Risk Of Joint Infection Research Articles

Hip & Pelvis

The October 2024 Hip & Pelvis Roundup360 looks at: Does the primary surgical approach matter when choosing the approach for revision total hip arthroplasty?; Time to achieve the minimal clinically important difference in primary total hip arthroplasty: comparison of anterior and posterior surgical approaches; To scope or not to scope: arthroscopy as an adjunct to PAO does not provide better clinical outcomes at one year than PAO alone; Re-exploring horizons in hip resurfacing: two-year results of a ceramic-on-ceramic hip resurfacing; Association between tranexamic acid and decreased periprosthetic joint infection risk in patients undergoing total hip and knee arthroplasty; Octogenarians fare well: in revision for infection age is not a bar.

Usage of Tranexamic Acid for Total Hip Arthroplasty: A Matched Cohort Analysis of 144,344 Patients.

Background: The literature is inconclusive regarding the potential complications of tranexamic acid (TXA), an antifibrinolytic drug, for total hip arthroplasty (THA). The purpose of this study is to compare complication rates and patient outcomes between THA patients administered TXA vs. THA patients not administered TXA. Methods: The TriNetX Research network was utilized to generate a cohort of adult patients who underwent THA between 2003 and 2024. These patients were categorized into two subgroups for the retrospective analysis: (1) patients who received TXA 24 h prior to THA (TXA), and (2) patients who did not receive TXA 24 h prior to total hip arthroplasty (no-TXA). The follow-up period was 30 and 90 days. Results: At 30 days following THA, the TXA patients had a reduced risk of transfusion (risk ratio (RR): 0.412; 95% confidence intervals (CI): 0.374, 0.453), reduced risk of DVT (RR: 0.856; CI: 0.768, 0.953), reduced risk of joint infection (RR: 0.808; CI: 0.710, 0.920), but a higher rate of periprosthetic fracture (RR: 1.234; CI: 1.065, 1.429) compared to patients who did not receive TXA. At 90 days following THA, TXA patients had a reduced risk of transfusion (RR: 0.446; CI: 0.408, 0.487), DVT (RR: 0.847; CI: 0.776, 0.924), and periprosthetic joint infection (RR: 0.894; CI: 0.815, 0.982) compared to patients who did not receive TXA. Patients who received TXA had higher rates of periprosthetic fracture (RR: 1.219; CI: 1.088, 1.365), acute postoperative anemia (RR: 1.222; CI: 1.171, 1.276), deep surgical site infection (SSI) (RR: 1.706; CI: 1.117, 2.605), and superficial SSI (RR: 1.950; CI: 1.567, 2.428) compared to patients who did not receive TXA. Conclusions: Patients receiving TXA prior to THA exhibited significantly reduced the prevalence of blood transfusions, DVT, and periprosthetic joint infection following THA. However, superficial SSI and periprosthetic fracture were seen with higher rates in the TXA cohort than in the no-TXA cohort.

Dilution of humoral immunity: Results from a natural history study of healthy total knee arthroplasty patients.

The incidence of prosthetic joint infection (PJI) following elective primary total knee arthroplasty (TKA) is very low but serious risk remains. To identify unknown risk factors, we completed a natural history study of IgG specific forStaphylococcus aureus antigens previously phenotyped as protective (anti-Atl) and pathogenic (anti-Isd). Twenty-five male and 25 female optimized patients 50-85 years of age and BMI 24-39 undergoing primary TKA were prospectively enrolled. Blood sampling was performed preoperatively, postoperative Day 1, and at 2, 6, and 12 weeks, to assess serum cytokine, anti-staphylococcal IgG levels and anti-tetanus toxoid IgG measured via custom Luminex assay. Clinical, demographic, and PROMIS-10 data were collected with outcomes to 2 years postop. All participants completed the study and 2-year follow-up. No patients were readmitted or noted to develop a surgical site infection or serious adverse event, and patient-reported outcomes were improved. Serology revealed a highly significant decrease in six out of eight antibody titers against specific S. aureus antigens on Day 1 (p < 0.0001), five of which normalized to preoperative levels within 2 weeks. These changes were commensurate with a decrease and recovery of anti-tetanus toxoid titers, and a 20% drop in hemoglobin 13.8 ± 1.7 at preop to 11.1 ± 1.8 mg/dL on Day 1 (p < 0.0001). After TKA, a significant decrease in humoral immunity commensurate with blood loss and hemodilution was recorded. This decrease in circulating anti-staphylococcal antibodies in the early postop period may represent a periprosthetic joint infection risk factor for patients.

Platelet-rich plasma intra-articular knee injections from open preparation techniques do not pose a higher risk of joint infection: A systematic review of 91 randomized controlled trials and 5914 injections.

To compare the infection rate of intraarticular platelet-rich plasma (PRP) knee injections between open and closed techniques in randomized controlled trials (RCTs) published in the last decade. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, PubMed, Scopus and Virtual Health Library were accessed in October 2022 using the terms 'platelet-rich plasma', 'PRP', 'knee' and 'tibiofemoral' alone and in combination with Boolean operators AND/OR. RCTs published during the last 10 years evaluating PRP intra-articular knee injections were considered eligible. Studies were excluded if the kit/preparation technique was not described. Data were presented using individual studies' absolute values, totals, and pooled percentages. Publication bias was assessed using the ROBIS tool. Ninety-one studies met the predetermined eligibility criteria. Forty-one implemented a closed technique, while 50 were open. All studies implementing a closed technique disclosed their commercial kits. Only 16 studies (17.58%) failed to report joint infections. Among the studies reporting joint infections as outcomes, 30 implemented a closed technique with 1195 patients, 1921 intra-articular knee injections and 95.44% of patient follow-up. On the other hand, 45 of them implemented an open technique with 2290 patients, 3993 intra-articular knee injections and 97.07% of patient follow-up. No patient had a joint infection among the included studies. Thirty-three studies prepared their PRP in controlled environments (36.26%). Most studies did not report where the preparation occurred (48.35%). Only twelve studies disclosed using laminar flow during preparation (13.19%). The infection rate for both techniques was 0 per 1000 knee injections. Open PRP preparation techniques do not pose a higher risk of joint infection and can lower manufacturing costs when appropriate facilities are available. However, PRP preparation setting and laminar flow implementation data are deficient, and minimal requirements for good manufacturing practices demand further studies while adhering to local and regional regulations. Level I, systematic review of RCTs.

Antibiotic Laden Bone Cement Does Not Reduce Acute Periprosthetic Joint Infection Risk in Primary Total Knee Arthroplasty

BackgroundPeriprosthetic joint infection (PJI) can be a serious complication of total knee arthroplasty (TKA). A method believed to decrease the incidence of PJI is antibiotic-laden bone cement (ALBC). Current clinical practice guidelines do not recommend ALBC in primary TKA. The purpose of this study was to compare ALBC to plain cement (PC) in preventing PJI in primary TKA. MethodsThis retrospective analysis included 109,242 Medicare patients in the American Joint Replacement Registry who underwent a cemented primary TKA from January 2017 to March 2021, and had at least 1 year of follow-up. Patients who received ALBC were compared to patients who received PC. Demographic and case-specific variables such as age, sex, race, body mass index, Charlson Comorbidity Index, anesthesia type, and operative time were used to create propensity scores. A logistic regression was run to predict the probability of receiving ALBC. Also, a multivariate model was run on the full unstratified population, using the same covariates as were used to create the propensity model. The primary outcome was differences in PJI rates. ResultsLogistic regression analysis showed that a higher preoperative diagnosis of osteoarthritis, higher Charlson Comorbidity Index, higher body mass index, women, race, and anesthesia requirements increased a patient’s probability of receiving ALBC. In the full unstratified multivariate model, ALBC did not show a statistically significant difference in risk of revision for infection compared to PC. ConclusionsThe use of ALBC in primary TKA has not been shown to be more efficacious in preventing PJI within the population of Medicare patients in the United States. However, this study is limited given it is a retrospective database study that may inherently have biases and the large dataset has a potential for overpowering the findings.

Enhancing Endogenous Hyaluronic Acid in Osteoarthritic Joints with an Anti-Inflammatory Supramolecular Nanofiber Hydrogel Delivering HAS2 Lentivirus.

Osteoarthritis (OA) management remains challenging because of its intricate pathogenesis. Intra-articular injections of drugs, such as glucocorticoids and hyaluronic acid (HA), have certain limitations, including the risk of joint infection, pain, and swelling. Hydrogel-based therapeutic strategies have attracted considerable attention because of their enormous therapeutic potential. Herein, a supramolecular nanofiber hydrogel is developed using dexamethasone sodium phosphate (DexP) as a vector to deliver lentivirus-encoding hyaluronan synthase 2 (HAS2) (HAS2@DexP-Gel). During hydrogel degradation, HAS2 lentivirus and DexP molecules are slowly released. Intra-articular injection of HAS2@DexP-Gel promotes endogenous HA production and suppresses synovial inflammation. Additionally, HAS2@DexP-Gel reduces subchondral bone resorption in the anterior cruciate ligament transection-induced OA mice, attenuates cartilage degeneration, and delays OA progression. HAS2@DexP-Gel exhibited good biocompatibility both in vitro and in vivo. The therapeutic mechanisms of the HAS2@DexP-Gel are investigated using single-cell RNA sequencing. HAS2@DexP-Gel optimizes the microenvironment of the synovial tissue by modulating the proportion of synovial cell subpopulations and regulating the interactions between synovial fibroblasts and macrophages. The innovative nanofiber hydrogel, HAS2@DexP-Gel, effectively enhances endogenous HA production while reducing synovial inflammation. This comprehensive approach holds promise for improving joint function, alleviating pain, and slowing OA progression, thereby providing significant benefits to patients.

Association Between Tranexamic Acid and Decreased Periprosthetic Joint Infection Risk in Patients Undergoing Total Hip and Knee Arthroplasty: A Systematic Review and Meta-Analysis of Over 2 Million Patients

BackgroundThe purpose of this study was to perform a systematic review and meta-analysis to evaluate the association between tranexamic acid (TXA) use during primary total hip arthroplasty (THA) and primary total knee arthroplasty (TKA), and the risk of developing periprosthetic joint infection (PJI) after these procedures. MethodsA systematic review was carried out from inception to October 17, 2022. There were 6 studies that were ultimately included in the meta-analysis. The association between the development of PJI and TXA was analyzed using odds ratios (ORs) with 95% confidence intervals (CIs) and estimates of risk difference (RD). Subgroup analysis was performed to evaluate only studies reporting out to 90 days of follow-up versus more than 90 days of follow-up. ResultsAmong 2,098,469 arthroplasties, TXA utilization was associated with an overall lower risk of PJI (OR = 0.63 [95% CI 0.42 to 0.96], P < .001) and a 0.4% lower incidence of PJI (RD = −0.0038, 95% CI [-0.005 to −0.002], P < .001). When subgrouping the studies according to length of follow-up, TXA was associated with a lower risk of PJI (OR = 0.43 [95% CI 0.35 to 0.53], P < .001) and a 1% lower incidence of PJI (RD = −0.0095 [95% CI −0.013 to −0.005], P < .001) in patients followed for more than 90 days. ConclusionsThis meta-analysis demonstrates that TXA use is associated with a reduced risk of PJI, with our RD analysis identifying an approximately 0.4% reduction in PJI rates with TXA use. These findings provide even more data to support the routine use of TXA during primary THA and primary TKA.

Revision Surgery Risk After Open Reduction and Internal Fixation Versus Acute Total Hip Arthroplasty in Geriatric Acetabular Fractures: A Nationwide Study.

The aging population has contributed to a rising incidence of acetabular fractures in older patients, yet current evidence guiding surgical treatment is limited by small sample sizes. This study used a nationwide database to investigate outcomes in older patients undergoing open reduction and internal fixation (ORIF) versus acute total hip arthroplasty (THA). The PearlDiver database was queried for patients aged 60 years and older with an acute acetabular fracture who underwent ORIF or acute THA (2010 to 2021). ORIF patients were matched 1:1 to THA patients based on age, sex, US region, insurance plan, and Charlson Comorbidity Index score. Patients with less than 2 years of follow-up were excluded. The primary outcome was revision surgery. Of 120,032 patients with an acetabular fracture, 3,768 (3.1%) underwent surgical treatment: 1,482 (39.3%) THA and 2,286 (60.7%) ORIF. Mean age was 71.0 ± 6.51 years. Mean follow-up duration was 5.2 ± 2.1 years. THA patients were slightly older (72.4 versus 70.2 years), had higher Charlson Comorbidity Index scores (3.3 versus 2.7), and had a higher percentage of female patients (62.5% versus 32.2%). After matching, 962 ORIF and 962 THA patients were included. ORIF patients had longer LOS (10.7 versus 8.1 days). ORIF patients were less likely to experience joint infections and periprosthetic fractures, but more likely to experience transfusions. The overall revision surgery rate within 10 years was 14.8% in the ORIF cohort and 6.2% in the THA cohort. In the ORIF cohort, 13.5% of patients had a delayed conversion to THA. In this large national database, acute with or without internal fixation for geriatric acetabular fractures was associated with lower rates of revision surgery within 10 years when compared with a matched cohort undergoing ORIF. ORIF was associated with increased LOS, increased transfusion risk, and lower risk of joint infection and periprosthetic fracture. III.

Periprosthetic Joint Infection Risk After Primary Total Knee Arthroplasty: Are All Preoperative Corticosteroid Injections the Same?

BackgroundPrevious evidence has demonstrated an increased risk of periprosthetic joint infection (PJI) following primary total knee arthroplasty (TKA) in patients receiving corticosteroid injection (CSI) within 3 months of surgery. The study aimed to determine if PJI risk after TKA varied among different corticosteroid agents. MethodsA total of 85,073 patients undergoing primary TKA from 2009 to 2019 were identified from a large national database. Of these, 1,092 (1.3%) received an ipsilateral, intra-articular CSI within 90 days of TKA. These patients were compared to those not receiving CSI using multivariate logistic regressions following 1:4 propensity score matching, with PJI development as the primary outcome. ResultsPatients given an injection of any corticosteroid within 90 days of TKA had significantly higher PJI rates compared to controls (1.6 versus 0.41%; P < .001). This finding was driven by patients receiving methylprednisolone acetate (n = 543) or betamethasone (n = 153), with prevalence rates of 1.7 and 2.6%, respectively (P = .003 and P = .01, respectively). No significant increase in the rate of PJI was observed for patients receiving triamcinolone (1.2%; P = .08; n = 342) or dexamethasone (0.0%; P = 1; n = 54) within 90 days preceding TKA. PJI risk for all agents, administered more than 90 days preoperatively normalized to control levels (0.51 versus 0.34%). ConclusionsThese results suggest that PJI risk varies with CSI type. In this large database study, only patients given methylprednisolone acetate or betamethasone injections within 90 days of surgery had significantly higher PJI rates compared to controls.

Foot &amp; Ankle

The August 2023 Foot &amp; Ankle Roundup360 looks at: Achilles tendon rupture: surgery or conservative treatment for the high-demand patient?; First ray amputation in diabetic patients; Survival of ankle arthroplasty in the UK; First metatarsophalangeal joint fusion and flat foot correction; Intra-articular corticosteroid injections with or without hyaluronic acid in the management of subtalar osteoarthritis; Factors associated with nonunion of post-traumatic subtalar arthrodesis; The Mayo Prosthetic Joint Infection Risk Score for total ankle arthroplasty.

Application of the Mayo Periprosthetic Joint Infection Risk Score for Total Ankle Arthroplasty.

Assessing patient's risk of infection is fundamental for prevention of periprosthetic joint infection (PJI) after total ankle arthroplasty (TAA). The Mayo Prosthetic Joint Infection Risk Score (Mayo Score) is based on data from total hip and knee arthroplasty and has not been validated for application for TAA. A total of 405 consecutive TAA cases were followed for 6 months for PJI. Individual patients' Mayo Scores were calculated and analyzed with logistic regression and receiver operating characteristic (ROC) for predictability for PJI. A critical cut-off Mayo Score for patients at high risk of PJI was determined by best Youden index. Among the Mayo Score-defined high-risk patients, the contribution of different risk factors were compared between the PJI and non-PJI patients. There were 10 cases of PJI (2.5%) among the 405 cases within 6 months after TAA. Of the 405 patients, the Mayo Scores ranged between -4 and 13 (median 2; interquartile range 0-5). The average Mayo Score was 2.5 ± 3.4 in the non-PJI patients and 7.7 ± 3.1 in the PJI patients (P < .001). Logistic regression showed that the probability of PJI increased with higher Mayo Scores (odds ratio 1.48, 95% CI 1.23-1.78). All but 1 PJI patients had a Mayo Score >5. The sensitivity and specificity were 90.0% and 84.3%, respectively, when a Mayo Score >5 was used as a criterion for high risk of PJI. This study demonstrated that the Mayo Score could similarly predict PJI risk after TAA as in total hip and knee arthroplasty. Data analysis suggests that a Mayo Score >5 could be a criterion for identifying high-risk patients for PJI, although further validation with a large number of PJI cases is necessary. Level II, developing diagnositic criteria with consecutive cases.

Validation of the Mayo Periprosthetic Joint Infection Risk Score for Total Ankle Arthroplasty

Category: Ankle; Other Introduction/Purpose: Periprosthetic joint infection (PJI) is a devastating complication of arthroplasty. The well known PJI risk factors are useful for identifying high-risk patients but would be even more helpful for clinical decision-making if they are converted to a risk assessment scores. The Mayo Prosthetic Joint Infection Risk Score was based on the data of total hip and knee arthroplasty and has not been validated for application for total ankle arthroplasty. Methods: A series of 398 consecutive cases of total ankle arthroplasty, with minimal follow-up of 6 months, was reviewed for Mayo Periprosthetic Joint Infection Risk Score (Mayo score) and PJI. The patients' Mayo scores and PJI was examined by logistic regression. T-test was performed to compare the Mayo score between the non-infected TAA cases and infected cases. Receiver Operating Characteristic (ROC) was used to identify the critical value of Mayo score for total ankle arthroplasty. Results: There were 12 cases of PJI or 3.0% in the series. Of the 398 patients, the Mayo scores were in the range from -4 to 13 (median 2; interquartile range (IQR) 0-4). Preliminary analysis showed that, by logistic regression, the probability of PJI was increased as increases of the Mayo scores (Fig A). The mean Mayo score of the PJI patients (8.6+-1.8) was significantly greater than the rest of the patients (mean Mayo score 1.9+-3.4; p &lt; .0001). ROC analysis showed that, when a Mayo score was greater than 5, the patient has a high probability of PJI (sensitivity = 100%; specificity = 86.9%; Fig B). Conclusion: This study showed a high correlation between the Mayo score and PJI in total ankle arthroplasty, which is the same trend as in total knee and hip arthroplasty. The preliminary results suggest that strategically focusing on the patients, who have a Mayo score &gt; 5, could be a more efficient approach to prevent PJI after total ankle arthroplasty.

How do pre-operative intra-articular injections impact periprosthetic joint infection risk following primary total hip arthroplasty? A systematic review and meta-analysis.

Although intra-articular injections (IAIs) serve as the first-line non-surgical management for severe osteoarthritis (OA), recent analyses have suggested they are associated with an increased infection risk following primary total hip arthroplasty (THA). Therefore, our systematic review and meta-analysis explored the relationship between IAIs and periprosthetic joint infection (PJI) following THA reported in the current literature. Five online databases were queried for analyses published from January 1st, 2000-May 1st, 2021 reporting on PJI rates between patients undergoing primary THA who did and did not preoperatively receive an IAI. The overall pooled effect of injection status on PJI incidence was determined using Mantel-Haenszel (M-H) models. This was similarly conducted for segregated preoperative intervals: 0-3months, > 3-6months, > 6 + months. A total of 11 articles were included in our analysis reporting on 278,782 THAs (IAI: n = 41,138; no IAI: n = 237,644). Patients receiving pre-operative injections had a significantly higher risk of PJI (OR: 1.31, 95% CI 1.07-1.62; p = 0.009). However, this finding was not robust. IAI receipt within 3-months of THA was associated with significantly higher PJI rates (OR: 1.68, 95% CI 1.48-1.90; p < 0.001). However, no significant difference was demonstrated in the > 3-6month (OR: 1.19, 95% CI 0.94-1.52; p = 0.16) and > 6 + month sub-analyses (OR: 1.20, 95% CI 0.96-1.50; p = 0.11). The results of all sub-analyses remained were robust. Our findings suggest that patients requiring THA should wait at least 3-months following IAI to reduce post-operative infection risk. This information can help inform patients considering OA management options, as well as adult reconstruction surgeons during preoperative optimization.

Soft-tissue thickness radiographic measurement: a marker to evaluate acute periprosthetic joint infection risk in total hip replacement.

The objective of our study was to evaluate the association between acute periprosthetic joint infection (APJI) and radiographic measurement of soft-tissue thickness in elective total hip replacement surgery. A case-control study was conducted to compare the soft-tissue thickness radiographic measurement (SRM) at the hip in patients diagnosed with APJI based on Tsukayama et al. (2003) criteria after total hip replacement with patients that were not infected, at a single institution from 2013 to 2019. To minimize selection bias, each case was matched with two controls using the following methodology: patients of the same sex, with an age variation of 5 years, and nearest in surgery date to the cases were selected. All postoperative radiographs were performed in the first 24 h after total hip arthroplasty (THA) surgery as it is protocolized in our institution. Soft-tissue thickness radiographic measurement was defined as the distance from the tip of the greater trochanter to the skin following a perpendicular line to the femoral diaphysis in postoperative anteroposterior hip radiographs. In total, 78 patients were included (26 cases and 52 controls). The SRM median of the cases was 76.19 mm (SD: 26.518) and 53.5 mm (SD: 20.47) in controls. A multivariate logistic regression model showed an independent association between APJI and SRM (odds ratio (OR) 1.033, 95 % confidence interval (CI) 1.007–1.059, .012). Patients with an SRM greater than 60 mm had a 7-fold increase in the odds of APJI (OR 7.295, 95 % CI 2.364–22.511, .001). The results of our study suggest an association between large SRM at the hip and the risk of APJI in patients with primary total hip arthroplasty. SRM may be a helpful and easy tool for evaluating the risk of APJI before elective primary total hip replacement surgery.

Intra-Articular Corticosteroid or Hyaluronic Acid Injections Are Not Associated with Periprosthetic Joint Infection Risk following Total Knee Arthroplasty.

This study evaluated whether the preoperative use and timing of the use of hyaluronic acid (HA) and/or corticosteroid (CS) injections were associated with an increased risk of periprosthetic joint infections (PJIs) following primary total knee arthroplasty (TKA). We tested the hypothesis that preoperative injection of HA or CS within 3 months prior to primary TKA was associated with an increased risk of PJI by specifically evaluating the association between PJI risk and (1) injection type; (2) timing; (3) patient demographic factors; and (4) surgery-related factors, such as surgeon injection volume, knee arthroscopy (pre- and postoperative), and hospital length of stay. The 5% Medicare part B claims database was queried for patients who received CS and/or HA injections. Cox proportional hazards regressions evaluated the risk of PJIs after TKA, adjusting for patient and clinical factors, as well as propensity scores. The unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 0.89% for the HA group, 0.96% for both CS and HA group, and 0.75% for those who did not use HA or CS in the 12 months before TKA. For patients who used HA and/or CS within 3 months prior to TKA, the unadjusted incidence of PJI at 2-year post-TKA was 0.75% for the CS group, 1.07% for the HA group, and 1.00% for both CS and HA group, compared with 0.77% for those who did not use HA or CS. The number of injections performed per year was inconsistently associated with PJI risk. Overall, we found that intra-articular injections given within the 4-month period prior to TKA were not associated with elevated PJI risk (evaluated at 1, 3, 12, and 24 months after the index TKA) within the elderly Medicare patient population.

Evaluation of results of arthroscopic debridement and lavage with injection of hylan polymer in the management of osteoarthritis of knee

Objective: An evaluation of safety and efficacy of high molecular weight hyaluronic acid (HA) delivered at the time of arthroscopic debridement of the osteoarthritic knee. Methods: Thirty-four consecutive patients who met inclusion and exclusion criteria underwent arthroscopic debridement by a single surgeon and concomitant delivery of 6 ml/90 mg HA. These patients were evaluated preoperatively, at 3 months, 6 months and 9 months postoperatively. Evaluations consisted of WOMAC pain score and complications. Results: No complications occurred during this study. Pre-op average mean WOMAC pain score was 65.050 (n = 34) and 80.544 at 3 months (n = 34). Final average WOMAC pain score improved to 79.994 at six months (n = 34). No patients had deterioration of the WOMAC pain score. Conclusion: The results show that concomitant delivery of high molecular weight hyaluronan is safe when given at the time of arthroscopic debridement of the osteoarthritic knee. By delivering HA at the time of the arthroscopic debridement, there may be a decreased risk of joint infection and/or injection site pain. Furthermore, the combination of both procedures show efficacy in change of WOMAC pain scores.

BMI is a Better Predictor of Periprosthetic Joint Infection Risk Than Local Measures of Adipose Tissue After TKA

BackgroundBoth body mass index (BMI) and local measures of adiposity at the surgical site have been identified as independent risk factors for periprosthetic joint infection (PJI) (periprosthetic joint infection) after total knee arthroplasty (TKA). We aimed to 1) evaluate previously used measures of assessing knee adiposity and 2) determine the best measure for predicting both surgical duration and PJI after TKA. MethodsWe performed a multicentre retrospective review of 4745 patients who underwent primary TKA between January 2013 and December 2016. Patient demographic information, surgical duration and postoperative infection status within one year were obtained. Preoperative weight-bearing AP and lateral x-rays were analyzed to determine prepatellar adipose thickness, bony width of the tibial plateau, and total soft tissue knee width. The knee adipose index (KAI) was calculated from the ratio of bone to total knee width. ResultsWe observed substantial variability in both local measures of adiposity compared with BMI. Neither measure of local knee adipose showed a significant correlation with PJI risk. By contrast, there was a strong correlation between PJI risk and BMI >35 (odds ratio 2.9, 95% CI 1.4-6.1). Surgical duration increased with both BMI and measures of local adipose tissue (KAI and prepatellar fat thickness). ConclusionLocal adipose deposition varies greatly for any given BMI. In this study, BMI was a better predictor of PJI after TKA than local measures of knee adipose tissue.

Cobalt and Chromium Ion Release in Metal-on-Polyethylene and Ceramic-on-Polyethylene THA: A Simulator Study With Cellular and Microbiological Correlations

BackgroundThe aims of this study were to determine the levels of cobalt (Co) and chromium (Cr) ions generated in simulators from metal-on-polyethylene (MoP) and ceramic-on-polyethylene (CoP) constructs. Furthermore, we aimed to investigate the cytotoxic effect of these ion levels on native tissues and their potential to modify periprosthetic joint infection risk. MethodsWe used in vitro culture of human adipose-derived mesenchymal stem cells (AMSCs) and Staphylococcus epidermidis cultures, respectively. Ten hip simulator constructs (5 MoP and 5 CoP) were assembled and run for 1,000,000 cycles in bovine serum and evaluated for CoCr concentration. Cytotoxicity and growth impact on AMSCs and S. epidermidis was compared between CoCr and inert silicon dioxide. ResultsAfter 1,000,000 cycles, mean MoP and CoP Co concentration was 2264 and 0.6 ng/mL, respectively (P < .001). Mean MoP and CoP Cr concentration was 217 and 4.3 ng/mL, respectively (P < .001). Mean MoP Co:Cr ratio was 10:1. Co ions were significantly more toxic to human AMSCs than control silicon dioxide in a dose-response manner (P < .001). S. epidermidis growth was not significantly impacted by Co concentrations observed in the simulators. ConclusionMoP constructs built in ideal conditions generated substantial CoCr debris, highlighting a baseline risk with these implants that may be exacerbated by host factors or imperfect surgical technique. Evaluation of impact on AMSCs suggests that debris levels produced under simulator conditions can be cytotoxic. In addition, these concentrations did not potentiate or inhibit S. epidermidis growth, suggesting that elevated periprosthetic joint infection rates with adverse local tissue reaction are related to other factors potentially associated with tissue necrosis.

Periprosthetic Joint Infection Risk After Total Joint Arthroplasty: There's Still More to Know: Commentary on an article by Ian Duensing, MD, et al.: "Patients with Type-1 Diabetes Are at Greater Risk of Periprosthetic Joint Infection. A Population-Based, Retrospective, Cohort Study".

Periprosthetic Joint Infection Risk After Total Joint Arthroplasty: There's Still More to Know: Commentary on an article by Ian Duensing, MD, et al.: "Patients with Type-1 Diabetes Are at Greater Risk of Periprosthetic Joint Infection. A Population-Based, Retrospective, Cohort Study".

Total Knee Arthroplasty: The Efficacy of Calcium Sulfate Beads in One-Stage Aseptic Revision

Background: The risk of periprosthetic joint infection following revision total knee arthroplasty is high, as is the cost of care. Decreasing periprosthetic joint infection risk may include utilization of calcium sulfate beads. Calcium sulfate beads have been gaining momentum in treating infected joints because of their potential advantages, including antibiotic elution and dissolvability. However, literature documenting their utilization in aseptic revision is sparse. This study compares: 1) infection rates; 2) length of stay; 3) subsequent infection procedures; and 4) final surgical outcome between one-stage aseptic revision total knee arthroplasty patients who received calcium sulfate beads and those who did not. Methods: We performed a retrospective chart review to identify patients who underwent aseptic one-stage revision total knee arthroplasty between January 2013 and December 2017. Outcomes collected included postoperative infection rate, length of stay, subsequent irrigation and debridement, and final surgical outcome, classified as a successful total knee arthroplasty reimplantation, a retained antibiotic spacer, or an above knee amputation. Chi-square analysis was used to analyze all categorical variables, while Student’s t-testing was used for continuous variables. A p-value of 0.5 was set as the threshold for statistical significance. Results: Calcium sulfate bead patients did not differ from non-calcium sulfate bead patients with regard to the number of postoperative infections (p=0.103), lengths of stay (p=0.210), irrigation and debridement procedures (p=0.063) and surgical outcome (p=0.085). Conclusion: Patients who received calcium sulfate beads had analogous surgical outcomes and infection rates to non-calcium sulfate bead patients. The use of calcium sulfate beads in aseptic one-stage revision total knee arthroplasty may not be beneficial in preventing infection and reducing costs.