Gender Differences in Contribution of Smoking, Low Physical Activity, and High BMI to Increased Risk of Early Reoperation After TKA

Survivorship of Primary NexGen Knee Replacement: Comparing Cementless Trabecular Metal to Other Designs of Tibial Component

The impact of cementless trabecular metal (TM) implants on implant survivorship are not well delineated. This study compares primary total knee arthroplasty (TKA) revision rates of cemented knee replacements with two cementless knee replacement designs-cementless TM and a non-TM cementless design. Data from a national registry queried TKA procedures performed for osteoarthritis from 1999 to 2020. The risk of revision of Zimmer NexGen TKA using cementless TM, cementless non-TM, and cemented non-TM were compared. Analyses included Kaplan-Meier estimates of survivorship and Cox hazard ratios (HR), stratified by age and gender. Cementless TM components had higher risks of revision compared with cementless non-TM implants (HR = 1.49; p ≤ 0.001). Cementless TM implants showed higher risks of revision compared with cemented non-TM prostheses for the first 2 years (HR = 1.75, p < 0.001). Non-TM prostheses posed equal risk of revision for cementless and cemented fixations (HR = 0.95, p = 0.522). Patients aged 55 to 64 years and 65 to 74 years had a higher risk of revision for cementless TM compared with cementless non-TM (HR = 1.40, p = 0.033 and HR = 1.79, p < 0.001, respectively) and cemented non-TM implants (HR = 1.51, p < 0.001 and HR = 1.54, p < 0.001, respectively). The study shows there is an increased risk of revision with TM cementless implants for patients aged 55 to 74 years. These results do not support the use of TM tibial implants for patients of this age group for primary TKA.

Sex-specific differences in 30-day outcomes following primary total hip replacement in 86,684 patients

INTRODUCTION

Although differential outcomes based on sex are widespread in medicine and surgery, evaluation of sex-specific differences in the field of orthopaedic surgery in general - and arthroplasty in particular - are lacking. We hypothesised that morbidly obese male and female patients would have differing risks of surgical complications following primary total hip replacement.

METHODS

We reviewed data contained within the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database from 2015 through 2018, inclusive. A multivariable binary logistic regression model was used to determine the adjusted odds ratios (OR) of relevant variables on primary and secondary outcomes.

RESULTS

A total of 86,684 patients undergoing THR were identified, of whom 9972 patients (4095 male and 5877 female) were morbidly obese. Among morbidly obese patients, odds of surgical site infection were higher in females than males within 30 days of surgery (adjusted OR 1.40; 95% CI, 1.10-1.79; p = 0.007). This comprised the odds of both superficial infection (1.8% vs. 1.1%, adjusted OR 1.67; 95% CI, 1.16-2.40; p = 0.006) and deep infection (1.9% vs. 1.4%, adjusted OR 1.22; 95% CI, 0.88-1.68; p = 0.24). Unexpected return to the operating room (i.e., reoperation) within 30 days of the surgical procedure was also higher among females than males (4.2% vs. 3.1%, adjusted OR 1.38, 95% CI, 1.10-1.71, p = 0.005). There were no differences between male and female patients in the non-obese cohort.

CONCLUSIONS

Among patients with morbid obesity, the risk of surgical site infection and reoperation within the first 30 days is greater in women as compared to men. Future research must address whether this early increased risk among morbidly obese women persists in the longer term, and whether it results in compromised function or quality of life.

Does Aseptic Revision Risk Differ for Primary Total Knee Arthroplasty Patients Who Have and Do not Have a Prior Primary or Revision Arthroplasty?

BACKGROUND

We sought to evaluate the risk of aseptic revision in total knee arthroplasty (TKA) patients who have and do not have a history of primary or revision arthroplasty of a different major joint.

METHODS

We conducted a matched cohort study using data from Kaiser Permanente's arthroplasty registries. Patients who underwent primary unilateral TKA (index knee) were identified (2009-2018). Two matches based on exposure history were performed: (1) 33,714 TKAs with a history of primary arthroplasty of a different joint (contralateral knee, either hip, and/or either shoulder) were matched to 67,121 TKAs without an arthroplasty history and (2) 597 TKAs with a history of aseptic revision in a different joint were matched to 1,190 TKAs with a history of a prior arthroplasty in a different joint, but without any revision. After the matches were performed, Cox regressions were used to evaluate aseptic revision risk of the index knee using the no history groups as the reference in regression models.

RESULTS

No difference in aseptic revision risk for the index knee was observed when comparing patients who had a prior primary arthroplasty in a different joint to those who did not have an arthroplasty history (hazard ratio = 0.95, 95% CI = 0.86-1.06). Those patients who did not have any prior aseptic revision history in a different joint had higher risk of aseptic revision in the index knee (hazard ratio = 2.06, 95% CI = 1.17-3.63).

CONCLUSION

Patients who had a prior revision history had over a 2-fold higher risk of aseptic revision in the index knee, warranting close surveillance of these patients.

LEVEL OF EVIDENCE

Level III.

Knee osteoarthritis phenotypes based on synovial fluid immune cells correlate with clinical outcome trajectories

BACKGROUND

Knee osteoarthritis (KOA) is a highly heterogeneous disease encompassing a wide range of clinical phenotypes. Phenotypes based on immune cells and protein pattern in synovial fluid (SF) and their relationship to clinical trajectories have not been described.

OBJECTIVE

To assess phenotypes based on immune cells and protein pattern of SF in KOA.

DESIGN

SF-derived immune cells were investigated in 119 patients with KOA using flow cytometry. Immune-phenotypes (iPhen) were determined by multivariate patient similarity network analysis and related to clinical trajectory (3-6 months post-sampling) along with protein pattern and macrophage chemokine receptors.

RESULTS

Four iPhen were detected based on the distribution of T-lymphocytes, monocyte-macrophage lineage cells and activated CD8+ T-lymphocytes. The 'activated' phenotype (n = 17) had high T-lymphocytes but low monocyte-macrophage lineage cells and neutrophils, all highly activated, and showed improved symptoms in 70% patients. The 'lymphoid progressive' phenotype (n = 31) had high neutrophils, low lymphocytes and monocyte-macrophage lineage cells, low activation and was associated with lower pain levels. The 'myeloid progressive' phenotype (n = 35) had high NK and monocyte-macrophage lineage cells but low T-lymphocytes and activation. The 'aggressive' phenotype (n = 36) had high lymphocytes, macrophages, NK cells and neutrophils and high activation, and only 39% of patients improved during follow-up. Low CXCR4 and CCR7 expression on macrophages and high CXCL10 in SF were linked to improved clinical trajectory.

CONCLUSION

We identified four immune-phenotypes that were associated with different clinical trajectories in KOA patients. How these phenotypes can be targeted therapeutically deserves further investigation.

Network Analysis for Uncovering the Relationship between Host Response and Clinical Factors to Virus Pathogen: Lessons from SARS-CoV-2

Analysing complex datasets while maintaining the interpretability and explainability of outcomes for clinicians and patients is challenging, not only in viral infections. These datasets often include a variety of heterogeneous clinical, demographic, laboratory, and personal data, and it is not a single factor but a combination of multiple factors that contribute to patient characterisation and host response. Therefore, multivariate approaches are needed to analyse these complex patient datasets, which are impossible to analyse with univariate comparisons (e.g., one immune cell subset versus one clinical factor). Using a SARS-CoV-2 infection as an example, we employed a patient similarity network (PSN) approach to assess the relationship between host immune factors and the clinical course of infection and performed visualisation and data interpretation. A PSN analysis of ~85 immunological (cellular and humoral) and ~70 clinical factors in 250 recruited patients with coronavirus disease (COVID-19) who were sampled four to eight weeks after a PCR-confirmed SARS-CoV-2 infection identified a minimal immune signature, as well as clinical and laboratory factors strongly associated with disease severity. Our study demonstrates the benefits of implementing multivariate network approaches to identify relevant factors and visualise their relationships in a SARS-CoV-2 infection, but the model is generally applicable to any complex dataset.

Odds-ratio network for postoperative factors revealing differences in the 2-year longitudinal pattern of satisfaction between women and men after total knee arthroplasty

Timely and accurate assessments of the factors influencing satisfaction, a key indicator of success in primary total knee arthroplasty (TKA), may help improve TKA outcomes. Here we performed the longitudinal trend analysis of relation between satisfaction and 12 postoperative factors, which positively or negatively influence the patient satisfaction 2 years after TKA. In a real-world registry cohort (women/men: 1121/650), we showed similarities and differences between women and men in the contribution of postoperative factors to satisfaction 2 years after TKA as assessed by odds-ratio-similarity network. In men, the strongest negative factors were pain and complications, followed by mechanical problems. In women, the strongest negative factors were the pain and knee instability, followed by other mechanical problems, complications and low levels of sports activity. In both sexes, physical activity and the Knee Society Score (general and functional) influenced positively satisfaction; long-distance walking was associated with satisfaction only in women. A trend analysis revealed a reduction in the strength of satisfaction-related factors over 2 years of check-ups, particularly in women. Our study demonstrates that the key check-up for assessing the evolution of satisfaction in the 2 years after TKA was at 3 months in both sexes.

Content and delivery of pre-operative interventions for patients undergoing total knee replacement: a rapid review

BACKGROUND

Total knee replacement (TKR) is a common operation typically performed for end-stage knee osteoarthritis. Patients awaiting TKR often have poor health-related quality of life. Approximately 20% of patients experience persistent pain post-TKR. Pre-operative TKR interventions could improve pre- and post-operative outcomes, but future research is required to inform their design. This review aimed to identify and synthesize recent literature on the content and delivery of pre-operative TKR interventions to help guide future research and clinical practice.

METHODS

This rapid review included randomized trials of pre-operative TKR interventions ("outcomes studies") and primary studies exploring patients' and/or health professionals' views of pre-operative TKR interventions ("views studies"). Medline, Embase, PsycINFO, CINAHL and the Cochrane Central Register of Controlled Trials were searched for English language studies published between January 2009 and December 2020. Eligible studies' reference lists were screened. Studies were appraised using the Mixed Methods Appraisal Tool. The findings were narratively synthesized using a convergent segregated approach.

RESULTS

From 3263 records identified, 52 studies were included (29 outcomes studies, 21 views studies, two outcomes/views studies). The studies' methodological quality varied but was generally highest in qualitative studies. The outcomes studies investigated education (n=5), exercise (n=20), psychological (n=2), lifestyle (n=1), and/or other interventions (n=5). The views studies addressed education (n=20), exercise (n=3), psychological (n=1), lifestyle (n=4), and/or other interventions (n=1). Only three outcomes studies (two randomized controlled trials (RCTs) and a pilot study) compared the effectiveness of intervention components/delivery approaches. The two RCTs' results suggest that pre-operative TKR exercise interventions are equally effective regardless of whether they include strength or strength plus balance training and whether they are hospital- or home-based. Personal tailoring and using more than one delivery format were associated with improved outcomes and/or perceived as beneficial for multiple intervention types.

CONCLUSIONS

Definitive evidence on the optimal design of pre-operative TKR interventions is lacking. Personal tailoring and employing multiple delivery formats appear to be valuable design elements. Preliminary evidence suggests that including balance training and hospital versus home delivery may not be critical design elements for pre-operative TKR exercise interventions.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019143248 FUNDER: National Institute for Health and Care Research (ICA-CDRF-2018-04-ST2-006).

Medium Activity Prevents Periprosthetic Bone Mass Loss in the Medial Metaphyseal Region of the Tibia after Posterior-Stabilized TKA: A 5-Year Follow-up Study of 110 Knees

Objective

The bone mass around the prosthesis plays an important role in the stability of the prosthesis. This study aimed to assess the effect of postoperative activity on bone mineral density (BMD) in the proximal tibia 5 years after total knee arthroplasty (TKA). To provide a scientific guidance for postoperative functional exercise.

Methods

110 patients underwent unilateral primary TKA were divided into three groups based on the University of California Los Angeles (UCLA) activity scale: low activity group (LA group, UCLA = 4, 5); medium activity group (MA group, UCLA = 6, 7); and high activity group (HA group, UCLA = 8, 9). The primary observation was a comparison of the BMD and BMD change percentage (ΔBMD (%)) in the periprosthetic tibia among the LA, MA and HA groups at 1 year, 3 years and 5 years. The secondary observations were radiographic evaluation (prosthetic stability, periprosthetic fractures, aseptic loosening and periprosthetic joint infection) and clinical evaluation (Knee Society Score (KSS), visual analogue score scores and range of motion (ROM)). A one‐way ANOVA was used to compare the clinical scores and BMD among the three groups.

Results

The BMD of medial region decreased by 10.80%, 12.64%, 13.61% at 1, 3, and 5 years respectively; these were 5.72%, 6.26%, 7.83% in lateral region and 1.42%, 1.78%, 3.28% in diaphyseal region. For medial metaphyseal region, the BMD of the MA group was significantly greater than that of the LA and HA groups at 1 and 3 years (108.9 ± 5.2 vs. 106.1 ± 6.69 vs. 105.4 ± 5.2 and 108.5 ± 6.0 vs. 101.2 ± 6.76 vs. 103.0 ± 6.8, P < 0.01 and P < 0.001), and the BMD changes (ΔBMD (%)) in the MA group were significantly smaller than those in the LA and HA groups (8.75 ± 5.36 vs. 11.92 ± 5.49 vs. 12.70 ± 5.21 and 9.11 ± 5.11 vs. 16.04 ± 4.79 vs. 14.82 ± 4.26, P < 0.01 and P < 0.001).

Regarding secondary observations, all of the prostheses were assessed as stable, without periprosthetic fractures, aseptic loosening and periprosthetic joint infection. Regarding KSS scores, there was no significant difference among the three groups. However, the VAS and ROM of the HA group were better than those of the MA and LA groups (1.65 ± 0.79 vs. 2.63 ± 0.77 vs. 3.00 ± 1.17, p < 0.001, and 111.90 ± 9.17 vs. 110.20 ± 6.78 vs. 102.90 ± 8.48, P < 0.001).

Conclusion

Medium activity prevented periprosthetic bone loss in the medial metaphyseal region of the tibia after posterior‐stabilized TKA, and moderate‐intensity exercise is recommended for patients after TKA to reduce periprosthetic bone loss.

A theoretical model of health management using data-driven decision-making: the future of precision medicine and health

BACKGROUND

The burden of chronic and societal diseases is affected by many risk factors that can change over time. The minimalisation of disease-associated risk factors may contribute to long-term health. Therefore, new data-driven health management should be used in clinical decision-making in order to minimise future individual risks of disease and adverse health effects.

METHODS

We aimed to develop a health trajectories (HT) management methodology based on electronic health records (EHR) and analysing overlapping groups of patients who share a similar risk of developing a particular disease or experiencing specific adverse health effects. Formal concept analysis (FCA) was applied to identify and visualise overlapping patient groups, as well as for decision-making. To demonstrate its capabilities, the theoretical model presented uses genuine data from a local total knee arthroplasty (TKA) register (a total of 1885 patients) and shows the influence of step by step changes in five lifestyle factors (BMI, smoking, activity, sports and long-distance walking) on the risk of early reoperation after TKA.

RESULTS

The theoretical model of HT management demonstrates the potential of using EHR data to make data-driven recommendations to support both patients' and physicians' decision-making. The model example developed from the TKA register acts as a clinical decision-making tool, built to show surgeons and patients the likelihood of early reoperation after TKA and how the likelihood changes when factors are modified. The presented data-driven tool suits an individualised approach to health management because it quantifies the impact of various combinations of factors on the early reoperation rate after TKA and shows alternative combinations of factors that may change the reoperation risk.

CONCLUSION

This theoretical model introduces future HT management as an understandable way of conceiving patients' futures with a view to positively (or negatively) changing their behaviour. The model's ability to influence beneficial health care decision-making to improve patient outcomes should be proved using various real-world data from EHR datasets.

Deciphering the complex circulating immune cell microenvironment in chronic lymphocytic leukaemia using patient similarity networks

The tissue microenvironment in chronic lymphocytic leukaemia (CLL) plays a key role in the pathogenesis of CLL, but the complex blood microenvironment in CLL has not yet been fully characterised. Therefore, immunophenotyping of circulating immune cells in 244 CLL patients and 52 healthy controls was performed using flow cytometry and analysed by multivariate Patient Similarity Networks (PSNs). Our study revealed high inter-individual heterogeneity in the distribution and activation of bystander immune cells in CLL, depending on the bulk of the CLL cells. High CLL counts were associated with low activation on circulating monocytes and T cells and vice versa. The highest activation of immune cells, particularly of intermediate and non-classical monocytes, was evident in patients treated with novel agents. PSNs revealed a low activation of immune cells in CLL progression, irrespective of IgHV status, Binet stage and TP53 disruption. Patients with high intermediate monocytes (> 5.4%) with low activation were 2.5 times more likely (95% confidence interval 1.421–4.403, P = 0.002) to had shorter time-to-treatment than those with low monocyte counts. Our study demonstrated the association between the activation of circulating immune cells and the bulk of CLL cells. The highest activation of bystander immune cells was detected in patients with slow disease course and in those treated with novel agents. The subset of intermediate monocytes showed predictive value for time-to-treatment in CLL.