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Background: Knee arthroplasty is an established surgical treatment for advanced osteoarthritis of the knee. In view of the rising number of surgical procedures, increasing costs in the healthcare system with a parallel increase in patient age and comorbidities, an evidence-based perioperative management is gaining importance. Fast Recovery concepts comprise a range of evidence-based strategies for optimizing the perioperative course. By reducing perioperative risks and optimizing pre-, peri- and postoperative processes, complications can be reduced, as well as perioperative morbidity, while comprising faster convalescence., Material and Methods: This review is based on a systematic literature search in the PubMed, Cochrane Library and Web of Science databases on the topic of perioperative optimization and evidence for Fast Recovery programs in knee resurfacing., Results: In knee arthroplasty, Fast Recovery protocols lead to a significant reduction in the length of stay in hospital without an increase in complication rates. Patients also benefit from a faster return to mobility and a reduced level of postoperative pain. The involvement of multidisciplinary teams, the optimization of pain therapy, the minimization of blood loss and early mobilization are key elements of these protocols. The implementation of Fast Recovery protocols in the perioperative care of patients is an effective strategy to improve surgical outcomes. Essential for the success of such programs is individualized multidisciplinary patient care with preoperative risk assessment, optimized pain management and early physiotherapeutic mobilization. Future research should focus on the long-term effects of these approaches and their adaptation to different patient populations., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: Periprosthetic Joint Infection (PJI) following hip and knee arthroplasty is a catastrophic complication in orthopaedic surgery. It has long been a key focus for orthopaedic surgeons in terms of prevention and management. With the increasing incidence of antibiotic resistance in recent years, finding more targeted treatment methods has become an increasingly urgent issue. Bacteriophage Therapy (BT) has emerged as a promising adjunctive treatment for bone and joint infections in recent years. It not only effectively kills bacteria but also demonstrates significant anti-biofilm activity, garnering substantial clinical interest due to its demonstrated efficacy and relatively low incidence of adverse effects., Purpose: This review aims to systematically evaluate the efficacy and safety of bacteriophage therapy in treating PJI following hip and knee arthroplasty, providing additional reference for its future clinical application., Methods: Following predefined inclusion and exclusion criteria, our team conducted a systematic literature search across seven databases (PubMed, Embase, Web of Science, Cochrane Library, ClinicalTrials.gov, CNKI, and WanFang Database). The search was conducted up to May 2024 and included multiple clinical studies on the use of bacteriophage therapy for treating PJI after hip and knee arthroplasty to assess its efficacy and safety., Results: This systematic review included 16 clinical studies after screening, consisting of 15 case reports and one prospective controlled clinical trial, involving a total of 42 patients with PJI treated with bacteriophage therapy. The average patient age was 62.86 years, and 43 joints were treated, with patients undergoing an average of 5.25 surgeries. The most common pathogen in these infections was Staphylococcus aureus, accounting for 18 cases. 33 patients received cocktail therapy, while nine were treated with a single bacteriophage preparation. Additionally, all patients underwent suppressive antibiotic therapy (SAT) postoperatively. All patients were followed up for an average of 13.55 months. There were two cases of recurrence, one of which resulted in amputation one year postoperatively. The remaining patients showed good recovery outcomes. Overall, the results from the included studies indicate that bacteriophage therapy effectively eradicates infectious strains in various cases of PJI, with minimal side effects, demonstrating promising clinical efficacy., Conclusion: In the treatment of PJI following hip and knee arthroplasty, bacteriophages, whether used alone or in combination as cocktail therapy, have shown therapeutic potential. However, thorough preoperative evaluation is essential, and appropriate bacteriophage types and treatment regimens must be selected based on bacteriological evidence. Future large-scale, randomized controlled, and prospective trials are necessary to validate the efficacy and safety of this therapy., (© 2024. The Author(s).)

Background: Osteophytes are commonly used to diagnose and guide knee osteoarthritis (OA) treatment, but their causes are unclear. Although they are not typically the focus of knee arthroplasty surgeons, they can predict case difficulty and length. Furthermore, their extent and location may yield much information about the knee joint status. The aims of this computed tomography-based study in patients awaiting total or partial knee arthroplasty were to: (1) measure osteophyte volume in anatomical subregions and relative change as total volume increases; (2) determine whether medial and/or lateral OA affects osteophyte distribution; and (3) explore relationships between osteophytes and OA severity., Methods: Data were obtained from 4,928 computed tomography scans. Machine-learning-based imaging analyses enabled osteophyte segmentation and quantification, divided into anatomical regions. Mean three-dimensional joint space narrowing was assessed in medial and lateral compartments. A Bayesian model assessed the uniformity of osteophyte distribution. We correlated femoral osteophyte volumes with B-scores, a validated OA status measure., Results: Total tibial (25%) and femoral osteophyte volumes (75%) within each knee correlated strongly (R 2  = 0.85). Medial osteophytes (65.3%) were larger than lateral osteophytes (34.6%), with similar proportions in both the femur and tibia. Osteophyte growth was found in all compartments, and as total osteophyte volume increased, the relative distribution of osteophytes between compartments did not markedly change. No evidence of variation was found in the regional distribution of osteophyte volume between knees with medial, lateral, both, or no three-dimensional joint space narrowing in the femur or tibia. There was a direct relationship between osteophyte volume and OA severity., Conclusions: Osteophyte volume increased in both medial and lateral compartments proportionally with total osteophyte volume, regardless of OA location. The peripheral position of femoral osteophytes does not appear to contribute to load-bearing. This suggests that osteophytic growth represents a 'whole-knee'/global response. This work may have broad applications for knee OA, both surgically and nonoperatively., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: Tibial plateau fractures are complex, peri-articular fractures that can have poor outcomes resulting in conversion to total knee arthroplasty (TKA). This study evaluates the 10-year survival of tibial plateau fractures treated with open reduction and internal fixation and identifies risk factors associated with conversion to TKA., Methods: This retrospective cohort study evaluates the outcomes of 126 patients undergoing tibial plateau ORIF from January 2011 to December 2012 at Glasgow Royal Infirmary. As well as patient factors, radiographic assessments were analysed including the degree of articular depression, medial proximal tibial angle, and femoral width ratio pre-operatively, peri-operatively and at the time of union. Patients requiring further surgical intervention, including TKA, were evaluated further., Results: A bell-shaped distribution of patient age was observed. Schatzker II fractures were most prevalent (48%). Pre-operative articular depression averaged 6.9 mm ranging from 0.0 - 36.0 mm. Operative reduction was generally satisfactory (mean articular depression 1.3 mm, femoral width 0.96, mPTA 89.6⁰), with 82% achieving an anatomical reduction. 12 patients (9.3%) required TKA during follow-up with Kaplan-Meier calculated as 91.9% at 5 years and 87.4% at 10 years. Articular depression > 4 mm (HR = 16.2), femoral width ratio > 1.05 (HR = 14.7) and age > 50 years (HR = 4.2) at time for fracture union were independently associated with progression to TKA., Conclusion: 9.3% of patients required TKA within 10 years of tibial plateau ORIF, Kaplan Meier 10-year survivorship was 87.4%. Joint depression and increased tibial width at time of union and age were independent risk factors associated with need for TKA. Particular care must be taken during operative intervention to ensure adequate reduction to lower this risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024. Published by Elsevier B.V. All rights reserved.)

Purpose: To investigate the impact of orthopaedic surgeons' arthroplasty distributions on patient-reported outcome measures (PROMs) following knee arthroplasty, thus addressing the gap in knowledge regarding the optimal distribution of arthroplasties., Methods: 2256 knee arthroplasties were included (total knee arthroplasty [TKA] or unicompartmental knee arthroplasty [UKA]). All were conducted at a single centre between August 2016 and August 2022 with a minimum of 1-year follow-up. The Oxford Knee Score (OKS), the Forgotten Joint Score (FJS) and the Activity and Participation Questionnaire (APQ) were assessed preoperatively, and at 3 and 12 months postoperatively. Patients were categorized based on the surgeons' yearly surgeries: (1) TKA only, (2) TKA+ <20% medial UKA, (3) TKA+ ≥20% medial UKA and (4) TKA+ ≥20% medial UKA + lateral UKA + patellofemoral UKA. Linear regression models adjusted for demographic variables and preoperative PROM scores were used to estimate changes in mean PROM scores., Results: Group 4 showed significantly higher improvements in PROM scores at 3 and 12 months compared to Group 1. In the 12-month adjusted analysis, Group 4 had 1.9 points (95% confidence interval [CI]: 1.0-2.8) higher OKS-, 7.0 points (95% CI: 3.9-10.2) higher FJS- and 8.3 points (95% CI: 4.8-11.8) higher APQ-change than Group 1. There were no significant differences between Groups 1 and 2, nor any clinically relevant differences between Groups 3 and 4. Additionally, the percentage of patients who achieved excellent OKS (>41) was significantly higher in Groups 3 + 4 compared to Groups 1 + 2 (p < 0.001)., Conclusion: Despite limitations, the findings of this study suggest that utilizing ≥20% medial UKA leads to greater postoperative improvements in PROM across all treated knee arthroplasty patients., Level of Evidence: Level III., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Background: Local infiltration analgesia (LIA) is a crucial component of pain management during total knee arthroplasty (TKA). Various formulations of the LIA drug cocktail have been described, with non-steroidal anti-inflammatory drugs (NSAIDs) commonly included. Although NSAIDs are highly effective in improving postoperative pain, they are associated with adverse renal, gastrointestinal, and cardiovascular effects. This study aimed to investigate whether the addition of an NSAID in LIA affects the incidence of acute kidney injury (AKI) in TKA patients, especially those who have pre-existing renal impairment. The secondary aim was to determine overall AKI incidence., Methods: A retrospective cohort study was conducted on elective, primary TKA patients in a single tertiary institution between January 2020 and April 2024. Data was obtained from a prospectively collected institutional knee arthroplasty registry. Patients were administered LIA intraoperatively, with or without an NSAID (30 mg of ketorolac). The study population was divided into two subpopulations, patients who did or did not have chronic kidney disease (CKD), and analyzed separately. Propensity matching was performed on the CKD group, correcting for age, sex, BMI, ASA score, and presence of diabetes mellitus/hypertension. The outcome of interest was the incidence of AKI. A t-test or Chi-square test was used, where appropriate, to determine the statistical significance of the results., Results: In patients who had CKD (n = 114), the presence of ketorolac in LIA was associated with a higher AKI incidence (12.7 versus 2.0%, P = 0.041). In patients who did not have CKD (n = 870), the presence of ketorolac in LIA was not associated with a higher AKI incidence (2.0 versus 1.9%, P = 1.0). Overall AKI incidence was 2.6%., Conclusion: In patients who have CKD, orthopaedic surgeons should be highly cautious of administering ketorolac in LIA during TKA, as it is associated with a higher risk of AKI. Patients who have normal renal function can be safely given ketorolac in LIA without an elevated risk of AKI. Further studies are needed to examine AKI incidence when other NSAIDs are used in LIA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Antigravity treadmill training provides a viable option for physiotherapeutic care after knee surgery, especially for conditions that do not allow full weight bearing during the early phase post-intervention. This overview of the current state of knowledge identifies gaps and highlights areas where more research on antigravity treadmill training after knee surgery is needed. This review aimed to analyze and summarize the available evidence concerning the effects of antigravity treadmill training on patients after knee joint surgical procedures, including anterior cruciate ligament reconstruction (ACLR) and total (TKA) and unicompartmental knee arthroplasty (UKA). Several databases were searched for relevant material, including PubMed, Epistemonikos, the Cochrane Library, the Web of Science, and Google Scholar. Seven studies investigating antigravity treadmill training after various procedures were included, including ACLR and TKA. The studies were summarized, and the quality of evidence was evaluated using the appropriate tools. The evidence yielded by these studies suggests that antigravity treadmill training might be useful after knee surgery. However, the superiority over traditional physiotherapeutic measures has yet to be established. Therefore, future high-quality randomized controlled trials (RCTs) are needed to investigate the effect of antigravity treadmill training due to the low quality of available evidence. Also, a cost-effectiveness analysis is required to determine whether the investigated intervention fits the purpose.

Background: Total knee arthroplasty (TKA) is the treatment of choice for advanced knee osteoarthritis. Long-term studies report high patient satisfaction, while complications such as periprosthetic joint infection (PJI) can be devastating. Knowledge regarding risk factors for PJI is critical to minimize and ideally avoid complications. The purpose of this study was to investigate the risk of PJI and revision in patients who had preoperative asymptomatic high C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) levels in primary TKAs., Methods: Patients undergoing primary TKA between 2010 and 2022 were eligible. Inclusion criteria were patients who had preoperative complete biochemical parameters and a minimum follow-up of 12 months. Patients who died during the first year, and those who had a history of inflammatory arthritis, autoimmune disease, renal pathologies or septic arthritis, were excluded. Patients who had elevated blood CRP and ESR levels taken within 48 hours before surgery underwent a thorough medical examination with a focus on infection symptoms. After screening and consultation, residual elevated CRP and ESR levels were classified as asymptomatic. After exclusions, 1,528 patients were included. The mean age was 66 years (range, 35 to 92) and the mean follow-up time was 6.4 years (range, 1.6 to 12.3)., Results: The rate of revision within one year after surgery was 1.6%, whereas the rate of revision in the first five years was 3.8%. The PJI rates for the 1 st and 5 th postoperative years were 1.7 and 2.9% respectively. Regression analysis did not show any of the potential variables to be a risk factor for revision or PJI., Conclusion: Asymptomatic elevated acute-phase reactants are not a risk factor for periprosthetic joint infection or aseptic revision. At a mean follow-up of 6.4 years, overall survival was 96.7%, with only 2.2% of patients revised due to a PJI., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Preoperative psychopharmacological treatment (PPT) has been associated with increased hospital length of stay and readmission rate after hip and knee arthroplasty. However, little is known regarding the association between PPT and improvements in patient-reported outcomes postoperatively in a multicenter fast-track setting. Thus, the primary objective was to investigate whether PPT is a risk factor for poorer patient-reported improvements 12 months after surgery. Secondary objectives included assessment of additional time points and subgroups of PPT., Methods: This multicenter registry-based cohort study included 4,021 primary hip and 3,226 primary knee arthroplasties performed from 2016 to 2020 at three fast-track departments in Denmark due to primary osteoarthritis. The Oxford Hip Score/Oxford Knee Score (OHS/OKS), EuroQol-5 Dimensions-3 Levels/EuroQol-5 Dimensions-5 Levels, and EuroQol visual analog scale were collected at baseline and 3, 6, 12, and 24 months after surgery. Exposure status was assigned using the Danish National Prescription Registry. Marginal mean differences (MD) with 95% confidence intervals (CIs) were estimated using multilevel Tobit regression and adjusted for age, sex, and the Charlson Comorbidity Index obtained from the Danish National Patient Register., Results: No associations were found between PPT and improvements in OHS (MD -0.5, CI -1.4 to 0.4) or OKS (MD -0.3, CI -1.2 to 0.5) after 12 months. However, PPT was associated with lower baseline OHS (MD -1.4, CI -2.2 to -0.6) and OKS (MD -2.1, CI -2.9 to -1.3), and 12 months follow-up OHS (MD -1.9, CI -2.8 to -1.1) and OKS (MD -2.4, CI -3.2 to -1.6). Similar findings were observed at other time points, using EuroQol-5 Dimensions-3 Levels/EuroQol-5 Dimensions-5 Levels or EuroQol visual analog scale, and when evaluating PPT subgroups., Conclusions: In hip and knee arthroplasty, PPT was not a risk factor for poorer patient-reported improvements 12 months after surgery. However, PPT was associated with marginally poorer baseline and follow-up scores. Thus, arthroplasties remain effective treatments despite PPT from a patient-centered perspective., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The mechanism of chronic knee osteoarthritis (OA) pain and postoperative pain due to knee arthroplasty has not been elucidated. This could be involved neuroplasticity in brain connectivity. To clarify the mechanism of chronic knee OA pain and postoperative pain, we examined the relationship between resting-state functional connectivity (rs-FC) and clinical measurements in knee OA before and after knee arthroplasty, focusing on rs-FCs with the anterior insular cortex (aIC) as the key region. Fifteen patients with knee OA underwent resting-state functional magnetic resonance imaging and clinical measurements shortly before and 6 months after knee arthroplasty, and 15 age- and sex-matched control patients underwent an identical protocol. Seed-to-voxel analysis was performed to compare the clinical measurements and changed rs-FCs, using the aIC as a seed region, between the preoperative and postoperative patients, as well as between the operative and control patients. In preoperative patients, rs-FCs of the aIC to the OFC, frontal pole, subcallosal area, and medial frontal cortex increased compared with those of the control patients. The strength of rs-FC between the left aIC and right OFC decreased before and after knee arthroplasty. The decrease in rs-FC between the left aIC and right OFC was associated with decreased subjective pain score. Our study showed a correlation between longitudinally changed rs-FC and clinical measurement before and after knee arthroplasty. Rs-FC between the aIC and OFC have the potential to elucidate the mechanisms of knee OA pain and postoperative pain due to knee arthroplasty., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Purpose: Total knee arthroplasty (TKA) is an effective treatment for advanced osteoarthritis, and achieving optimal outcomes can be challenging due to various influencing factors. Previous research has focused on identifying factors that affect postoperative functional outcomes. However, there is a paucity of studies predicting individual postoperative improvement following TKA. Therefore, a quantitative prediction model for individual patient outcomes is necessary., Materials and Methods: Demographic data, radiologic variables, intraoperative variables, and physical examination findings were collected from 976 patients undergoing TKA. Preoperative and 1-year postoperative Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were assessed, and multivariate regression analysis was conducted to identify significant factors influencing one-year WOMAC scores and changes in WOMAC scores. A predictive model was developed on the basis of the findings., Results: The predictive accuracy of the model for 1-year WOMAC scores was poor (all adjusted R 2  < 0.08), whereas the model for changes in WOMAC scores demonstrated strong predictability (all adjusted R 2  > 0.75). Preoperative WOMAC scores, sex, and postoperative knee range of motion significantly affected all pain, stiffness, and physical function aspects of the WOMAC scores (all P < 0.05). Age, cerebrovascular disease, and patellar resurfacing were associated with changes in physical function (all P < 0.05)., Conclusions: The developed quantitative model demonstrated high accuracy in predicting changes in WOMAC scores after TKA. The identified factors influencing postoperative improvement in WOMAC scores can assist in optimizing patient outcomes after TKA., (© 2024. The Author(s).)

Background: Age-related loss of skeletal muscle strength and mass is linked to adverse postoperative outcomes in older individuals with sarcopenia. Half of patients suffer from severe associated osteoarthritis requiring orthopedic interventions. Mitigating the onset and progression of sarcopenia before surgery is essential to improve the prognosis and reduce surgical complications. The aim of this research was to innovatively explore whether the preoperative period could be the appropriate timeframe to empower surgical resilience, through prehabilitation and dietary supplementation, in older sarcopenic patients undergoing knee arthroplasty., Methods: The current literature concerning the effectiveness of prehabilitation and dietary supplementation before knee arthroplasty in sarcopenic older individuals was reviewed, following the SANRA criteria, between December 2023 and February 2024. The study inclusion criteria were as follows: (1) prehabilitation and/or dietary supplementation interventions; (2) human participants aged 65 years and older; (3) relevant outcome reporting (functional status, postoperative complications, and patient-reported outcomes); and (4) articles written in English The extracted information included study characteristics, demographics, intervention details, outcomes, and the main findings., Results: Merged prehabilitation and dietary supplementation strategies extrapolated from the current literature and involving strength, resistance, balance, and flexibility training, as well as essential amino acids, iron, vitamin D, adenosine triphosphate, and glucosamine sulphate supplementation, could improve the functional capacity, ability to withstand the upcoming surgical stressors, and postoperative outcomes in older people undergoing knee arthroplasty., Conclusions: Addressing complex links between knee osteoarthritis and sarcopenia in older individuals undergoing knee arthroplasty requires a multidimensional approach. Prehabilitation emerges as a crucial preliminary step, allowing the optimization of surgical outcomes. Nutraceutical integration, included in a comprehensive care plan, could have a synergic effect in achieving prehabilitation goals. Those interventions are essential for surgical resilience, in terms of muscle function preservation, recovery acceleration, and overall quality of life enhancement. Intensive collaboration among specialists could advance knowledge and the sharable consensus concerning the critical and evolutive field of perioperative care.

We present the radiological findings in the case of a failed unicompartmental knee arthroplasty (UKA). Although uncommon, these features are highly specific for implant failure and are an indication to consider revision. The aim of this case report is to highlight these characteristic appearances across multiple imaging modalities to both surgeons and radiologists should they encounter this in their practise., Competing Interests: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Institute of Radiology.)

Purpose: Changes in knee surgery incidence are important factors for stakeholders and healthcare providers. The aim of this study was to examine trends and patterns in knee surgeries in Sweden from 2010 to 2022. The study focuses on gender-specific and overall rates of knee surgeries., Methods: The analysis is based on a data set sourced from national healthcare records. The data was stratified based on surgical rates and categorized by gender, year and the specific knee arthroplasty technique used. We tracked year-to-year changes in surgical rates to identify overarching patterns. We used Poisson regression to predict future trends. Comparisons were made between various surgical subcategories, such as those with and without cement in knee arthroplasty surgeries., Results: In 2010, the rate of knee surgeries per 100,000 person-years was 518.7 for males and 448.0 for females. These rates exhibited fluctuations over time, reaching their lowest point in 2020, attributed to the pandemic's disruption of elective procedures, with 386.4 surgeries per 100,000 males and 386.3 surgeries per 100,000 females. A resurgence was observed in 2022. The rates of primary knee arthroplasty increased, with a male rate of 106.2 and a female rate of 150.7 surgeries per 100,000 inhabitants in 2010, rising to 126.8 for males and 166.2 for females in 2022., Conclusion: This comprehensive nationwide open-source data analysis of knee surgeries in Sweden shows that the COVID-19 pandemic significantly impacted knee surgery rates in Sweden, causing a notable decline in 2020, followed by a resurgence in 2022. Furthermore, while men had higher surgery rates than women, they experienced a larger decline in the incidence of knee surgeries compared to women. Understanding these trends is crucial for stakeholders and healthcare providers to improve resource allocation, address gender disparities, and maintain the resilience of surgical services in the face of disruptions., Level of Evidence: Level III., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s). Journal of Experimental Orthopaedics published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Patients undergoing knee replacement, which is mainly indicated in severe osteoarthritis, are frequently co-affected by osteoporosis and osteopenia. With a prevalence standing at around 20% in patients receiving knee arthroplasty, osteoporosis could lead to poor outcomes postoperatively. Some of these complications include periprosthetic fractures and an increased revision rate. Antiresorptive medications have been shown to be beneficial postoperatively. However, no studies have been conducted on whether they had any benefits if given preoperatively. Surgical management may also be beneficial, but this area remains full of controversy., (© 2024. The Author(s).)

Background: Improving mobility - specifically walking - is an important treatment goal of total knee arthroplasty. Objective indicators for mobility, however, are lacking in clinical evaluations. This study aimed to compare real-world gait and turning between individuals scheduled for total knee arthroplasty and healthy controls, using continuous monitoring with inertial measurement units., Methods: Real-world gait and turning data were collected for 5-7 days in individuals scheduled for total knee arthroplasty (n = 34) and healthy controls (n = 32) using inertial measurement units on the feet and lower back. Gait and turning parameters were compared between groups using a linear regression model. Data was further analyzed by stratification of gait bouts based on bout length, and turns based on turning angle and turning direction., Findings: Dominant real-world gait speed was 0.21 m/s lower in individuals scheduled for total knee arthroplasty compared to healthy controls. Stride time was 0.05 s higher in individuals scheduled for total knee arthroplasty. Step time asymmetry was not different between the groups. Regarding walking activity, individuals scheduled for total knee arthroplasty walked 72 strides/h less than healthy controls, and maximum bout length was 316 strides shorter. Irrespective of the size of the turn, turning velocity was lower in individuals scheduled for total knee arthroplasty., Interpretation: Individuals scheduled for total knee arthroplasty showed specific walking and turning limitations in the real-world. Parameters derived from inertial measurement units reflected a rich profile of real-world mobility measures indicative of walking limitation of individuals scheduled for total knee arthroplasty, which may provide a relevant outcome dimension for future studies., Competing Interests: Declaration of competing interest Mahmoud El-Gohary has a significant financial interest in APDM Wearable Technologies, a company that may have a commercial interest in the results of this research and technology., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: The incidence of vascular injury associated with knee arthroplasty is scarce, but, when they occur, the consequences are serious., Objectives: Describe the incidence of vascular lesions in our center and evaluate time to diagnosis, resolution and follow-up., Materials and Methods: Retrospective cohort during the 2010-2019 period of primary arthroplasties and knee revision. The incidence of vascular lesions and their demographic characteristics were analyzed. Type of lesion, diagnostic method and treatment were recorded. It was evaluated in distant follow-up of pain and functionality., Results: 7.940 primary total knee arthroplasty and revision surgeries were recorded, and a report of 7 emergency cases for vascular lesions was also recorded, with an incidence of 0.088%. 3 vascular lesions were caused by direct laceration of the popliteal artery, 1 case of thrombosis of the popliteal artery and 3 cases of pseudoaneurysmal lesion of the superior genicular artery. Three vascular lesions that occurred in primary arthroplasty were immediately repaired by a vascular surgeon. Pseudoaneurysm lesions and thrombosis were resolved by angiographic procedure., Discussion: Vascular complications around the knee are rare. Time to diagnosis and treatment is essential. Digital angiography is a diagnostic and therapeutic tool. There are various repair techniques, whether it's embolization, cauterization, stenting or endoprosthesis; therefore, digital angiography is a safe method with a low complication rate., Conclusion: The incidence of vascular lesions in knee arthroplasty in our center is very low. The cases were diagnosed and resolved early, without registering subsequent complications with good functional results in distant follow-up., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: The purpose of this study was to investigate if patient's gender significantly affected the long-term outcome of patients undergoing total knee arthroplasty (TKA) and to provide a cross-gender comparison of a large patient sample from a single regional register., Methods: The Registry of Prosthetic Orthopedic Implant of Emilia Romagna (RIPO) investigated all primary TKAs performed from July 2000 to December 2020 by collecting data of men and women separately. Primary bicompartmental and tricompartmental TKAs were included. The survival rates and the reasons for revision were assessed to check if any other factor could have influenced implant failure., Results: In total, 66,032 TKAs were included and analysed, comprising 46,774 women and 19,258 men. The 15-year Kaplan-Meier survival percentage was 93.6% for women and 92.5% for men (p = 0.001). Men exhibited a higher revision risk following primary TKA (p = 0.012), particularly when the primary diagnosis was arthritis resulting from rheumatic disorders (p = 0.018) and arthritis following high-tibial osteotomy (p = 0.024). Failure risk was also higher for men below the age of 60 years (p = 0.038)., Conclusion: The long-term outcome in TKA showed significant differences between men and women, with a significantly lower survival rate in men at 15 years, especially when they are under 60 years old or with a diagnosis of rheumatic disorders or arthritis following high-tibial osteotomy. It is necessary to design specific studies to have relevant data concerning gender differences in prosthetic surgery and to customise treatments to improve outcome and patient satisfaction., Level of Evidence: Level III., (© 2024 The Authors. Knee Surgery, Sports Traumatology, Arthroscopy published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Aim of the Study: The purpose of this study is to conduct a comparative analysis of the microbiological profiles in periprosthetic joint infections (PJIs) after total knee arthroplasty (TKA) between diabetic and non-diabetic patients. The study aims to address what are the variations in microbial colonization and infection patterns between diabetic and non-diabetic patients undergoing total knee arthroplasty., Methods: A retrospective analysis of 2,569 culture-positive cases of PJIs post-TKA was conducted, comparing outcomes between diabetic (n = 321) and non-diabetic (n = 2,248) patients. Demographic, clinical, and microbiological data were collected and analyzed using descriptive statistics, chi-squared tests, logistic regression, and other statistical tests., Results: Diabetic patients exhibited distinct microbial colonization patterns, with a higher prevalence of pathogens such as Staphylococcus aureus (p = 0.033), Pseudomonas aeruginosa (p < 0.001), Streptococcus spp. (Streptococcus agalactiae and Streptococcus dysgalactiae; p = 0.010, 0.016 respectively), Candida spp. (p = 0.010), and Corynebacterium spp. (p = 0.024). Additionally, diabetic patients were at increased risk of polymicrobial infections. Comorbidities associated with diabetes, including chronic pulmonary disease, renal insufficiency, and peripheral artery disease, were significantly more prevalent in diabetic patients and further complicated PJI outcomes., Conclusion: This study underscores the importance of tailored perioperative antimicrobial strategies and vigilant infection control measures in diabetic patients undergoing TKA. Understanding the differential microbial profiles and associated comorbidities can inform targeted interventions to mitigate the risk of PJIs and improve outcomes in this high-risk population. Further research is warranted to elucidate the underlying mechanisms and optimize management strategies for diabetic patients undergoing TKA., (© 2024. The Author(s) under exclusive licence to SICOT aisbl.)

Background and Objectives: The aim of this study was to assess postural stability in patients after total and unicompartmental knee arthroplasties. Materials and Methods : The study included 40 women who had undergone knee arthroplasties-20 women who had undergone total knee arthroplasty (TKA) (mean age 63.47 ± 2.17) and 20 women who had undergone unicompartmental knee arthroplasty (UKA) (mean age 64.65 ± 1.93). The comparison group consisted of 20 healthy women aged 60-69 years (mean age 64.45 ± 3.12). The average time from surgery to stabilometry was 14.4 months. Each patient underwent stabilography using a single-plate stabilography platform, which included both Romberg's test and a dynamic test. Additionally, the WOMAC scale was administered, where patients assessed their condition both before surgery and at the present time. Results : The averaged Romberg's test results show a slight displacement in the center of mass (COM) toward the forefoot and towards the right limb in both the TKA and UKA groups. The WOMAC scale results showed significant improvement and satisfactory functional outcomes in both groups. Conclusions: The study indicated that one year after surgery, patients in both groups required a larger base of support to maintain postural control. However, the results for the UKA group were more similar to those of healthy individuals.

Objectives: The aim of this study is to analyse the efficacy of using a combined infiltration between a popliteal artery and knee cap (IPACK) anaesthetic block and a selective saphenous nerve block compared to local infiltration with anaesthetic in knee replacement surgery. Methods: A retrospective observational study was conducted. A total of 312 patients who underwent primary total knee arthroplasty in our hospital between January 2019 and December 2022 were reviewed. Local intra-articular anaesthesia was used in 207 patients and combined nerve block in 105 patients (IPACK group). The mean age in the LIA group was 72.9 years and 70.4 years in the IPACK group. There were 44% men in the LIA group and 53.3% in the IPACK group. The primary outcome was the presence of poorly controlled pain requiring rescue opioid analgesia in the postoperative period. Secondary outcomes included pain scores, range of motion and length of hospital stay. Results: There were no significant differences in the age or gender distribution of patients between the two groups. One patient treated with anaesthetic blocks required rescue analgesia with opioids, while in the LIA group this occurred in 28.5% of cases. There were statistically significant higher VAS scores in the LIA group ( p < 0.001). Range of motion was slightly greater in the block group (4.6°, p < 0.05). There were significant differences in hospital stay (2.4 days in the blocks group and 2.8 days in the LIA group ( p < 0.05). Conclusions: In our series, patients treated with anaesthetic blocks showed better results with similar postoperative pain control. However, further studies are needed.

Background: Length variations of the lower limbs after total knee arthroplasty (TKA) constitute a poorly evaluated parameter and can be associated with worse functional outcomes. The objectives of this study were to: (1) describe the variations in the lower limb length after TKA according to the digital accuracy of the computerized navigation system used for prosthesis implantation, (2) describe patient sensation of limb length modification at 3 months postoperatively and to identify its risk factors, (3) identify factors affecting lower limb length modification and to analyze the predictive value causing in the patient the sensation of lower limb discrepancy., Hypothesis: We hypothesize that there may be a lower limb length discrepancy after TKA, which may cause some distress to the patient., Patients and Methods: This prospective study included 100 TKAs implanted with navigation gap-balanced adjusted mechanical alignment. Were compared the length of the lower limb before and after implantation and the patient's changes in leg length perception at 3 months postoperatively. A subgroup analysis was performed according to preoperative knee deformities: varus knee was an HKA < 177 °, normal knee was an HKA between 117° and 183 ° and valgus was an HKA >183 °., Results: Ninety-seven out of 100 patients experienced lengthening compared to the preoperative ipsilateral length, and twenty-three experienced lengthening greater than 10 mm. The mean lengthening was 7.3 mm (maximum 24.8 mm). Lengthening was significantly greater in valgus knees 9.9 mm [range, 2.0-24.8] than in varus 7.2 mm [range, 1.46-19.4] and normal knees 4.11 mm [range, 0.4-11.4] (p < 0.05). The correction of frontal and sagittal deformation were risk factors for limb length modification (OR = 0.595; 95% CI [0.544-0.816] [p = 0.001], OR = 0.396; 95% CI [0.351-0.653] [p = 0.001]). Twenty-two patients reported a sensation of limb length change: 11 (50%) reported equalization, whereas the remainder reported lengthening with a leg length difference. The preoperative sensation of lower limb length inequality was the unique factor affecting the patient's perception post-surgery (OR = 37.50; 95% CI [9.730-144.526] [p = 0.0001]). A threshold value of 6.6 mm was identified for the sensation of limb length modification., Conclusion: Navigation is a tool for describing ipsilateral leg length variations after TKA. These variations are significant and perhaps explain some patient dissatisfaction. A partial correction of the frontal deformity according to the knee phenotype could limit the risk of modification of the native length., Level of Evidence: IV; Descriptive therapeutic prospective study., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Objective: The aim of the present study was to determine physiological reference values for the morphology of the patella and to analyse these parameters according to patella position in healthy knee joints., Material and Methods: Healthy knee joints of 409 patients (mean age, 52.3 years [± 16.8]) were analysed retrospectively on MRI images for Insall-Salvati index (ISI), sagittal patella thickness (PTS) and patella length (PLS) as well as axial patella thickness (PTA) and patella width (PWA). Differences between patellar diameters were analysed depending on ISI, side, age and gender., Results: Mean PTS was 20.1 mm (± 2.4), PLS 44.0 mm (± 4.4), PTA 21.8 mm (± 2.4) and PWA 44.5 mm (± 4.7). Depending on the vertical patellar position (ISI), all patellar parameters (p < 0.01) showed significant differences between patients with a patella alta, norma and baja. In general, a smaller ISI showed higher measured values for the patellar parameters. There were no significant differences for the laterality. Only PTS showed a significant age difference (p = 0.031). All parameters were significantly larger in male compared to female knees (p < 0.001)., Conclusion: Reference parameters for the patella morphology are reported. Concluding from the results, a relationship between vertical patellar position and patellar morphology seems to exist. This finding should be taken into account in diagnostics and therapy of patella disorders., (© 2024. The Author(s).)

Background: Robotic-assisted surgical technique has been clinically available for decades, yet real-world adverse events (AEs) and complications associated with primary knee arthroplasty remain unclear., Methods: In March 2023, we searched the FDA website and extracted AEs related to robotic assisted knee arthroplasty (RAKA) from the MAUDE database over the past 10 years. The "Brand Name" function queried major robotic platforms, including active and semi-active systems. The overall incidence of AEs was estimated based on annual surgical volume from the current American Joint Replacement Registry (AJRR). Two authors independently collected data on event date, event type, device problem, and patient problem., Results: Of 839 eligible reports, device malfunction comprised mechanical failure (343/839, 40.88%) and software failure (261/839, 31.11%). For surgical complications, inappropriate bone resection (115/839, 13.71%) was most frequent, followed by bone/soft tissue damage (83/839, 9.89%). Notably, over-resection exceeding 2 mm (88/839, 10.49%), joint infection (25/839, 2.98%), and aseptic loosening (1/839, 0.12%) were major complications. Only two track pins related AEs were found. Moreover, the distribution of these AEs differed substantially between robot manufacturers. According to the AEs volume and AJRR data, the overall incidences of AEs related to RAKAs were calculated with 0.83% (839/100,892) between November 2010 and March 2023., Conclusion: Our analysis shows that while reported AEs might be increasing for RAKAs, the overall rate remains relatively low. Reassuringly, device malfunction was the most commonly AEs observed, with a minor impact on postoperative outcomes. Furthermore, our data provide a benchmark for patients, surgeons, and manufacturers to evaluate RAKA performance, though continued improvement in reducing serious AEs incidence is warranted., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: This study aimed to evaluate post-operative lower limb function following second-generation mechanically aligned medial pivot (MP) TKA implantation. Standard gait analysis was performed to collect kinematic and kinetic data, which were then compared with physiological data from the literature obtained using the same evaluation methodology as the present study. The hypothesis was that this TKA would not fully restore normal knee and adjacent joint motion during walking. Methods: Our cohort comprised 15 patients consecutively enrolled from September 2019 to December 2022 who underwent primary TKA with the second-generation MP Evolution Knee System (MicroPort Orthopaedics Inc., Arlington, TN, USA). Pre-operatively and 6 months post-surgery, gait analysis during level walking was performed on all patients, as well as clinical evaluations using the Knee Society Score (KSS), the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Visual Analogue Scale (VAS). Results: The clinical scores improved significantly ( p < 0.001) after surgery (pre-/post-operative KSS functional, KSS clinical, VAS, and KOOS: 51.7 ± 17.3/84 ± 18.4, 45.3 ± 16.2/74.1 ± 12.6, 6.9 ± 1.8/2.0 ± 1.9, and 33.9 ± 11.8/69.1 ± 16.5, respectively). The statistical parametric mapping (SPM) analysis between the post-operative and reference control data revealed significant differences in the initial and final 20% of the gait cycle for the rotation of the knee in the frontal and transverse planes and for the rotation of the ankle in the sagittal plane. Conclusions: This study shows that new-generation MP TKA with mechanical alignment does not fully restore normal gait biomechanics, particularly in knee rotational movements, indicating a need for improved surgical techniques and prosthetic designs.

Background Improvement in quality of life is the primary goal following total knee arthroplasty (TKA). Patient-reported outcome measures (PROMs) have become the standard for evaluating TKA results, capturing the patient's perspective. However, PROMs face challenges such as inconsistent presurgery data collection and ambiguity in determining clinical significance. Establishing reliable thresholds for success and failure is crucial for comparing outcomes. Purpose To determine cutoff values for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Kujala score, and Knee Injury and Osteoarthritis Outcome Score for Quality of Life (KOOS-QL) that significantly change the likelihood of success (TIS) or failure (TIF) to improve self-reported quality of life one year after TKA compared to the baseline probability of the studied cohort. Methods A retrospective study was conducted to evaluate PROMs following conventional cruciate-retaining (CR) TKA without patellar replacement. Patients were evaluated during 2022 and 2023, with a minimum one-year follow-up. A total of 161 successful evaluations were identified, representing 81% of all CR TKA procedures without patellar replacement performed between January 2018 and June 2022 at a single university hospital. Assessments included the three dimensions of the WOMAC scale (pain, stiffness, and function), Kujala score, and KOOS-QL. The primary outcome was to determine the threshold value of each PROM that significantly reduced or increased the likelihood of "same or worse" self-perceived improvement in quality of life compared to the cohort. Logistic regression with 200 iterations was used for statistical analysis. Results The threshold for improvement success was <4 for WOMAC-Pain, <1 for WOMAC-Stiffness, <15 for WOMAC-Function, >70 for Kujala, and >62 for KOOS-QL. Meanwhile, the threshold for increased failure was >7 for WOMAC-Pain, >3 for WOMAC-Stiffness, >26 for WOMAC-Function, <55 for Kujala, and <41 for KOOS-QL. Conclusions The study successfully established significant thresholds for success and failure in improving quality of life following CR TKA without patellar replacement. The identified thresholds for WOMAC-Pain, WOMAC-Function, and Kujala scores have good-excellent discrimination and can be confidently used to estimate sample sizes and compare quality of life improvements post-TKA., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Scientific Ethical Committee of the Hospital of the University of Chile issued approval 63. Prof. Dra. María Graciela Rojas Castillo, Directora General del Hospital Clínico de la Universidad de Chile, certifica que ha aprobado la realización del proyecto de investigación denominado, "Predictores de dolor anterior de rodilla en pacientes operados de artroplastía total de rodilla sin reemplazo patelar". Esta solicitud ha sido debidamente discutida y aprobada por el Comité Ético Científico o de Investigación del Hospital Clínico de la Universidad de Chile, según consta en el Acta de Aprobación N°63 del 15 de diciembre 2021 y será conducido por el Investigador Principal, Dr. Maximiliano Barahona Vásquez, del Servicio de Traumatología de nuestro Hospital Clínico. Dado que se han cumplido los requisitos establecidos para conducir estudios en seres humanos en nuestra Institución, este Estudio Clínico cuenta con la autorización de la Dirección del Hospital para su realización, en los términos que establece el protocolo antes mencionado. Este documento de aprobación tendrá vigencia hasta finalizar el Estudio Clínico o hasta que la Aprobación iicial sea revocada. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: This study was funding by CICA: Centro de Investigación Clínica Avanzada at the Clinical Hospital of the University of Chile. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Barahona et al.)

Purpose: This study aimed to investigate the correlation between preoperative pain catastrophizing and social support, and acute post-surgical pain in patients who underwent knee arthroplasty. The study also aimed to determine whether social support moderates the role of pain catastrophizing psychologically in acute post-surgical pain after knee arthroplasty., Patients and Methods: This study recruited participants to survey a tertiary hospital in Dalian, China, between November 2022 and October 2023. Participants completed pain catastrophizing scales and social support reevaluated scales one day (T1) before they were confirmed to undergo knee arthroplasty, and finished the Numeric Rating Scale at 24h (T2), 48h (T3), and 72h (T4) postoperatively. Pearson correlation analyses were used to explore the relationship between social support, pain catastrophizing, and acute post-surgical pain, hierarchical regression analysis was used to test the moderating role of social support between pain catastrophizing and acute post-surgical pain., Results: This study recruited 178 knee arthroplasty patients. The results of the t -test or one-way ANOVA indicated that there were statistically significant differences in gender, age, education, occupation, disease duration, whether the knee replacement was performed for the first time, preoperative pain scores, and operation time in patients with knee arthroplasty ( P < 0.05). The correlation analysis of social support, pain catastrophization, and acute post-surgical pain in knee arthroplasty patients showed that social support was negatively correlated with acute post-surgical pain ( r =-0.584, P <0.01), and pain catastrophizing was positively correlated with postoperative acute pain ( r =0.601, P <0.01); The hierarchical regression analysis revealed that social support had a significant moderating effect on the relationship between pain catastrophizing and acute post-surgical pain ( ΔR2 =0.606, P <0.05)., Conclusion: The acute post-surgical pain of knee arthroplasty patients was affected by gender, age, education, occupation, disease duration, whether the knee arthroplasty was performed for the first time, preoperative pain scores, and operation time. Acute Post-surgical pain in patients with knee arthroplasty was affected by social support and pain catastrophizing, and social support had a moderating effect on the relationship between pain catastrophizing and acute post-surgical pain., Competing Interests: The authors report no conflicts of interest in this work., (© 2024 Ai et al.)

Background: Total joint arthroplasty (TJA) is the most common procedure associated with malpractice claims within orthopaedic surgery. Although prior research has assessed prevalent causes and outcomes of TJA-related lawsuits before 2018, the dynamic healthcare environment demands regular re-evaluations. This study aimed to provide an updated analysis of the predominant causes and outcomes of TJA-related malpractice lawsuits and analyze the outcomes of subsequent appeals following initial jury verdicts., Methods: A legal database was queried for cases between 2018 and 2022 involving primary hip and knee TJA in the United States. Cases were listed as original rulings or appeals and reviewed for the alleged negligence, damages incurred, demographics, and verdicts. Appeals were further assessed for appellant details, preliminary judgment, and outcomes. The findings were compared to previous litigation data using descriptive statistics., Results: The final cohort comprised 59 cases: 33 (56%) total knee arthroplasty (TKA) and 26 (44%) total hip arthroplasty (THA). The TKA cases primarily cited pain (24%), while the THA cases cited nerve injuries (31%). Negligence largely stemmed from procedural error (47%), postsurgical error (27%), and failure to inform (14%). Case outcomes were in favor of the defense in 66% of cases. Overall, 90% of primary verdicts led to appeals, with 71% by the plaintiff. Initial rulings were upheld in 87% of plaintiff appeals, whereas 53% of defendant appeals retained the initial judgment., Conclusions: The primary cause of litigation shifted from infection to ongoing/worsening pain in TKA cases over time. While nerve injury TKA cases have decreased, it remains the most cited damage after THA. Defense verdicts are common, but there is an increasing number of verdicts against defendants. Plaintiffs are more likely to appeal, but are less successful in appellate courts. These findings allow surgeons and policymakers to address emerging litigation trends in TJA to mitigate risks and improve the overall quality of TJA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: It is clinically important to anticipate the likelihood of pain catastrophizing in patients who undergo total knee arthroplasty (TKA). Persistent pain and diminished physical function following TKA are independently associated with preoperative pain catastrophizing. The purpose of this study was to develop and validate a nomogram model to predict pain catastrophizing in patients who have severe osteoarthritis undergoing primary TKA., Methods: Data were collected from patients who have severe osteoarthritis undergoing primary TKA at four tertiary general hospitals in Changsha, China, from September to December 2023. The study cohort was randomly divided into a training group and a validation group in the proportion of 70 to 30%. Least absolute shrinkage and selection operator regression analysis was utilized to select the optimal predictive variables for the model. A nomogram model was created using independent risk factors that were identified through multivariate regression analysis. Their performance was assessed using the concordance index and calibration curves, and their clinical utility was analyzed using decision curve analysis., Results: A total of 416 patients were included, 291 in the training group and 125 in the validation group. There were 115 (27.6%) who had pain catastrophizing. The predictors contained in the nomogram were pain intensity during activity, anxiety and depression, body mass index, social support, and household. The area under the curve of the nomogram was 0.976 (95% confidence interval = 0.96 to 0.99) for the training group and 0.917 (95% confidence interval = 0.88 to 0.96) for the validation group. The calibration curves confirmed the nomogram's accuracy, and decision curve analysis showed its strong predictive performance., Conclusions: The comprehensive nomogram generated in this study was a valid and easy-to-use tool for assessing the risk of pain catastrophizing in preoperative TKA patients, and helped healthcare professionals to screen the high-risk population., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Purpose: The implantation rate of total knee arthroplasties (TKA) is continuously growing. Aseptic problems are a major cause of revision. The aim of the following study was to determinate the incidence of aseptic revisions in primary knee arthroplasty as well as aseptic revision rates and influencing factors according to the patients' age and type of procedure., Methods: Data collection was performed using the German Arthroplasty Registry. Influencing factors were analyzed according to the patients' age and type of procedure. Risk factors were calculated using multiple Log-rank test with the Holm's method. Incidence and comparison of aseptic revisions according to the patients' age and type of procedure were analyzed using Kaplan-Meier-estimates. Cox regression was applied to calculate the hazard ratio., Results: Overall, 300,998 knee arthroplasties with 254,144 (84.4%) unconstrained TKA, 9,993 (3.3%) constrained TKA and 36,861 (12.3%) unicondylar knee arthroplasties (UKA) were analyzed. Patients younger than 65 years suffered a significantly higher aseptic revision rate than older patients (p < 0.0001). After one year, a revision rate of 1.1% was recorded for patients 65-74 years, 1.6% for patients under 65 years, and 1.3% for patients beyond 74 years. After seven years, patients younger than 65 years sustained in 5.0%, patients 65-74 years in 2.9% and patients beyond 74 years in 2.4% revision. In unconstrained TKA, an increased Elixhauser-score (HR = 1,75; HR = 1,54; HR = 1,7; p < 0,001) was a risk factor regardless the age. A TKA volume of 101-250 regardless the age (HR = 0,66; HR = 0,69; HR = 0,79) and > 250 under 75 years (< 65: HR = 0,72; 65-74: HR = 0,78; p = 0,001) were protective for aseptic revision. In UKA, male gender (HR = 0,81; HR = 0,72; HR = 0,57; p < 0,001), a UKA volume ≥ 51 for patients under 75 years (< 65: HR = 0,62; 65-74: HR = 0,59; p = 0,003) as well as cemented UKA for patients younger than 75 years (< 65: HR = 0,37; 65-74: HR = 0,37; p < 0,001) were detected as preventive factors., Conclusion: A significant increased rate of aseptic revisions was reported for patients younger than 65 years compared to older patients. An increased Elixhauser score was a risk factor, whereas male and a high volume of performed UKA or TKA could be identified as preventive factors., Level of Evidence: III, cohort study., (© 2024. The Author(s).)

Background: Unicompartmental knee replacements (UKRs) have become an increasingly attractive option for end-stage single-compartment knee osteoarthritis (OA). However, there remains controversy in patient selection. Natural language processing (NLP) is a form of artificial intelligence (AI). We aimed to determine whether general-purpose open-source natural language programs can make decisions regarding a patient's suitability for a total knee replacement (TKR) or a UKR and how confident AI NLP programs are in surgical decision making., Methods: We conducted a case-based cohort study using data from a separate study, where participants (73 surgeons and AI NLP programs) were presented with 32 fictitious clinical case scenarios that simulated patients with predominantly medial knee OA who would require surgery. Using the overall UKR/TKR judgments of the 73 experienced knee surgeons as the gold standard reference, we calculated the sensitivity, specificity, and positive predictive value of AI NLP programs to identify whether a patient should undergo UKR., Results: There was disagreement between the surgeons and ChatGPT in only five scenarios (15.6%). With the 73 surgeons' decision as the gold standard, the sensitivity of ChatGPT in determining whether a patient should undergo UKR was 0.91 (95% confidence interval (CI): 0.71 to 0.98). The positive predictive value for ChatGPT was 0.87 (95% CI: 0.72 to 0.94). ChatGPT was more confident in its UKR decision making (surgeon mean confidence = 1.7, ChatGPT mean confidence = 2.4)., Conclusions: It has been demonstrated that ChatGPT can make surgical decisions, and exceeded the confidence of experienced knee surgeons with substantial inter-rater agreement when deciding whether a patient was most appropriate for a UKR., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 IMPERIAL COLLEGE LONDON. Published by Elsevier B.V. All rights reserved.)

Introduction: Total knee arthroplasty (TKA) is used for tricompartmental knee osteoarthritis, while unicompartmental knee arthroplasty (UKA) is preferred for unicompartmental knee osteoarthritis. Bicompartmental knee arthroplasty (BKA) aims to address 2 knee compartments by combining 2 UKA's or 1 UKA with a patellofemoral replacement. This study examines the clinical outcomes of BKA, focusing on pain alleviation and knee function. The aim of this study is to report the functional outcome of BKA and see if this aligns with BKA outcomes from literature in terms of patient reported outcome measurements (PROMs) and range of motion (ROM) after a 2-year follow-up. Additionally, radiographic alignment, implant survivorship, adverse events and length of stay are secondary outcomes., Methods: This is a cohort study of 21 patients who underwent BKA for medial and patellofemoral osteoarthritis. The patients had follow-up for at least 2 years postoperatively. PROMs were assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS), Knee Society Score (KSS), Oxford Knee Score, Western Ontario and McMaster University Osteoarthritis index (WOMAC) and the Visual Analogue Scale (VAS). ROM was measured using a goniometer. Pre- and postoperative radiographic coronal alignment was measured using standard full leg radiographs. Patient demographics, implant survivorship, length of stay and adverse events were recorded., Result: Twenty-one patients (23 knees) were included, with a mean follow-up of 41 months (standard deviation [SD] 12 months; range 24-59 months). Patient-reported outcome measures (PROMs) demonstrated significant improvements, with 80% achieving good to excellent OKS and KSS scores. KOOS scores were similar to scores found in literature. The WOMAC score was higher in our results compared to other authors. Which indicates worse outcome. The mean preoperative hip-knee-ankle angle (HKAA) was 2.4 degrees varus (SD 1.9 degrees; range 1.2 degrees valgus - 6.1 degrees varus), while the mean postoperative HKAA was 0.3 degrees valgus (SD 2.8 degrees; range 4.6 degrees valgus - 5.6 degrees varus) (p < 0.001). Postoperative range of motion averaged 117 degrees (SD 10 degrees; range 98-132)., Conclusions: BKA shows promise in alleviating pain and improving knee function in patients with medial and patellofemoral osteoarthritis. Challenges include the risk of revision and technical difficulties during surgery. Comparative studies suggest similar outcomes between BKA and TKA, with potential advantages for younger, more active patients. Further research, particularly randomized trials with larger cohorts, is necessary to elucidate the long-term benefits and drawbacks of BKA compared to other knee arthroplasty options., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: During kinematically aligned (KA) total knee arthroplasty (TKA), the surgeon may need to rectify an over-resection of the medial, lateral or posterior tibia. This study tested the hypothesis that a bone graft taken from the tibial resection or patella and impacted beneath a tibial baseplate would heal, regardless of whether the tibial component and knee were in outlier ranges according to mechanical alignment (MA) criteria. The study also tested the hypothesis that the Oxford Knee Score (OKS) and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR) would improve beyond the substantial clinical benefit and that the source and thickness of the bone graft would not influence their improvement., Methods: This retrospective study radiographically assessed the healing of a bone graft from the tibial resection (n = 19) or patella (n = 10) in 29 KA TKAs (18 females, mean age 65 years). The tibial component and knee alignment were categorized as in-range or outliers based on reported MA criteria for bone graft healing and implant survival. The one-sample t test identified differences in the improvement of the OKS and KOOS JR from their reported substantial clinical benefit of 16 and 20 points, respectively., Results: At an average follow-up of 37 months, all bone grafts healed even though ≥55% of tibial components and 34% of knees were varus outliers according to MA criteria for bone healing and implant survival. Amongst the 29 patients, the mean OKS and KOOS JR improvements of 25 ± 11 and 47 ± 21 points, respectively, surpassed the threshold of their respective substantial clinical benefit (p < 0.01) and were not influenced by the bone graft's source and thickness (p ≥ 0.51)., Conclusions: During cemented KA TKA, the surgeon can use a bone graft from the tibial resection or patella to rectify a tibial over-resection. This technique led to consistent bone healing and improved outcome scores., Level of Evidence: Level IV., (© 2024 European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

Background: Patients with knee arthroplasty often have problems such as slow recovery of knee function, which may cause negative emotions and affect their postoperative rehabilitation. The application of sensory and motor training in the Acknowledge, Introduce, Duration, Evaluation, Thank You (AIDET) communication mode in patients after knee arthroplasty can provide reference for the selection of postoperative rehabilitation training measures., Aim: To explore the sensory and motor training effects in AIDET communication mode on knee function recovery and resilience of patients after knee arthroplasty., Methods: One hundred patients who underwent knee arthroplasty at our hospital between January 2022 and January 2024 were randomly divided into two groups. The control group ( n = 50) received routine rehabilitation training. In the observation group ( n = 50), the AIDET communication mode was used to perform sensory and motor training, in addition to routine rehabilitation training. The rehabilitation training was administered for 8 weeks. After surgery, knee function, balance ability, walking ability, proprioception, and resilience were compared between the two groups., Results: The New York Hospital for Special Surgery knee scores of the observation group at the time of discharge and 8 weeks after intervention were (65.23 ± 6.84, 84.53 ± 5.27), which was higher than those of the control group (61.03 ± 7.15, 74.92 ± 6.52) ( P < 0.05). The balance ability of the observation group at the time of discharge and 8 weeks after the intervention was higher than that of the control group, the time of time up to go test was shorter than that of the control group, and proprioceptive function was higher than that of the control group ( P < 0.05). The resilience level in the observation group after the intervention was higher than that in the control group ( P < 0.05)., Conclusion: Sensory and motor training in AIDET communication mode promotes knee function recovery of patients after knee arthroplasty, improves their limb walking ability and balance function, and increases their resilience level., Competing Interests: Conflict-of-interest statement: The authors declare no conflict of interest., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Introduction Knee osteoarthritis (KOA) is a progressive degenerative disease, with an increasing prevalence among the population. The degenerative changes in KOA affect the cartilage, menisci, synovial tissue, and subchondral bone. The treatment for patients in advanced stages of the disease is total knee arthroplasty (TKA). The purpose of this descriptive study is to identify the MRI features in the case of patients with KOA who did not obtain an improvement in symptoms and joint function after the non-surgical treatments and who applied for surgical treatment, i.e. TKA. Also, we aimed to identify the correlations between the MRI changes and the functional score of the patients, as well as the inter-variable correlations. Materials and methods The study was conducted in the Department of Orthopedics and Traumatology at the University Emergency Hospital of Bucharest between January 1, 2023, and January 31, 2024. It included 50 patients who required TKA. This study is a prospective, observational, and descriptive analysis focusing on patients scheduled for TKA. Results The patients in the study group who required TKA had a Knee Society Score (KSS) ranging from 35 to 70 and a KSS function score between 24 and 60. Among them, 98% had tricompartmental lesions of the articular cartilage, and 100% presented with osteophytes, even when they were not identifiable radiologically. Additionally, 58% of the patients had changes in the infrapatellar fat pad, 66% presented with joint effusion without any traumatic history, and 86% of the patients had partial or complete lesions of the anterior cruciate ligament. Conclusion The MRI pattern of the patient who requires TKA consists of the presence of articular cartilage lesions in more than two compartments with exposure of the subchondral bone and diameter greater than 1 cm, meniscus lesions (>grade 2), meniscus extrusion (>grade 1), the presence of bone marrow lesions (BMLs) in the medial or lateral compartment of the femur or tibia, hyperintense signal of the infrapatellar fat pad, anterior cruciate ligament (ACL) lesions (>grade 2), and the presence of osteophytes together with the presence of effusion in the suprapatellar bursa. BMLs and changes in the infrapatellar fat pad may lead to the opening of new research perspectives explaining the complex changes in KOA in relation to the inflammatory process and gene expression., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Ethics Committee of University Emergency Hospital Bucharest issued approval no. 40545/2023. The study was conducted according to the guidelines of the Declaration of Helsinki. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Iordache et al.)

Background/Objectives : To investigate if intra-articular biomarkers relate to peripheral and central sensitization in patients with late-stage knee osteoarthritis (KOA). Methods : A total of 17 (6M, 11F) patients (aged 69 ± 10 years) were assessed for peripheral (pressure pain thresholds (PPT)) and central (temporal summation (TS) and conditioned pain modulation (CPM)) sensitization the day before total knee arthroplasty. Synovial fluid was collected during surgery and assayed for IL-6, IL-8, IL-10, TNF-α, CXCL-10, BDNF, NGF, CCL2, CCL5, VEGF, IL-1RI, MMP-1, MMP-7, IL-1β, and CXCL-9. Associations of biomarkers and their combinations reflecting chronic (CXCL-9) and acute ((CCL2×CXCL-10)/IL-10)) inflammation, cartilage degeneration (MMP-1×MMP-7), and neurotrophy (NGF×BDNF) with PPT, TS, and CPM were analyzed by bivariate correlations and by multiple linear regression analyses corrected for BMI, sex, and age. Results : The medial joint line and the superior medial joint region showed the lowest PPT. Higher acute inflammation related significantly to worse pressure tenderness at the superior medial joint region (R 2 = 0.642; p = 0.010). Cartilage degeneration and chronic inflammation were associated with both absolute (R 2 = 0.827; p = 0.001) and relative CPM (R 2 = 0.882; p < 0.001). Acute inflammation and neurotrophy were related to relative TS at the m. tibialis anterior (R 2 = 0.728; p = 0.02). Conclusions : This study demonstrates that increased levels of intra-articular biomarkers of acute inflammation are related to peripheral sensitization and that biomarkers of cartilage degeneration and chronic inflammation are associated with central sensitization. These results may be a stepping-stone toward a better understanding of the working mechanism of peripheral and central sensitization in KOA pain and the development of more targeted therapeutic interventions.

Background: Persistent high levels of knee pain after a total knee replacement have been estimated to affect 5%-10% of people and this is related to dissatisfaction with surgery, reduced function and reduced quality of life. This systematic review aims to evaluate the effectiveness of rehabilitation programs or strategies to reduce persistent pain and improve function and quality of life in people following a total knee replacement., Methods: The systematic review was conducted following PRISMA guidelines with a search of relevant online databases up to 17 July 2024. The search criteria included English language randomised controlled trials of rehabilitation programs or strategies in any setting to treat people with persistent knee pain more than 3 months after a total knee replacement. Rehabilitation could include exercise, education, cognitive strategies and self-management programs and excluded medication trials, procedural techniques and complementary therapies., Results: After removal of duplicates, there were 468 abstracts screened for eligibility with 23 remaining for full-text screening and finally, one study meeting the eligibility criteria. This study's interventions were pain neuroscience education alone and pain neuroscience education plus neuromuscular exercise. There were no statistically significant between-group differences for pain reduction or functional improvement., Conclusion: The evidence examining the value of rehabilitation programs or strategies for pain reduction and functional improvement in people with persistent pain following total knee replacement is deficient. Given the high number of people affected annually, further research concerning both prevention and management of persistent pain after knee replacement is warranted., (© 2024 The Author(s). Musculoskeletal Care published by John Wiley & Sons Ltd.)

Objective: Arthroplasty patients undergo pre-operative assessment and medical optimization before surgery with the objective to mobilize and discharge home as soon as deemed fit to reduce hospital stay. This study was aimed to investigate factors delaying mobilization after hip and knee arthroplasty in our hospital., Methods: This observational study was conducted in our hospital between August 2021 and October 2021. We included all elective orthopedic patients who were admitted for hip and knee arthroplasty during this period. Patients admitted for revision arthroplasty were excluded from the study. We collected data prospectively on a pro forma including patient demographics and different other variables. All patients were reviewed on the first post-operative day by one of the authors and pro formas were completed. We used SPSS to analyze data., Results: Sixty patients were included; 32 females and 28 males with a mean age of 69.62 years. Primary knee arthroplasty was done in 30 patients while 30 underwent primary hip arthroplasty. Most of the patients ( n = 50) were mobilized on the 1 st day; however, ten patients were unable to mobilize. Orthostatic hypotension, dizziness, and pain were statistically significant factors responsible for failed mobilization on day one. Patients who failed to mobilize on day one had longer hospital stay ( P = 0.018)., Conclusion: Orthostatic intolerance and post-operative pain were independent factors delaying mobilization after hip and knee arthroplasty thereby increasing the length of stay in these patients., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright: © International Journal of Health Sciences.)

Introduction: For several years, ropivacaine has been the standard-of-care for establishing postoperative femoral nerve block in total knee arthroplasty (TKA) setting and is still widely in use but new approaches such as the patient-controlled administration of sublingual sufentanil tablets system (SSTS) seem to offer good clinical results. Our aim is to compare the SSTS to single shot peri-nervous injection of ropivacaine (single shot) after TKA in terms of effectiveness in pain management and of time to recovery., Materials and Methods: A total of 165 patients undergoing TKA were enrolled. Eighty-four patients were randomly allocated in the SSTS group and 81 patients in the single shot group. The primary objective of the study was to evaluate performance of Timed Up and Go test. Secondary objectives were to measure the length of stay, NRS pain scale, the adherence to the prescribed plan, the joint mobility, the frequency of rescue analgesic use, side effects and patients' satisfaction., Results: Of all patients of the single shot group, 64 were withdrawn from the study as they unable to achieve pain control; only one patient was withdrawn from the SSTS group. Times for the "Timed Up and Go" test on the 3rd postoperative day were 8.4 ± 1.6 and 11.8 ± 3.6 in the SSTS group (n = 83) and single shot group (n = 17), respectively (p < .001)., Conclusions: SSTS provides better pain management when compared to peri-nervous ropivacaine single shot injection after TKA., (© 2024. The Author(s), under exclusive licence to Istituto Ortopedico Rizzoli.)

Background: Anaemia, blood loss, and blood transfusion are critical aspects of patient care in major orthopaedic surgery. We assessed hospital adherence to guideline-recommended Patient Blood Management (PBM) care, analysed variations between hospitals, and validated two composite indicators of hospital PBM performance in patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA)., Methods: This retrospective cohort study included all primary TKA and THA procedures performed during 2021 across 39 hospitals in Spain. We assessed hospital adherence to key guideline-recommended PBM interventions using nine individual quality indicators and two types of composite quality indicators (cQIs): opportunity-based (cQI1) and all-or-none (cQI2). We validated these cQIs by analysing their associations with the adjusted total transfusion index using linear regression., Results: We included 8561 patient episodes from 33 hospitals in the analysis. Delivery of PBM care was similar for TKA and THA. Patients received 62% of the analysed PBM interventions and only 12% of patients underwent the full PBM pathway. Higher hospital cQIs scores were associated with a lower adjusted total transfusion index, both in TKA and THA. The greatest association was found for cQI1 in THA patients (β=-1.18 [95% confidence interval -2.00 to -0.36]; P=0.007)., Conclusions: Hospital adherence to guideline-recommended patient blood management care in total hip and knee arthroplasty was suboptimal and varied across centres. Using data that are widely available in hospitals, quality indicators and composite scores could become valuable tools for patient blood management monitoring and comparisons between healthcare organisations., (Copyright © 2024 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: A number of tools exist to aid surgeons in risk assessment, including the Charlson Comorbidity Index (CCI), the Elixhauser Comorbidity Index (ECI), and various measures of frailty, such as the Hospital Frailty Risk Score (HFR). While all of these tools have been validated for general use, the best risk assessment tool is still debated. Risk assessment is particularly important in elective surgery, such as total joint arthroplasty. The aim of this study is to compare the predictive power of the CCI, ECI, and HFR in the setting of total knee arthroplasty (TKA)., Methods: All patients who underwent TKA were identified via International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code from the National Readmissions Database, years 2016 to 2019. Patient demographics, perioperative complications, and hospital-associated outcomes were recorded. Receiver operating characteristic (ROC) curves were created and area under the curves (AUCs) evaluated to gauge the predictive capabilities of each risk assessment tool (CCI, ECI, and HFR) across a range of outcomes., Results: A total of 1,930,803 patients undergoing TKA were included in our analysis. For mortality, ECI was most predictive (0.95 AUC), while HFR and CCI were 0.75 and 0.74 AUC, respectively. For periprosthetic fractures, ECI was 0.78 AUC, HFR was 0.68 AUC, and CCI was 0.66 AUC. For joint infections, the ECI was 0.78 AUC, the HFR was 0.63 AUC, and the CCI was 0.62 AUC. For 30-day readmission, ECI was 0.79 AUC, while HFR and CCI were 0.6 AUC. For 30-day reoperation, ECI was 0.69 AUC, while HFR was 0.58 AUC and CCI was 0.56 AUC., Conclusions: Our analysis shows that ECI is superior to CCI and HFR for predicting 30-day postoperative outcomes following TKA. Surgeons should consider assessing patients using ECI prior to TKA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Core muscles constitute the centre of the kinetic chain, and core exercises have been effective in improving outcomes in many postsurgical lower extremity musculoskeletal conditions. However, the literature on the implementation of core exercises after TKA has not been summarised., Objective: The objective was to review the evidence on the effect of core exercises on clinical and functional outcomes after TKA in individuals with knee osteoarthritis (OA)., Methods: PubMed, Scopus, CINAHL, Web of Science, the Cochrane Library, and ProQuest databases were explored with appropriate keywords for studies published on the effect of core exercises on TKA from inception to 1 April 2024. Two authors independently screened the titles and abstracts and full-texts, and a third author solved the discrepancies. Risk of bias assessment was done with the Joanna Briggs Critical Appraisal tool. The final articles were systematically summarised., Results: A total of 1485 records were retrieved. Sixty-four articles were included for screening full-texts, and four articles were ultimately included. Core exercises were administered for three to 6 weeks. The administration of core exercises along with the standard knee rehabilitation programme significantly improved balance, mobility, knee function, transverse abdominis muscle thickness, transversus abdominis contraction, and quality of life after TKA (p < 0.05)., Conclusions: Core exercises can be administered as an adjunct to standard rehabilitation programs to improve clinical and functional outcomes after TKA. However, there is a dearth of literature in this domain, and more studies are warranted., Trial Registration: PROSPERO Registration Number: CRD42024542992., (© 2024 The Author(s). Musculoskeletal Care published by John Wiley & Sons Ltd.)

Background: The aim of this study was to compare the clinical results of kinematic alignment (KA) with those of mechanical alignment (MA) in single-stage bilateral total knee arthroplasty., Methods: In this double-blinded randomized controlled trial, 65 patients who had bilateral knee osteoarthritis underwent simultaneous bilateral total knee arthroplasty. One knee was randomly selected to be operated on with the calipered-KA technique and the other with MA. The participants were assessed via the Oxford Knee Score, Western Ontario and McMaster Universities Osteoarthritis Index questionnaire, and visual analog scale before the surgery and the same plus the Forgotten Joint Score at their last follow-up visit, 2 years postoperatively. Maximum knee flexion and the time reaching maximum knee flexion, named the recovery time, were also recorded. Hip-knee-ankle angle, medial proximal tibial angle, and lateral distal femoral angle were measured before and after the surgery using 3-joint-view radiographs., Results: At 2 years, there were significant differences between the KA and MA techniques in terms of duration of surgery, recovery time, and final Western Ontario and McMaster Universities Osteoarthritis Index, Forgotten Joint Score, and maximum flexion range in favor of KA (P < .05), but no significant difference in visual analog scale score or Oxford Knee Score. In patients who have a preferred knee, the KA knee was preferred over the MA knee by most patients. No prosthetic failure or revision was reported in either group., Conclusions: The KA technique yields acceptable functional outcomes compared to the MA technique. The KA technique was associated with a shorter surgery time, a faster recovery time, and higher patient satisfaction in 2-year follow-ups. Larger multicenter studies with longer follow-ups are warranted to confirm these findings., Level of Evidence: I., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Introduction: In recent years, different factors such as population aging have caused escalating demand for hip and knee arthroplasty straining already limited hospitals' resources. To address this challenge, focus is put on medical and operational efficiency improvements. This includes an increased use of machine learning (ML) to predict duration of surgery (DOS) and length of stay (LOS) for total knee and total hip arthroplasty, which can be utilized for optimizing resource allocation to satisfy medical and operational limitations. This paper explores the development and performance of ML models in predicting DOS and LOS., Methods: A systematic search of publications between 2010-2023 was conducted following PRISMA guidelines. Considering the inclusion and exclusion criteria, 28 out of 722 gathered papers from PubMed, Web of Science, and manual search were included in the study. Descriptive statistics was used to analyze the extracted data regarding data preprocessing, model development, and model performance assessment., Results: Most of the papers work on LOS as a binary variable. Patient's age was identified as the most frequently used and reported as important variable for predicting DOS and LOS. Investigations also illustrated that within the resulting 28 papers, more than 71% of models reached good to perfect performance based on the area under the receiver operating characteristic curve (AUC), where artificial neural networks and ensemble learning models had the biggest share among the best-performing models., Conclusion: The utilization of ML models is increasing in the literature. The current performance level indicates that ML can potentially turn to powerful tools in predicting DOS and LOS for different purposes. Meanwhile, the literature is not matured yet in reporting real-life application. Future studies can focus on model specification and validation by considering empirical application., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Background: Accurate estimation of implant size before surgery is crucial in preparing for total knee arthroplasty. However, this task is time-consuming and labor-intensive. To alleviate this burden on surgeons, we developed a reliable artificial intelligence (AI) model to predict implant size., Methods: We enrolled 714 patients with knee osteoarthritis who underwent total knee arthroplasty from March 2010 to February 2014. All surgeries were performed by the same surgeon using implants from the same manufacturer. We collected 1412 knee anteroposterior (AP) and lateral view x-ray images and retrospectively investigated the implant size. We trained the AI model using both AP and lateral images without any clinical or demographic information and performed data augmentation to resolve issues of uneven distribution and insufficient data. Using data augmentation techniques, we generated 500 images for each size of the femur and tibia, which were then used to train the model. Using data augmentation techniques, we generated 500 images for each size of the femur and tibia, which were then used to train the model. We used ResNet-101 and optimized the model with the aim of minimizing the cross-entropy loss function using both the Stochastic Gradient Descent (SGD) and Adam optimizer., Results: The SGD optimizer achieved the best performance in internal validation. The model showed micro F1-score 0.91 for femur and 0.87 for tibia. For predicting within ± one size, micro F1-score was 0.99 for femur and 0.98 for tibia., Conclusion: We developed a deep learning model with high predictive power for implant size using only simple x-ray images. This could help surgeons reduce the time and labor required for preoperative preparation in total knee arthroplasty. While similar studies have been conducted, our work is unique in its use of simple x-ray images without any other data, like demographic features, to achieve a model with strong predictive power., (© 2024. The Author(s).)

Introduction Knee osteoarthritis (KOA) is the most common form of osteoarthritis. It is diagnosed based on clinical symptoms, physical examination, and imaging, most frequently by knee X-ray in at least two views. In front of a patient with early KOA, all the predictive factors and risk factors that can be modified, but also that can lead to a rapid evolution of the symptoms and the need for total knee arthroplasty (TKA), must be taken into account and identified. There were a series of prognostic factors associated with KOA, such as age, sex, BMI, degree of physical activity, decrease in bone mineral density, C-reactive protein, malalignment, clinical severity at baseline, and previous traumas. The treatment of KOA is varied and involves pharmacological and non-pharmacological measures and surgical treatment in the final stages of evolution. Materials and methods In the University Emergency Hospital of Bucharest, Bucharest, Romania, patients with KOA presented to the Department of Orthopedics and Traumatology, and those who required surgical treatment, such as TKA, arthroscopy, or non-surgical treatment, were enrolled. We conducted a descriptive and prospective observational study that included 70 patients clinically and imaging diagnosed with KOA. The inclusion criteria consisted of a patient over 45 years old with knee pain and radiological signs of KOA. The exclusion criteria referred to patients with recent traumatic history, signs of active osteoarticular infection, the lack of radiological changes of KOA that imposed the differential diagnosis, patients known to have rheumatological diseases in the Algic phase, and patients in whom it was not possible to collect complete required data. Results Patients who required TKA were older (65.12 ± 8.19 years) than patients who required other therapeutic interventions (52.55 ± 3.63 years), the difference of 12.57 years being statistically significant (t = -8.882, p ≤ 0.001). Women were more than three times more likely to require TKA than men (80.85% vs. 52.17%, OR = 3.87, CI [1.29, 11.56]). Patients with HBP were more than four times more likely to require TKA than patients without HBP (78.57% vs. 42.86%, OR = 4.88, CI [1.42, 16.82]). Patients with elevated ESR were more than 26 times more likely to require TKA than patients with normal ESR (96.67% vs. 52.50%, OR = 26.23, CI [3.25, 211.67]). There are statistically significant differences between the non-TKA group (mean rank = 60.20) and TKA patients' score (mean rank = 25.62) (U = 6.000, Z = -6.606, p ≤ 0.001). Thus, patients who required TKA had a significantly lower KSS score than patients who required other treatments. Conclusion According to the data obtained in the studied group of patients, the characteristics of the patient at high risk of requiring TKA are the following: a female patient over 65 years of age who associates hypertension, high ESR, and fibrinogen values ​​with KSS score and KSS function with low values, recording an average value of 56.70., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Ethics Committee of University Emergency Hospital Bucharest issued approval 40525 / 2023. The study was conducted according to the guidelines of the Declaration of Helsinki and approved by the Ethics Committee of University Emergency Hospital Bucharest (no. 40525 / 2023). Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Iordache et al.)

Background: Total knee arthroplasty (TKA) using implants with a high level of constraint has generally been recommended for patients with osteoarthritis (OA) who have valgus alignment. However, studies have reported favorable outcomes even with cruciate-retaining (CR) implants., Aim: To evaluate the coronal plane stability of CR-TKA in patients with valgus OA at the mid-term follow-up., Methods: Patients with primary valgus OA of the knee who underwent TKA from January 2014 to January 2021 were evaluated through stress radiography using a digital stress device with 100 N of force on both the medial and lateral side. Gap openings and degrees of angulation change were determined. Descriptive statistical analysis was performed for both continuous and categorical variables. Inter-rater reliability of the radiographic measurements was evaluated using Cronbach's alpha., Results: This study included 25 patients (28 knees) with a mean preoperative mechanical valgus axis of 11.3 (3.6-27.3) degrees. The mean follow-up duration was 3.4 (1.04-7.4) years. Stress radiographs showed a median varus and valgus gap opening of 1.6 (IQR 0.6-3.0) mm and 1.7 (IQR 1.3-2.3) mm and varus and valgus angulation changes of 2.5 (IQR 1.3-4.8) degrees and 2.3 (IQR 2.0-3.6) degrees, respectively. No clinical signs of instability, implant loosening, or revision due to instability were observed throughout this case series., Conclusion: The present study demonstrated that using CR-TKA for patients with valgus OA of the knee promoted excellent coronal plane stability., Competing Interests: Conflict-of-interest statement: There are no conflicts of interest to report., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: Surgical site infection (SSI) is an important cause of disease burden and healthcare costs. Fully manual surveillance is time-consuming and prone to subjectivity and inter-individual variability, which can be partly overcome by semi-automated surveillance. Algorithms used in orthopaedic SSI semi-automated surveillance have reported high sensitivity and important workload reduction. This study aimed to design and validate different algorithms to identify patients at high risk of SSI after hip or knee arthroplasty., Methods: Retrospective data from manual SSI surveillance between May 2015 and December 2017 were used as gold standard for validation. Knee and hip arthroplasty were included, patients were followed up for 90 days and European Centre for Disease Prevention and Control SSI classification was applied. Electronic health records data was used to generate different algorithms, considering combinations of the following variables: ≥1 positive culture, ≥ 3 microbiological requests, antimicrobial therapy ≥ 7 days, length of hospital stay ≥ 14 days, orthopaedics readmission, orthopaedics surgery and emergency department attendance. Sensitivity, specificity, negative and predictive value, and workload reduction were calculated., Results: In total 1631 surgical procedures were included, of which 67.5% (n = 1101) in women; patients' median age was 69 years (IQR 62 to 77) and median Charlson index 2 (IQR 1 to 3). Most surgeries were elective (92.5%; n = 1508) and half were hip arthroplasty (52.8%; n = 861). SSI incidence was 3.8% (n = 62), of which 64.5% were deep or organ/space infections. Positive culture was the single variable with highest sensitivity (64.5%), followed by orthopaedic reintervention (59.7%). Twenty-four algorithms presented 90.3% sensitivity for all SSI types and 100% for deep and organ/space SSI. Workload reduction ranged from 59.7 to 67.7%. The algorithm including ≥ 3 microbiological requests, length of hospital stay ≥ 14 days and emergency department attendance, was one of the best options in terms of sensitivity, workload reduction and feasibility for implementation., Conclusions: Different algorithms with high sensitivity to detect all types of SSI can be used in real life, tailored to clinical practice and data availability. Emergency department attendance can be an important variable to identify superficial SSI in semi-automated surveillance., (© 2024. The Author(s).)