Complications and Safety of Simultaneous Bilateral Total Knee Arthroplasty: A Patient Characteristic and Comorbidity-Matched Analysis

Clinical safety and efficacy of simultaneous bilateral total knee arthroplasty in an Asian population: a propensity score-matched analysis

BACKGROUND

Clear clinical guidelines on performing simultaneous bilateral total knee arthroplasty (BTKA) are lacking. We compare the clinical outcomes between BTKA and unilateral total knee arthroplasty (UTKA) using propensity score matching to assess safety and clinical efficacy, hypothesizing no difference in clinical safety.

METHODS

Among 1,665 BTKA and UTKA cases, patients were matched in a 1:1 ratio by age, sex, body mass index, follow-up, and comorbidities, resulting in 653 patients per group. Primary outcomes included 30-day complication rates and intensive care unit (ICU) admission rates. Secondary outcomes included length of stay (LOS), transfusion rate, estimated blood loss, hemoglobin (Hb) levels (preoperative and two days postoperative), Hb decrease, and 1-year mortality rate. The patient-reported outcomes (PROMs) was measured preoperatively and at 3, 6, and 12 months postoperatively using the American Knee Society Score, Western Ontario and McMaster Universities Osteoarthritis Index, and EuroQol 5-Dimension.

RESULTS

There were no differences in the 30-day complication rates and ICU admission rate between the BTKA and UTKA groups after matching (1.4% vs. 0.9%; p = 0.60, 0.5% vs. 0.6%; p = 1.00). However, patients who underwent BTKA had a longer LOS, a higher incidence of transfusion (7.2% vs. 2.1%; p < 0.001), greater blood loss (128.6 ± 75.5 vs. 72.5 ± 45.6 mL; p < 0.001), and a more pronounced decrease in Hb levels (3.1 vs. 2.9 g/dL; p < 0.001) than those who underwent UTKA. No significant differences were observed in PROMs at one year postoperatively.

CONCLUSIONS

Patients who underwent BTKA reported similar 30-day complication rates, ICU admissions, and PROMs compared to UTKA. Despite higher LOS, transfusion rates, blood loss, and Hb decrease, BTKA remains a safe, effective option. It should be performed cautiously, considering patient comorbidities and overall health in treating bilateral knee OA.

Effect of Race and Socioeconomic Status on the Attainment of Substantial Clinical Benefit on Patient-Reported Outcome Measures Following Total Joint Arthroplasty

BACKGROUND

Utilization of and access to total joint arthroplasty (TJA) are disproportionately skewed in patients who have low socioeconomic status (SES) and in minority populations. Patient-reported outcome measures (PROMs) are critical markers of post-surgical outcomes following TJA. This study aimed to: 1) evaluate differences in race, SES, and demographic factors between TJA patients who achieved substantial clinical benefit (SCB) and those who did not; 2) assess differences between preoperative PROMs in these patients; and 3) identify whether race and SES are associated with SCB achievement at 1-year post-TJA.

METHODS

This retrospective cohort study included 1,154 total hip arthroplasty (THA) and 1,879 total knee arthroplasty (TKA) patients who underwent surgery at a single academic medical center from May 2019 to February 2023. Preoperative and postoperative PROMs were collected using the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement and Hip Disability and Osteoarthritis Outcome Score for Joint Replacement surveys. Demographic and comorbidity data were collected from charts. Multivariable logistic regression analyzed the association between predictive variables and SCB achievement.

RESULTS

No differences in race were found between patients who achieved SCB and those who did not for both TKA and THA (P > 0.05). However, preoperative Knee Injury and Osteoarthritis Outcome Score for Joint Replacement scores were lower in Black (P = 0.004) and Hispanic (P < 0.001) patients and preoperative Hip Disability and Osteoarthritis Outcome Score for Joint Replacement scores were lower in Black patients (P < 0.001) than White patients. A higher proportion of patients in the lowest income category achieved SCB for both THA and TKA than those in other income categories (P = 0.04, P = 0.03, respectively). However, race was not associated with SCB likelihood at one year. For TKA patients, men were negative, and bilateral simultaneous TKA was positively associated with SCB achievement when controlling for race, income, and body mass index (P < 0.001, P = 0.01, respectively).

CONCLUSIONS

Race and income category were not significantly associated with achieving SCB at one year among TJA patients. However, non-White patients had a similar likelihood of achieving SCB as White patients, even with lower preoperative PROMs, indicating that these patients may benefit greatly from TJA despite delays in care. Men were negatively associated with TKA SCB achievement, while bilateral simultaneous TKA was positively associated with SCB.

Comparative Outcomes of Bilateral Versus Unilateral Total Knee Arthroplasty: A Big Data Analysis

Background: Bilateral total knee arthroplasty (B-TKA) is a surgical option for patients with bilateral osteoarthritis, offering potential efficiency and cost advantages but with increased perioperative risk. Methods: We conducted a retrospective analysis of 2,299,979 elective TKA cases from the Nationwide Inpatient Sample (2016-2019). Propensity score matching (PSM) was used to compare 83,980 B-TKA patients with matched unilateral TKA (U-TKA) patients. Outcomes included in-hospital mortality, complications, length of stay, and hospital charges. Results: B-TKA patients had higher rates of complications such as deep vein thrombosis (OR 1.798) and pulmonary embolism (OR 1.883), longer hospital stays (3.03 vs. 2.49 days), and higher charges (USD 83,639 vs. USD 59,215; all p < 0.001). Conclusions: Although B-TKA is associated with increased perioperative risk, it may offer logistical and economic advantages in well-selected patients. These findings support the need for risk stratification in surgical decision-making.

Safety and early outcomes of simultaneous bilateral TKA in patients with BMI > 40: A retrospective comparative study

INTRODUCTION

Simultaneous bilateral total knee arthroplasties (SBTKA) are common in Asia, but surgeons may have a body mass index (BMI) threshold for performing these procedures. However, no guidelines regarding patient weight and SBTKA exist in the literature. We hypothesized that SBTKA can be performed safely and efficiently for morbidly obese patients. We aimed to compare 1) the rate of complications within one year after surgery, 2) operative time, blood loss, and length of stay, and 3) clinical outcomes at one year after SBTKA in patients with BMI < 30 versus 30 < BMI < 40 and BMI > 40.

METHODS

In this retrospective comparative matched (age, ASA score) study, we evaluated 113 patients who underwent SBTKA (posterior stabilized cemented TKA), between 2019 and 2022. The patient population was grouped based on their BMI: BMI < 30 (33 patients), 30 < BMI < 40 (43 patients), and BMI > 40 (37 patients). A complication was defined as an event that could be classified as a grade > 3 according to the Clavien-Dindo classification within one year of surgery. Data on complication rate, operation time, blood loss, and preoperative and post-operative function KSS at one year were compared.

RESULTS

No significant difference in the occurrence of early complications between the three groups was observed. One patient was readmitted for periprosthetic fracture in the BMI < 30 group. There was no significant difference in operative time, blood loss, and KSS score at one year between the three groups. A significant functional improvement was observed in all three groups at the one-year follow-up.

DISCUSSION

This study suggests that SBTKA in patients with a BMI > 40 is safe, with no increased complications, similar surgical time, and blood loss. Significant functional improvement was observed at one year postoperatively. While promising, further multi-center studies are needed to confirm these findings and evaluate long-term outcomes.

Predicting Blood Loss and Evaluating Tranexamic Acid Efficacy in Staged Bilateral Total Knee Arthroplasty

Background This retrospective study aimed to evaluate the predictive capacity of first-stage blood loss for second-stage blood loss and to assess the impact of varying tranexamic acid (TXA) administration timing on hemostatic efficacy within the same patient undergoing staged bilateral total knee arthroplasty (TKA). Methods A retrospective analysis was conducted on 100 patients (200 knees) who underwent staged bilateral primary TKA performed by a single surgeon. Patients were categorized into three groups based on TXA administration: no TXA (NT, 106 knees), TXA administered only during the second stage (H, 42 knees), and TXA administered during both procedures (T, 52 knees). Results In the NT group, a moderate correlation was observed between blood loss in the first and second legs (p=0.042, r=0.438), suggesting that first-stage blood loss can predict second-stage blood loss. The H group showed a trend towards reduced blood loss in the second, TXA-treated leg (p=0.068), indicating a potential benefit of TXA administration in the second stage. However, no significant difference in blood loss was observed between the two legs in the T group (p=0.657), and no correlation was found between blood loss in the two legs (p=0.070). Conclusions These findings suggest that in non-TXA cases, first-stage blood loss can be used to tailor perioperative management for the second stage. Furthermore, the variability in TXA efficacy highlights the need for individualized TXA dosing strategies. Future studies should investigate optimal TXA dosing and administration methods to enhance bleeding management in staged bilateral TKA.

High Pain Self-Efficacy Reduces the Use of Analgesics in the Early Postoperative Period After Total Knee Arthroplasty: A Retrospective Cohort Study

Background

Total knee arthroplasty (TKA) is an effective treatment for relieving pain and restoring physical function in individuals with severe knee osteoarthritis (KOA). However, the persistence of postoperative pain is an unresolved problem, and the use of postoperative analgesics to deal with this pain is increasing. The positive cognitive factor known as pain self-efficacy (PSE) has been shown to moderate the intensity of pain, but there are few reports of PSE concerning analgesic use after TKA. We sought to clarify the effect of PSE on postoperative analgesic use in TKA cases.

Patients and Methods

We conducted a retrospective cohort study of 60 patients who underwent bilateral TKA surgery for bilateral severe KOA. A multiple linear regression model including covariates and scaling estimation coefficients was used to investigate the effect of PSE on the patients' postoperative analgesic use. We identified the presence/absence of postoperative analgesic use at 3 and 6 months postoperatively, and other evaluation items such as the Pain Self-Efficacy Questionnaire (PSEQ) were evaluated at the time of the patients' admission for surgery.

Results

In a multiple linear regression model, only high PSE had a significant impact on the postoperative 3-month use of nonsteroidal anti-inflammatory drugs (NSAIDs) (β: -0.27, 95% confidence interval [CI]: -0.51, -0.01). However, the significant difference had disappeared postoperative 6 months (β: -0.06, 95% CI: -0.19, 0.31).

Conclusion

These results demonstrated that high pain self-efficacy reduced the analgesic use at 3 months postoperatively by patients who have undergone bilateral TKA surgery, but it did not affect analgesic use at 6 months postoperatively. Pain self-efficacy can be an intervention target for reducing the use of analgesics after TKA surgery. Further research is needed to clarify the relationship between pain self-efficacy and the post-TKA use of analgesics.

Simultaneous bilateral total knee arthroplasty has higher risk of asymptomatic deep vein thrombosis in patients in their 80s compared with unilateral total knee arthroplasty: a propensity score-matched comparative study across different age groups

INTRODUCTION

This study compared complications and clinical outcomes between simultaneous bilateral total knee arthroplasty (SBTKA) and unilateral total knee arthroplasty (UTKA) across different age groups.

MATERIALS AND METHODS

This retrospective single-center study included 939 consecutive patients aged 60-89 years who underwent primary total knee arthroplasty between 2019 and 2023. After applying propensity score matching for preoperative deep vein thrombosis (DVT), American Society of Anesthesiologists (ASA) classification, and preoperative functional activity according to the Knee Society Score 2011 (KSS) to 223 patients who underwent SBTKA and 716 patients who underwent UTKA, SBTKA and UTKA were compared in the following age groups: 60s (28 vs. 28), 70s (110 vs. 110), and 80s (60 vs. 60). Perioperative complications and clinical outcomes at 1 year after surgery were compared between SBTKA and UTKA. Lower limb Doppler ultrasound was performed to screen for asymptomatic DVT preoperatively and on postoperative day 7.

RESULTS

Average ASA classification ranged from 2.0 to 2.2 across all age groups, with no difference between SBTKA and UTKA. Compared with UTKA, the decrease in hemoglobin was significantly greater after SBTKA in patients in their 70s and 80s (both p < 0.001). The proportion of blood transfusion showed no significant difference across all age groups. Asymptomatic DVT was more frequent after SBTKA than after UTKA in patients in their 80s (58.3% vs. 40.0%, p < 0.045), but not those in their 60s (42.9% vs. 32.1%) or 70s (50.9% vs. 46.3%). Clinical outcomes (knee symptoms, patient satisfaction, patient expectations, functional activity according to the KSS) were comparable between SBTKA and UTKA across all age groups at 1 year postoperatively.

CONCLUSIONS

SBTKA had higher risk of asymptomatic DVT in patients in their 80s. With evaluation of risk factors and careful patient selection, SBTKA is a valid option in terms of safety and clinical outcomes in elderly patients with ASA 2.

Comparison of clinical outcomes of bilateral and unilateral unicompartmental knee arthroplasty for the treatment of knee osteoarthritis

The risks and benefits associated with simultaneous bilateral unicompartmental knee arthroplasty (UKA) continue to engender contentious debate. The aim of this study was to compare the clinical outcomes of simultaneous bilateral and unilateral UKA. A retrospective review was performed between 2019 and 2022 on 280 patients (130 simultaneous bilateral vs. 150 unilateral Oxford UKA) who performed by two experienced surgeons. Patients in both groups underwent surgery according to the Microplasty instrumentation system, with congruent postoperative management and carefully standardized follow-up. This study performed a comparative analysis between the two groups of patients with regard to postoperative laboratory tests, knee functionality, postoperative discomfort, and incidence of complications. There was a significant difference in the duration of disease between the two groups (U-UKA:6.05 vs. SB-UKA:7.80, P < 0.05). When it comes to laboratory examinations, a notable disparity emerged in hemoglobin levels, erythrocyte pressure volume, D-dimer concentrations, albumin levels, as well as indicators of inflammation among the two groups of patients (P < 0.05). There was a significant difference in operative time and blood loss between the two groups (P < 0.05), with no significant difference in complications. There was no significant difference in radiographic and prosthetic survival between the two groups (U-UKA: 99.3% vs. 98.5%). The HSS score, VAS, and ROM showed remarkable disparities between the two groups in the initial postoperative phase, albeit these distinctions gradually attenuated with the passage of time. Simultaneous bilateral UKA reduces the number of procedures without increasing the risk of surgical complications, but results in a markedly enhanced physiological response and a suboptimal perioperative experience. We strongly encourage the surgeon to work with the patient to determine a surgical strategy.

Association between metallic implants and stroke in US adults from NHANES 2015-2023 a cross-sectional study

Objective

Metal implants play a vital role in orthopedic treatment and are widely used in fracture repair, joint replacement and spinal surgery. Although these implants often contain key elements such as chromium (Cr), their potential health effects, particularly their association with stroke risk, have not been fully elucidated. This study aimed to evaluate the association between metallic implants and stroke.

Methods

Using data from the 2015 to 2023 National Health and Nutrition Examination Survey (NHANES), we conducted a cross-sectional analysis of 12,337 US adults, in which 3,699 participants reported having metal implants and 8,638 without. Implant-like.

Results

Through logistic regression analysis, we revealed a significant positive association between metallic implants and stroke risk (adjusted OR = 1.458, 95%CI (1.130, 1.881), p = 0.004). Further stratified analysis found that this positive association was more significant among older and less physically active participants.

Conclusion

Findings suggest that metallic implants may be associated with an increased risk of stroke, but given the inherent limitations of cross-sectional studies, this study cannot establish causality.

Comparison of the Cost-Effectiveness and Safety between Staged Bilateral Total Knee Arthroplasty and Simultaneous Bilateral Total Knee Arthroplasty: A Retrospective Cohort Study between 2001 and 2022

A substantial proportion of Hong Kong's aging population suffers from osteoarthritis in both knees. Bilateral total knee arthroplasty (BTKA) is a surgical option for addressing this condition and can be performed via two approaches: simultaneous BTKA (SimBTKA) and staged BTKA (StaBTKA). We compared the cost-effectiveness and safety of these two methods in our institution. We retrospectively reviewed 2,372 patients (SimBTKA, 772; StaBTKA, 1,600; females, 1,780; males, 592; mean age at SimBTKA, 70.4 ± 7.99 years; mean age at StaBTKA, 66.4 ± 7.50 years; p < 0.001) who underwent BTKA in our institution from 2001 to 2022. Patients were categorized according to the surgical approach. Patients undergoing BTKA in our institution were included. Particularly for SimBTKA, patients were assessed by anesthetists to be medically fit before undergoing the procedure according to their age, American Society of Anesthesiologists status, and osteoarthritis severity. The primary outcome was the length of stay (LOS) after surgery. The secondary outcomes were the 30-day unintended readmission, intensive care unit (ICU) admission, and death. SimBTKA had a shorter mean total LOS (acute hospital + rehabilitation center; SimBTKA, 13.09 days; StaBTKA, 18.12 days; p < 0.001) and mean LOS in acute hospital (SimBTKA, 7.70 days; StaBTKA, 10.42 days; p < 0.001). However, no significant difference was found in the mean LOS in rehabilitation centers (SimBTKA, 5.47 days; StaBTKA, 6.32 days; p > 0.05) between the two approaches. The 30-day unintended readmission rate was lower in SimBTKA (SimBTKA, 2.07%; StaBTKA, 3.30%; odds ratio [OR] = 1.60; p > 0.05) but statistically insignificant. SimBTKA was less costly than StaBTKA by US$ 8,422.22 per patient. No significant differences in ICU admission and death rates were found (p > 0.05) between the two groups. SimBTKA had a shorter LOS and lower cost than StaBTKA and comparable complication rates. Therefore, SimBTKA should be indicated in medically stable patients.

Hip and knee arthroplasty in one surgical session: early morbi-mortality study

INTRODUCTION

Bilateral prosthetic hip or knee replacement in one surgical session is a procedure that has been widely validated in the literature, whereas hip and knee replacement in one surgical session remains poorly documented. This study reports on the results of these procedures by analyzing early post-operative complications in a retrospective multicenter study.

MATERIAL AND METHODS

Between 2009 and 2023, 51 patients underwent hip and knee replacement surgery in a single surgical session at 4 French centers. They were 24 men and 27 women, with a mean age of 68.8 years (36-87); 7 patients were ASA 1, 30 were ASA 2 and 14 ASA 3. Prosthetic hip replacement was always performed first, associated 33 times with the ipsi-lateral knee and 18 times with the contralateral knee. All early complications, within the first 90 days post-operatively, were recorded: death, phlebitis, pulmonary embolism, myocardial infarction, surgical site infection (SSI), knee stiffness treated by mobilization under general anesthesia, urinary tract infection, acute urine retention or any other adverse event related to care. Transfusion rates were also reported.

RESULTS

The rate of early complications was 9.8% (5/51). No deaths, no phlebitis, no pulmonary embolism and no SSI were observed. Complications included one myocardial infarction, one urinary tract infection, one superficial infection, one haematoma treated by surgical evacuation and one recurrent instability requiring revision surgery (hip arthroplasty). The transfusion rate was 17.6% (9/51). The complication rate of ASA 3 patients was higher than that of ASA 1 and 2 patients, while there was no difference related to age or BMI.

DISCUSSION

Our results confirm the feasibility of single-stage hip and knee replacement, with a low complication rate in ASA 1 and 2 patients. This study adds to the few published works on the subject and reports comparable results. The small sample size and the heterogeneity of patients and centers limit the scope of the results, these limitations being relative to the volume expected for a rare procedure.

CONCLUSION

Single-session hip and knee arthroplasty should be reserved for patients selected according to comorbidities: ASA score, age and body mass index. ASA 3 patients have a higher risk of complications.

LEVEL OF EVIDENCE

IV; retrospective.

Inferior vena cava collapsibility index for predicting hypotension after spinal anesthesia in patients undergoing total knee arthroplasty

OBJECTIVE

This study aimed to identify risk factors associated with hypotension in patients undergoing total knee arthroplasty (TKA) under spinal anesthesia.

METHOD

A total of 200 patients (50-75 years of age) who underwent elective TKA under spinal anesthesia between October 2023 and January 2024 were enrolled. Patients were divided into two groups (hypotensive and nonhypotensive) depending on the occurrence of postspinal anesthesia hypotension (PSAH). Patient characteristics (age, sex, body mass index, and medical history), blood pressure, heart rate, and ultrasound data before anesthesia were documented. Multivariate logistic regression models were used to determine risk factors for hypotension after spinal anesthesia. Furthermore, a nomogram was constructed according to independent predictive factors. The area under the curve (AUC) and calibration curves were employed to assess the performance of the nomogram.

RESULTS

In total, 175 patients were analyzed and 79 (45.1%) developed PSAH. Logistic regression analysis revealed that variability of the inferior vena cava (odds ratio, OR, 1.147; 95% confidence interval, CI: 1.090-1.207; p < 0.001) and systolic arterial blood pressure (SABP, OR 1.078; 95% CI: 1.043-1.115; p < 0.001) were independent risk factors for PSAH. Receiver operating characteristic (ROC) curve analysis showed that the AUC of the inferior vena cava collapsibility index (IVCCI) and SABP alone were 0.806 and 0.701, respectively, while the AUC of both combined was 0.841. Specifically, an IVCCI of > 37.5% and systolic arterial blood pressure of > 157 mm Hg were considered threshold values. Furthermore, we found that the combination had a better predictive value with higher AUC value, sensitivity, and specificity than the index alone. The nomogram model and calibration curves demonstrated the satisfactory predictive performance of the model.

CONCLUSION

Elevated preoperative systolic arterial blood pressure and a higher IVCCI were identified as independent risk factors for hypotension in patients receiving spinal anesthesia, which may help guide personalized treatment.

Simultaneous bilateral and staged total knee arthroplasty combined with unicompartmental knee arthroplasty in the treatment of bilateral knee osteoarthritis: comparison of early clinical outcomes, complications, and prosthesis survival

OBJECTIVE

Knee osteoarthritis (KOA) is usually bilateral. In many patients, the degree of bilateral knee degeneration varies, with one side involving multiple compartments and the other a single compartment degeneration. Therefore, the objective of this study was to compare the early clinical efficacy of simultaneous bilateral and staged total knee arthroplasty (TKA) combined with unicompartmental knee arthroplasty (UKA) in the treatment of bilateral KOA with different degrees.

METHODS

We compared clinical data from 71 simultaneous bilateral TKA/UKA (SB-TKA/UKA) patients with 52 Staged TKA/UKA (Staged-TKA/UKA) patients. Staged-TKA/UKA is defined as TKA on one knee followed by UKA on the other knee. The comparison included Hospital for Special Surgery (HSS) score, range of motion(ROM), complication rate and prosthetic survival rate at the last follow-up between the two groups.

RESULTS

The follow-up time of SB-TKA/UKA group was (69.08 ± 14.35) months, and that of Staged-TKA/UKA group was (73.25 ± 18.39) months. Staged-KA/UKA group had a shorter hospital stays, less hospitalization costs and shorter operating time (p < 0.001 for hospital stay, p < 0.001 for hospitalization costs and p < 0.001 for operating time). There were no significant differences in HSS and ROM between the two groups at the last follow-up (p > 0.05). There was no significant difference in complication rate between the two groups (χ2 = 0.56, p = 0.454). For the TKA-side knee joint, there was no significant difference in the prosthetic survival rate (χ2 = 0.05, p = 0.824) and the prosthetic survival curve (χ2 = 0.052, p = 0.82) between the two groups. For UKA-side knee joint, there was no significant difference in prosthetic survival rate (χ2 = 0.08, p = 0.777) and prosthetic survival curve (χ2 = 0.074, p = 0.786) between the two groups.

CONCLUSIONS

Compared to Staged-TKA/UKA, SB-TKA/UKA has the same early clinical efficacy, shorter operating time and hospital stays, less hospitalization costs, and no increased postoperative complications and prosthesis revision rates. Therefore, SB-TKA/UKA may be recommended for patients who can tolerate simultaneous bilateral surgery as assessed before surgery.

Should Chronological Age be a Consideration in Patients Undergoing Elective Primary Total Knee Arthroplasty?

BACKGROUND

The optimal time for total knee arthroplasty (TKA) requires a balance between patient disability and health state to minimize complications. While chronological age has not been shown to be predictive of complications in elective surgical patients, there is a point beyond which even optimized elderly patients would be at increased risk for complications. The purpose of this study was to examine the impact of chronological age on complications following primary TKA.

METHODS

Using an administrative database, the records of 2,129,191 patients undergoing elective unilateral TKA between 2006 and 2021 were reviewed. The primary outcomes of interest were cardiac and pulmonary complications, and their relationship to the Charlson-Deyo Comorbidity Index (CDI) and chronological age. Secondary outcomes included risk of renal, neurologic, infection, and intensive care utilization postoperatively. The results were analyzed using a graphical method. The impact of chronological age as a modifier of overall risk for complications was modeled as a continuous variable. An age cutoff threshold of 80 years was also assigned for clinical convenience.

RESULTS

The risk of complications correlated more closely to the CDI (odds ratio (OR) 1.37 to 2.1) than chronological age (OR 1.0 to 1.1) across the various complications [Table 1. However, beyond age 80 years, the risks of cardiac, pulmonary, renal, and cerebrovascular complications were significantly increased for all CDI categories (OR 1.73 to 3.40) compared to patients below age 80 years [Table 2] [Figures 1A and 1B].

CONCLUSIONS

Chronologic age can impact the risk of complications even in well-optimized elderly patients undergoing primary TKA. As arthroplasty continues to transition to outpatient settings and inpatient denials increase, these results can help patients, physicians, and payors mitigate risk while optimizing the allocation of resources.

Obesity aggravates the role of C-reactive protein on knee pain: A cross-sectional analysis with NHANES data

OBJECTIVE

To examine the relationship between C-reactive protein (CRP) and knee pain, and further explore whether this association is mediated by obesity.

METHODS

The population was derived from 1999 to 2004 National Health and Nutrition Examination Survey. Logistic regression was used to analyze the relationship between CRP and knee pain in three different models, and the linear trend was analyzed. A restricted cubic spline model to assess the nonlinear dose-response relationship between CRP and knee pain. Mediation analyses were used to assess the potential mediating role of obesity. Subgroup analyses and sensitivity analyses were performed to ensure robustness.

RESULTS

Compared with adults with lower CRP (first quartile), those with higher CRP had higher risks of knee pain (odds ratio 1.39, 95% confidence interval 1.12-1.72 in third quartile; 1.56, 1.25-1.95 in fourth quartile) after adjusting for covariates (except body mass index [BMI]), and the proportion mediated by BMI was 76.10% (p < .001). BMI and CRP were linear dose-response correlated with knee pain. The odds ratio for those with obesity compared with normal to knee pain was 2.27 (1.42-3.65) in the first quartile of CRP, 1.99 (1.38-2.86) in the second, 2.15 (1.38-3.33) in the third, and 2.92 (1.72-4.97) in the fourth.

CONCLUSION

Obesity mediated the systemic inflammation results in knee pain in US adults. Moreover, higher BMI was associated with higher knee pain risk in different degree CRP subgroups, supporting an important role of weight loss in reducing knee pain caused by systemic inflammation.

Mendelian randomization of stroke risk after total hip and knee replacements

Objective

Previous epidemiological studies have indicated an increased risk of neurovascular diseases in patients following total hip and knee replacements. However, definitive conclusions regarding the increased risk of stroke post-replacement remain elusive. Therefore, we conducted a two-sample Mendelian randomization study to investigate the causal relationship between total hip and knee replacements and stroke.

Methods

We utilized summary data from publicly available genome-wide association studies (GWAS). Data concerning total hip replacements (THR, N = 319,037) and total knee replacements (TKR, N = 252,041) were sourced from the Genetics of Osteoarthritis (GO) Consortium. Stroke-related data were obtained from the International Stroke Genetics Consortium, encompassing any stroke (AS), any ischemic stroke (AIS), large vessel ischemic stroke (LV-IS), cardioembolic ischemic stroke (CE-IS), and small vessel ischemic stroke (SV-IS). Our primary causal inference method was the inverse variance weighted (IVW) approach, supplemented by weighted median and MR-Egger regression as secondary inference methods. We utilized the MR-PRESSO global test for outlier detection, Cochran's Q statistic to assess heterogeneity, and assessed the multiplicity and stability of our findings using p-values from MR-PRESSO and MR-Egger regressions, and the leave-one-out method, respectively.

Results

We identified significant genetic associations between THR and both AS (IVW p = 0.0001, OR = 1.08, 95% CI = 1.04-1.12) and AIS (IVW p = 0.0016, OR = 1.07, 95% CI = 1.03-1.12). Significant associations were also observed between TKR and AS (IVW p = 0.0002, OR = 1.08, 95% CI = 1.04-1.12), as well as AIS (IVW p = 0.0005, OR = 1.15, 95% CI = 1.06-1.24).

Conclusion

Our findings genetically support an increased risk of stroke following total hip and knee replacements. However, further studies are necessary to elucidate the specific mechanisms underlying stroke episodes post-replacement.

Mental Robustness May Be Associated With Improved Physical Function in Bilateral Total Knee Arthroplasty Patients

BACKGROUND

In accordance with the high incidence of bilateral knee osteoarthritis, many patients have undergone bilateral total knee arthroplasty (BTKA). Whether patients undergo bilateral procedures in a staged or simultaneous fashion, the physical and mental burden of undergoing 2 major orthopedic procedures is considerable. The aims of this study were to (1) investigate differences between minimal clinically important difference (MCID) achievement between staged versus simultaneous BTKA, and (2) identify the patient variables, specifically mental scores, that were associated with MCID achievement in patients undergoing BTKA.

METHODS

Simultaneous and staged BTKA patients within a single health care network from 2016 to 2021 were retrospectively reviewed. Patient demographics, surgery details, and Patient-Reported Outcome Measurement Information System Physical Function Short Forms 10a (PROMIS PF10a), PROMIS Mental scores, and Knee Disability Osteoarthritis Outcome Scores (KOOS) were reviewed. Preoperative and postoperative patient-reported outcome measures were collected before the first total knee arthroplasty (TKA) and after the second TKA, respectively, in staged BTKA patients. The final cohort consisted of 249 patients, with an average age of 66 years (range, 21 to 87), 63% women, and an average body mass index of 32 (range, 20 to 52), at a mean follow-up of 1.1 years (range, 0.5 to 2.4). Multivariate regressions were performed on MCID PF10a and KOOS achievement, as well as whether the BTKA was performed simultaneously versus staged.

RESULTS

A preoperative PROMIS Mental score in the upper 2 quartiles was associated with MCID PF10a achievement in BTKA. Men and surgeries performed at an Academic Medical Center were negatively associated with the achievement of MCID KOOS. Interestingly, those who underwent simultaneous BTKA were less likely to achieve MCID KOOS than those who underwent a staged BTKA.

CONCLUSIONS

Preoperative mental robustness may be positively associated with improved physical function outcome in BTKA patients.