The Gut Microbiome and Joint Microbiome Show Alterations in Patients with Knee Osteoarthritis Versus Controls: A Systematic Review.

PURPOSE: To assess the current scientific literature on the microbiome's relationship with knee osteoarthritis (OA), with specific focuses on the gut microbiome-joint axis and joint microbiome-joint axis. METHODS: A systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, searching PubMed, Embase, and Cochrane databases for relevant English-language clinical studies on the gut and/or joint microbiomes' association with knee OA in humans. Bias was evaluated using the methodological index for non-randomized studies score. RESULTS: Thirty-five thousand bacterial species comprise the gut microbiome; approximately 90% are members of the phyla Bacteroides and Firmicutes. Symbiosis between the gut microbiome and host under normal physiological conditions positively affects host growth, development, immunity, and longevity. Gut microbiome imbalance can negatively influence various physiological processes, including immune response, inflammation, metabolism, and joint health including development of knee OA. In addition, next generation gene sequencing suggests the presence of microorganisms in the synovial fluid of osteoarthritic knees, and distinct microbiome profiles detected are presumed to play a role in the development of OA. With regard to the gut microbiome, consistent alterations in microbial composition between OA patients and controls are noted, in addition to several associations between certain gut bacteria with OA-related knee pain, patient-reported outcome measure performance, imaging findings, and changes in metabolic and inflammatory pathways. Regarding the joint microbiome, studies revealed increased levels of lipopolysaccharide (LPS) and LPS-binding protein in synovial fluid are associated with activated macrophages, and correlated with worsened osteophyte severity, joint space narrowing, and pain scores in knee OA patients. In addition, studies demonstrated various microbial composition differences in OA patients compared to control, with certain joint microbes directly associated with OA pathogenesis, inflammation, and metabolic dysregulation. CONCLUSIONS: The gut microbiome-joint axis and joint microbiome shows alterations in microbial composition between osteoarthritic patients and controls. These alterations are associated with perturbations of metabolic and inflammatory pathways, imaging findings, osteoarthritis-related pain, and patient reported outcome measure performance. LEVEL OF EVIDENCE: Systematic Review; Level III.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

A Simple Algorithmic Approach Allows the Safe Use of Cephalosporin in "Penicillin-Allergic" Patients without the Need for Allergy Testing.

BACKGROUND: Patients who report a penicillin allergy are often given second-line antibiotic prophylaxis during total joint arthroplasty (TJA), with only a minority of patients undergoing additional consultations and allergy testing. In an effort to increase the use of cephalosporin prophylaxis in TJA, the present study aimed to assess the effectiveness of a simple, protocol-driven penicillin allergy screening program without the need for additional work-up. METHODS: Following implementation of a questionnaire-based screening protocol in May 2019, all patients scheduled for primary TJA were risk-stratified into low or high-risk categories. The low-risk cohort received cefazolin, and the high-risk cohort received non-cefazolin antibiotics. Patients were monitored prospectively, and data on antibiotic usage and adverse outcomes were documented. The protocol group (n = 2,078) was propensity score matched 1:1 with a control group that included patients who underwent TJA in the same institution prior to implementation of the protocol. The primary end point was the efficacy of the protocol in reducing unnecessary use of non-cephalosporin antibiotics for prophylaxis. Secondary outcomes included the rate of surgical site infections and allergic reactions to the administered antibiotic. RESULTS: A total of 357 patients (17.2%) reported a penicillin allergy in the protocol group compared with 310 patients (14.9%) with a recorded allergy in the control group (p = 0.052). The number of patients who received non-cephalosporin antibiotics was significantly lower in the protocol group (5.7% compared with 15.2% in the control group; p < 0.001), whereas there was no difference in the rate of total allergic reactions (0.8% compared with 0.7%, respectively; p = 0.857). Of the 239 low-risk patients (66.9%) in the protocol group, only 3 (1.3%) experienced a mild cutaneous reaction following cefazolin administration. There were no differences in the rates of superficial wound, deep periprosthetic, or Clostridioides difficile infections between the protocol and control groups. CONCLUSIONS: A simple screening protocol allowed two-thirds of patients with a self-reported allergy to receive cefazolin without the need for additional consultations or testing. We believe this protocol can be safely implemented to increase the rate of cefazolin usage without a corresponding increase in the number of allergic reactions. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Thirty Days of Aspirin for Venous Thromboembolism Prophylaxis Is Adequate Following Total Knee Arthroplasty, Regardless of the Dose Used.

BACKGROUND: The optimal length of aspirin prophylaxis to minimize venous thromboembolism (VTE) following total knee arthroplasty (TKA) remains unknown. This study aimed to determine the timing of VTE after TKA in patients who received low and high dose aspirin, and determine if 30 days of prophylaxis remains adequate. METHODS: We retrospectively reviewed records of 9208 patients undergoing primary TKA between 2010 and 2020 who received either low (81 mg twice daily, n = 4413) or high (325 mg twice daily, n = 4795) dose aspirin for VTE prophylaxis. Symptomatic VTEs occurring within 90 days of surgery were identified from medical records and phone call logs. Major bleeding events (MBE) within the first 30 days were also documented. Time to event was recorded. RESULTS: Overall, 88 patients (1.0%) developed symptomatic VTE, with no significant differences in incidence between the low (n = 40, 0.9%) and high (n = 48, 1.0%) dose groups (P = .669). The median time to VTE was 8 days (interquartile range [IQR] 2-15.5), median time to deep vein thrombosis was 12 days (IQR 5-18), and median time to pulmonary embolism was 5 days (IQR 1.5-15). There was a similar distribution in time to VTE in both the low and high dose groups. Aside from a single DVT occurring at day 44, all VTE occurred within 30 days of surgery. During the prophylactic time period, 41 patients (0.4%) developed MBE, which tended to occur more frequently (0.6% vs 0.3%, P = .018) and earlier in the high dose group. CONCLUSION: Based on the findings, a 30-day low or high dose aspirin regimen remains optimal for prevention of VTE without increasing MBE in TKA patients.

Does Radial Head Resection Impair Hand and Wrist Function? A Long-Term Follow-Up.

OBJECTIVE: To evaluate the long-term outcome in patients after radial head resection surgery for isolated Mason type III radial head fractures. DESIGN: An observational retrospective case series. SETTING: A Hand and Upper-Extremity Surgery Unit in a tertiary care center. PATIENTS: Data were collected from files of patients who were operated between the years 1980 and 2020. Of 352 patients who underwent surgery for radial head fractures, 25 patients were eligible and were enrolled in the study. INTERVENTION: All participants underwent radial head resection surgery and a follow-up clinical and radiographic evaluation by 2 senior orthopaedic surgeons. OUTCOME MEASUREMENTS: Objective evaluation included active range of motion of the elbow and wrist joints, ulnohumeral angle, key pinch and grip measurements, and radiographic imaging of elbow and wrist joints. Subjective evaluation included visual analog scale measurements, disability of arm shoulder and hand questionnaire, Mayo wrist score, Michigan hand outcome, and Oxford elbow score. RESULTS: The mean follow-up was 18 years. Mean elbow range of motion and mean grip strength were lower in the operated hand, as compared to the contralateral hand. Mean proximal radial migration was 1.6 mm. Mean results of visual analog scale, disability of arm shoulder and hand, Mayo wrist score, Michigan hand outcome, and Oxford elbow score indicated good functional outcome and high patient satisfaction. CONCLUSIONS: In our study population, long-term functional outcomes after radial head resection were encouraging. Thus, this procedure may be considered as a surgical alternative when radial head reconstruction or replacement fails. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Fructosamine is a valuable marker for glycemic control and predicting adverse outcomes following total hip arthroplasty: a prospective multi-institutional investigation.

Recently, fructosamine has shown promising results in predicting adverse outcomes following total knee arthroplasty. The purpose of this study was to assess the utility of fructosamine to predict adverse outcomes following total hip arthroplasty (THA). A prospective multi-center study involving four institutions was conducted. All primary THA were evaluated for glycemic control using fructosamine levels prior to surgery. Adverse outcomes were assessed at a minimum 1 year from surgery. Primary outcome of interest was periprosthetic joint infection (PJI) based on the International Consensus Meeting (ICM) criteria. Secondary outcomes assessed were superficial infections, readmissions and death. Based on previous studies on the subject, fructosamine levels above 293 µmol/L were used to define inadequate glycemic control. Overall 1212 patients were enrolled in the present study and were available for follow up at a minimum 1 year from surgery. Of those, 54 patients (4.5%) had elevated fructosamine levels (> 293 µmol/L) and these patients were 6.7 times more likely to develop PJI compared to patients with fructosamine levels below 293 µmol/L (p = 0.002). Patients with elevated fructosamine were also associated with more readmissions (16.7% vs. 4.4%, p < 0.007) and a higher mortality rate (3.7% vs. 0.6%, p = 0.057). These associations remained statistically significant in a multi-regression analysis after adjusting for age, comorbidities and length of stay; Adjusted odds ratio were 6.37 (95% confidence interval 1.98-20.49, p = 0.002) for PJI and 2.68 (95% confidence interval 1.14-6.29, p = 0.023) for readmissions. Fructosamine is a good predictor of adverse outcomes in patients undergoing THA and should be used routinely to mitigate morbidity and mortality risk.

Effect of Mini-invasive Floating Metatarsal Osteotomy on Plantar Pressure in Patients With Diabetic Plantar Metatarsal Head Ulcers.

BACKGROUND: Distal metatarsal osteotomy has been used to alleviate plantar pressure caused by anatomic deformities. This study's purpose was to examine the effect of minimally invasive floating metatarsal osteotomy on plantar pressure in patients with diabetic metatarsal head ulcers. METHODS: We performed a retrospective case series of prospectively collected data on 32 patients with diabetes complicated by plantar metatarsal head ulcers without ischemia. Peak plantar pressure and pressure time integrals were examined using the Tekscan MatScan prior to surgery and 6 months following minimally invasive floating metatarsal osteotomy. Patients were followed for complications for at least 1 year. RESULTS: Peak plantar pressure at the level of the osteotomized metatarsal head decreased from 338.1 to 225.4 kPa (P < .0001). The pressure time integral decreased from 82.4 to 65.0 kPa·s (P < .0001). All ulcers healed within a mean of 3.7 ± 4.2 weeks. There was 1 recurrence (under a hypertrophic callus of the osteotomy) during a median follow-up of 18.3 months (range, 12.2-27). Following surgery, adjacent sites showed increased plantar pressure and 4 patients developed transfer lesions (under an adjacent metatarsal head); all were managed successfully. There was 1 serious adverse event related to surgery (operative site infection) that resolved with antibiotics. CONCLUSION: This study showed that the minimally invasive floating metatarsal osteotomy successfully reduced local plantar pressure and that the method was safe and effective, both in treatment and prevention of recurrence. LEVEL OF EVIDENCE: Level III, retrospective case series of prospectively collected data.

2020 Frank Stinchfield Award: Identifying who will fail following irrigation and debridement for prosthetic joint infection.

AIMS: Failure of irrigation and debridement (I&D) for prosthetic joint infection (PJI) is influenced by numerous host, surgical, and pathogen-related factors. We aimed to develop and validate a practical, easy-to-use tool based on machine learning that may accurately predict outcome following I&D surgery taking into account the influence of numerous factors. METHODS: This was an international, multicentre retrospective study of 1,174 revision total hip (THA) and knee arthroplasties (TKA) undergoing I&D for PJI between January 2005 and December 2017. PJI was defined using the Musculoskeletal Infection Society (MSIS) criteria. A total of 52 variables including demographics, comorbidities, and clinical and laboratory findings were evaluated using random forest machine learning analysis. The algorithm was then verified through cross-validation. RESULTS: Of the 1,174 patients that were included in the study, 405 patients (34.5%) failed treatment. Using random forest analysis, an algorithm that provides the probability for failure for each specific patient was created. By order of importance, the ten most important variables associated with failure of I&D were serum CRP levels, positive blood cultures, indication for index arthroplasty other than osteoarthritis, not exchanging the modular components, use of immunosuppressive medication, late acute (haematogenous) infections, methicillin-resistant Staphylococcus aureus infection, overlying skin infection, polymicrobial infection, and older age. The algorithm had good discriminatory capability (area under the curve = 0.74). Cross-validation showed similar probabilities comparing predicted and observed failures indicating high accuracy of the model. CONCLUSION: This is the first study in the orthopaedic literature to use machine learning as a tool for predicting outcomes following I&D surgery. The developed algorithm provides the medical profession with a tool that can be employed in clinical decision-making and improve patient care. Future studies should aid in further validating this tool on additional cohorts. Cite this article: Bone Joint J 2020;102-B(7 Supple B):11-19.

Greater Knee Soft Tissue Thickness Predisposes Patients to Subsequent Periprosthetic Joint Infection After Total Knee Arthroplasty.

BACKGROUND: Although obesity is a risk factor for periprosthetic joint infection (PJI) after total knee arthroplasty (TKA), the role of soft tissue thickness (STT) at the surgical site has not been well studied. This study examined if increased STT in the medial and anterior aspects of the knee are independent risk factors for PJI. METHODS: A retrospective study was conducted on 206 patients who underwent 2-stage exchange arthroplasty for PJI from 2000 to 2015. They were matched 1:3 to a control group of primary, noninfected TKA patients with minimum 2 years infection-free survival by age, gender, age-adjusted Charlson Comorbidity Index, date of surgery, and body mass index (BMI). Two blinded orthopedic surgeons measured the medial STT from the medial aspect of the knee at the level of the joint line on an anteroposterior radiograph, and anterior STT 8 cm above the joint line on a lateral radiograph from the skin to the quadriceps tendon. RESULTS: Increased STT was significantly associated with a higher risk for PJI. The mean anterior STT was 29.74 ± 13.76 mm in the PJI group and 24.88 ± 9.76 mm in the control group. The mean medial STT was 42.42 ± 14.66 mm for PJI and 37.27 ± 12.51 mm for control. Both STT measurements were significantly higher in PJI cases with BMI <30 kg/m2 vs control patients with BMI <30 kg/m2. CONCLUSION: Anterior and medial knee STT was an independent risk factor for PJI after primary TKA and represents a simple radiographic method to assess postoperative infection risk. Excess adipose tissue around the surgical site can predispose patients to PJI after TKA regardless of BMI.