthroplasty-a prospective study

OBJECTIVES

To investigate the preventive effect of intraarticularly administered vancomycin on acute postoperative periprosthetic joint infection (PJI) in total joint arthroplasty (TJA).

METHODS

Consecutive patients who underwent unilateral primary TJA were prospectively enrolled. The patients were divided into vancomycin group and control group according to whether 1 g of vancomycin powder suspended in 30 ml normal saline was intraarticularly administered after arthrotomy closure. Acute postoperative PJI and aseptic wound complication were evaluated within 3 months postoperatively. Vancomycin-associated toxicity including acute renal failure, ototoxicity and anaphylaxis was also evaluated.

RESULTS

In terms of demographic parameters and comorbidities, no significant difference was found between the two groups. Intra-articular vancomycin significantly lowered the risk of acute postoperative PJI after primary TJA (P = 0.015) and primary total knee arthroplasty (P = 0.031). However, for patients who underwent total hip arthroplasty, the PJI rate was comparable between the two groups. Overall, the risk of aseptic wound complication between the two groups was also similar. Vancomycin-associated acute renal injury, ototoxicity, or anaphylaxis was not observed.

CONCLUSIONS

Intra-articular injection of 1 g of vancomycin suspension after arthrotomy closure during TJA lowered the risk of acute postoperative PJI without increasing the risk of aseptic wound complication and vancomycin-associated systemic toxicity.

Go Big or Go Home: Obesity and Total Joint Arthroplasty

Obesity is highly prevalent, and it is expected to grow considerably in the United States. The association between obesity and an increased risk of complications following total joint arthroplasty (TJA) is widely accepted. Many believe that patients with body mass index (BMI) >40 have complications rates that may outweigh the benefits of surgery and should consider delaying it. However, the current literature on obesity and outcomes following TJA is observational, very heterogeneous, and full of confounding variables. BMI in isolation has several flaws and recent literature suggests shifting from an exclusively BMI <40 cutoff to considering 5 to 10% preoperative weight loss. BMI cutoffs to TJA may also restrict access to care to our most vulnerable, marginalized populations. Moreover, only roughly 20% of patients instructed to lose weight for surgery are successful and the practice of demanding mandatory weight loss needs to be reconsidered until convincing evidence exists that supports risk reduction as a result of preoperative weight loss. Obese patients can benefit greatly from this life-changing procedure. When addressing the potential difficulties and by optimizing preoperative assessment and intraoperative management, the surgery can be conducted safely. A multidisciplinary patient-centered approach with patient engagement, shared decision-making, and informed consent is recommended.

The Use of Oral Antibiotics After Total Joint Arthroplasty: A Critical Analysis Review

» There is conflicting and insufficient evidence that extended oral antibiotic (EOA) therapy prevents infection in high-risk patients undergoing primary total joint arthroplasty (TJA), limiting recommendation for or against the practice.» In the case of aseptic revision TJA, the evidence is also conflicting and limited by underlying confounders, preventing recommendation for use of EOA.» There is fair evidence that use of EOA after debridement antibiotic therapy and implant retention of the prosthesis prolongs infection-free survival, but randomized controlled trials are needed. On the other hand, there is strong evidence that patients undergoing 2-stage revision should receive a period of suppressive oral antibiotics after the second stage.» The optimal duration of EOA in primary TJA, aseptic revision, and debridement antibiotic therapy and implant retention of the prosthesis is unknown. However, there is strong evidence that 3 months of EOA suppression may be appropriate after reimplantation as part of 2-stage exchange arthroplasty.» Complications secondary to EOA are reported to be between 0% and 13.7%, yet are inconsistently reported and poorly defined. The risks associated with antibiotic use, including development of antimicrobial resistance, must be weighed against a possible decrease in infection rate.

Super-obese patients are associated with significant infection burden after total hip arthroplasty

INTRODUCTION

Over ⅓ of the population in the United State is obese (body mass index [BMI] >30 kg/m2), with an increasing proportion being morbidly obese (BMI >40 kg/m2). As the obesity rate climbs, an increasing number have entered the super-obese category (BMI >50 kg/m2), theoretically increasing risk for complications after total hip arthroplasty (THA). This study compared complications in non-obese, obese, morbidly obese, and super-obese patients undergoing THA. We specifically assessed: (1) 1- and 2-year peri-prosthetic joint infection (PJI) rates; (2) complication rates; as well as (3) 1- and 2-year revision rates.

METHODS

A database review identified patients undergoing primary THA from 01 January 2010 to 31 December 2019. Patients were stratified based on the presence of International Classification of Diseases, 9th and 10th revision diagnosis codes of non-obese (BMI <30 kg/m2) (n = 8680), obese (BMI <40 kg/m2) (n = 12,443), morbidly obese (BMI <50 kg/m2) (n = 5250), and super-obese (BMI >50 kg/m2) (n = 814) prior to THA. Complication rates at 90 days, 1 year, and 2 years were compared across groups.

RESULTS

At all time points, super-obese patients were associated with higher rates of PJI, even when compared to morbidly obese patients. Complications such as sepsis, venous thrombo-embolism, and revision surgeries were found in higher numbers in super-obese as well as morbidly obese patients, compared to obese and non-obese patients.

CONCLUSIONS

This study provides large-scale analyses demonstrating the association between super-obese and morbidly obese patients and higher infection rates, as well as complications, following THA. Importantly, the association of PJI is highest among super-obese patients, even when compared to morbidly obese patients. Attaining a BMI <40 kg/m2 prior to surgery may be an important goal discussed with patients to lower the chance of postoperative infections.

Treating Hepatitis C Prior to Total Hip Arthroplasty is Cost Effective: A Markov Analysis

INTRODUCTION

Patients infected with the hepatitis C virus (HCV) have high complication rates following total hip arthroplasty (THA). Advances in HCV therapy now enable clinicians to eradicate the disease, however, its cost effectiveness from an orthopaedic perspective remains to be demonstrated. We sought to conduct a cost effectiveness analysis comparing no therapy to direct acting antiviral therapy (DAA) prior to THA among HCV positive patients.

METHODS

A Markov model was utilized to evaluate the cost-effectiveness of treating HCV with DAA prior to THA. The model was powered with event probabilities, mortality, cost and quality adjusted life-year values for patients with and without HCV that were obtained from the published literature. This included treatment costs, successes of HCV eradication, incidences of superficial or periprosthetic joint infection (PJI), probabilities of utilizing various PJI treatment modalities, PJI treatment success/failures, and mortality rates. The incremental cost-effectiveness ratio (ICER) was compared to a willingness-to-pay threshold of $50,000/QALY.

RESULTS

Our Markov model indicates that in comparison to no therapy, DAA prior to THA is cost-effective for HCV positive patients. THA in the setting of no therapy and DAA added 8.06 and 14.39 QALYs at a mean cost of $28,800 and $115,800. The ICER associated with HCV DAA in comparison to no therapy was $13,800/QALY, below the willingness-to-pay threshold of $50,000/QALY.

CONCLUSION

Hepatitis-C treatment with DAA prior to THA is cost-effective at all current drug list prices. Given these findings, strong consideration should be given to treating patients for HCV prior to elective THA.

Hospital Readmissions After Total Joint Arthroplasty: An Updated Analysis and Implications for Value-Based Care

BACKGROUND

While risk factors have been published for readmissions following primary total joint arthroplasty, little is known about the etiology of those costly adverse events. In this study, we sought to identify the reasons for 30-day readmission following primary total joint arthroplasty in a contemporary national patient sample.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify 367,199 patients who underwent primary total knee (TKA) or hip arthroplasty (THA) between 2011 and 2018. The primary outcomes were the annual rates of 30-day readmissions and the causes of those readmissions.

RESULTS

The 30-day readmission rate trended downward from 4.5% in 2011 to 3.3% in 2018. Medical complications accounted for 52.6% and 38.5% of readmissions following TKA and THA, respectively. Diseases of the circulatory system, abnormal laboratory values, and diseases of the digestive system were the leading causes of medical readmissions. Surgical complications accounted for 37.7% and 50.7% of readmissions following TKA and THA, respectively. Surgical site infections/wound disruption and venous thromboembolism were the leading two causes of surgical readmissions for THA and TKA. Prosthetic complications-namely dislocations and periprosthetic fractures-were the third leading cause of surgical readmissions for THA. For TKA, musculoskeletal conditions-namely pain and hematoma-were the third leading cause of surgical readmissions.

CONCLUSION

Medical complications accounted for half of all TKA readmissions and more than a third of THA readmissions. This could penalize institutions participating in value-based payment programs or dissuade others who are considering participation in such programs.

Debridement, antibiotics and implant retention for prosthetic joint infection: comparison of outcomes between total hip arthroplasty and hip resurfacing

INTRODUCTION

The management of prosthetic joint infection (PJI) has been widely studied in the context of total hip arthroplasty (THA). However, the outcomes of debridement, antibiotics and implant retention (DAIR) for PJI have never been compared between hip resurfacing arthroplasty (HRA) and THA. This led us to carry out a retrospective case-control study comparing the surgical treatment of post-operative infections between HRA and THA to determine the infection remission rate and the medium-term functional outcomes.

METHODS

This single-centre case-control study analysed 3056 HRA cases of which 13 patients had a PJI treated by DAIR. These patients were age-matched with 15 infected THA hips treated by DAIR and modular component exchange (controls). Their survival (no recurrence of the infection) was compared and factors that could affect the success of the DAIR were explored: sex, body mass index, age at surgery, presence of haematoma, type of bacteria present and antibiotic therapy.

RESULTS

At a mean follow-up of five years (2-7), the infection control rate was significantly higher in the HRA group (100% [13/13]) than in the THA group (67% [10/15]) (p = 0.044). More patients in the THA group had undergone early DAIR (< 30 days) (73% [11/15]) than in the HRA group (54% [7/13]). There was no significant difference between the two groups in the ASA score, presence of comorbidities, body mass index and duration of the initial arthroplasty procedure. At the review, the Oxford-12 score of 17/60 (12-28) was better in the HRA group than the score of 25/60 (12-40) in the THA group (p = 0.004).

CONCLUSION

DAIR, no matter the time frame, is a viable therapeutic option for infection control after HRA.

Decrease in acute periprosthetic joint infections incidence with vancomycin-loaded calcium sulfate beads in patients with non-modifiable risk factors. A randomized clinical trial

OBJECTIVES

The influence of local antibiotic therapy in orthopedic surgery remains unclear. In this trial, we evaluated the incidence of periprosthetic joint infections (PJI), after local or intravenous (IV) antibiotic prophylaxis. The aim of this intervention was to compare the PJI incidence in a population with non-modifiable risk factors after local prophylaxis with vancomycin-loaded calcium sulfate beads versus a control group.

METHODS

A total of 83 subjects were evaluated, inclusion criteria included participants over 60 years of age, with at least one main risk factor for PJI who underwent total hip or knee joint replacement between June 2019 and May 2020. Cases were randomized, and the intervention group received local prophylactic antibiotic therapy with calcium sulfate beads impregnated with vancomycin; conventional IV prophylactic antibiotic therapy was administered for the control group. C-reactive protein (CRP) and erythrocyte sedimentation rate (ERS) serum biomarkers were analyzed on the day 5 and weeks 4, 8, and 12. When needed, the synovial fluid sample was obtained and cultured for the early acute PJI diagnosis.

RESULTS

Acute PJI was found in 27 patients (67.5%) in the control group and 4 (9.3%) in the intervention group. The variable analysis identified that local prophylaxis with calcium sulfate beads reduces the incidence of acute knee or hip PJI in patients with non-modifiable risk factors compared to conventional prophylaxis (p < 0.0001) with a relative risk of 0.13 (CI:0.05-0.35). Length of hospital stay was also shorter in the intervention group at 4.6 days, compared to 15.25 days in the control group; p < 0.001.

CONCLUSIONS

Local antibiotic prophylaxis in patients with non-modifiable risk factors undergoing hip or knee replacement reduces the incidence of acute PJI compared to IV antibiotics.

CLINICAL TRIALS

NCT03976466 (clnicaltrials.gov) LEVEL OF EVIDENCE: II.

Utility of synovial calprotectin lateral flow test to exclude chronic prosthetic joint infection in periprosthetic fractures: a prospective cohort study

The diagnosis of periprosthetic joint infection (PJI) requires a combination of various clinical, laboratory, microbiological and histopathological parameters. A concomitant periprosthetic fracture (PPF) further complicates the diagnosis as it causes a confounding local inflammatory response. Synovial calprotectin has been demonstrated as a promising biomarker of PJI. The purpose of the present study was to evaluate the reliability of synovial calprotectin for the pre- or intraoperative diagnosis of PJI in PFF. 30 patients with PPF and implant loosening were included in this prospective study. Synovial fluid with white blood cells and percentage of polymorphonuclear neutrophils, serum C-reactive protein, and synovial calprotectin using a lateral-flow assay were tested against the EBJIS definition with adjusted thresholds to account for the local inflammation. 14 patients were postoperatively classified as confirmed infections (ten total hip arthroplasties and fourtotal knee arthroplasties). The calprotectin assay yielded a sensitivity of 0.71 [0.48; 0.95], a specificity of 0.69 [0.46; 0.91], a positive predictive value of 0.67 [0.43; 0.91] and a negative predictive value of 0.73 [0.51; 0.96]. Calprotectin is a promising diagnostic parameter for the detection of a PJI in a PPF. The lateral flow assay offers prompt results, which may further assist the surgeon in addition to already existing parameters of PJI diagnostics to diagnose concomitant PJI in PPF during surgery.

Patient-related factors associated with superficial surgical site infection and progression to a periprosthetic joint infection after elective primary total joint arthroplasty: a single-centre, retrospective study in Sweden

OBJECTIVES

Superficial surgical site infection (SSSI) may increase the risk of serious complications such as periprosthetic joint infection (PJI). This study aims to identify patient-related risk factors associated with SSSI and investigate their correlation with the progression of PJI.

DESIGN

In this retrospective study, 1191 elective hip and knee prostheses were included. Patients were interviewed 3-5 months after surgery to answer questions about the postoperative period. Patient records were reviewed to determine whether there had been any documentation of wound-healing difficulties or whether antibiotics were prescribed to treat an infection related to arthroplasty surgery.

SETTING

Uppsala University Hospital, patients treated between November 2008 and December 2012.

PARTICIPANTS

The study population comprised 433 knees and 758 hips.

OUTCOME MEASURES

We studied patient-related risk factors (joint, age, sex, the American Society of Anesthesiologists (ASA) classification, body mass index (BMI), smoking, diabetes and rheumatic disease) to determine whether they were associated with (1) SSSI and (2) the progress from SSSI to PJI.

RESULTS

84 (7%) patients of the total cohort developed SSSI. This infection progressed to a PJI in 24 (29%) of the patients. Factors with increased adjusted risk ratios (aRRs) for SSSIs were knee surgery (1.7; 95% CI: 1.1 to 2.7), age≥65 years (1.7; 95% CI: 1.1 to 2.8), BMI≥30 (1.9; 95% CI: 1.0 to 3.4) and ASA classification≥3 (1.7; 95% CI: 1.0 to 2.9). ASA classification≥3 was the only factor showing a significant progression from SSSI to PJI (aRR=3.3; 95% CI: 1.0 to 10.3).

CONCLUSIONS

The risk of progressing from an SSSI to a PJI is high. Older patients, patients with obesity, and those with a high ASA classification considered for elective total knee arthroplasty seem to have an increased risk of developing SSSI. Patients with a high ASA classification seem to have an increased risk of progressing from SSSI to PJI.

Preoperative Patient Optimization in Total Joint Arthroplasty-The Paradigm Shift from Preoperative Clearance: A Narrative Review

Background: Total joint arthroplasty (TJA) is one of the most common procedures performed in the United States. Outcomes of this elective procedure may be improved via preoperative optimization of modifiable risk factors. Purposes: We sought to summarize the literature on the clinical implications of preoperative risk factors in TJA and to develop recommendations regarding preoperative optimization of these risk factors. Methods: We searched PubMed in August 2019 with an update in September 2020 for English-language, peer-reviewed publications assessing the influence on outcomes in total hip and knee replacement of 7 preoperative risk factors-obesity, malnutrition, hypoalbuminemia, diabetes, anemia, smoking, and opioid use-and recommendations to mitigate them. Results: Sixty-nine studies were identified, including 3 randomized controlled trials, 8 prospective cohort studies, 42 retrospective studies, 6 systematic reviews, 3 narrative reviews, and 7 consensus guidelines. These studies described worse outcomes associated with these 7 risk factors, including increased rates of in-hospital complications, transfusions, periprosthetic joint infections, revisions, and deaths. Recommendations for strategies to screen and address these risk factors are provided. Conclusions: Risk factors can be optimized, with evidence suggesting the following thresholds prior to surgery: a body mass index <40 kg/m², serum albumin ≥3.5 g/dL, hemoglobin A1C ≤7.5%, hemoglobin >12.0 g/dL in women and >13.0 g/dL in men, and smoking cessation and ≥50% decrease in opioid use by 4 weeks prior to surgery. Surgery should be delayed until these risk factors are adequately optimized.

Comparison of dynamic and static spacers for the treatment of infections following total knee replacement: a systematic review and meta-analysis

Background

Revision surgery is the most common treatment for patients who develop infection after total knee arthroplasty (TKA). Two types of spacers are often used in revision surgery: dynamic spacers and static spacers. The comparative efficacy of these two types of spacers on knee prosthesis infections is not well established. Therefore, we carried out a systematic evaluation and meta-analysis with the aim of comparing the difference in efficacy between dynamic and static spacers.

Methods

We conducted the literature search in PubMed, Web of Science, Cochrane Library, and Embase databases. The articles searched were clinical study comparing the difference in efficacy between dynamic spacers and static spacers for the treatment of prosthetic infections occurring after total knee arthroplasty.

Results

We conducted a literature search and screening based on the principles of PICOS. Ultimately, 14 relevant clinical studies were included in our current study. We use infection control rate as the primary evaluation indicator. The KSS knee scores (KSSs), KSS functional scores, bone loss and range of motion (ROM) are secondary indicators of evaluation. Thirteen of these included studies reported the infection control rates, with no significant difference between dynamic and static shims (RR: 1.03; 95% Cl 0.98, 1.09; P = 0.179 > 0.05). The KSSs were reported in 10 articles (RR: 5.98; 95% CI 0.52, 11.43; P = 0.032 < 0.05). Six articles reported the KSS functional scores (RR: 13.90; 95% CI 4.95, 22.85; P = 0.02 < 0.05). Twelve articles reported the ROM (RR: 17.23. 95% CI 10.18, 24.27; P < 0.0001). Six articles reported the bone loss (RR: 2.04; 95% CI 1.11, 3.77; P = 0.022 < 0.05).

Conclusion

Current evidence demonstrates that dynamic spacers are comparable to static spacers in controlling prosthetic joint infection. In terms of improving the functional prognosis of the knee joint, dynamic spacers are more effective than static spacers.

Scientometric Analysis of the Top 50 Most-Cited Joint Arthroplasty Papers: Traditional vs Altmetric Measures

Background

Material and methods

Results

Conclusion

Are Body Mass Index Cutoffs Creating Racial, Ethnic, and Gender Disparities in Eligibility for Primary Total Hip and Knee Arthroplasty?

BACKGROUND

Unabated increases in the prevalence of obesity among American adults have disproportionately affected women, Black persons, and Hispanic persons. The purpose of this study was to evaluate for disparity in rates of patient eligibility for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on race and ethnicity and gender by applying commonly used body mass index (BMI) eligibility criteria to two large national databases.

METHODS

We retrospectively reviewed data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for the years 2015-2019 for primary THA and TKA and the National Health and Nutrition Examination Survey (NHANES) from 2011-2018. Designations of race and ethnicity were standardized between cohorts. BMI cutoffs of <50 kg/m², <45 kg/m², <40 kg/m², and <35 kg/m² were then applied. Rates of eligibility for surgery were examined for each respective BMI cutoff and stratified by age, race and ethnicity, and gender.

RESULTS

143,973 NSQIP THA patients, 242,518 NSQIP TKA patients, and 13,255 NHANES participants were analyzed. Female patients were more likely to be ineligible for surgery across all cohorts for all modeled BMI cutoffs (P < .001 for all). Black patients had relatively lower rates of eligibility across all cohorts for all modeled BMI cutoffs (P < .0001 for all). Hispanic patients had disproportionately lower rates of eligibility only at a BMI cutoff of <35 kg/m².

CONCLUSION

Using BMI cutoffs alone to determine the eligibility for primary THA and TKA may disproportionally exclude women, Black persons, and Hispanic persons. These data raise concerns regarding further disparity and restriction of arthroplasty care to vulnerable populations that are already marginalized.

LEVEL OF EVIDENCE

Retrospective Cohort Study, Level III.

Extended Postoperative Prophylactic Antibiotics for Primary and Aseptic Revision Total Joint Arthroplasty: A Systematic Review

INTRODUCTION

Limited literature is available about the effects of extended (>24 hours) antibiotic use after primary and aseptic revision total joint arthroplasty (TJA) on rates of periprosthetic joint infection (PJI). The purpose of this study was to systematically review the outcomes of extended prophylactic antibiotic use.

METHODS

A systematic search on PubMed and EMBASE databases was done in August 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Articles that met inclusion criteria were screened by two separate authors. Basic patient demographics, route of delivery, type, dose, frequency of the antibiotic, rates of PJI, and length of stay were extracted.

RESULTS

A total of 11 articles published from 1979 to 2021 were included in the final analysis. Two studies evaluated aseptic revisions, seven evaluated primary TJA, and two studies evaluated both. Five studies were randomized controlled trials, one multicenter nonrandomized trial, and five retrospective cohort studies. All 11 studies used a cephalosporin or a penicillin antibiotic in both the control and cohort groups. Five studies used intravenous (IV) antibiotics, one study used oral (PO) antibiotics, and the other five studies used both IV and PO antibiotics. Length of stay was reported in three studies, all using IV antibiotics. All 11 studies evaluated rates of PJI, while four studies evaluated included rates of superficial surgical site infections. Four studies showed a statistically significant decrease in PJI when compared with a control group, while seven studies showed no statistically significant difference.

CONCLUSION

There is conflicting evidence regarding the benefit of extended (>24 hours) antibiotics, IV or PO, after TJA. As of now, current guidelines do not support the use of extended antibiotics; future prospective clinical trials are needed to help support these claims.

Projected Prevalence of Obesity in Primary Total Hip Arthroplasty: How Big Will the Problem Get?

BACKGROUND

Obesity is associated with higher rates of adverse outcomes following primary total hip arthroplasty (THA). The purpose of this study is to utilize 3 national databases to develop projections of obesity within the general population and primary THA patients in the United States through 2029.

METHODS

Data from the National Surgical Quality Improvement Program (NSQIP), the Behavior Risk Factor Surveillance System (BRFSS), and the National Health and Nutrition Examination Survey were queried for years 1999-2019. Current Procedural Terminology code 27130 was used to identify primary THA patients in NSQIP. Individuals were categorized according to body mass index (kg/m²) by year: normal weight (≤24.9); overweight (25.0-29.9); obese (30.0-39.9); and morbidly obese (≥40). Multinomial logistic regression was used to project categorical body mass index data for years 2020-2029.

RESULTS

A total of 8,222,013 individuals were included (7,986,414 BRFSS, 235,599 NSQIP THA). From 2011 to 2019, the prevalence of normal weight and overweight individuals declined in the general population (BRFSS) and in primary THA. Prevalence of obese/morbidly obese individuals increased in the general population from 31% to 36% and in primary THA from 42% to 49%. Projection models estimate that by 2029, 46% of the general population will be obese/morbidly obese and 55% of primary THA will be obese/morbidly obese.

CONCLUSION

By 2029, we estimate ≥55% of primary THA to be obese/morbidly obese. Increased resources dedicated to care pathways and research focused on improving outcomes in obese arthroplasty patients will be necessary as this population continues to grow.

LEVEL OF EVIDENCE

Level III, Retrospective Cohort Study.

Risk factors associated with surgical site infections following joint replacement surgery: a narrative review

Background

Surgical site infection following joint replacement surgery is still a significant complication, resulting in repeated surgery, prolonged antibiotic therapy, extended postoperative hospital stay, periprosthetic joint infection, and increased morbidity and mortality. This review discusses the risk factors associated with surgical site infection.

Related risk factors

The patient-related factors include sex, age, body mass index (BMI), obesity, nutritional status, comorbidities, primary diagnosis, living habits, and scores of the American Society of Anesthesiologists physical status classification system, etc. Surgery-related factors involve preoperative skin preparation, prolonged duration of surgery, one-stage bilateral joint replacement surgery, blood loss, glove changes, anti-microbial prophylaxis, topical anti-bacterial preparations, wound management, postoperative hematoma, etc. Those risk factors are detailed in the review.

Conclusion

Preventive measures must be taken from multiple perspectives to reduce the incidence of surgical site infection after joint replacement surgery.

Prediction of Early Periprosthetic Joint Infection After Total Hip Arthroplasty

Purpose

To develop a parsimonious risk prediction model for periprosthetic joint infection (PJI) within 90 days after total hip arthroplasty (THA).

Patients and Methods

We used logistic LASSO regression with bootstrap ranking to develop a risk prediction model for PJI within 90 days based on a Swedish cohort of 88,830 patients with elective THA 2008–2015. The model was externally validated on a Danish cohort with 18,854 patients.

Results

Incidence of PJI was 2.45% in Sweden and 2.17% in Denmark. A model with the underlying diagnosis for THA, body mass index (BMI), American Society for Anesthesiologists (ASA) class, sex, age, and the presence of five defined comorbidities had an area under the curve (AUC) of 0.68 (95% CI: 0.66 to 0.69) in Sweden and 0.66 (95% CI: 0.64 to 0.69) in Denmark. This was superior to traditional models based on ASA class, Charlson, Elixhauser, or the Rx Risk V comorbidity indices. Internal calibration was good for predicted probabilities up to 10%.

Conclusion

A new PJI prediction model based on easily accessible data available before THA was developed and externally validated. The model had superior discriminatory ability compared to ASA class alone or more complex comorbidity indices and had good calibration. We provide a web-based calculator (https://erikbulow.shinyapps.io/thamortpred/) to facilitate shared decision making by patients and surgeons.

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Insulin-dependent diabetes mellitus is an independent risk factor for postoperative complications in aseptic revision total hip arthroplasty

INTRODUCTION

Revision total hip arthroplasty (rTHA) is becoming a more common procedure due to the increasing volume of primary total hip arthroplasty. Diabetes mellitus (DM) is currently projected to affect 4.4% of the global population by 2030. Diabetes has been associated with poor outcomes for a variety of surgical interventions. However, the impact of insulin dependence has yet to be fully understood. The aim of this study was to determine the impact of insulin dependence on acute postoperative complications following rTHA.

METHODS

A retrospective cohort study was conducted using the American College of Surgeons National Quality Improvement Program database. All patients who underwent rTHA between 2006 and 2016 were identified and recorded as having non-insulin-dependent DM (NIDDM), insulin-dependent DM (IDDM) or no DM. Univariate and multivariate analysis were used to evaluate the incidence of multiple adverse events within 30 days after rTHA.

RESULTS

A total of 7685 patients were evaluated (No DM = 6651, NIDDM = 700, IDDM = 334). Univariate analysis revealed that all patients with DM had significantly higher incidences of postoperative complications (NIDDM: p < 0.001; IDDM: p < 0.001) and extended hospital length of stay (NIDDM: p = 0.015; IDDM: p < 0.0001). NIDDM was associated with increased rates of superficial surgical site infection (SSI) (p = 0.001), deep SSI (p = 0.038), and stroke (p = 0.013), while IDDM was associated with increased rates of pneumonia (p < 0.001), renal failure (p < 0.001), and postoperative transfusion (p < 0.001). On multivariate analysis, insulin-dependence was determined to be an independent risk factor for extended hospital length of stay (OR 1.905; 95% CI, 1.410-2.577; p < 0.001), pneumonia (OR 4.016; 95% CI, 1.799-8.929; p = 0.001), renal failure (OR 7.143; 95% CI, 2.203-23.256; p = 0.001) and postoperative transfusion (OR 1.366; 95% CI, 1.076-1.733; p = 0.01).

CONCLUSIONS

Insulin dependence is an independent risk factor for numerous short-term postoperative complications following rTHA. When assessing risk and planning perioperative management, surgeons should consider insulin-dependent diabetics as a sub-cohort within the diabetic population.

Obesity, Comorbidities, and Prior Operations Additively Increase Failure in 2-Stage Revision Total Knee Arthroplasty for Prosthetic Joint Infection

BACKGROUND

Prosthetic joint infection (PJI) of the knee carries significant morbidity, mortality, and economic cost. We hypothesize that obese and poor medical hosts will have a significant and additive increase in failure rate undergoing 2-stage revision total knee arthroplasty for PJI.

METHODS

All 2-stage revision total knee arthroplasty procedures for PJI performed at one institution were identified between 2005 and 2020. In total, 144 patients were included and defined as success or failure based on published criteria regarding infection eradication, further intervention, or mortality. The American Society of Anesthesiologists score and the Charlson Comorbidity Index were utilized to assess host grade. Patient, surgical, and microbiologic variables were investigated with univariable and multivariable analysis to explore association with risk of failure.

RESULTS

In the cohort, 32.4% of patients failed with mean follow-up of 5.1 years. In multivariable analysis, the number of major operations requiring arthrotomy and implantation of new material between the primary and first stage, host grade, and elevated body mass index were the major contributors to failure. Combining these factors, with body mass index >30 and 2 or more major operations, the failure rate increased to 76.5% and 71.4% respectively for American Society of Anesthesiologists score 3 (P ≤ .001) and Charlson Comorbidity Index ≥2 (P ≤ .001).

CONCLUSION

In this cohort, multiple major operations between the primary and first stage, host grade, and obesity were the major contributors to failure. When combining these factors, patients had an additive increase in failure rate. Treatments such as amputation or less invasive options and suppression should be discussed and considered in these patients.

Repeat two-stage revision for knee prosthetic joint infection results in very high failure rates

INTRODUCTION

Two stage revision total knee arthroplasty (TKA) is the gold standard for treatment and eradication of knee prosthetic joint infections (PJI), but the literature is limited on the outcomes of repeat two-stage TKA after PJI recurrence. This study presents the outcomes of repeat two-stage revision TKA and investigates potential factors contributing to success or failure, aiming to assist counselling and decision-making.

METHODS

A retrospective study was undertaken investigating all two-stage revision TKA performed at one institution between 2005 and 2020. Twenty cases underwent repeat two-stage revision TKA. Patient outcomes and factors contributing to treatment success or failure were investigated. PJI was diagnosed according to MSIS criteria.

RESULTS

Of the 20 cases, 14 were classified as failed treatment (70%) due to a failure to eradicate infection, further surgical intervention or death. In this cohort, there were no statistically significant differences between the groups regarding factors contributing to treatment success or failure. In the success group, patient reported functional outcomes were variable.

CONCLUSION

This study demonstrates that patients undergoing a repeat two-stage TKA have very poor outcomes. This study did not identify any factors that predicted failure. Patients need to be counselled regarding poor outcomes with repeat two-stage TKA, and other treatment options such as early amputation or lifelong suppression should be considered.

Procedures With Longer Intraoperative Times Undervalue Surgeon Work in Total Joint Arthroplasty: A Large, Nationwide Database Study

BACKGROUND

Work relative value units (wRVUs) measure a surgeon's time and intensity required to perform the pre-service, intra-service, and post-service work of a surgical procedure and are commonly used to compare a physician's work between different procedures. Previous literature across multiple specialties report that longer, often revision, operations are undervalued when compared to primary procedures. Our study aims to analyze the differences in intra-operative time, and its corresponding wRVU/h between the Medicare benchmarks and real-world time-stamped data for total joint arthroplasty procedures.

METHODS

Thirteen primary and revision hip and knee arthroplasty procedures were identified, and intra-operative times were collected using the National Surgical Quality Improvement Program databases from 2014 to 2019. The Relative Value Scale Update Committee's (RUC) estimated median intra-operative times for each procedure was compared to the calculated median intra-operative times from National Surgical Quality Improvement Program, as were their corresponding wRVU/h. Procedures were additionally stratified by "long" (>110 minutes) and "short" (≤110 minutes) intra-operative times.

RESULTS

The RUC over-estimated intra-operative time by 35.24% on average and this overestimation was more profound in longer operations than shorter operations (47.75% vs 15.22%, P = .011). The RUC intensity per unit time values (wRVU/h) between "long" and "short" procedures were significantly different (P < .001) and showed the undervaluation of intensity for the longer procedures by an average of 3.47 wRVU/h.

CONCLUSION

Our study provides further evidence that physician work is undervalued in revision total hip and knee surgeries.

Perioperative Management of Immunosuppressive Medications in Rheumatic Disease Patients Undergoing Arthroscopy

PURPOSE OF REVIEW

This manuscript reviews relevant prior literature regarding management of immunosuppressants in patients with rheumatic diseases around the time of orthopedic surgery, highlighting important considerations specifically regarding arthroscopy.

RECENT FINDINGS

Utilization rates of arthroscopic surgery in patients with rheumatic diseases are on the rise, as immunosuppressive treatment options enable them to lead more active lives and hence experience more injuries. Physicians regularly manage patients' glucocorticoids and conventional synthetic and biologic disease modifying antirheumatic drugs around the time of orthopedic surgery, aiming to minimize infection risk while optimizing disease control. However, there is a paucity of randomized controlled trial data for orthopedic surgery-and specifically nothing in the literature pertaining to arthroscopic surgery. Recent guidelines for rheumatic disease patients undergoing elective total hip and knee arthroplasty recommend that most immunosuppressive medications should be held perioperatively, citing the high-risk profile of arthroplasty cases and arthroplasty patients. While 2017 societal guidelines for perioperative immunosuppression during arthroplasty currently serve as a guide for physicians, they may not be applicable to arthroscopy. The less aggressive arthroscopic surgeries span a broader range of patient ages and risk profiles, indications for surgery, and procedural complexity and associated risks. Given these considerations, the majority of routine arthroscopic patients may not require holding of their immunosuppressive medications in the perioperative period.

Patients' risk factors for periprosthetic joint infection in primary total hip arthroplasty: a meta-analysis of 40 studies

BACKGROUND

Periprosthetic joint infection (PJI) is a catastrophic complication after total hip arthroplasty (THA). Our meta-analysis aimed to identify the individual-related risk factors that predispose patients to PJI following primary THA.

METHODS

Comprehensive literature retrieval from Pubmed, Web of Science, and the Cochrane Library was performed from inception to Feb 20th, 2021. Patient-related risk factors were compared as per the modifiable factors (BMI, smoke and alcohol abuse), non-modifiable factors (gender, age), and medical history characteristics, such as diabetes mellitus (DM), avascular necrosis (AVN) of femoral head, femoral neck fracture, rheumatoid arthritis (RA), cardiovascular disease (CVD), and osteoarthritis (OA) etc. The meta-analysis was applied by using risk ratios with 95% corresponding intervals. Sensitivity analysis and publication bias were performed to further assess the credibility of the results.

RESULTS

Overall, 40 studies with 3,561,446 hips were enrolled in our study. By implementing cumulative meta-analysis, higher BMI was found associated with markedly increased PJI risk after primary THA [2.40 (2.01-2.85)]. Meanwhile, medical characteristics including DM [1.64 (1.25-2.21)], AVN [1.65 (1.07-2.56)], femoral neck fracture [1.75 (1.39-2.20)], RA [1.37 (1.23-1.54)], CVD [1.34 (1.03-1.74)], chronic pulmonary disease (CPD) [1.22 (1.08-1.37)], neurological disease [1.19 (1.05-1.35)], opioid use [1.53 (1.35-1.73)] and iron-deficiency anemia (IDA) [1.15 (1.13-1.17)] were also significantly correlated with higher rate of PJI. Conversely, dysplasia or dislocation [0.65 (0.45-0.93)], and OA [0.70 (0.62-0.79)] were protective factors. Of Note, female gender was protective for PJI only after longer follow-up. Besides, age, smoking, alcohol abuse, previous joint surgery, renal disease, hypertension, cancer, steroid use and liver disease were not closely related with PJI risk.

CONCLUSION

Our finding suggested that the individual-related risk factors for PJI after primary THA included high BMI, DM, AVN, femoral neck fracture, RA, CVD, CPD, neurological disease, opioid use and IDA, while protective factors were female gender, dysplasia/ dislocation and OA.

Do Extended Oral Postoperative Antibiotics Prevent Early Periprosthetic Joint Infection in Morbidly Obese Patients Undergoing Primary Total Joint Arthroplasty?

BACKGROUND

Extended oral antibiotic prophylaxis after primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) in patients with body mass index (BMI) ≥40 kg/m² may reduce the rate of early periprosthetic joint infection (PJI); however, existing data are limited. The purpose of this study was to examine rates of wound complications and PJI in patients with BMI ≥40 kg/m² treated with and without extended oral antibiotic prophylaxis after surgery.

METHODS

We retrospectively identified all primary THA and TKA performed since 2015 in patients with a BMI ≥40 kg/m² at a single institution. Extended oral antibiotic prophylaxis for 7-14 days after surgery was prescribed at the discretion of each surgeon. Wound complications and PJI were examined at 90 days postoperatively.

RESULTS

In total, 650 cases (205 THA and 445 TKA) were analyzed. Mean age was 58 years and 62% were women. Mean BMI was 44 kg/m². Extended oral antibiotic prophylaxis was prescribed in 177 cases (27%). At 90 days, there was no difference between prophylaxis and nonprophylaxis groups in rate of wound complications (11% vs 8%; P = .41) or PJI (1.7% vs 0.6%; P = .35). The univariate analysis demonstrated increased operative time (odds ratio (OR) 1.01; 95% confidence interval (95% CI) 1.01-1.02) and diabetes mellitus (OR 1.88; 95% CI 1.03-3.46) to be associated with increased risk of 90-day wound complications. No patient factors were associated with increased risk of PJI at 90 days postoperatively.

CONCLUSION

Extended oral antibiotic prophylaxis after primary THA and TKA did not reduce rates of wound complications or early PJI in a morbidly obese patient population.

Failure to Medically Optimize Before Total Hip Arthroplasty: Which Modifiable Risk Factor Is the Most Dangerous?

Background

There is mounting evidence that smoking, abnormal body mass index (BMI), uncontrolled diabetes, and poor nutritional status are associated with complications after total hip arthroplasty (THA). The goal of the present study was to evaluate the consequences of failure to medically optimize Medicare-eligible patients with respect to these key modifiable health targets by assessing complications in the early postoperative period after THA.

Methods

The National Surgical Quality Improvement Program database was queried for all primary THAs performed in 2018. Data were collected on preoperative serum albumin, BMI, diabetes, and tobacco use as well as postoperative infections, readmissions, complications, and mortality. We identified 47,924 THA patients with a median BMI of 29 kg/m² and age of 72 years, and 60% of whom were female.

Results

We found that preoperative albumin <3.5 g/dL, BMI ≥40 kg/m², tobacco use, and diabetes were all individually associated with increased risk of postoperative complications. Serum albumin <3.5 g/dL was the greatest overall risk factor for infection (odds ratio [OR]: 3.1, 95% confidence interval [CI]: 2.3-4.4, P < .0001), readmission (OR: 2.2, 95% CI: 1.9-2.5, P < .0001), any complication (OR: 4.2, 95% CI: 3.8-4.6, P < .0001), and mortality (OR: 7.5, 95% CI: 5.3-10.6, P < .0001).

Conclusions

Low albumin, elevated BMI, tobacco use, and diabetes are associated with increased risk of postoperative infection, readmission, any complication, and mortality after primary THA. Low albumin poses the greatest risk of these. Preoperative optimization should be obtained in all patients before elective surgery, and the final decision for surgery should be individually made between a surgeon and patient.

Level of Evidence

IV.

External Validation Demonstrates Limited Clinical Utility of a Preoperative Prognostic Calculator for Periprosthetic Joint Infection

BACKGROUND

Preoperative calculation of treatment failure risk in patients undergoing surgery for periprosthetic joint infection (PJI) is imperative to allow for medical optimization and targeted prevention. A preoperative prognostic model for PJI treatment failure was previously developed, and this study sought to externally validate the model.

METHODS

A retrospective review was performed of 380 PJIs treated at two institutions. The model was used to calculate the risk of treatment failure, and receiver operating characteristic curves were generated to calculate the area under the curve (AUC) for each institution.

RESULTS

When applying this model to institution 1, an AUC of 0.795 (95% confidence interval [CI]: 0.693-0.897) was found, whereas institution 2 had an AUC of 0.592 (95% CI: 0.502-0.683). Comparing all institutions in which the model had been applied to, we found institution 2 represented a significantly sicker population and different infection profile.

CONCLUSION

In this cohort study, we externally validated the prior published model for institution 1. However, institution 2 had a decreased AUC using the prior model and represented a sicker and less homogenous cohort compared with institution 1. When matching for chronicity of the infection, the AUC of the model was not affected. This study highlights the impact of comorbidities and their distributions on PJI prognosis and brings to question the clinical utility of the algorithm which requires further external validation.

'Should we stop or continue conventional synthetic (including glucocorticoids) and targeted DMARDs before surgery in patients with inflammatory rheumatic diseases?'

Total hip and total knee arthroplasty) remain important interventions to treat symptomatic knee and hip damage in patients with rheumatoid arthritis, with little change in utilisation rates despite the increasingly widespread use of potent conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) and targeted DMARDs including Janus kinase inhibitors and biologics. The majority of patients are receiving these immunosuppressing medications and glucocorticoids at the time they present for arthroplasty. There is minimal randomised controlled trial data addressing the use of DMARDs in the perioperative period, yet patients and their physicians face these decisions daily. This paper reviews what is known regarding perioperative management of targeted and csDMARDs and glucocorticoids.

Platelet Deficiency Represents a Modifiable Risk Factor for Periprosthetic Joint Infection in a Preclinical Mouse Model

BACKGROUND

Well known for their hemostatic function, platelets are increasingly becoming recognized as important immunomodulators. The purpose of the present study was to assess the impact of platelet depletion on antimicrobial host defense in a mouse model of periprosthetic joint infection (PJI).

METHODS

Thrombocytopenia (TCP) was induced in C57BL/6 mice with use of a selective antibody against platelet CD41 (anti-CD41). Whole blood from pre-treated mice was incubated with Staphylococcus aureus to assess antimicrobial efficacy with use of bioluminescent imaging, quantitative histological staining, and colony forming unit (CFU) quantification. In parallel, untreated heterologous platelets were added to TCP blood to assess potential rescue of antimicrobial efficacy. In vivo, TCP and control mice underwent placement of a titanium implant in the femur inoculated with bioluminescent Xen36 S. aureus. Longitudinal bioluminescent imaging was performed postoperatively to quantify the evolution of bacterial burden, which was confirmed via assessment of S. aureus CFUs on the implant and in peri-implant tissue on postoperative day (POD) 28.

RESULTS

Anti-CD41 treatment resulted in significant dose-dependent reductions in platelet count. Ex vivo, platelet-depleted whole blood demonstrated significantly less bacterial reduction than control blood. These outcomes were reversed with the addition of untreated rescue platelets. In vivo, infection burden was significantly higher in TCP mice and was inversely correlated with preoperative platelet count (r2 = 0.63, p = 0.037). Likewise, CFU quantification on POD28 was associated with increased bacterial proliferation and severity of periprosthetic infection in TCP mice compared with controls.

CONCLUSIONS

Thrombocytopenia resulted in an increased bacterial burden both ex vivo and in vivo in a mouse model of PJI.

CLINICAL RELEVANCE

In orthopaedic patients, deficiencies in platelet quantity or function represent an easily modifiable risk factor for PJI.

Preoperative Anemia Independently Predicts Significantly Increased Odds of Short-Term Complications Following Aseptic Revision Hip and Knee Arthroplasty

BACKGROUND

Preoperative anemia is an important risk factor for developing complications following revision hip (rTHA) and knee (rTKA) arthroplasty. We aim to determine the effect of anemia severity on 30-day postoperative complications following revision hip and knee arthroplasty.

METHODS

A retrospective cohort study was conducted using the American College of Surgeons National Quality Improvement Program Database. All patients who underwent revision joint arthroplasty (rTJA) between 2006 to 2017 were identified and grouped based upon the hematocrit (Hct) level. Anemia was defined as Hct <36% for women and <39% for men, and further stratified into mild anemia (Hct 33% to 36% for women, Hct 33% to 39% for men), and moderate to severe anemia (Hct <33% for both men and women). Univariate and multivariate analysis were used to evaluate the incidence of multiple adverse events within 30 days after TJA.

RESULTS

A total of 8932 patients undergoing rTHA and 13,313 patients undergoing rTKA were included for analysis. On multivariate adjustment, patients undergoing rTHA with moderate to severe anemia had an increased odds of 5.437 (95% Confidence Interval (CI) 4.604 to 6.421; P < .001) of developing any postoperative complication. On multivariate adjustment, patients undergoing rTKA with moderate to severe anemia had increased odds of 6.731 (95% Confidence Interval (CI) 5.540 to 8.179; P < .001) of developing any postoperative complication.

CONCLUSION

The increasing severity of anemia was associated with an increasing risk of developing any postoperative complication and death following revision hip and knee arthroplasty. There is a significant trend between diminishing preoperative hematocrit levels and increasing odds of postoperative complication.

Hepatitis C infection and complication rates after total shoulder arthroplasty in United States veterans

Background

Few studies have evaluated the effect of hepatitis C (HCV) on primary total shoulder arthroplasty (TSA). Our purpose was to determine if HCV infection is associated with increased complication rates after TSA in United States (US) veterans and, secondarily, to determine if preoperative HCV treatment with direct-acting antivirals (DAAs) affects postoperative complication rates.

Methods

US Department of Veterans Affairs (VA) data sets were used to retrospectively identify patients without HCV, patients with untreated HCV, and patients with HCV treated with DAAs who underwent TSA from 2014 to 2019. Medical and surgical complications were assessed using International Classification of Diseases codes. Complication rates between patients with HCV (treated and untreated) and patients without HCV and between HCV-treated patients and HCV-untreated patients were compared at 90 days and 1 year after surgery.

Results

We identified 5774 primary TSAs that were performed at VA hospitals between 2014 and 2019. A minority (9.5%) of TSA patients had HCV, 23.4% of whom were treated preoperatively with DAAs. On multivariate analysis, HCV patients had increased odds of 1-year medical complications (odds ratio, 1.39; 95% confidence interval, 1.06-1.81, P = .016), when compared with patients without HCV. No statistically significant difference in complication rates was observed between HCV-treated and HCV-untreated patients.

Discussion

US veterans with a history of HCV are at an increased risk of developing medical but not surgical complications within the first year after TSA. Larger studies are necessary to evaluate the effects of DAA treatment on complication rates.

Ceramic-on-Ceramic Bearing in Total Hip Arthroplasty Reduces the Risk for Revision for Periprosthetic Joint Infection Compared to Ceramic-on-Polyethylene: A Matched Analysis of 118,753 Cementless THA Based on the German Arthroplasty Registry

Periprosthetic joint infection (PJI) is one of the most common complications in total hip arthroplasty (THA). The influence of bearing material on the risk of PJI remains unclear to date. This registry-based matched study investigates the role of bearing partners in primary cementless THA. Primary cementless THAs recorded in the German Arthroplasty Registry since 2012 with either a ceramic-on-ceramic (CoC) or ceramic-on-polyethylene (CoP) bearings were included in the analysis. Using propensity score matching (PSM) for age, sex, obesity, diabetes mellitus, Elixhauser comorbidity index, year of surgery and head size, we compared the risk for revision for PJI for CoC and CoP. Within the 115,538 THAs (87.1% CoP; 12.9% CoC), 977 revisions were performed due to PJI. There was a significantly higher risk for revision for PJI for CoP compared with CoC over the whole study period (p < 0.01) after 2:1 matching (CoP:CoC) with a hazard ratio of 1.41 (95% confidence interval (CI), 1.09 to 1.80) After 3 years, the risk for revision for PJI was 0.7% (CI 0.5–0.9%) for CoC and 0.9% (CI 0.8–1.1%) for CoP. The risk for revision for all other reasons except PJI did not significantly differ between the two groups over the whole study period (p = 0.4). Cementless THAs with CoC bearings were less likely to be revised because of infection in mid-term follow-up. In the future, registry-embedded studies focusing on long-term follow-up, including clinical data, as well as basic science studies, may give a deeper insight into the influence of the bearing partners.

Rate of infection following revision anterior cruciate ligament reconstruction and associated patient- and surgeon-dependent risk factors: Retrospective results from MOON and MARS data collected from 2002 to 2011

Infection is a rare occurrence after revision anterior cruciate ligament reconstruction (rACLR). Because of the low rates of infection, it has been difficult to identify risk factors for infection in this patient population. The purpose of this study was to report the rate of infection following rACLR and assess whether infection is associated with patient- and surgeon-dependent risk factors. We reviewed two large prospective cohorts to identify patients with postoperative infections following rACLR. Age, sex, body mass index (BMI), smoking status, history of diabetes, and graft choice were recorded for each patient. The association of these factors with postoperative infection following rACLR was assessed. There were 1423 rACLR cases in the combined cohort, with 9 (0.6%) reporting postoperative infections. Allografts had a higher risk of infection than autografts (odds ratio, 6.8; 95% CI, 0.9-54.5; p = .045). Diabetes (odds ratio, 28.6; 95% CI, 5.5-149.9; p = .004) was a risk factor for infection. Patient age, sex, BMI, and smoking status were not associated with risk of infection after rACLR.

Does performing total joint arthroplasty in the afternoon or evening increase the risk of prosthetic joint infection?

PURPOSE

Does performing total joint arthroplasty in the afternoon or evening increase the rate of early prosthetic joint infection and the likelihood of early prosthetic joint infection?

METHODS

We evaluated patients retrospectively, who underwent primary total hip (THA) or knee arthroplasty (TKA) between January 2016 and December 2019, met the inclusion criteria and had at least 90 days of follow-up. Patients were divided into two groups. Group I consisted of patients whose surgeries had been started and finished before 14:00, and group II included patients whose surgeries started after 14:01. All patients were operated after non-septic cases in specific orthopedic operating rooms. Their demographic data and comorbidities were noted. Primary outcome was to compare the risk of PJI between the groups.

RESULTS

Group I and group II included 2309 and 1881 patients. Total number of patients with the diagnosis of PJI was 58 (1.4%). It was 31 (1.3%) and 27 (1.4%), respectively (p = 0.79). Performing total joint arthroplasty after 14:01 did not increase likelihood of infection (p = 0.83, OR 1.03). Among the parameters, PJI was significantly associated with age (p < 0.01, OR 0.99), smoking status (p < 0.01, OR 0.15) and operating time (p = 0.04, OR 0.99) in TKA and with direct anterior approach (p = 0.02, OR 4.72) in THA. Age (p = 0.06, OR 1.03) was the factor affecting the risk of subsequent PJI after total joint arthroplasty.

CONCLUSION

Performing total joint arthroplasty in the afternoon or in the evening, after aseptic cases does not increase the risk of subsequent of PJI.

Preoperative Allergy Testing for Patients Reporting Penicillin and Cephalosporin Allergies is Cost-Effective in Preventing Infection after Total Knee and Hip Arthroplasty

BACKGROUND

Routine preoperative allergy testing in patients reporting penicillin and cephalosporin allergies increases the number able to receive cefazolin, which should reduce the risk of infection after total knee and hip arthroplasty (TKA/THA), but it remains unclear whether this practice is cost-effective. Using a break-even analysis, we calculated the cost-effectiveness of routine preoperative allergy testing for infection prevention in total joint arthroplasty patients reporting penicillin and cephalosporin allergies.

METHODS

The cost of a penicillin allergy evaluation, the cost of revision arthroplasty for prosthetic joint infection (PJI), and baseline rates of PJI in patients receiving a noncefazolin antibiotic in the perioperative period were derived from existing literature. A break-even economic model using these variables was constructed to calculate the absolute risk reduction (ARR) in infection rate needed for preoperative allergy testing to be cost-effective. The number needed to treat (NNT) was calculated from the ARR.

RESULTS

Preoperative allergy testing before TKA and THA in patients reporting penicillin and cephalosporin allergies was cost-effective if the initial infection rate decreased by an ARR of 0.810% (NNT = 123) and 0.655% (NNT = 153) for TKA and THA, respectively. Cost-effectiveness was maintained with varying allergy consultation costs, infection rates, and costs associated with PJI treatment.

CONCLUSION

Routine preoperative allergy testing and clearance are cost-effective infection prevention strategies among patients reporting penicillin and cephalosporin allergies in the setting of elective joint arthroplasty. Widespread adoption of this practice may considerably reduce the economic and societal burden associated with prosthetic infections.

Is Preoperative Staphylococcus aureus Screening and Decolonization Effective at Reducing Surgical Site Infection in Patients Undergoing Orthopedic Surgery? A Systematic Review and Meta-Analysis With a Special Focus on Elective Total Joint Arthroplasty

BACKGROUND

Staphylococcus aureus is a major pathogen implicated in orthopedic infections worldwide. Preoperative decolonization has been promoted but different strategies present mixed results. Thus, the goals of this study are to determine (1) whether S aureus screening and/or decolonization is effective at reducing surgical site infection in orthopedic surgery, (2) with a special focus on elective total joint arthroplasty (TJA), and (3) which preoperative S aureus screening/treatment strategy is most cost-effective for TJA.

METHODS

PubMed, Ovid MEDLINE, and Cochrane databases were searched on January 1, 2020, using a systematic strategy. We included papers with data comparing surgical site infection and periprosthetic joint infection rate in orthopedic surgery and/or elective total hip and knee arthroplasty patients before/after S aureus screening and/or decolonization protocol and papers evaluating the cost-effectiveness of different S aureus screening/treatment strategies.

RESULTS

A total of 1260 papers were screened, and 32 papers were ultimately included. Results showed an increased risk of developing any infection (relative risk [RR] = 1.71 ± 0.16) and S aureus infection (RR = 2.79 ± 0.45) after orthopedic surgery without previous nares and whole-body decolonization. Focusing exclusively on elective TJA, there was an increased risk of developing any infection (RR = 1.70 ± 0.17) and S aureus infection (RR = 2.18 ± 0.41) if no decolonization is performed. All strategies appeared to be cost-effective, although universal decolonization without screening seemed to be the most advantageous.

CONCLUSION

Preoperative S aureus screening/decolonization protocol lowered the risk of infection after elective orthopedic and TJA surgeries. However, further studies are needed to determine optimal clinical and cost-effective methodologies.

Direct Anterior Approach Total Hip Arthroplasty Is Not Associated with Increased Infection Rates: A Systematic Review and Meta-Analysis

BACKGROUND

The direct anterior approach (DAA) for primary total hip arthroplasty (THA) has recently increased in popularity. Recent evidence has raised concerns about whether use of the DAA is associated with increased rates of superficial and deep infection. The aim of this study was to systematically assess the literature and comparatively evaluate the rate of superficial and deep infection following primary THA using the DAA and non-direct anterior (non-DAA) approaches.

METHODS

This study was conducted in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) statement. Primary outcome measures evaluated were rates of superficial and deep infection in patients undergoing DAA and non-DAA primary THA.

RESULTS

A total of 1,872 studies were identified in the original search, of which 15 studies satisfied inclusion criteria. Our analysis evaluated 120,910 primary THAs, including 14,908 DAA and 106,002 non-DAA. The rate of superficial infection was 1.08% for DAA compared with 1.24% for non-DAA (odds ratio [OR] = 1.01, 95% confidence interval [CI] = 0.79 to 1.30, p = 0.921). The rate of deep infection was 0.73% for DAA compared with 0.51% for non-DAA (OR = 1.03, 95% CI = 0.80 to 1.32, p = 0.831).

CONCLUSIONS

This study found no difference in the rate of superficial or deep infection after primary THA using the DAA versus other surgical approaches. Our results suggest that comparative infection risk need not be a primary driver in the choice of surgical approach.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Treatment options in PJI - is two-stage still gold standard?

Total knee arthroplasty (TKA) is a successful treatment for osteoarthritis with good clinical outcomes 1,2. Periprosthetic joint infection (PJI) in TKA has a low incidence between 0.5 and 3% but it is nevertheless one of the most dreadful complications 3-6. Two-staged revisions are considered to be the gold standard for revision in chronic PJI with infection eradication rates of over 90% 7. Recently, similar infection eradication rates after one-staged revision arthroplasty have been reported 8-10, raising the question whether the two-staged approach can still be considered the gold standard. We therefore performed a literature review to analyse the correlation of one-staged and two-staged TKA revisions with recurrent infection rates and functional outcomes. Studies concerning PJI treated by one- or two-staged revision published between 2000 and 2020 were retrieved by searching the databases PubMed/Medline and the Cochrane Database of Systematic Reviews. 29 studies were included in this qualitative synthesis. Mean follow-up was at 4.9 ± 2.6 years. The mean infection eradication rate after one-staged revision vs. two-staged revision in TKA was 87 ± 8.8% vs. 83 ± 11.7%. The functional outcome measured by the mean Knee Society Score (KSS) of one-staged revision vs. two-staged revision in TKA was 80 ± 5.9 vs. 80 ± 3.9 points. One-staged revision arthroplasty in TKA appears to have similar infection eradication rates and functional outcomes compared to two-staged revision arthroplasty. However, these results should be interpreted with caution, since selection bias may have played a significant role. Several criteria to guide the surgeon in selecting the appropriate procedure have been described, but the current recommendations are based on poor evidence as randomized controlled trials are lacking 11,12. Two-staged revision remains a successful treatment option which is rightly the gold standard. However, there is a variety of cases in which one-staged revision is a viable alternative, where similar success rates and functional outcome can be expected 7,13.

Systematic Review and Meta-Analysis of Tobacco Use as a Risk Factor for Prosthetic Joint Infection After Total Hip Replacement

Background

A prosthetic joint infection (PJI) is one of the possible complications after total hip arthroplasty (THA). Several studies, but not all, have reported smoking as a risk factor of PJIs in orthopaedic surgery. This study summarizes the most recent evidence using a systematic review of whether tobacco use (not only tobacco smoking) is a risk factor in developing PJIs, specifically after THA.

Methods

Ovid Medline, EMBASE, Scopus, Web of Science, and Cochrane databases were searched from inception to July 2019 to identify case-control studies that examined the PJI risk in tobacco users and tobacco nonusers undergoing THA. Publication bias was also assessed through funnel plots.

Results

Searches identified 2689 articles, and 10 of these, involving a total of 20,640 patients, met the inclusion criteria. The overall odds ratio (pooled odds ratio) to develop either a superficial infection, a deep infection, or an infection requiring revision surgery for tobacco users vs nonusers was 1.54 (95% confidence interval: 1.25-1.91) when a fixed-effect model was used and 1.56 (95% confidence interval: 1.10-2.21) when a random-effect model was used. No publication bias was observed among the identified studies.

Conclusions

The findings of the study indicated that tobacco use is associated with a higher risk of PJIs in patients undergoing THA.

Antibiotic-Laden Bone Cement Use and Revision Risk After Primary Total Knee Arthroplasty in U.S. Veterans

BACKGROUND

It is controversial whether the use of antibiotic-laden bone cement (ALBC) in primary total knee arthroplasty (TKA) affects periprosthetic joint infection (PJI) or revision rates. The impact of ALBC on outcomes of primary TKA have not been previously investigated in U.S. veterans, to our knowledge. The purposes of this study were to quantify utilization of ALBC among U.S. veterans undergoing primary TKA and to determine if ALBC usage is associated with differences in revision TKA rates.

METHODS

Patients who had TKA with cement from 2007 to 2015 at U.S. Veterans Health Administration (VHA) hospitals with at least 2 years of follow-up were retrospectively identified. Patients who received high-viscosity Palacos bone cement with or without gentamicin were selected as the final study cohort. Patient demographic and comorbidity data were collected. Revision TKA was the primary outcome. All-cause revisions and revisions for PJI were identified from both VHA and non-VHA hospitals. Unadjusted and adjusted regression analyses were performed to identify variables that were associated with increased revision rates.

RESULTS

The study included 15,972 patients who had primary TKA with Palacos bone cement at VHA hospitals from 2007 to 2015. Plain bone cement was used for 4,741 patients and ALBC was used for 11,231 patients. Utilization of ALBC increased from 50.6% in 2007 to 69.4% in 2015. At a mean follow-up of 5 years, TKAs with ALBC had a lower all-cause revision rate than those with plain bone cement (5.3% versus 6.7%; p = 0.0009) and a lower rate of revision for PJI (1.9% versus 2.6%; p = 0.005). On multivariable regression, ALBC use was associated with a lower risk of all-cause revision compared with plain bone cement (hazard ratio [HR]: 0.79, 95% confidence interval [CI]: 0.68 to 0.92; p = 0.0019). Seventy-one primary TKAs needed to be implanted with ALBC to avoid 1 revision TKA.

CONCLUSIONS

The utilization of ALBC for primary TKAs performed at VHA hospitals has increased over time and was associated with a lower all-cause revision rate and a lower rate of revision for PJI.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Fluctuation of fasting blood glucose in patients who underwent primary or revision total joint arthroplasty: a retrospective review

Background

Perioperative hyperglycemia is a risk factor for postoperative complications after total joint arthroplasty (TJA). However, the variability of fasting blood glucose (FBG) after TJA remains unknown. We aimed to assess the fluctuation and extent of elevation of FBG following primary or revision TJA.

Methods

We retrospectively evaluated the medical records of 1788 patients who underwent primary or revision TJA between 2013 and 2018. We examined FBG values collected during 6 days of the perioperative period. The findings for each time point were evaluated with descriptive statistics. Postoperative glycemic variability was assessed by the coefficient of variation (CV).

Results

The final cohort included the medical records of 1480 patients (1417 primary and 63 revision). FBG was highest on postoperative day 1 in the primary and revision groups (P < 0.001), which had the highest number of hyperglycemic patients (FBG > 100 mg/dL), with 66.4% and 75.5% in the primary and revision groups, respectively. The CV of diabetics in the primary group, and diabetics and non-diabetics in the revision group, was higher than that of non-diabetics in the primary group.

Conclusion

Postoperative day 1 showed the highest FBG levels and proportion of patients with hyperglycemia in the perioperative period. Primary group diabetics, and revision group diabetics and non-diabetics, had higher postoperative fluctuation of FBG than primary group non-diabetics. Frequent FBG monitoring may therefore be warranted in diabetic patients undergoing TJA, and all patients undergoing revision TJA.

Metabolic Syndrome Is Associated With Higher Risk of Wound Complications After Total Hip Arthroplasty

Background

Obesity is prevalent among patients undergoing total hip arthroplasty and has been associated with the risk of wound complications, particularly when an anterior approach is used. However, most studies have focused on obesity defined by the body mass index (BMI), without considering the metabolic effects of adiposity. Thus, in this study, we investigated the independent effects of the BMI and metabolic syndrome on wound complications after total hip arthroplasty.

Methods

Among 804 consecutive patients undergoing total hip arthroplasty between October 2013 and July 2016, we evaluated the associations between obesity (BMI ≥30 mg/kg²), metabolic syndrome (defined by the National Cholesterol Education Program Adult Treatment Panel III guidelines), and wound complication (defined as documented wound dehiscence, drainage, erythema, hematoma, infection, or seroma) over a 1-year follow-up period. We used Cox proportional hazards models adjusting for demographics, smoking status, and hospital length of stay.

Results

Patients’ mean age at time of surgery was 62.0 ± 11.9 years. Forty-seven percent were male, 27.9% were obese, and 11.6% met the definition for metabolic syndrome. Metabolic syndrome was associated with a 4-fold higher risk of wound complication (95% confidence interval: 1.4-11.1) after adjusting for all covariates including the BMI. In unadjusted analysis, obesity was associated with a higher risk of wound complication (hazard ratio: 2.8, 95% confidence interval: 1.3-6.2). However, obesity was not associated with the risk of wound complication after adjusting for the metabolic syndrome (P = .16).

Conclusions

Metabolic syndrome, but not obesity, defined by a BMI ≥30, was associated with wound complications, suggesting that metabolic effects of adiposity may represent a distinct risk factor in the development of wound complications from a higher BMI alone.