Declining Trends in Septic Revision Following Total Knee Arthroplasty From 2010 to 2019: A National Cohort Analysis.

INTRODUCTION: Periprosthetic joint infections (PJI) following total knee arthroplasty (TKA) are associated with high patient morbidity, mortality, and healthcare costs. Methods to reduce the burden of PJI have been shown to be efficacious on a small scale. On a national scale, it is unknown whether these methods have reduced PJI rates. METHODS: A retrospective trend analysis was conducted using a national database. The incidence of 2-year septic revision was observed for the entire cohort and patients who had high-risk co-morbidities from 2010 to 2019. A multivariable logistic regression was performed to compare the odds ratios of 2-year septic revision rates from 2011 to 2019 to the reference year of 2010. Linear regression was used to compare the change throughout this period in the overall and high-risk sub-analysis groups. RESULTS: Among the 860,185 patients, 5,589 underwent septic revision within 2 years. The 2-year septic revision rate decreased from 0.75% in 2010 to 0.69% in 2019 (compounded annual growth rate [CAGR] = -0.94%, P = 0.049). Multivariable logistic regressions demonstrated that the odds of septic revision in 2019 were significantly lower than those in 2010 (OR [odds ratio]: 0.83, 95% CI [confidence interval]: [0.70 to 0.96], P = 0.017). In high-risk patients, the septic revision rate decreased from 1.04 to 0.80% (CAGR = -2.80%, P = 0.004), specifically in those who had a history of psychoses, Medicaid insurance, anemia, heart failure, obesity, liver disease, tobacco use, and drug abuse (P < 0.05 for all). DISCUSSION: This study demonstrates a national reduction in the 2-year septic revision rate in all TKA patients, including patients considered at high risk for PJI. This suggests current preventative methods may be efficacious on a national scale in TKA. Further research is needed to identify more modalities to reduce the national incidence of this morbid and costly complication.

Reassessing Glycemic Control: A Novel Method for 90-Day Major Complication Stratification Based on Hemoglobin A1c and Same-Day Glucose Levels for Patients Undergoing Total Knee Arthroplasty.

INTRODUCTION: Glucose levels obtained on day of surgery may be predictive of complications following total knee arthroplasty (TKA). Established glucose thresholds for TKA are either non-specific or have low predictive power. Therefore, the purpose of this study was to create data-driven hemoglobin A1c (HbA1c) and same-day glucose thresholds associated with varying risks of 90-day major and surgical site infection (SSI) complications following TKA. METHODS: Stratum-specific likelihood ratio analysis was conducted to determine data-driven HbA1c and glucose strata associated with varying risks of 90-day major and SSI complications. Each strata was then propensity-score matched to the lowest strata based on age, sex, hypertension, heart failure, chronic obstructive pulmonary disorder, and obesity. The risk ratio (RR) for complications in each stratum with respect to the lowest matched stratum was analyzed. RESULTS: Four data-driven HbA1c (%) strata (4.5 to 5.9, 6.0 to 6.4, 6.5 to 7.9, and 8.0+) and two same-day glucose (mg/dl) strata (60 to 189 and 190+) were identified that predicted 90-day major complications. When compared to the propensity-matched lowest strata (4.5 to 5.9%), the risk of 90-day major complications sequentially increased as the HbA1c (%) strata increased: 6.0 to 6.4 (RR: 1.23; P = 0.024), 6.5 to 7.9 (RR 1.38; P < 0.001), 8.0+ (RR 2.0; P < 0.001). When compared to the propensity-matched lowest strata (60 to 189 mg/dl), the 190+ mg/dl strata had a higher risk of 90-day major complications (RR: 1.18; P = 0.016). No HbA1c or same-day glucose strata had significantly different risks of 90-day SSI. CONCLUSION: The multiple strata identified for HbA1c demonstrate that a single HbA1c cut-off as identified in prior literature may be missing a larger picture for risk stratification. The threshold identified for same-day glucose can be utilized in day-of-surgery glycemic control guidelines to further reduce the risk of 90-day major complications.

Increased Risk of 10-Year Revision Following Total Hip Arthroplasty for Femoral Neck Fracture.

BACKGROUND: As the incidence of femoral neck fractures (FNFs) increases with the aging population, understanding its impact on surgical outcomes is important to improving implant survival and patient satisfaction. Despite increasing use of total hip arthroplasty (THA) as management for FNF, few studies have examined long-term implant survivability. Thus, this study sought to determine the 10-years cumulative incidence of revision and indications for revision in patients undergoing THA for FNF in comparison to osteoarthritis. METHODS: Patients who underwent primary THA for FNF or osteoarthritis were identified using a national administrative claims database and propensity-score matched in a 1:2 ratio based on age, gender, the Charlson Comorbidity Index (CCI), smoking, obesity, and diabetes mellitus. Kaplan-Meier and Cox proportional hazards analyses were used to observe the cumulative incidence and risk of all-cause revision, periprosthetic joint infection (PJI), dislocation, mechanical loosening, and periprosthetic fracture (PPF) within 10 years of primary THA. In total, 19,735 patients who underwent THA for FNF and 39,383 patients who underwent THA for osteoarthritis were included. RESULTS: The 10-years cumulative incidences of all-cause revision (7.1 versus 4.9%), PJI (5.0 versus 3.3%), dislocation (6.8 versus 3.8%), mechanical loosening (3.1 versus 1.9%), and PPF (7.8 versus 4.0%) were significantly higher for those who underwent THA for FNF versus osteoarthritis. Femoral neck fractures were associated with higher risks of revision (hazard ratio [HR]: 1.6), PJI (HR: 1.7), dislocation (HR: 2.0), mechanical loosening (HR: 1.6), and PPF (HR: 2.2) (P < 0.001 for all). CONCLUSIONS: Despite the advantages of THA, femoral neck fractures remain a major risk factor for long-term complications. Tailored preoperative planning, surgical techniques, and postoperative bone health optimization in these patients may help minimize poor outcomes.

No Difference in 30-day Mortality Between Patients Undergoing Bilateral Simultaneous Total Knee Arthroplasty With Technology Assistance Compared to Conventional Instrumentation.

Background: Bilateral simultaneous total knee arthroplasty (BSTKA) has decreased in frequency due to concerns about higher rates of early mortality and complications than unilateral or staged surgeries. Purpose: We sought to evaluate whether technology assistance (encompassing robotics and computer assistance) decreases early mortality following BSTKA. Methods: We conducted a retrospective cohort study using a national all-payer claims database. Patients who underwent BSTKA from October 2015 to December 2020 were identified. Univariate and multivariable analyses were conducted to compare outcomes in patients who underwent BSTKA with technology assistance compared to conventional instrumentation. The primary outcome was 30-day postoperative mortality. Secondary outcomes were respiratory failure and fat embolism. A post-hoc analysis was performed to evaluate length of stay, readmission, and other medical complications. Results: A total of 14,870 patients who underwent BSTKA were included in this study. Of these, 860 patients underwent technology-assisted BSTKA, and 14,010 patients underwent BSTKA without technology assistance. After a multivariable analysis, patients who underwent technology-assisted BSTKA had equivalent odds of 30-day mortality compared to those who underwent BSTKA without technology assistance. Technology assistance was not protective against the development of acute respiratory failure or fat embolism. Conclusion: This retrospective cohort study found no differences in the rates of 30-day mortality, respiratory failure, or fat embolism after technology-assisted BSTKA compared to conventional BSTKA. On the post-hoc analysis, technology use was associated with a decreased length of stay, lower readmission risk, and decreased rates of deep vein thrombosis, pulmonary embolism, and blood transfusion.

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 for Staphylococcus 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.

Identification of Data-Driven Preoperative Hemoglobin Strata That Predict the Likelihood of Blood Transfusion and the Risk of Major Complications and Prosthetic Joint Infection After Total Hip Arthroplasty.

INTRODUCTION: Preoperative anemia is an independent risk factor of complications after primary total hip arthroplasty (THA). Currently used hemoglobin thresholds are not developed for risk stratification of arthroplasty patients and do not provide surgery-specific information on postoperative complication risk. Thus, we aimed to calculate THA-specific preoperative hemoglobin strata that observe the likelihood of 90-day blood transfusion and determine whether these strata are associated with increased risk of 90-day complications and 2-year prosthetic joint infection (PJI). METHODS: A retrospective cohort analysis identified 56,101 patients who underwent primary THA from 2013 to 2022. Using the lowest hemoglobin value for each patient one month before THA, stratum-specific likelihood ratio (SSLR) analysis calculated sex-based hemoglobin strata associated with the likelihood of 90-day postoperative blood transfusion. Propensity score matching was performed. Incidence rates and risk of 90-day major complications and 2-year PJI were observed for each identified preoperative hemoglobin stratum. RESULTS: SSLR analysis identified five male (strata, likelihood ratio [<10.4 g/dL, 12.5; 10.5 to 11.4 g/dL, 8.0; 11.5 to 12.4 g/dL, 2.4; 12.5 to 13.4 g/dL, 1.3; 13.5 to 13.9 g/dL, 0.5]) and five female (<8.9 g/dL, 10.7; 9.0 to 10.9 g/dL, 4.0; 11.0 to 11.4 g/dL, 2.0; 12.0 to 12.9 g/dL, 1.0; 13.0 to 13.4 g/dL, 0.6) preoperative hemoglobin strata associated with varying likelihoods of 90-day blood transfusion after THA. After matching in both male and female cohorts, as the calculated preoperative hemoglobin strata decreased, the relative risk of overall 90-day major complications and 2-year PJI increased incrementally (all P < 0.05). CONCLUSION: SSLR analysis established THA-specific sex-based preoperative hemoglobin strata that observe the likelihood of 90-day blood transfusion and predict the risk of 90-day medical complications and 2-year PJI. These strata are a first of their kind in THA research. While preoperatively optimizing patients, we recommend using these hemoglobin thresholds to help guide decisions on presurgery anemia optimization and to reduce the need for postoperative blood transfusion. LEVEL OF EVIDENCE: Level III.

10-Year Cumulative Incidence and Indications for Revision Total Joint Arthroplasty for Patients Who Have Ehlers-Danlos Syndrome.

BACKGROUND: Long-term complications following total joint arthroplasty are not well established for patients who have Ehlers-Danlos syndrome (EDS), a group of connective tissue disorders. This study compared 10-year incidence of revision surgery after total hip arthroplasty (THA) and total knee arthroplasty (TKA) in patients who have and do not have EDS. METHODS: A retrospective cohort analysis was conducted using a national all-payer claims database from 2010 to 2021 to identify patients who underwent primary TKA or THA. Patients who had and did not have EDS were propensity score-matched by age, sex, and a comorbidity index. Kaplan-Meier analyses and Cox proportional hazard models were used to determine the cumulative incidence and risks of revision experienced by patients who have and do not have EDS. RESULTS: The EDS patients who underwent TKA had a higher risk of all-cause revision (hazard ratio [HR]: 1.50, 95% confidence interval [95% CI]: 1.09 to 2.07, P < .014) and risk of revision due to instability (HR = 2.49, 95% CI: 1.37 to 4.52, P < .003). The EDS patients who underwent THA had a higher risk of all-cause revision (HR = 2.32, 95% CI: 1.47 to 3.65, P < .001), revision due to instability (HR = 4.26, 95% CI: 2.17 to 8.36, P < .001), and mechanical loosening (HR = 3.63, 95% CI: 2.05 to 6.44, P < .001). CONCLUSIONS: Patients who had EDS were found to have a higher incidence of revision within 10 years of undergoing TKA and THA compared to matched controls, especially for instability. Patients who have EDS should be counseled accordingly. Surgical technique and implant selection should include consideration for increased constraint in TKA and larger femoral heads or dual mobility articulations for THA.

Evaluating the Effect of Decreasing Preoperative Hemoglobin on Blood Transfusions, Major Complications, and Periprosthetic Joint Infection After Primary Total Knee Arthroplasty.

INTRODUCTION: Preoperative anemia is associated with increased postoperative transfusion and complication rates after total knee arthroplasty (TKA). We aimed to create TKA-specific data-driven preoperative hemoglobin strata that quantify the likelihood of 90-day postoperative blood transfusion and evaluate whether these strata are associated with increased risk of 90-day major complications and 2-year prosthetic joint infection (PJI). METHODS: Primary TKA patients from 2013 to 2022 were identified using a national database. Stratum-specific likelihood ratio (SSLR) analysis defined hemoglobin strata associated with the risk of 90-day blood transfusion. Each stratum was propensity score matched to the highest identified hemoglobin strata. Unmatched incidence rates and matched risk of 90-day major complications and 2-year PJI between strata were compared. RESULTS: SSLR identified four 90-day blood transfusion hemoglobin strata for men (strata [g/dL], likelihood ratio [<11.4, 8.06; 11.5 to 11.9, 4.34; 12.0 to 12.9, 1.70; 13.0 to 17.0, 0.54]) and women (<10.4, 8.22; 10.5 to 11.4, 2.84; 11.5 to 12.4, 1.38; 12.5 to 17.0, 0.50). Increased 2-year PJI risk was associated with three male strata (<11.4, 11.5 to 11.9, 12.0 to 12.9; all P < 0.001) and three female strata (<10.4, 10.5 to 11.4, 11.5 to 12.4; all P < 0.001). Increased 90-day major complication risk was associated with three male strata (<11.4, 11.5 to 11.9, 12.0 to 12.9; all P < 0.001) and three female strata (<10.4, 10.5 to 11.4, 11.5 to 12.4; all P < 0.001). CONCLUSIONS: Using SSLR analysis, we identified unique TKA-specific data-driven hemoglobin strata for both men and women that quantify the likelihood of 90-day blood transfusions and predict the risk of both 90-day major complications and 2-year PJI. These strata are a first in the TKA literature and can assist surgeons in stratifying patients' transfusion and complication risk based on their preoperative hemoglobin value. While optimizing patients in the preoperative setting, we recommend using these TKA-specific hemoglobin thresholds to help guide decision making on the need for presurgery anemia optimization and to help reduce the need for blood transfusion.

Trends in Venous Thromboembolism and Chemoprophylaxis Utilization in Elective Total Knee Arthroplasty From 2011 to 2020.

BACKGROUND: Venous thromboembolism (VTE) is a feared complication of joint arthroplasty, leading to recent clinical practice guidelines aimed at VTE prevention and prophylaxis. However, limited studies have examined national changes in practice regarding chemoprophylaxis and the resultant changes in VTE rates. The purpose of this study was to identify: (1) the temporal trends in thrombotic complications; and (2) changes in chemoprophylaxis utilization in patients undergoing elective total knee arthroplasty (TKA). METHODS: A retrospective study was conducted using a large all-payer claims dataset. Patients who underwent osteoarthritis-indicated TKA between 2011 and 2020 were identified. Annual rates of VTE, including deep vein thrombosis and pulmonary embolism, within 90 days of TKA were determined. Utilization patterns for postoperative aspirin and anticoagulant medications were observed. Temporal trends were analyzed with linear regression and the calculation of the cumulative annual growth rate. Multivariable logistic regression was conducted to account for the effects of age and comorbidities. RESULTS: A total of 1,263,351 TKA patients were identified between 2011 and 2020. There were significant reductions in VTE rates (2.9% in 2011 to 1.8% in 2020), deep vein thrombosis rates (2.0% in 2011 to 1.3% in 2020), and pulmonary embolism rates (1.1% in 2011 to 0.6% in 2020). Postoperative utilization of aspirin increased from 5.9% in 2011 to 53.2% in 2020, whereas utilization of anticoagulants decreased from 94.1% in 2011 to 46.8% in 2020. Among anticoagulants, direct factor Xa inhibitors had the greatest increase in utilization (4.6 to 69.7%). The average reimbursement associated with VTE after TKA decreased from $18,061 in 2011 to $7,835 in 2020. CONCLUSIONS: The incidence rate and economic burden of VTE after TKA have significantly declined since 2011. There has been a trend toward increased aspirin and direct oral anticoagulant utilization for postoperative chemoprophylaxis. LEVEL OF EVIDENCE: Level III.

Improved outcomes with perioperative dietitian-led interventions in patients undergoing total joint arthroplasty: A systematic review.

Background: Nutritional assessment is important for optimization of patients undergoing elective total joint arthroplasty (TJA). Preoperative nutritional intervention is a potentially modifiable optimization target, but the outcomes of such intervention are not well-studied. The purpose of this study is to assess the impact of nutritional interventions on elective TJA outcomes. Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized to perform a systematic review of the Ovid Medline, Embase, and Cochrane Library systems. Included studies were comprised of patients greater than 18 years of age undergoing a primary unilateral TJA who received a perioperative dietitian-led intervention. Data analyzed included nutritional intervention protocol, patient demographics, length of stay (LOS), postoperative labs and complications, among others. Results: Our initial search identified a total of 1766 articles. Four studies representing 5006 patients met inclusion criteria. The studies utilized a protein-dominant diet, with or without a carbohydrate solution accompanied by dietitian assessment or education. The 4 studies found that the intervention group had significantly decreased LOS, fewer albumin infusions, less wound drainage, lower rates of hypocalcemia and hypokalemia, reduced C-reactive protein (CRP) values, improved time out of bed, and decreased overall costs. Conclusion: The findings support the potential benefits of perioperative dietitian-led intervention on key outcomes for patients undergoing primary TJA. Surgeons should consider nutritional intervention in their preoperative optimization protocols. Future studies could help elucidate the optimum nutritional regimens and monitoring for idealized intervention and surgical timing. Prospero registration number: CRD4202338494.

Risk of revision total knee arthroplasty for patients with prior bariatric surgery or class III obesity.

BACKGROUND: Bariatric surgery (BS) is indicated for select class III obesity patients undergoing total knee arthroplasty (TKA) to reduce obesity-related complications. This study assessed the effect of BS on TKA revision rates compared to the general population and class III obesity patients without a history of BS. METHODS: A national database identified patients who had primary TKA. They were divided into two groups: those with BS prior to TKA and those without. Patients without BS formed two control groups, a matched general population, and a matched class III obese cohort. The BS group was matched with controls based on age, Charlson Comorbidity Index (CCI), gender, and diabetes mellitus. Revision rates were analyzed using Kaplan-Meier survival analysis and hazard ratios (HR), calculated using Cox proportional hazard modeling. RESULTS: 14,292 BS patients were compared to 57,006 matched general population controls, and 19,504 BS patients were compared to 77,846 matched class III obesity control patients. BS patients had a higher risk of 5-year all-cause revision (HR: 1.13; P = 0.014) and revision due to periprosthetic fracture (HR: 1.39; P < 0.001) compared to the general population. Compared to class III obesity controls, BS patients had a lower risk of 5-year revision due to prosthetic joint infection (HR: 0.77; P = 0.001), with no difference in all-cause revision (P = 0.362). CONCLUSION: BS does not reduce all-cause TKA revision risk compared to the general or matched class III obesity population. However, it lowers the risk of revision due to prosthetic joint infection when compared to patients with class III obesity. LEVEL OF EVIDENCE: IV.

The cost-effectiveness of osteoporosis medications for preventing periprosthetic fractures following femoral neck fracture indicated hip arthroplasty: a break-even analysis.

Osteoporosis treatment following arthroplasty for femoral neck fracture (FNF) is associated with lower rates of periprosthetic fracture (PPF). Our study evaluated the economic viability of treatment in patients following arthroplasty and demonstrates that treatment with oral bisphosphonates can be cost-effective in preventing PPF. INTRODUCTION: Osteoporosis treatment following arthroplasty for femoral neck fracture (FNF) is associated with lower rates of periprosthetic fracture (PPF). Although cost-effective in reducing the rate of secondary fragility fracture, the economic viability of osteoporosis treatment in preventing PPF has not been evaluated. Therefore, the purpose of this study is to use a break-even analysis to determine whether and which current osteoporosis medications are cost-effective in preventing PPF following arthroplasty for FNFs. METHODS: Three-year average cost of osteoporosis medication (oral bisphosphonates, estrogen hormonal therapy, intravenous (IV) bisphosphonates, denosumab, teriparatide, and abaloparatide), costs of PPF care, and PPF rates in patients who underwent hip arthroplasty for FNFs without osteoporosis treatment were used to perform a break-even analysis. The absolute risk reduction (ARR) related to osteoporosis treatment and sensitivity analyses were used to evaluate the cost-effectiveness of this intervention and break-even PPF rates. RESULTS: Oral bisphosphonate therapy following arthroplasty for hip fractures would be economically justified if it prevents one out of 56 PPFs (ARR, 1.8%). Given the current cost and incidence of PPF, overall treatment can only be economically viable for PPF prophylaxis if the 3-year costs of these agents are less than $1500. CONCLUSION: The utilization of lower cost osteoporosis medications such as oral bisphosphonates and estrogen hormonal therapy as PPF prophylaxis in this patient population would be economically viable if they reduce the PPF rate by 1.8% and 1.5%, respectively. For IV bisphosphonates and newer agents to be economically viable as PPF prophylaxis in the USA, their costs need to be significantly reduced.

Chronic Oral Corticosteroid Use and 10-Year Incidence of Major Complications Following Total Knee Arthroplasty.

BACKGROUND: Oral corticosteroids are the primary treatment for several autoimmune conditions. The risk of long-term implant, bone health, and infectious-related complications in patients taking chronic oral corticosteroids before total knee arthroplasty (TKA) is unknown. We compared the 10-year cumulative incidence of revision, periprosthetic joint infection (PJI), fragility fracture (FF), and periprosthetic fracture following TKA in patients who had and did not have preoperative chronic oral corticosteroid use. METHODS: A retrospective cohort analysis was conducted using a national database. Primary TKA patients who had chronic preoperative oral corticosteroid use were identified using Current Procedural Terminology and International Classification of Disease 9 and 10 codes. Exclusion criteria included malignancy, osteoporosis treatment, trauma, and < 2-year follow-up. Primary outcomes were 10-year cumulative incidence and hazard ratios (HRs) of all-cause revision (ACR), aseptic revision, PJI, FF, and periprosthetic fracture. A Kaplan-Meier analysis and a multivariable Cox proportional hazards model were utilized. Overall, 611,596 patients were identified, and 5,217 (0.85%) were prescribed chronic corticosteroids. There were 10,000 control patients randomly sampled for analysis. RESULTS: Corticosteroid patients had significantly higher 10-year HR of FF (HR; 95% confidence interval); P value (1.47; 1.34 to 1.62; P < .001)], ACR (1.21; 1.05 to 1.40; P = .009), and PJI (1.30; 1.01 to 1.69; P = .045) when compared to the control. CONCLUSIONS: Patients prescribed preoperative chronic oral corticosteroids had higher risks of ACR, PJI, and FF within 10 years following TKA compared to patients not taking corticosteroids. This information can be used by surgeons during preoperative counseling to educate this high-risk patient population about their increased risk of postoperative complications.

Trend of using cementless total knee arthroplasty: a nationwide analysis from 2015 to 2021.

BACKGROUND: Modern cementless total knee arthroplasty (TKA) fixation has shown comparable long-term outcomes to cemented TKA, but the trend of using cementless TKA remains unclear. This study aimed to investigate the trend of using cementless TKA based on a national database. METHODS: The patients undergoing cementless TKA between 2015 and 2021 were retrospectively extracted from the PearlDiver (Mariner dataset) Database. The annual percentage of cementless TKA was calculated using the following formula: annual number of cementless TKA/annual number of TKA. The trend of the number of patients undergoing cementless TKA was created according to a compounded annual growth rate (CAGR) calculation of annual percentages. Patient age, comorbidity, region, insurance type, etc., were also investigated. Differences were considered statistically significant at P < 0.05. RESULTS: Of the 574,848 patients who received TKA, 546,731 (95%) underwent cemented fixation and 28,117 (5%) underwent cementless fixation. From 2015 to 2021, the use of cementless TKA significantly increased by 242% from 3 to 9% (compounded annual growth rate (CAGR): + 20%; P < 0.05). From 2015 to 2021, we observed a CAGR greater than 15% for all age groups (< 50, 50-59, 60-69, 70-74, 75 +), insurance types (cash, commercial, government, Medicare, Medicaid), regions (Midwest, Northeast, South, West), sex (male and female), and certain comorbidities (osteoporosis, diabetes mellitus, tobacco use, underweight (BMI < 18.5), rheumatoid arthritis) (P < 0.05 for all). Patients undergoing TKA with chronic kidney disease, prior fragility fractures, and dementia demonstrated a CAGR of + 9%-13% from 2015 to 2021 (P < 0.05). CONCLUSION: From 2015 to 2021, the use of cementless TKA saw a dramatic increase in all patient populations. However, there is still no consensus on when to cement and in whom. Clinical practice guidelines are needed to ensure safe and effective use of cementless fixation.

The Association Between Oral Bone Mineral Density-Reducing Medications and the Risk of 2-Year Implant-Related Complications Following Total Knee Arthroplasty.

BACKGROUND: Certain medications interfere with the bone remodeling process and may potentially increase the risk of complications after total knee arthroplasty (TKA). As patients undergoing TKA may be taking these bone mineral density (BMD)-reducing medications, it is unclear as to whether and which medications impact TKA outcomes. Therefore, the purpose of this study was to observe the impact of various BMD-reducing medications on 2-year implant-related complications following TKA. METHODS: A retrospective analysis of patients undergoing primary TKA was conducted using a national administrative claims database. Patients were identified if they were taking any known BMD-reducing medication and were compared to control patients. To control for confounders associated with taking multiple agents, multivariable logistic regression analyses were conducted for each 2-year outcome (all-cause revision, loosening-indicated revision, and periprosthetic fracture--indicated revision), with the output recorded as odds ratios (ORs). RESULTS: In our study, 502,927 of 1,276,209 TKA patients (39.4%) were taking at least one BMD-reducing medication perioperatively. On multivariable analysis, medications associated with a higher likelihood of 2-year all-cause revision included first- and second-generation antipsychotics (SGAs) (OR: 1.42 and 1.26, respectively), selective serotonin reuptake inhibitors (SSRIs) (OR: 1.14), glucocorticoids (1.13), and proton pump inhibitors (PPIs) (OR: 1.23) (P < .05 for all). Medications associated with a higher likelihood of 2-year periprosthetic fracture included SGAs (OR: 1.51), SSRIs (OR: 1.27), aromatase inhibitors (OR: 1.29), and PPIs (OR: 1.42) (P < .05 for all). CONCLUSIONS: Of the drug classes observed, the utilization of perioperative PPIs, SSRIs, glucocorticoids, first-generation antipsychotics, and SGAs was associated with the highest odds of all-cause revision. Our findings suggest a relationship between these medications and BMD-related complications; however, further studies should seek to determine the causality of these relationships.

AIDS but not asymptomatic HIV is associated with lower 2-10-year implant survivorship following total knee arthroplasty.

INTRODUCTION: Prior studies have demonstrated HIV does not increase the risk of 2-year complications following TKA; however, the literature is sparse regarding the impact of HIV and AIDS on long-term implant survivorship. The purpose of this study was to compare the 10-year cumulative incidence and risk of revision TKA in patients with and without asymptomatic HIV, and with and without AIDS. METHODS: Patients with HIV who underwent elective TKA were identified using a national database and divided into subgroups of asymptomatic HIV (AHIV) and acquired immunodeficiency syndrome (AIDS). These patients with HIV were propensity matched based on age, sex, and Charlson Comorbidity Index (CCI) to a control group of elective TKA patients without HIV in a 1:2 ratio. Patients were also compared to an unmatched control group. RESULTS: The 10-year risk for all-cause revision TKA was higher in the HIV group compared to unmatched controls (HR 1.40, 95% CI 1.02-1.93, p = 0.038) but not matched controls (HR 1.13, 95% CI 0.77-1.63, p = 0.594). When compared to both control groups (unmatched; matched), the AIDS group had a higher risk of 10-year all-cause revision (HR 2.74, 95% CI 1.51-4.99, p < 0.001; HR 2.19, 95% CI 1.17-4.11, p = 0.014), dislocation/instability (HR 4.89, 95% CI 1.54-15.51, p = 0.007; HR 3.86, 95% CI 1.12-13.34, p = 0.033), and periprosthetic fracture [PPF] (HR 0.67, 95% CI 0.16-2.74, p = 0.002; HR 3.82, 95% CI 1.08-13.45, p = 0.037). However, patients with AIDS were not at increased risk of PJI or mechanical loosening compared to unmatched controls or matched controls. DISCUSSION: This study expands on current literature by following a nationwide cohort of HIV/AIDS patients for 10 years after TKA. Although a diagnosis of asymptomatic HIV was not associated with increased risk of 10-year revision rates following TKA, a diagnosis of AIDS was. Surgeons should ensure patients' serum CD4 level is sufficient, ideally in the normal range of 500-1500 cells per mm3, before undergoing TKA.

Risk Factors Associated With Quadriceps Tendon Extensor Mechanism Disruption Following Total Knee Arthroplasty.

BACKGROUND: Quadriceps tendon extensor mechanism disruption is an infrequent but devastating complication after total knee arthroplasty (TKA). Our knowledge of specific risk factors for this complication is limited by the current literature. Thus, this study aimed to identify potential risk factors for quadriceps tendon extensor mechanism disruption following TKA. METHODS: A retrospective cohort analysis was performed using the PearlDiver Administrative Claims Database. Patients undergoing TKA without a prior history of quadriceps tendon extensor mechanism disruption were identified. Quadriceps tendon extensor mechanism disruption included rupture of the quadriceps tendon, patellar tendon, or fracture of the patella. Patients who had a minimum of 5 years of follow-up after TKA were included. A total of 126,819 patients were included. Among them, 517 cases of quadriceps tendon extensor mechanism disruption occurred (incidence 0.41%). Hypothesized risk factors were compared between those who had postoperative quadriceps tendon extensor mechanism disruption and those who did not. RESULTS: On multivariate analysis, increased Charlson Comorbidity Index (odds ratio (OR): 1.10, 95% confidence interval (CI) [1.07 to 1.13]; P < .001), obesity (OR: 1.49, 95% CI [1.24 to 1.79]; P < .001), and fluoroquinolone use any time after TKA (OR: 1.24, 95% CI [1.01 to 1.52]; P = .036) were significantly associated with quadriceps tendon extensor mechanism disruption. CONCLUSIONS: Our study identified the incidence of quadriceps tendon extensor mechanism disruption following TKA as 0.41%. Identified risk factors for quadriceps tendon extensor mechanism disruption after TKA include an increased Charlson Comorbidity Index, obesity, and use of fluoroquinolones postoperatively.