Rate Of Prosthetic Joint Infection Research Articles

Nontobacco Nicotine Dependence and Rates of Periprosthetic Joint Infection and Other Postoperative Complications in Shoulder Arthroplasty: A Retrospective Analysis.

Nontobacco nicotine products, including e-cigarettes and vaping, are marketed as healthier alternatives to tobacco. However, the literature on nontobacco nicotine dependence (NTND) is scarce. It is important to analyze the influence of these products as they pertain to medical and surgical postoperative complications. This study hypothesizes that patients with NTND will experience more postoperative complications. Using the TriNetX database, which aggregates deidentified medical records from 89 healthcare organizations in the Research Network, Current Procedural Terminology and 10th revision of the International Classification of Diseases codes were used to identify patients undergoing primary shoulder arthroplasty (SA) from January 2012 to February 2024. Patients were divided into cohorts based on their NTND status before surgery. 90-day major medical complications and 2-year implant-related complications were assessed. Statistical analyses involved calculating risk ratios for postoperative complications. This study analyzed a total of 89,910 SA patients, of which 6,756 were 1:1 propensity matched into NTND or control cohorts. Within the 90-day postoperative period, the NTND cohort exhibited significantly higher rates of sepsis (1.80 vs. 1.20, P = 0.012), surgical site infection (1.20 vs. 0.70%, P = 0.007), and wound disruptions (0.70 vs. 0.40%, P = 0.048), average opioids prescribed (4.46 vs. 3.338, P < 0.001), readmission (10.20% vs. 6.20%, P 0.001) compared with the non-NTND cohort. At the 2-year follow-up, mechanical loosening was notably higher in the NTND group (1.10 vs. 0.30%, P 0.001), as were rates of prosthetic joint infections (2.20 vs. 1.20%, P 0.001). No significant difference was observed for revision rates (3.20% vs. 2.90%, P = 0.269). NTND is associated with higher 90-day rates of wound distruptions, infections, sepsis, as well as increased rates of mechanical loosening and prosthetic joint infection at 2 years postoperatively after SA. These results highlight the need for comprehensive NTND preoperative screening and tailored patient counseling in this patient population.

Impact of Extended Prophylactic Antibiotics on Risk of Prosthetic Joint Infection in Primary Total Hip Arthroplasty: A Matched Cohort Analysis.

Extended oral prophylactic antibiotics have been increasingly used in arthroplasty with the goal of reducing the risk of prosthetic joint infection (PJI). While a reduction in the rate of PJI has been noted with extended oral antibiotic regimens in high-risk patients, no large database study has assessed infection risk after primary total hip arthroplasty among well-balanced cohorts receiving and not receiving postoperative extended oral antibiotics. A retrospective cohort study was conducted using a national database, TriNetX, to identify patients who underwent primary total hip arthroplasty. This cohort was stratified by oral antibiotic prescription within one day of procedure. A one-to-one propensity score matching based on age, sex, class of obesity, and medical comorbidities was conducted. Outcomes explored in this study were 90-day risk of PJI, superficial skin infection, deep skin infection, and all-cause revision. 90-day postoperative infection complications of PJI were higher in the group receiving antibiotics (hazard ratio: 1.83, P-value = 0.012). Other complications such as superficial skin infection, deep skin infection, and all-cause revision showed no statistically significant differences. This database analysis of 5,476 patients demonstrated no decrease in complications of PJI, superficial or deep skin infection, or revision at 90 days. Future randomized controlled trials are needed to evaluate the efficacy of extended oral antibiotics. III.

THE ROLE OF ANTIBACTERIAL HYDROGEL COATING ON COMPLICATION RISKS AFTER COMPLEX PRIMARY AND CEMENTLESS HIP REVISION ARTHROPLASTY: A RETROSPECTIVE MATCHED COHORT STUDY

This study aimed to verify the hypothesis that an antibiotic loaded hydrogel, defensive antimicrobial coating (DAC), reduces overall complication and infection rates when used for high-risk primary and revision total hip arthroplasty (THA).This was a retrospective study matched cohort study of 238 patients, treated with cementless implants with and without DAC. A sub-group analysis of patients undergoing 2nd stage revision THA for prosthetic joint infection (PJI) was also conducted. Re-infection rates within 2 years, complications necessitating surgical intervention and radiographic analysis for aseptic loosening was assessed.The mean age was 68.3±11.5 years, with 39 (32.8%) Macpherson class A, 64 (53.8%) class B and 16 (13.4%) class C patients. 4 (3.4%) patients in the DAC group developed complications including 1 PJI and 1 delayed wound healing, while 13 (10.9%) patients in the control group developed complications including 5 PJIs and 3 delayed wound healing (p=0.032). PJI rates (p=0.136) and delayed wound healing rates (p=0.337) were not statistically significant. For 2nd stage revision THA for PJI there were 86 patients in the DAC group and 45 in the control group. 1 (1.2%) patient in the DAC group developed complications with no recurrences of infection or delayed wound healing, while 10 (22.2%) patients in the control group developed complications including 4 recurrent PJI and 1 delayed wound healing (p=0.003). Recurrent PJI rates were statistically significant (p=0.005) while delayed wound healing rates were not (p=0.165). Patients treated with DAC also had lower rates of aseptic loosening (0% vs 6.7%; p=0.015).Antibiotic impregnated hydrogel coatings on cementless implants showed decreased complication rates after complex primary or revision THA. In 2nd stage revision THA for PJI, it was associated with reduced risk of re-infection and aseptic loosening.

Ankylosing spondylitis in patients undergoing total hip arthroplasty increases the risk of medical and implant-related complications: a case control analysis.

Ankylosing spondylitis (AS) is an inflammatory spondyloarthropathy, often involving the spine and sacroiliac joints. Total hip arthroplasty (THA) has been shown to be effective in improving pain and function in patients with AS with hip involvement. However, extraskeletal manifestations and altered mechanics in those with AS leads to increased complications. Thus, the aims of this study were to assess the effects that AS has on medical and implant complications, falls, length of stay, and readmissions following THA. A retrospective review of the Mariner private insurance claims database was conducted from 2010 to 2020. All cases of THA and those with AS were identified using Current Procedural Terminology, and International Classification of Disease 9th and 10th revision codes. Patients who underwent THA with a diagnosis of AS were matched to non-AS patients 1:5 based on demographic and comorbidity profiles. 90-day medical complications, falls, and readmission rates, as well as 2-year implant complications were compared between cohorts. A total of 6509 AS patients were matched to 32,489 control patients. The AS group had significantly higher rates of myocardial infarction, cerebrovascular accident, deep vein thrombosis, pulmonary embolism, urinary tract infection, wound complications, acute kidney injury, pneumonia, sepsis, transfusions, and falls when compared to the control group. The AS group had significantly higher rates of prosthetic joint infection, dislocation, mechanical loosening, and periprosthetic fracture (all p < 0.0001). Likewise, mean length of stay and readmissions were significantly greater in the AS group. Ankylosing spondylitis in patients undergoing THA is associated with significant risk of medical and implant complications, as well as fall risk, length of stay, and readmission rates. These findings may allow orthopaedic surgeons to be more attentive in identifying those patients at risk and allow for more educated patient counseling and perioperative planning.

After primary shoulder arthroplasty appropriate vancomycin antibiotic prophylaxis does not lead to increased infectious complications when compared to cefazolin

INTRODUCTIONIn primary shoulder arthroplasty (SA), intravenous (IV) cefazolin has demonstrated lower rates of infectious complications when compared to IV vancomycin. However, previous analyses included SA cohorts with both complete and incomplete vancomycin administration. Therefore, it is currently unclear whether cefazolin still maintains a prophylactic advantage to vancomycin when it is appropriately indicated and sufficiently administered at the time of surgical incision. This study evaluated the comparative efficacy of cefazolin and complete vancomycin administration for surgical prophylaxis in primary shoulder arthroplasty with respect to infectious complications. METHODSA retrospective cohort study was conducted utilizing a single institution total joint registry database, where all primary SA types (hemiarthroplasty, anatomic total shoulder arthroplasty, reverse shoulder arthroplasty) performed between 2000 to 2019 for elective and trauma indications using IV cefazolin or complete vancomycin administration as the primary antibiotic prophylaxis were identified. Vancomycin was primarily indicated for patients with a severe self-reported penicillin or cephalosporin allergy and/or MRSA colonization. Complete administration was defined as at least 30 minutes of antibiotic infusion prior to incision. All included SA had at least 2 years of clinical follow-up. Multivariable Cox proportional hazard regression was used to evaluate all-cause infectious complications including survival free of prosthetic joint infection (PJI). RESULTSThe final cohort included 7,177 primary SA, 6,879 (95.8%) received IV cefazolin and 298 (4.2%) received complete vancomycin administration. Infectious complications occurred in 120 (1.7%) SA leading to 81 (1.1%) infectious reoperations. Of the infectious complications 41 (0.6%) were superficial infections and 79 were (1.1%) PJIs. When categorized by administered antibiotics, there were no differences in rates of all infectious complications (1.6% vs. 2.3%; P = .352), superficial complications (0.5% vs. 1.3%; P = .071), PJI (1.1% vs. 1.0%; P = .874), or infectious reoperations (1.1% vs. 1.0%; P = .839). On multivariable analyses, complete vancomycin infusion demonstrated no difference in rates of infectious complications compared to cefazolin administration (hazard ratio [HR], 1.50 [95% confidence interval (CI), 0.70 to 3.25]; P = .297), even when other independent predictors of PJI (male sex, prior surgery, and Methicillin-resistant Staphylococcus aureus colonization) were considered. CONCLUSIONSIn comparison to cefazolin, complete administration of vancomycin (infusion to incision time greater than 30 minutes) as the primary prophylactic agent does not adversely increase the rates of infectious complications and PJI. Prophylaxis protocols should promote appropriate indications for the use of cefazolin or vancomycin, and when necessary, ensure complete administration of vancomycin to mitigate additional infectious risks after primary SA.

A “Dry Tap” in Prosthetic Joint Infection Workup of Total Hip Arthroplasty Is Not Reassuring

BackgroundSynovial fluid analysis is important in diagnosing prosthetic joint infection (PJI). The rate of culture-positive PJI in patients who have a dry tap of a total hip arthroplasty (THA) is not well described. MethodsWe reviewed all image-guided THA aspirations, performed from 2014 to 2021 at a single academic institution. Aspirations were categorized as successful (≥ 0.5 mL) or unsuccessful (< 0.5 mL, “dry tap”). We analyzed culture data on all repeat aspirations and revision surgeries performed within 90 days of the initial dry tap. ResultsWe reviewed 275 consecutive attempted THA aspirations of which 100 (36.4%) resulted in a dry tap. The dry tap cohort had a significantly higher percentage of fluoroscopic-guided aspirations (64%) and fewer ultrasound-guided aspirations (36%) compared to the successful aspiration cohort (48.9% fluoroscopic, 53.1% ultrasound, P = .0061). Of the 100 patients who have dry taps, 48 underwent revision surgery within 90 days of the initial dry tap, and 15 resulted in 2 or more positive cultures. The rate of PJI defined by MusculoSkeletal Infection Society major criteria in the dry tap cohort was 16.0%. ConclusionsAttempted aspiration of a THA resulted in a dry tap 36.4% of the time. Of those patients who had a dry tap, 16.0% were subsequently found to have PJI based on MusculoSkeletal Infection Society major criteria. Therefore, a “dry tap” does not exclude the diagnosis of infection and should not be considered reassuring for the absence of PJI.

Antibiotic prophylaxis before tissue biopsy has no effect on culture results in presumed aseptic revision total hip arthroplasty.

Background: Antibiotic prophylaxis (AP) is considered to be the gold standard for revision total hip arthroplasty (R-THA) due to the high incidence of prosthetic joint infection (PJI). To diagnose PJI, intraoperative tissue biopsies for culture are of particular importance. However, antibiotic interference could theoretically lead to less reliable culture results. Currently, there is no consensus on whether AP should be administered before or after tissue biopsy. In this study, we aimed to investigate the effect of AP timing on culture results and PJI rates in presumed aseptic R-THA. Methods: A retrospective single-center cohort study among 490 patients was performed; 61 patients received AP pre-incision, and 429 patients received AP post-biopsy. At least three intraoperative tissues were sampled for each patient and cultured for a minimum of 2 weeks. Minimum follow-up was 6 months. Epidemiological and clinical data (including culture results and incidence of PJI during follow-up) were gathered and analyzed. Results: Positive (4.9 % vs. 5.4 %, ) and contaminated culture results (23.0 % vs. 22.6 %, ) were not significantly different between pre-incisional and post-biopsy AP administration. Post-operative PJI incidence during follow-up was 1.6 % and 3.0 %, respectively. This difference was not statistically significant (). Conclusion: Pre-incisional AP administration does not yield fewer culture results compared to post-biopsy AP administration. Although statistically not significant, PJI during follow-up was almost twice as high when AP was withheld until after tissue biopsy. Other literature also supports the additional protective benefit of pre-incisional AP. Therefore, we believe pre-incisional AP administration is preferable for presumed aseptic R-THA.

Trends in Extended Oral Antibiotic Prophylaxis Utilization Following Primary and Revision Total Hip Arthroplasty From 2010 to 2022

BackgroundIn patients considered high-risk for infection, extended oral antibiotic (EOA) prophylaxis has been demonstrated to reduce rates of prosthetic joint infection following total hip arthroplasty (THA). Although national guidelines regarding their use have not yet been created, the increase in literature surrounding EOA prophylaxis suggests a potential change in practice patterns. The purpose of this study was to investigate the trends in utilization of EOA prophylaxis following THA from 2010 to 2022 and identify prescription patterns. MethodsA total of 646,059 primary THA and 51,879 aseptic revision THA patients were included in this study. Patients who underwent primary or aseptic revision THA between 2010 and 2022 were identified in a national administrative claims database. Rates and duration of EOA prescriptions were calculated. A secondary analysis examined rates of utilization across demographics, including patients considered high risk for infection. ResultsFrom 2010 to 2022, utilization of EOA increased by 366% and 298% following primary and revision THA, respectively. Of patients prescribed postoperative antibiotics, 30% and 59% were prescribed antibiotics for more than 7 days following primary and revision THA, respectively. Rates of utilization were similar between high-risk individuals and the general population. ConclusionsRates of utilization of EOA prophylaxis after THA have increased significantly since 2010. As current trends demonstrate a wide variation in prescription patterns, including in length of antibiotic duration and in patient population prescribed, guidelines surrounding the use of EOA prophylaxis after THA are necessary to promote antibiotic stewardship while preventing rates of periprosthetic joint infection.

Curtailing infection risks in hepatitis C patients: the effect of antiviral treatment in revision shoulder arthroplasty

BackgroundRevision shoulder arthroplasty (RevSA) is a complex procedure that can result in various postoperative complications. However, the impact of hepatitis C virus (HCV) on postoperative complications after RevSA remains unclear due to limited and inconsistent evidence. This study aims (1) to investigate the incidence of postoperative complications in patients with HCV undergoing RevSA, and (2) to evaluate the impact of HCV treatment on complication rates at different time points after the revision procedure, specifically at 90 days, 1 year, and 2 years MethodsWe queried a national, all-payer database to investigate recent trends in the utilization of RevSA among HCV patients to assess postoperative complication rates, including venous thromboembolism, wound complication, transfusion, and prosthetic joint infection. Statistical analyses involved propensity score matching to create balanced cohorts and logistic regression to determine the relative risk of postoperative complications. "Data was analyzed with the SPSS Statistics software (version 24.0 for Windows; IBM, Armonk, NY, USA). The study included patients who underwent partial or total RevSA procedures between January 1, 2010, and December 31, 2020. Patients were identified based on medical claims that included procedural codes for RevSA and associated diagnosis codes for PJI or insertion/removal of an antibiotic spacer. A Bonferroni correction was utilized because many tests were performed and statistical significance was set at p=0.0125. ResultsThe HCV cohort demonstrated higher prosthetic joint infection (PJI) rates at one-year (5.5 vs 3.9%, p=0.006) and two-year follow-ups (6.7 vs 4.6%, p=0.006). However, no significant differences emerged in venous thromboembolism (VTE) and wound complications rates between the HCV and non-HCV cohorts. Comparing untreated and treated HCV patients, the former showed significantly higher PJI rates at two-year p=0.010, while the treated group had significantly lower odds ratios for PJI. When comparing treated HCV patients with the no HCV cohort, minimal differences were found in postoperative outcomes, indicating no significant difference in the risk of complications between the groups ConclusionOur study observed an association between HCV patients who received antiviral treatment prior to RevSA and a reduced incidence of PJI compared to untreated HCV patients. When comparing this group to the non-HCV controls, there was no significant difference in the incidence of PJI, suggesting a potential association between antiviral treatment and the observed risk patterns in HCV patients. Proper management of HCV-positive patients during RevSA is crucial for improving outcomes and reducing complications.

1297. Implementation of a Prosthetic Joint Infection Clinic in a Rural Setting

Abstract Background Nearly one million patients undergo hip or knee replacements in the United States every year This number is expected to double by 2030. The rate of prosthetic joint infection (PJI) ranges from 0.5 to 2% which translates to between 50,000 to 200,000 PJIs annually. Prosthetic joint infections have high rates of morbidity and mortality. These complex patients are best managed in a multidisciplinary clinic. In 2018, we implemented a specialized Ortho ID clinic where PJI patients are seen by their joint surgeon and ID physician in a single coordinated visit. In this study, we compared no-show rate, miles traveled to clinic, C diff rates, and other complication rates for PJI patients before and after the implementation of our Ortho ID clinic. Methods We performed a chart review of PJI patients treated at our institution, comparing a group of patients who were treated prior 2018 in the General ID clinic to a group of patients who were treated after 2018 in the Ortho ID clinic. We assessed no-show rates, cumulative distance driven and time spent driving (calculated using Google Maps), C. diff rate, and rates of side effects between the 2 groups. Results The combination clinic improved ID follow-up. Prior to the clinic, only 70% of PJI patients were followed by ID after hospital discharge compared to 100% after the clinic was founded. The no-show rate for PJI patients decreased from 18.2% pre-clinic to 6.9% post-clinic. The mean distance traveled pre-clinic was 226 miles compared to 192 miles post-clinic. The C diff rate decreased from 9.09% pre-clinic to 5.22% post-clinic. Rate of acute kidney injury decreased from 11.1% pre-clinic to 3.45% post-clinic. Conclusion Our Ortho ID Clinic’s biggest impact was improving ID follow-up for these complicated patients. Prior to the Clinic’s implementation, approximately 30% of PJI patients never followed up with ID after being discharged from the hospital. We saw positive outcomes with regards to reducing C diff rates and rates of acute kidney injury. Disclosures All Authors: No reported disclosures

1312. Incidence and Microbiology of Prosthetic Joint Infection According to Time Following Total Knee Arthroplasty: A Retrospective Cohort Study Among US Veterans

Abstract Background Despite the frequency of total knee arthroplasty (TKA) and clinical impact of prosthetic joint infections (PJIs), the incidence and microbiology of these infections in the United States remains unclear. Our objective was to determine the incidence of PJI occurring ≤ 3 months (early), between &amp;gt; 3 and ≤ 12 months (delayed), and &amp;gt; 12 months (late) after primary TKA and to identify the organisms isolated from microbiologic cultures during each of these periods. Methods We conducted a retrospective study of patients in the Veterans Aging Cohort Study- National Cohort who underwent elective primary TKA in the VA between October 1, 1999 to September 30, 2019. The primary outcome was incident hospitalization with PJI. We estimated incidence rates (events/10,000 person-months) with 95% confidence intervals (CIs) of early, delayed, and late PJI. Poisson regression was used to estimate the incidence rate ratio (IRR) with 95% CI of early and delayed PJI compared to late PJI. The Kaplan-Meier method was used to demonstrate the cumulative incidence of PJI at 3, 12 and 24 months. We measured the frequency of Gram-positive, Gram-negative, fungal, polymicrobial, and culture-negative PJI occurring within each of the three time periods and compared frequencies of interest using Pearson’s chi-squared tests. Results Among 82,401 VHA patients who underwent primary TKA, a total of 1,605 incident PJIs (1.9%) were identified. The incidence rate of PJI was higher in the first 12 months after primary TKA surgery, with an IRR of 20.4 (95% CI, 18.2-222.8) for early and 4.2 (95% CI, 3.7-4.8) for delayed periods when compared to late. The cumulative incidence of PJI at 3 months was 0.77% (95% CI, 0.71-0.83%), at 12 months was 1.25% (95% CI 1.17-1.33%), and at 24 months was 1.56% (95% CI 1.48-1.65%) (Figure 1). Staphylococcus aureus was the most common organism isolated (33.2%) across the periods. Gram-negative bacteria were isolated in 11.1% of all infections, and 15.1% of early PJIs (Table 1). Kaplan Meier failure curves for prosthetic joint infection for the overall study period (upper panel) as well as the first 24 months (lower panel) following primary total knee arthroplasty. Abbreviations: PJI, prosthetic joint infection; CI, confidence interval.Table 1.Organisms isolated from synovial fluid or operative tissue cultures of early, delayed and late prosthetic joint infections after primary total knee arthroplasty. aAmong the 1,605 PJIs in the Overall Cohort, the microbiology data for 103 were missing and 1,502 PJIs with available microbiology data were included in these results. bPolymicrobial defined by multiple genera of organisms identified cIncludes: Micrococcus species, diphtheroids dIncludes: Salmonella, Pasteurella, Citrobacter, Morganella, Acinetobacter, Pasteurella, Burkholderia species, and Gram-negative organisms not otherwise specified eAll fungal infections were identified as Candida species fNumbers may not sum to group totals or percentages as polymicrobial infections with more than one organism were possible Abbreviations: PJI, prosthetic joint infection. Conclusion Incidence rates of early and delayed PJI were significantly higher than late PJI following primary TKA. Gram-negative organisms were more prevalent in early compared to delayed or late PJI. Empiric Gram-negative antibiotic therapy should be considered with a suspected PJI within 3 months after elective primary TKA. Disclosures Alisa Stephens-Shields, PhD, Gilead Sciences: Advisor/Consultant Charles Nelson, MD, Stryker: Advisor/Consultant|Zimmer-Biomet: Advisor/Consultant|Zimmer-Biomet: Grant/Research Support

Addition of gentamicin for antibiotic prophylaxis in hip hemiarthroplasty does not decrease the rate of surgical site infection.

The addition of Gram-negative coverage to antibiotic prophylaxis protocols prior to elective total hip arthroplasty (THA) has been reported to reduce periprosthetic joint infection (PJI). However, it is unknown whether adding a Gram-negative-targeted antibiotic agent improves outcomes in the trauma population. This study aimed to investigate whether the addition of a single, pre-operative dose of Gentamicin is associated with lower rates of PJI in patients undergoing hemiarthroplasty (HA) as treatment for a hip fracture. We retrospectively reviewed cases of patients who underwent HA as treatment for a hip fracture from January 2011 to January 2022, and had a minimum 1-year of follow-up. Patients were divided into two groups based on the antibiotic prophylaxis they received during surgery: cefazolin (control group) or cefazolin with addition of Gentamicin (case group). The primary outcome was the rate of surgical site infections (SSI), and secondary outcomes included rates of prosthetic joint infection (PJI) and superficial SSIs. The final study population consisted of 1521 patients. 336 patients (22.1%) were in the case group and 1185 (77.9%) patients were in the control group. Rates of SSI were comparable between the groups (3.8% for the case group vs. 2.8% in the control group, p = 0.34). This held true for both PJIs (3.5 vs. 2.5%, p = 0.3) and superficial SSIs (0.29 vs. 0.33%, p = 0.91). The distribution of the causing pathogen was similar between the groups (p = 0.84). Gentamicin susceptibility rates of the Gram-negative bacteria associated with PJI were similar between the cohorts (p = 0.51). The addition of a single, pre-operative dose of Gentamicin to the antibiotic prophylaxis protocol of patients undergoing HA as treatment for a hip fracture was not associated with lower rates of SSI, PJI or superficial SSI. The findings of this study indicate that the prophylactic benefits of Gentamicin may not apply to HA as they do to THA.

BORS/BJR TRAVELLING FELLOWSHIP ABSTRACT: THE EFFECT OF INCREASING BONE LOSS ON THE PRIMARY STABILITY OF METAPHYSEAL SLEEVES IN THE PROXIMAL TIBIA. AN EXPERIMENTAL STUDY USING SAWBONE TIBIAS

AbstractApproximately 20% of primary and revision Total Knee Arthroplasty (TKA) patients require multiple revisions, which are associated with poor survivorship, with worsening outcomes for subsequent revisions. For revision surgery, either endoprosthetic replacements or metaphyseal sleeves can be used for the repair, however, in cases of severe defects that are deemed “too severe” for reconstruction, endoprosthetic replacement of the affected area is recommended. However, endoprosthetic replacements have been associated with high complication rates (high incidence rates of prosthetic joint infection), while metaphyseal sleeves have a more acceptable complication profile and are therefore preferred. Despite this, no guidance exists as to the maximal limit of bone loss, which is acceptable for the use of metaphyseal sleeves to ensure sufficient axial and rotational stability. Therefore, this study assessed the effect of increasing bone loss on the primary stability of the metaphyseal sleeve in the proximal tibia to determine the maximal bone loss that retains axial and rotational stability comparable to a no defect control.Methodsto determine the pattern of bone loss and the average defect size that corresponds to the clinically defined defect sizes of small, medium and large defects, a series of pre-operative x-rays of patients with who underwent revision TKA were retrospectively analysed. Ten tibiae sawbones were used for the experiment. To prepare the bones, the joint surface was resected the typical resection depth required during a primary TKA (10mm). Each tibia was secured distally in a metal pot with perpendicular screws to ensure rotational and axial fixation to the testing machine. Based on X-ray findings, a fine guide wire was placed 5mm below the cut joint surface in the most medial region of the plateau. Core drills (15mm, 25mm and 35mm) corresponding to small, medium and large defects were passed over the guide wire allowing to act at the centre point, before the bone defect was created. The test was carried out on a control specimen with no defect, and subsequently on a Sawbone with a small, medium or large defect. Sleeves were inserted using the published operative technique, by trained individual using standard instruments supplied by the manufacturers. Standard axial pull-out (0 – 10mm) force and torque (0 – 30°) tests were carried out, recording the force (N) vs. displacement (mm) curves.ResultsA circular defect pattern was identified across all defects, with the centre of the defect located 5mm below the medial tibial base plate, and as medial as possible. Unlike with large defects, small and medium sized defects reduced the pull-out force and torque at the bone-implant interface, however, these reductions were not statistically significant when compared to no bony defect.ConclusionsThis experimental study demonstrated that up to 35mm radial defects may be an acceptable “critical limit” for bone loss below which metaphyseal sleeve use may still be appropriate. Further clinical assessment may help to confirm the findings of this experimental study. This study is the first in the literature to aim to quantify “critical bone loss” limit in the tibia for revision knee arthroplasty.Declaration of Interest(a) fully declare any financial or other potential conflict of interest

Data-driven body mass index threshold associated with increased risk of 2-year periprosthetic joint infection following total shoulder arthroplasty

Body mass index (BMI) is a modifiable risk factor for medical and infectious complications following total shoulder arthroplasty (TSA). Previous studies investigating BMI were limited to the conventional classification system, which may be outdated for modern day patients. Therefore, the purpose of this study was to identify BMI thresholds that are associated with varying risk of 90-day medical complications and 2-year prosthetic joint infection (PJI) following TSA. A national database was utilized to identify 10,901 patients who underwent primary elective TSA from 2013 to 2022. Patients were only included if they had a BMI value recorded within 1 month prior to TSA. Separate stratum-specific likelihood ratio analyses, an adaptive technique to identify data-driven thresholds, were performed to determine data-driven BMI strata associated with varying risk of 90-day medical complications and 2-year PJI. The incidence rates of these complications were recorded for each stratum. To control for confounders, each BMI strata was propensity-score matched based on age, sex, hypertension, heart failure, chronic obstructive pulmonary disease, and diabetes mellitus to the lowest identified BMI strata for both outcomes of interest. The risk ratio (RR) and 95% confidence interval (CI) were recorded for each matched analysis. The average age and BMI of patients was 70.5years (standard deviation ±9.8) and 30.7 (standard deviation±6.2), respectively. Stratum-specific likelihood ratio analysis identified two BMI strata associated with differences in the rate of 2-year PJI: 19-39 and 40+. The same strata were identified for 90-day major complications. When compared to the matched BMI 19-39 cohort, the risk of 2-year PJI was higher in the BMI 40+ cohort (RR: 2.7; 95% CI 1.39-5.29; P=.020). After matching, there was no significant difference in the risk of 90-day major complications between identified strata (RR: 1.19, 95% CI: 0.86-1.64; P=.288). A data-driven BMI threshold of 40 was associated with a significantly increased risk of 2-year PJI following TSA. This is the first TSA study to observe BMI on a continuum and observe at what point BMI is associated with increased risk of 2-year PJI following TSA. Our identified BMI strata can be incorporated into risk-stratifying models for predicting both PJI and 90-day major complications to minimize both.

Incidence, Microbiological Studies, and Factors Associated With Prosthetic Joint Infection After Total Knee Arthroplasty

Despite the frequency of total knee arthroplasty (TKA) and clinical implications of prosthetic joint infections (PJIs), knowledge gaps remain concerning the incidence, microbiological study results, and factors associated with these infections. To identify the incidence rates, organisms isolated from microbiological studies, and patient and surgical factors of PJI occurring early, delayed, and late after primary TKA. This cohort study obtained data from the US Department of Veterans Affairs (VA) Corporate Data Warehouse on patients who underwent elective primary TKA in the VA system between October 1, 1999, and September 30, 2019, and had at least 1 year of care in the VA prior to TKA. Patients who met these criteria were included in the overall cohort, and patients with linked Veterans Affairs Surgical Quality Improvement Program (VASQIP) data composed the VASQIP cohort. Data were analyzed between December 9, 2021, and September 18, 2023. Primary TKA as well as demographic, clinical, and perioperative factors. Incident hospitalization with early, delayed, or late PJI. Incidence rate (events per 10 000 person-months) was measured in 3 postoperative periods: early (≤3 months), delayed (between >3 and ≤12 months), and late (>12 months). Unadjusted Poisson regression was used to estimate incidence rate ratios (IRRs) with 95% CIs of early and delayed PJI compared with late PJI. The frequency of organisms isolated from synovial or operative tissue culture results of PJIs during each postoperative period was identified. A piecewise exponential parametric survival model was used to estimate IRRs with 95% CIs associated with demographic and clinical factors in each postoperative period. The 79 367 patients (median (IQR) age of 65 (60-71) years) in the overall cohort who underwent primary TKA included 75 274 males (94.8%). A total of 1599 PJIs (2.0%) were identified. The incidence rate of PJI was higher in the early (26.8 [95% CI, 24.8-29.0] events per 10 000 person-months; IRR, 20.7 [95% CI, 18.5-23.1]) and delayed periods (5.4 [95% CI, 4.9-6.0] events per 10 000 person-months; IRR, 4.2 [95% CI, 3.7-4.8]) vs the late postoperative period (1.3 events per 10 000 person-months). Staphylococcus aureus was the most common organism isolated overall (489 [33.2%]); however, gram-negative infections were isolated in 15.4% (86) of early PJIs. In multivariable analyses, hepatitis C virus infection, peripheral artery disease, and autoimmune inflammatory arthritis were associated with PJI across all postoperative periods. Diabetes, chronic kidney disease, and obesity (body mass index of ≥30) were not associated factors. Other period-specific factors were identified. This cohort study found that incidence rates of PJIs were higher in the early and delayed vs late post-TKA period; there were differences in microbiological cultures and factors associated with each postoperative period. These findings have implications for postoperative antibiotic use, stratification of PJI risk according to postoperative time, and PJI risk factor modification.

Antimicrobial prophylaxis with teicoplanin plus gentamicin in primary total joint arthroplasty.

Objectives: To compare prosthetic joint infection (PJI) and acute kidney injury (AKI) rates among cohorts before and after changing our hospital's antimicrobial prophylactic regimen from cefuroxime to teicoplanin plus gentamicin. Methods: We retrospectively studied all patients undergoing primary total joint arthroplasty at our hospital 18months pre- and post-implementation of the change in practice. All deep infections identified during follow-up were assessed against the European Bone and Joint Infection Society (EBJIS) definitions for PJI. Survival analysis using Cox regression was employed to adjust for differences in baseline characteristics and compare the risk of PJI between the groups. AKIs were identified using pathology records and categorized according to the KDIGO (Kidney Disease - Improving Global Outcomes) criteria. AKI rates were calculated for the pre- and post-intervention periods. Results: Of 1994 evaluable patients, 1114 (55.9 %) received cefuroxime only (pre-intervention group) and 880 (44.1 %) patients received teicoplanin plus gentamicin (post-intervention group). The overall rate of PJI in our study was 1.50 % (30 of 1994), with a lower PJI rate in the post-intervention group (0.57 %; 5 of 880) compared with the pre-intervention group (2.24 %; 25 of 1114). A corresponding risk reduction for PJI of 75.2 % (95 % CI of 35.2-90.5; .004) was seen in the post-intervention group, which was most pronounced for early-onset and delayed infections due to coagulase-negative staphylococci (CoNS) and cefuroxime-resistant Enterobacteriaceae. Significantly higher AKI rates were seen in the post-intervention group; however, 84 % of cases (32 of 38) were stage1, and there were no differences in the rate of stage-2 or -3 AKI. Conclusions: Teicoplanin plus gentamicin was associated with a significant reduction in PJI rates compared with cefuroxime. Increases in stage-1 AKI were seen with teicoplanin plus gentamicin.

The Financial Burden of Aspirin versus Oral Factor Xa Inhibitors for Thromboprophylaxis Following Total Knee Arthroplasty

BackgroundAspirin and oral factor Xa inhibitor thromboprophylaxis regimens are associated with similarly low rates of venous thromboembolism following total knee arthroplasty (TKA). However, the rate of prosthetic joint infection (PJI) is lower with aspirin use. This study aimed to compare the cost differential between aspirin and factor Xa inhibitor thromboprophylaxis with respect to PJI management. MethodsWe used previously published rates of PJI following aspirin and factor Xa inhibitor thromboprophylaxis in primary TKA patients at a single, large institution. Prices for individual drugs were obtained from our hospital’s pharmacy service. The cost of PJI included that of 2-stage septic revision, with or without the cost of 1-year follow-up. National data were obtained to determine annual projected TKA volume. ResultsThe per-patient costs associated with a 28-day course of aspirin versus factor Xa inhibitor thromboprophylaxis were $17.36 and $3,784.20, respectively. Including cost of follow-up, per-patient costs for a 28-day course of aspirin versus factor Xa inhibitors increased to $73,358.76 and $77,125.60, respectively. The weighted average per-patient costs for a 28-day course were $237.38 and $4,370.93, respectively. The annual cost difference could amount to over $14.1 billion in the United States by 2040. ConclusionsThe per-patient cost associated with factor Xa inhibitor thromboprophylaxis is as much as 1,980.6% higher than that of an aspirin regimen due to increased costs of primary treatment, differential PJI rates, and high costs of management. In an era of value-based care, the use of aspirin is associated with major cost advantages.

Prosthetic joint infections following a total knee arthroplasty: A retrospective analysis

Background: Total knee arthroplasty, especially, has been a resort for many individuals plagued with deforming joint pathologies, alleviating pain, and improving joint mobility, but is not without complications. Prosthetic joint infection (PJI) is the most commonly occurring early and late complication of total knee arthroplasty. In one study, they observed that even though the rate of PJI after TKA is 0.6-0.9%, the financial burden is enormous. Therefore, it is imperative for surgeons to find the ideal management strategies, both non-surgical and surgical, to tackle PJI. Here, we conducted this study to demonstrate the occurrence of PJI following an uneventful arthroplasty, and the management strategies in a tertiary care hospital. Methods and materials: This was a retrospective study performed in the Department of Orthopaedics, Kanachur Institute of Medical sciences, between January 2021 to January 2023. The case records of all patients with culture proven prosthetic joint infection was identified. Demographic details, surgery performed, type of implant, duration of surgery, ICU stay, intra-operative and post-operative complications were recorded in a semi-structured pro forma. The data was analysed using SPSS v20. A p value &lt; 0.05 was considered statistically significant. Results: The most common presenting complaint in the patients was pain and fever &gt; 38 degrees C (67.5%), followed by discharge from wound site (34.23%). Four patients required ICU admission due to features of sepsis, and 2 patients died following the revision surgery. Most common organism isolated was Staphylococcus aureus in the synovial fluid cultures. We found that there was a statistically significant difference in the operative time between single staged and two staged procedure, but there was no correlation between that and the re-infection rates. Conclusion: PJI following TKA is a dreadful complication, which requires swift diagnosis and prompt management. Most patients present with pain initially, which should alert the treating physician towards an ongoing inflammatory process in the joint. Appropriate antibiotics, single stage/two-staged surgical correction and adequate limb movement restriction can aid in reducing risk of morbidity while maintaining functionality in the operated joint.

Does Computer Navigation or Robotic Assistance Affect the Risk of Periprosthetic Joint Infection in Primary Total Knee Arthroplasty? A Propensity Score-Matched Cohort Analysis

BackgroundThe use of technology during total knee arthroplasty (TKA) has been associated with more accurate component position and less blood loss. Yet to date, the risk of developing prosthetic joint infection (PJI) associated with computer navigation (CN) or robotic assistance (RA) has not been thoroughly evaluated. This study used propensity score-matching (PSM) in a large cohort of primary TKA patients to compare the rate of PJI following conventional TKA (TKA) versus CN-TKA and RA-TKA. MethodsWe retrospectively reviewed 13,015 knees in 11,727 patients who underwent primary TKA at a single institution from 2018 to 2021. The cohort was stratified into TKA, CN-TKA, and RA-TKA groups. 1:1 PSM was applied to 11,834 patients. Propensity score-matching was performed using logistic regression accounting for age, sex, body mass index, Charlson Comorbidity Index (CCI) score, CCI components, and smoking status. Univariate and multivariable analyses were performed to evaluate differences in surgical time and PJI rate. ResultsSignificantly longer median operating times were noted in the RA-TKA group (14 minutes) compared to TKA (P < .001). The PJI rates among matched cohorts were similar among RA-TKA (0.3%), CN-TKA (0.3%), and conventional TKA (0.5%). Multivariable logistic regressions demonstrated that the use of robotic assistance (odds ratio (OR) = 0.5, P = .423) or computer navigation (OR = 0.61, P = .128) was not associated with increased risk of PJI when compared to conventional TKA. ConclusionsUse of computer navigation and robotic assistance during primary TKA are associated with longer surgical times, but no difference in PJI frequency within 90 days of surgery.

Effect of supplemental testosterone use on shoulder arthroplasty infection rates

BackgroundSupplemental testosterone use among patients undergoing shoulder arthroplasty can increase the Cutibacterium acnes load on the skin. Although higher C acnes loads on the skin are associated with higher amounts of bacteria in deep tissues, it is unknown whether preoperative testosterone use increases the risk of shoulder prosthetic joint infection. Therefore, the purpose of this study was to determine if there is a temporal relationship between testosterone use and the risk of prosthetic joint infection after shoulder arthroplasty. MethodsThe PearlDiver database was queried to identify a cohort of patients who underwent shoulder arthroplasty (hemiarthroplasty, anatomic or reverse total shoulder arthroplasty) with a minimum 2-year follow-up. Current Procedural Terminology and International Classification of Diseases codes were used to compare the demographics and comorbidities of patients with (n = 2285) and without testosterone use (n = 41,712). Patients with testosterone use were further stratified by the duration between last testosterone use and surgery. Prosthetic joint infection rates were compared between those with and without testosterone use. ResultsThe overall prevalence of testosterone use was 3.4%. Patients who used testosterone within 6 months prior to shoulder arthroplasty had a significantly higher rate of prosthetic joint infection at 3.4% compared to those without use at 2.4% [odds ratio (OR) = 1.44 (95% confidence interval (CI): 1.03-2.01), P = .042]. However, patients who used testosterone between 6 and 12 months before surgery did not have a significantly higher rate of infection. On multivariate analysis, only younger age [OR = 0.98 (95% CI: 0.97-0.99), P < .001] and diabetes [OR = 1.26 (95% CI: 1.10-1.44), P < .001] were independent risk factors for the development of an infection. ConclusionTestosterone use within 6 months of shoulder arthroplasty may be associated with higher rates of prosthesis joint infection. However, patients who were taking testosterone but stopped before surgery did not have a higher rate of infection compared to those who never used the medication. Surgeons should actively screen patients for testosterone use. A referral to the patient’s endocrinologist to discuss the risks and benefits of testosterone cessation prior to shoulder arthroplasty may also be warranted.