Total Knee Replacement Surgery Research Articles

Preoperative prediction model for risk of readmission after total joint replacement surgery: a random forest approach leveraging NLP and unfairness mitigation for improved patient care and cost-effectiveness

BackgroundThe Center for Medicare and Medicaid Services (CMS) imposes payment penalties for readmissions following total joint replacement surgeries. This study focuses on total hip, knee, and shoulder arthroplasty procedures as they account for most joint replacement surgeries. Apart from being a burden to healthcare systems, readmissions are also troublesome for patients. There are several studies which only utilized structured data from Electronic Health Records (EHR) without considering any gender and payor bias adjustments.MethodsFor this study, dataset of 38,581 total knee, hip, and shoulder replacement surgeries performed from 2015 to 2021 at Novant Health was gathered. This data was used to train a random forest machine learning model to predict the combined endpoint of emergency department (ED) visit or unplanned readmissions within 30 days of discharge or discharge to Skilled Nursing Facility (SNF) following the surgery. 98 features of laboratory results, diagnoses, vitals, medications, and utilization history were extracted. A natural language processing (NLP) model finetuned from Clinical BERT was used to generate an NLP risk score feature for each patient based on their clinical notes. To address societal biases, a feature bias analysis was performed in conjunction with propensity score matching. A threshold optimization algorithm from the Fairlearn toolkit was used to mitigate gender and payor biases to promote fairness in predictions.ResultsThe model achieved an Area Under the Receiver Operating characteristic Curve (AUROC) of 0.738 (95% confidence interval, 0.724 to 0.754) and an Area Under the Precision-Recall Curve (AUPRC) of 0.406 (95% confidence interval, 0.384 to 0.433). Considering an outcome prevalence of 16%, these metrics indicate the model’s ability to accurately discriminate between readmission and non-readmission cases within the context of total arthroplasty surgeries while adjusting patient scores in the model to mitigate bias based on patient gender and payor.ConclusionThis work culminated in a model that identifies the most predictive and protective features associated with the combined endpoint. This model serves as a tool to empower healthcare providers to proactively intervene based on these influential factors without introducing bias towards protected patient classes, effectively mitigating the risk of negative outcomes and ultimately improving quality of care regardless of socioeconomic factors.

The use of triple antibiotic prophylaxis during total knee replacement surgeries in Awka, Nigeria

Introduction: Total knee arthroplasty periprosthetic joint infection (PJI) poses a significant challenge in orthopaedic surgery, often resulting in early failure and associated with high morbidity and mortality rates. Various treatment strategies exist, including debridement, antibiotic therapy, and prosthesis retention, with preventive measures such as antibiotic-impregnated cement and prophylactic antibiotics administration recommended by the American Academy of Orthopaedic Surgeons (AAOS). Methodology: This prospective cohort study was conducted in an orthopaedic hospital in Awka, Southeast Nigeria, spanning seven years (2014-2021). A total of 134 patients who underwent primary and revision knee arthroplasty were included. The hospital's antibiotic prophylaxis protocol for implant surgeries, including arthroplasties, involved a triple combination of ceftriaxone, ciprofloxacin, and metronidazole administered pre-, intra-, and postoperatively for a minimum of 7 days. Results: The study population had a mean age of 63.6 years, predominantly female (77.7%), and of Christian faith (100%). Most participants were of Igbo ethnicity (99.3%), married (90.7%), and engaged in business (37.7%). Severe osteoarthritis was the primary diagnosis in 97.0% of cases, while rheumatoid arthritis accounted for 3.0%. The triple antibiotic prophylaxis regimen resulted in only one case of superficial infection, with no instances of deep infection recorded. Conclusion: Triple antibiotics prophylaxis, comprising ceftriaxone, ciprofloxacin, and metronidazole, demonstrated effectiveness in preventing infections associated with total knee arthroplasty. This regimen maintained surgical site infection prevalence within acceptable limits for clean surgeries, without observable antibiotic resistance in the study population.

Influence of Changes in Patella Indices on Total Knee Replacement Surgery Outcomes.

Total knee replacement is increasingly widely prescribed, not only for degenerative joint disease but also for other problems such as articular cartilage disease, misalignment due to causes other than degeneration, bone and joint cancer, and diseases that cause joint destruction. However, changes in knee joint biomechanics as well as complications of the patellofemoral joint after surgery lead to instability, joint pain, patellar rupture, and patellar tendon rupture. These are issues that challenge surgeons as well as make patients hesitant when considering knee replacement surgery. Understanding the changes in patella index that can occur after total knee replacement surgery will help surgeons carefully evaluate patients before surgery and calculate intraoperative techniques to minimize complications. Fifty-eight patients with 62 knees were diagnosed with osteoarthritis and underwent total knee replacement surgery. All patients had clinical and radiographic evaluation of the knee joint before and after surgery. Patellar indexes did not change significantly after surgery compared to before surgery. Before surgery, 2 patients (3.23%) had true patella baja. After surgery, 7 patients (11.29%) had true patella baja and 3 patients (4.84%) had pseudo-patella baja. The average knee flexion amplitude after surgery was 103.11±15.440, with only 2 patients losing extension >50º. The average KS score after surgery was 83.69±9.98, significantly improved compared to before surgery 33.44±11.38. Similarly, KFS score after surgery was 81.01±8.84 compared to before surgery 37.05±8.08. Changes in index of the patella before and after surgery affect the surgical results, the normal patella group has better results than the group with patella baja.

Navigating the Divide: A Comprehensive Review of the Mechanical and Anatomical Axis Approaches in Total Knee Replacement.

This comprehensive review explores the mechanical and anatomical axis approaches in total knee replacement (TKR) surgery, addressing the ongoing debate within the orthopedic community. Emphasizing the significance of TKR in alleviating knee-related disorders, this review underscores the pivotal role of accurate alignment in achieving optimal surgical outcomes. The purpose is to navigate the divide between the well-established mechanical axis approach, focusing on a straight-line alignment, and the anatomical axis approach, aligning with natural knee landmarks. The analysis delves into the advantages, disadvantages, and clinical implications of each approach, offering a nuanced perspective on their efficacy. The conclusion emphasizes a patient-centric approach, recommending the adoption of hybrid strategies and the incorporation of emerging technologies for enhanced precision. The future of TKR aligns with personalized medicine, leveraging advancements in computer-assisted navigation, robotics, and patient-specific implants. Ongoing professional development and interdisciplinary collaboration are crucial for surgeons, and as the field evolves, innovations in artificial intelligence, imaging, and 3D printing are expected to shape the trajectory of TKR alignment approaches.

Evaluating the Efficacy and Safety of Combined Administration of Systemic and Topical Tranexamic Acid in Total Knee Arthroplasty.

Tranexamic acid (TXA) is an antifibrinolytic agent, thatagent that reduces substantial blood loss in total knee arthroplasty (TKA) surgeries without increasing the risk of thromboembolic complications. The purpose of our study was to assess the effectiveness and safety of the combined use of intravenousIV and topical TXAtranexamic acid in uncomplicated primary Total knee Arthroplasty (TKA) without complications. In this prospective study, we enrolled 61 patients who underwent unilateral primary TKR and were randomly divided into two groups: Group I received intravenous (IV) TXA and Group II received both IV and intraarticular (IA) TXA. Patients assigned to Group I received IV TXA preoperatively 30 mins before surgery and postoperatively at 3 and 6 hours after surgery, whereas in the combined group, in addition to IV doses, topical TXA was applied as mop 2 g of TXA diluted in 30 mL of isotonic sodium chloride solution) intraarticularly for about 5 minutes before closing the arthrotomy. We measured total blood loss (TBL), ) and mean reduction in haemoglobin (Hb) levels as primary outcomes. Transfusion rates, incidence of thromboembolic events (TE), and other adverse effects as secondary outcomes. Total blood loss TBL and Hb drops was were noted on the 3rd post-operative day. All the patients were followed-up for 6 months to note the incidence of deep venous thrombosisDVT and Thromboembolic Events (TE). An Iindependent t-test was used to evaluate between--group differences. P < 0.05 as is the cut-off for statistically significant differences. The Total blood loss (TBL) in Group I was 780.05 ± 158.05 mL, compared to 660.80 ± 156.45 mL in Group II. (P < 0.001). The Hb drop was significantly lower in IV TXA group (2.3 ± 0.37) than the combined TXA group (1.40 ± 0.32). Furthermore, both groups required no transfusions. No thromboembolic complications was were noted postoperatively and at 6 6-month follow-up. TXATranexamic acid in total knee replacement surgery effectively decreases blood loss and significantly reduces the need for blood transfusions. Based on our study, the combined use of intravenous (IV) and IAintraarticular TXA in total knee replacement was found to be superior in reducing blood loss and significantly reducing the need for blood transfusions in TKA.

Dexmedetomidine Effects on Surgical Stress Hormones

Background: Increased levels of cortisol and catecholamines are the reaction to tissue damage due to surgical trauma. Dexmedetomidine inhibits the synthesis of these two hormones.Objective: This study aimed to prove that dexmedetomidine reduces the endocrine response to surgical stress.Method: 40 patients who underwent Total Knee or Hip Replacement surgery with regional anesthesia were involved in the Double-Blind Randomized Controlled Trial Pre-Test – Post-Test Design, which was divided into two research groups: the therapy group and the control group. Changes in the body's response to stress during surgery were compared by assessing blood cortisol levels, heart rates (HRs), and mean arterial pressures (MAPs). The Beck Depression Inventory (BDI) was used to evaluate the level of depression. The numeric rating scale is used to evaluate perioperative pain, while the Ramsay scale is used to measure the level of sedation. Data analysis was carried out using the Statistical Program for Social Sciences (SPSS).Results: The cortisol levels of the therapy group compared to the control group (p = 0.016) decreased significantly immediately after surgery. Hemodynamic changes in the study, the heart rate (p=0.001), and mean arterial pressure (p=0.000) were significantly lower than the control group.Conclusion: Administration of dexmedetomidine during the surgical period reduces stress hormone responses. These results indicate that dexmedetomidine administration is good to apply, especially in TKR/THR.

Optimising total knee replacement imaging: a novel 3D printed PET/CT anthropomorphic phantom for metal artefact simulation

PurposeArthroplasty phantoms, including total knee replacement (TKR) phantoms, have been frequently used to test metal artefact reduction methods applied to positron emission tomography/computed tomography (PET/CT) images. These phantoms generally simulate either simple anatomical features or simple activity distribution around the metal inserts in the PET/CT scans. 3D printing has been used recently to fabricate fillable anthropomorphic phantoms that accurately simulate volume and geometry. This study aims to describe the process of image segmentation, phantom modelling, 3D printing and validation of a population-based fillable TKR phantom that simulates human TKR PET/CT metal artefacts.Methods10 participants (5 male and 5 female) were scanned using 3T MRI and the images were segmented to create average male and average female 3D knee models, inversely with void cortical and porous trabecular compartments for 3D printing and contrast media. Virtual total knee replacement (TKR) surgery was implemented on these models to prepare the insertion locations for knee prosthetic implants. Subsequently, TKR models were printed using a 3D photopolymer resin printer and then injected with normal saline to test the phantoms for any leaks. Subsequently, diluted iodinated contrast media was injected into the cortical compartment and saline with 18F-FDG was injected into the trabecular compartment and the phantom was scanned with PET/CT. The images were then evaluated and compared to the human knee radiographic features reported in the literature.ResultsPhantoms were shown to be fluid-tight with distinct compartments. They showed comparable volume and geometry to the segmented human MRI knees. The phantoms demonstrated similar values for x-ray attenuation and Hounsfield units (HU) to the literature for both cortical and trabecular compartments. The phantoms displayed a uniform distribution for the radioactive tracer, resembling that seen in human trabecular bone PET. TKR phantom PET/CT images with metal inserts replicated the clinical metal artefacts seen clinically in the periprosthetic area.ConclusionThis novel, 3D-printed, and customisable phantom effectively mimics the geometric, radiographic and radiotracer distribution features of real TKRs. Importantly, it simulates TKR image metal artefacts, making it suitable for repeatable and comprehensive evaluation of various metal artefact reduction methods in future research.

The effect of cryotherapy on pain in patients with total knee replacement surgery: a meta-analysis.

Cryotherapy is used to reduce edema and pain after total knee replacement surgery. This study was conducted as a meta-analysis study to determine the effect of cryotherapy on pain in patients undergoing total knee arthroplasty. The words 'total knee prosthesis,' 'pain,' 'cryotherapy,' 'cold application,' and 'orthopedic surgery' were searched in Turkish and English in scientific articles in the last 20 years from Scopus, Science Direct, Google Scholar, Pubmed databases. As a result of the research, a total of 8.406 studies were identified. Funnel Plot, Rosenthal's Secure N, and Orwin's Secure N methods were used to demonstrate that the meta-analysis study was reliable and valid and to determine publication bias. The sample size of the studies included in the analysis was 1462. The total effect size was 2.929, with a lower bound of 1.641 and an upper bound of 5.223 at a 95% confidence interval. The study determined that patients who underwent cryotherapy in total knee replacement surgery had 2.9 times less pain than patients who did not undergo cryotherapy.

A preliminary study on analysis of lower limb energy during walking in the patients with knee replacement

BackgroundKnee replacement surgeries are used to reduce pain and enhance functionality for individuals with knee arthritis. It is predicted that the annual volume of total knee replacement surgeries conducted in the US will surge by a substantial 673% by 2030. Though a lot of studies have done gait analysis on patients with knee replacement, little research is on energy changes in the lower limbs during gait. This study aimed to investigate the mechanical energy changes in the lower limbs for patients with total knee arthroplasty (TKA) and unicondylar knee arthroplasty (UKA), and ultimately to provide a specific tool to analyze limb energy during gait in clinical practice. Methods10 TKA and 8 UKA patients were recruited for gait analysis. The control group consisted of 11 individuals without knee replacement surgery. Vicon motion capture system and Plug-in-Gait model were used to collect gait data to obtain marker coordinates and gait parameters. The kinetic energy, potential energy, and rotational energy for each segment in the lower limbs were calculated. The energies in the centre of pelvis were considered as the approximate to the centre of mass. The energy recovery coefficients were analysed for each segment during gait. SPSS was used to identify the differences between different groups. ResultsThe results showed that during walking, the upper leg had the highest recovery coefficient, approximately 40%, followed by the foot at 10%, and the lowest recovery coefficient was observed in the lower leg, approximately 1–3%. However, the energy recovery coefficients at the centre of pelvis were significantly higher in the control group than the TKA and UKA groups by roughly 12%–15%. ConclusionsThe energy difference between the operative and non-operative sides is not significant regardless of the type of surgery. The TKA and UKA groups were more active in potential energy than control group. The upper leg has the highest recovery efficiency of kinetic and potential energy exchanges when walking. The control group used the energy for whole body is better than the patient groups. This study provides a new and useful way to analyze mechanical energy in the lower limbs during gait and could be applied in clinical practice.

Cemented vs. Cementless Fixation in Primary Knee Replacement: A Narrative Review.

Knee osteoarthritis (OA) is one of the leading causes of disability around the globe. Osteoarthritis is mainly considered a disease affecting the elderly. However, more and more studies show that sports overuse, obesity, or congenital disorders can initiate a pathologic cascade that leads to OA changes in the younger population. Nevertheless, OA mostly affects the elderly, and with increasing life expectancy, the disease will develop in more and more individuals. To date, the golden standard in the treatment of the end-stage of the disease is total joint replacement (TJR), which restores painless knee motion and function. One of the weakest elements in TJR is its bonding with the bone, which can be achieved by bonding material, such as poly methyl-methacrylate (PMMA), or by cementless fixation supported by bone ingrowth onto the endoprosthesis surface. Each technique has its advantages; however, the most important factor is the revision rate and survivor time. In the past, numerous articles were published regarding TJR revision rate, but no consensus has been established yet. In this review, we focused on a comparison of cemented and cementless total knee replacement surgeries. We introduced PICO rules, including population, intervention, comparison and outcomes of TJR in a PubMed search. We identified 783 articles published between 2010 and 2023, out of which we included 14 in our review. Our review reveals that there is no universally prescribed approach to fixate knee prostheses. The determination of the most suitable method necessitates an individualized decision-making process involving the active participation and informed consent of each patient.

A potential link between inflammatory profiles, clinical pain, pain catastrophizing and long-term outcomes after total knee arthroplasty surgery.

Chronic postoperative pain after total knee replacement (TKR) is a major clinical problem. It is still unclear if specific inflammatory mediators are associated with long-term postoperative pain complications. The current exploratory study aimed to (1) evaluate a multiplex of inflammatory mediators 5 years after TKR surgery in patients with different degrees of postoperative pain intensities and (2) study any association of the markers with clinical pain intensity, cognitive and functional outcomes. Plasma samples were collected 5 years after TKR surgery from 76 knee patients (43 females; 33 males) and analysed for 44 inflammatory markers. Pain (using visual analogue scale, VAS), the pain catastrophizing scale (PCS) and the Oxford knee score (OKS) were evaluated. Patients were categorized as high or low groups based on VAS, PCS and OKS scores. Associations between inflammatory markers, VAS, PCS and OKS were analysed and the marker expressions were compared between groups. Pearson's correlations found 12 biomarkers associated with VAS (p < 0.05), 4 biomarkers with PCS and 3 biomarkers with OKS (p < 0.05). Four markers were altered in patients suffering from high compared to low chronic postoperative pain, three markers were altered in high compared to low catastrophizers and three markers were altered in patients with poor functional scores (p < 0.05). The present exploratory study suggests that low-grade inflammation might be present in a subset of patients with high pain, high catastrophizing and low function 5 years after TKR. These exploratory results provide insights into some of the long-term postoperative complications after TKR surgery. This exploratory study evaluated a subset of inflammatory markers and the association to clinical pain intensity, knee function and pain catastrophizing in patients 5 years after total knee replacement surgery. Our results provide insights into the understanding of the underlying mechanisms that may drive the long experience of pain after TKR surgery.

Individual Factors Modifying Postoperative Pain Management in Elective Total Hip and Total Knee Replacement Surgery.

Total hip and knee replacements are the most common orthopedic procedures performed due to osteoarthritis. Pain is an intrinsic symptom accompanying osteoarthritis, persisting long before surgery, and continuing during the preoperative and postoperative periods. Appropriate pain management after surgery determines the comfort, duration, and cost of hospitalization, as well as the effectiveness of postoperative rehabilitation. Individual differences in pain perception and tolerance in orthopedic patients remain an important research topic. Therefore, the aim of this study was to investigate the predictors of analgesic requirements (morphine, acetaminophen, and ketoprofen), including individual pain threshold and tolerance, body mass index (BMI), diabetes, and beliefs about pain control in patients undergoing elective hip or knee arthroplasty using a multilevel regression model (N = 147, 85 women, 62 men, 107 after hip replacement, and 40 after knee replacement). Results: Higher pain tolerance was associated with a lower dose of morphine per kg after surgery. Patients undergoing hip surgery received a lower dose of ketoprofen than patients undergoing knee surgery. The more the patient believed in personal pain control, the stronger the negative relationship between pain tolerance and morphine requirement. The lowest doses were given to patients with the highest pain tolerance and the greatest belief in personal control. Factors such as belief in pain control and pain tolerance should be considered in comprehensive postoperative pain management in orthopedic patients to reduce opioid doses and, thus, side effects.

Advancing total knee replacement surgery Assessment with Wearable Sensors and AI: A Case Study

Background: India has a higher prevalence of about 20-24%.of people suffering from osteoarthiritis. Due tothe load effect, forces between two and three times body weight are transmitted across the knee joint during anormal stride, which accounts for the higher risk of OA.A Qualitative Analysis of Decision-Making for Total KneeReplacement in Patients with Osteoarthritis. A cutting-edge wearable sensor system called Fitknees deliversa complex arrangement of motion sensors that are carefully placed on the lower limb. These sensors outlinethorough kinematic data that include gait analysis, muscle strength, knee range of motion, and balance metrics.Objective: Utilizing individualised measurements, using wearable sensors and AI tool to assess preoperativeevaluations and postoperative rehabilitation programs.Results: camping between affected and unaffected side with the normative data provided by the AI.Conclusion:advancement in the medical technologies have made it easier for medial professionals to detect and early diagnosethe diseases. Plan a better treatment plan with the aid of artificial intelligence to achieve better results.

A Device for Prehabilitation of Total Knee Replacement Surgery (Slider): Usability Study.

Rehabilitation, or "prehabilitation," is essential in preparing for and recovering from knee replacement surgery. The recent demand for these services has surpassed available resources, a situation further strained by the COVID-19 pandemic, which has led to a pivot toward digital solutions such as web- or app-based videos and wearables. These solutions, however, face challenges with user engagement, calibration requirements, and skin contact issues. This study evaluated the practicality of a low-contact, gamified device designed to assist with prehabilitation exercises. The study aimed to assess the practicality and user-friendliness of a newly designed physiotherapy device (Slider) that enables exercise monitoring without the need for direct contact with the skin. A total of 17 patients awaiting knee replacement surgery at a UK National Health Service (NHS) hospital participated in this study. They used the device over a 2-week period and subsequently provided feedback through a usability and acceptability questionnaire. The study was completed by all participants, with a majority (13/17, 76%) finding the device intuitive and easy to use. The majority of patients were satisfied with the device's ability to meet their presurgery physiotherapy requirements (16/17, 94%) and expressed a willingness to continue using it (17/17, 100%). No safety issues or adverse effects were reported by the participants. The results indicate that the device was found to be a feasible option for patients to conduct presurgery physiotherapy exercises independently, away from a clinical setting. Further research involving a larger and more diverse group of participants is recommended to validate these findings more robustly.

Qualitative and quantitative analysis of post-operative drainage: pilot study.

Surgical drains can be placed after an operation to collect postoperative blood loss. However, these could be overestimated. Indeed, the fluid elapsed after the first postoperative day would no longer be pure blood. An early withdrawal of redon could then be considered. A monocentric prospective study of 25 patients undergoing total knee or primary hip replacement surgery, for osteo-arthritis, was conducted. Redon flow was evaluated in total volume and in composition by the sedimentation study. A qualitative analysis of the content of the redon was also carried out. To compare the elements found in the drained liquid with the blood data, a preoperative and two postoperative blood samples were taken. 18 TKA and 7 THA were included. A qualitative analysis of the postoperative flow of 11 TKA and 5 THA was requested. Decreases of sedimentation volumes and protein levels were found in the drained liquid compared to the blood for both TKA and THA. Our results tend to prove that on postoperative D1, the liquid drained in the redon would be blood, but that the liquid drained on D2 and D3 would be a mixture of blood and serum. Therefore, the real postoperative blood loss would be overestimated.

Outcomes of Physiotherapy Exercises After Total Knee Replacement Surgery

Introduction: Total knee replacement (TKR) surgery is a common procedure for severe knee osteoarthritis, improving the quality of life for many patients. Despite surgical success, optimal recovery heavily relies on effective post-operative rehabilitation. This systematic review aimed to evaluate the effectiveness of various physiotherapy exercises in enhancing recovery outcomes following TKR, focusing on knee function, pain reduction, and patient satisfaction. Methods: A comprehensive search of PubMed, Scopus, Cochrane Library, and Web of Science was conducted, focusing on interventional studies and clinical trials published in the last five years up to 2022. Studies included were those evaluating physiotherapy interventions post-TKR, with clear measures on efficacy regarding patient outcomes. Exclusion criteria encompassed non-exercise-based rehabilitations, observational studies, and non-English publications. Data extraction focused on intervention types, sample sizes, and outcome measures. Results: Twelve studies were included, with sample sizes ranging from 30 to over 200 participants. Interventions varied from in-person physiotherapy, home-based exercises, high-intensity training, to tele-rehabilitation. High-intensity physiotherapy programs were associated with a 40% greater improvement in knee function compared to standard care. Tele-rehabilitation provided comparable outcomes in terms of pain management and mobility improvements, with patient satisfaction exceeding 80% in some studies. However, adherence and exercise intensity were noted challenges in remote settings. Conclusions: The review highlights physiotherapy's pivotal role in post-TKR recovery, with high-intensity programs showing significant benefits in knee function. Tele-rehabilitation emerges as a promising alternative, potentially increasing access to care. These findings support the integration of structured physiotherapy into rehabilitation protocols to maximize recovery outcomes. Future research should explore strategies to enhance adherence and effectiveness of tele-rehabilitation services.

The optimized tourniquet versus no tourniquet in total knee arthroplasty. Analysis of muscle injury, functional recovery, and knee strength

BackgroundTourniquet is widely used in total knee replacement surgery because it reduces intraoperative hemorrhage and provides a comfortable surgical area for the surgeon. It's possible that its use could lead to impaired postoperative functional and motor recovery, as well as local and systemic complications. Our goal was to compare the outcomes of total knee replacement without ischemia using an optimized protocol, consisting of tourniquet inflation before skin incision and deflation after cementing, with a pressure of one hundred millimeters above systolic blood pressure and without postoperative articular suction drains.). We believed that tourniquet effectively would result in no additional muscle damage and no functional or knee strength impairment compared to no tourniquet. MethodsIn a prospective and randomized study, 60 patients with osteoarthritis were evaluated for total knee replacement, divided in two groups: 'without tourniquet' and 'optimized tourniquet'. Outcomes were mean creatine phosphokinase levels, Knee Society Score and knee isokinetic strength. Data were considered significant when p < 0.05. ResultsCreatine phosphokinase levels and functional score were similar between groups. There were no differences between groups regarding knee extension strength on the operated limbs, although the knee flexors' peak torque in the operated limb in the optimized tourniquet group was significantly higher at 6 months relative to preoperative and 3 months assessments. ConclusionsThe optimized tourniquet protocol use in total knee replacement combines the benefits of tourniquet use without compromising functional recovery and without additional muscle damage and strength deficits compared to surgery without its use.

Epigenomic profiling of the infrapatellar fat pad in osteoarthritis.

Osteoarthritis is a prevalent, complex disease of the joints, and affects multiple intra-articular tissues. Here, we have examined genome-wide DNA methylation profiles of primary infrapatellar fat pad and matched blood samples from 70 osteoarthritis patients undergoing total knee replacement surgery. Comparing the DNA methylation profiles between these tissues reveal widespread epigenetic differences. We produce the first genome-wide methylation quantitative trait locus (mQTL) map of fat pad, and make the resource available to the wider community. Using two-sample Mendelian randomization and colocalization analyses, we resolve osteoarthritis GWAS signals and provide insights into the molecular mechanisms underpinning disease aetiopathology. Our findings provide the first view of the epigenetic landscape of infrapatellar fat pad primary tissue in osteoarthritis.

THE EFFECT OF CHRONOLOGICAL AGE AND GENDER AND DIFFERENT SOURCE OF TISSUE ON THE IN VITRO PROPERTIES OF MESENCHYMAL STROMAL CELLS

AbstractObjectivesOsteoarthritis is a common articular cartilage disorder and causes a significant global disease burden. Articular cartilage has a limited capacity of repair and there is increasing interest in the use of cell-based therapies to facilitate repair including the use of Mesenchymal Stromal Cells (MSCs). There is some evidence in the literature that suggests that advancing age and gender is associated with declining MSC function, including reduced proliferation and differentiation potential, and greater cellular apoptosis. In our study, we first performed a systematic review of the literature to determine the effects of chronological age and gender on the in vitro properties of MSCs, and then performed a laboratory study to investigate these properties.Methods and ResultsWe initially conducted a PRISMA systematic review of the literature to review the evidence base for the effects of chronological age and gender on the in vitro properties of MSCs including cell numbers, expansion, cell surface characterization and differentiation potential. This was followed by laboratory-based experiments to assess these properties. Compare the extent of the effect of age on MSC cell marker expression, proliferation and pathways. Tissue from patients undergoing total knee replacement surgery was used to isolate MSCs from the synovium, fat pad and bone fragments using a method developed in our laboratory. The growth kinetics was determined by calculating the population doublings per day. Following expansion in culture, MSCs at P2 were characterised for a panel of cell surface markers using flow cytometry. The cells were positive for CD73, CD90 and CD105, and negative for antibody cocktail (eg included CD34, CD45). The differentiation potential of the MSCs was assessed through tri-lineage differentiation assays. At P2 after extracting RNA, we investigate the gene analysis using Bulk seq. Clear differences between the younger and older patients and gender were indicated.ConclusionsChronological age and gender-related changes in MSC function have important implications on the use of these cells in clinical applications for an ageing population. The results from this study will be used to plan further work looking at the effects of chronological age and gender on cellular senescence and identify pathways that could be targeted to potentially reverse any age and gender-related changes.Declaration of Interest(b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Time Effect on Acute Postoperative Pain After Total Knee Replacement Surgery: An Exploratory Study Using the Experience Sampling Method.

Acute postoperative pain (APP) is the main cause of postoperative dissatisfaction; however, traditional methods of pain assessment provide limited insights into the dynamics and development of APP. This study used the experience sampling method (ESM) to understand the dynamics of APP over time in relation to various patient factors. Forty patients scheduled to undergo total knee replacement surgery were recruited in this study. Following an initial assessment, a short report questionnaire was sent to the patients via 10 digital alerts per day to assess the pain levels during two preoperative and the first 6 postoperative days. The data were analyzed using multilevel regression including random intercept and slope. Thirty-two patients submitted the pre-specified minimum of 30% of their short reports, yielding 1217 records. The analysis revealed significant (P<0.001) linear and quadratic decreases in APP and a quadratic time effect. The lowest between-days and within-day pain levels were observed on postoperative day 4.8 and during the time slot 3.8 or approximately 19:15, respectively. Significant random intercepts and slopes were noted, indicating variations in the mean pain level between patients and a decrease in pain. None of the 10 patient factors had any confounding effect. Using ESM data combined with multilevel analysis, we were able to evaluate the postoperative pain course while considering inter-individual differences in the baseline pain level and non-linear pain course over time. The findings of this study could aid clinicians in personalizing the treatment for APP.