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Background: While evidence-based indications are established for medial UKA, the optimal indications for lateral UKA have not received as much attention. There exists significant anatomical, osteoarthritis phenotype, kinematic, and surgical technique differences between medial and lateral UKA. The indications for the two procedures may therefore not be identical. Hence, this review aims to access the indications and contraindications in published cohort studies on lateral UKA, to assess if consensus exists., Methods: In May 2024, a systematic review was carried out following the Preferred Reporting Item for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Cohort studies on lateral UKA with a clear report of indications were included. Data on indications and contraindications were extracted to evaluate consensus. Furthermore, outcomes related to expanding or testing indications for lateral UKA were obtained., Results: 38 studies were included. Lateral UKA was mostly performed for primary lateral osteoarthritis. The most reported indications were moderate to severe lateral osteoarthritis, with full-thickness cartilage in the medial compartment, intact ligaments, a correctable valgus deformity, and a flexion contracture < 10-15 degrees. The most reported contraindications were inflammatory arthritis and severe patellofemoral involvement. Eight studies investigated different indications on outcomes after lateral UKA; suggesting better outcomes for primary lateral osteoarthritis, no significant impact from the state of the patellofemoral joint, and conflicting results regarding age and weight., Conclusion: While the literature suggests that some agreement does exist regarding indications for lateral UKA, a strong consensus was not found, indicating that well-defined and consensus-based indications for lateral UKA do not yet exist., 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 B.V. All rights reserved.)

Background: Contemporary evidence-based indications no longer consider age regarding eligibility for medial unicompartmental knee arthroplasty (mUKA). This has led to more surgical candidates; however, whether patients still have satisfactory outcomes lacks evidence. This study examined the association between age and change in patient-reported outcome measures (PROMs) after mUKA as well as the achievement of Patient Acceptable Symptom State (PASS) and Minimal Important Change (MIC)., Methods: We included 782 mUKAs performed between February 1, 2016, and April 26, 2023. The mean change from preoperative Oxford Knee Score (OKS), Forgotten Joint Score (FJS), and Activity and Participation Questionnaire (APQ) was assessed at three, 12, and 24 months after surgery. The achievement of 12-month PASS (OKS ≥ 30) and MIC (changes in OKS ≥ 8; FJS ≥ 14) was also assessed. Patients were divided into age groups: < 55, 55 to < 65, 65 to < 75 years (reference group), and ≥ 75 years. There were 432 women (55%), patients had a mean age of 67 years (range, 29 to 93) and a mean BMI of 30 (range, 20 to 53)., Results: Median OKS, youngest to eldest, were 34, 35, 36, and 35 (three months); 40, 39, 41, and 43 (12 months); 42, 41, 43, and 42 (24 months). We found no differences in change in OKS between groups. Patients aged 55 to < 65 years had lower changes in FJS at 24 months and APQ at 12 and 24 months. Patients ≥ 75 years had lower 24-month change in APQ. We found no association between age and the fraction achieving either PASS or MIC (youngest to eldest, 90, 90, 94, and 95%)., Conclusion: We found good PROM improvements and satisfactory outcomes after mUKA in all age groups; however, patients aged 55 to < 65 years had worse changes in FJS and APQ. Results support contemporary indications for mUKA, and applying an age cutoff is unwarranted., (Copyright © 2024. Published by Elsevier Inc.)

Aims: Day-case success rates after primary total hip arthroplasty (THA), total knee arthroplasty (TKA), and medial unicompartmental knee arthroplasty (mUKA) may vary, and detailed data are needed on causes of not being discharged. The aim of this study was to analyze the association between surgical procedure type and successful day-case surgery, and to analyze causes of not being discharged on the day of surgery when eligible and scheduled for day-case THA, TKA, and mUKA., Methods: A multicentre, prospective consecutive cohort study was carried out from September 2022 to August 2023. Patients were screened for day-case eligibility using well defined inclusion and exclusion criteria, and discharged when fulfilling predetermined discharge criteria. Day-case eligible patients were scheduled for surgery with intended start of surgery before 1.00 pm., Results: Of 6,142 primary hip and knee arthroplasties, eligibility rates for day-case surgery were 34% for THA (95% CI 32% to 36%), 34% for TKA (95% CI 32% to 36%), and 52% for mUKA (95% CI 49% to 55%). Surgery before 1.00 pm was achieved in 85% of eligible patients. The day-case success rate among patients with surgery before 1.00 pm was 59% (95% CI 55% to 62%) for THA, 61% (95% CI 57% to 65%) for TKA, and 72% (95% CI 68% to 76%) for mUKA. Overall day-case success rates (eligible and non-eligible) were 19% (95% CI 17% to 20%) for THA, 20% (95% CI 18% to 21%) for TKA, and 42% (95% CI 39% to 45%) for mUKA. Adjusted analysis confirmed higher day-case success in eligible mUKA patients (odds ratio 1.9 (1.6 to 2.3)) compared to TKA and THA patients. Primary causes for day-case failure were mobilization issues (9% to 12% between procedures), prolonged spinal anaesthesia (4% to 9%), and postoperative nausea and vomiting (PONV) (4% to 14%)., Conclusion: THA and TKA patients showed comparable eligibility (34%) with similar day-case success rates (59 to 61%), whereas mUKA patients demonstrated higher eligibility (52%) and day-case success (72%). Mobilization issues, prolonged spinal anaesthesia, and PONV were the most frequent causes for not being discharged., Competing Interests: The salary for PhD student O. Danielsen was provided through funding from the Candy's Foundation, the University of Southern Denmark, and the Region of Southern Denmark. C. Varnum received travel expenses from Stryker, which is unrelated to this work. M. R. Andersen is secretary of the Danish Society for Hip and Knee Arthroplasty, which is unrelated. S. Overgaard received personal payment for a lecture from Johnson & Johnson, and institutional payment for being a course moderator and lectures from Heraeus, which are unrelated. C. C. Jørgensen received personal speaker fees and travel support from Pharmacosmos, unrelated to this work. H. Kehlet is on the Zimmer Biomet advisory board on rapid recovery. K. Gromov received research and institutional support from Zimmer Biomet, which was also unrelated., (© 2024 Danielsen et al.)

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: 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.)

Background: Total knee arthroplasty is associated with an inflammatory response and high levels of pain in a subset of patients. Pain catastrophizing has been associated with acute postoperative pain. The association between these variables has not been investigated in an optimised fast-track setup including preoperative glucocorticoids. The aim of this study was, first, to investigate the correlation between the increase in postoperative c-reactive protein (CRP) and acute postoperative pain after total knee arthroplasty, and second, to investigate the correlation between the increase in CRP and preoperative pain catastrophizing., Methods: This study is a secondary analysis of data from 119 patients participating in two randomised controlled trials. Correlation analyses were performed for preoperative CRP and CRP increase at 24 and 48 h and pain during a well-defined mobilisation at 24 and 48 h after total knee arthroplasty. Additionally, correlation analyses were performed between CRP increase and pain catastrophizing using the pain catastrophizing scale., Results: There was no correlation between preoperative CRP or postoperative CRP increase and pain at both 24 and 48 h. Analyses were similar when separated into high and low pain catastrophizers. There was no correlation between preoperative CRP or postoperative CRP increase and pain catastrophizing., Conclusion: There was no association between the postoperative CRP response and postoperative acute pain or pain catastrophizing in patients undergoing total knee arthroplasty in a well-defined multimodal fast-track regime including preoperative glucocorticoids. These results suggest that acute pain after knee arthroplasty is not reflected by CRP when applying preoperative glucocorticoids., (© 2024 Acta Anaesthesiologica Scandinavica Foundation.)

Background: Methods for identifying high-pain responders undergoing total knee arthroplasty remain important to improve individualized pain management. This study aimed at evaluating pre- and perioperative predictors of pain on Days 2-7 after total knee arthroplasty., Methods: This is a secondary analysis of data from 227 patients participating in two randomized trials. Pain outcomes were mean pain during walking on Days 2-7 and on Days 2, 4 and 7. Multivariable linear and logistic regressions were carried out in two steps. First, only preoperative available variables including demographics, comorbidities, pain catastrophizing scale and preoperative pain were evaluated while controlling for trial intervention and recruitment site. In the second step, perioperative variables and pain during walking 24 h postoperatively were added., Results: The model with only preoperative predictors for mean pain Days 2-7 showed preoperative pain (R-squared 0.097) as the only predictor. In the second model, adding postoperative available variables, only pain 24 h postoperatively (R-squared 0.248) was significant, with a significant main effect of recruitment site. Results for the separate day analysis similarly showed preoperative pain and pain during walking 24 h postoperatively as predictors. The overall best sensitivity (60%) and specificity (74%) for predicting a high-subacute postoperative pain response on Days 2-7 was with cut-off values of VAS 45.5 (out of 100) for pain during walking 24 h postoperatively., Conclusions: Postoperative pain during walking at 24 h is predictive of subacute postoperative pain on Days 2-7 after total knee arthroplasty, while preoperative pain was only a weak predictor., Significance Statement: This study investigated factors associated with pain after total knee arthroplasty beyond the immediate postoperative period. The analysis revealed significant associations between preoperative pain levels and, particularly, pain 24 h postoperatively, with subsequent subacute pain the following week. These findings can assist in identifying patients who would benefit from enhanced, individualized analgesic interventions to facilitate postoperative recovery., (© 2024 European Pain Federation ‐ EFIC ®.)

Background: In the past, the utilization of lateral unicompartmental knee arthroplasty (UKA) has been limited at national levels, despite the fact that an estimated 10% of patients who have an indication for arthroplasty, present with isolated lateral compartment osteoarthritis (OA). Units dedicated to UKA have reported good outcomes. Identifying patients for the procedure has been less clear, and the procedure has been perceived to be technically more demanding than medial UKA. This may result in a reluctance to start a lateral UKA practice and challenge the early phase. Therefore, this paper aimed to present the outcomes and learning curve when starting up a lateral UKA practice, as this theme remains unelucidated., Methods: There were 85 primary fixed-bearing lateral UKAs, with a minimum of 1-year follow-up, performed between 2016 and 2022 by 2 arthroplasty surgeons with existing UKA practices. The indications were primary (n = 79) or post-traumatic (n = 6) OA. Patient-reported outcome measures (PROMs) were assessed at 3, 12, and 24 months. A cumulative sum (CUSUM) analysis was used to evaluate surgical duration and the 12-month Oxford Knee Score (OKS)., Results: Median (interquartile range) 12-month OKS, activity and participation questionnaire, and Forgotten Joint Score (FJS) were 43 (37.5 to 46), 78 (42.5 to 98.5), and 72 (55 to 90), respectively. The OKS outcomes did not reveal adverse effects from the learning curve. A performance shift in surgical duration was observed around case 33. Kaplan-Meier implant survival reached 95.4% at 7 years for the endpoint "implant revision" and 93.5% for "implant revision or implant addition.", Conclusions: Starting up a lateral UKA practice is safe and efficient for surgeons who have prior medial UKA experience, provided strict adherence to indications. While surgical duration indicated a learning curve over approximately 33 cases, PROMs remained stable, suggesting proficient outcomes irrespective of the learning curve., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Psychopharmacological treatment may be an independent risk factor for increased length of stay and readmission after hip and knee replacement. Thus, temporary perioperative discontinuation may be beneficial. However, little is known regarding the treatments, and not all are feasible to discontinue. Therefore, the aim of this study was to describe the treatments in terms of type, dose, duration, indication and initiating physician to assess the feasibility of temporary perioperative discontinuation. We included 482 patients planned for hip or knee replacement in psychopharmacological treatment for psychiatric disorders from 2021 to 2023 at five orthopaedic departments in Denmark. Most patients were treated with antidepressants (89%); most frequently, either selective serotonin reuptake inhibitors (SSRIs; 48%) or serotonin-norepinephrine reuptake inhibitors (SNRIs; 21%). The majority received monotherapy (70%); most frequently, an SSRI (36%) or an SNRI (12%). Most antidepressants were initiated by general practitioners (71%), and the treatments had lasted for more than a year (87%). The doses of SSRIs/SNRIs were moderate, and the most frequent indication for antidepressants was depression (77%). These results imply that temporary perioperative SSRI/SNRI discontinuation may be feasible in hip and knee replacement patients and support a future randomized controlled trial investigating the potential benefits of temporary discontinuation., (© 2024 The Authors. Basic & Clinical Pharmacology & Toxicology published by John Wiley & Sons Ltd on behalf of Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).)

Background: Vitamin E-doped cross-linked polyethylene (VEPE) has encouraged the use of larger heads in thinner liners in total hip arthroplasty (THA). However, there are concerns about wear and mechanical failure of the thin liner, especially when metal heads are used. The aim of this randomized controlled trial was to investigate if the use of a large metal head in thin VEPE liner would increase polyethylene wear compared with a standard 32-mm metal head and to compare periacetabular radiolucencies and patient-reported outcomes in THA., Methods: There were 96 candidates for uncemented THA who were randomly allocated to either the largest possible metal head (36 to 44 mm) that could be fitted in the thinnest available VEPE liner (intervention group) or a standard 32-mm metal head (control group). The primary outcome was proximal head penetration, measured with a model-based radiostereometric analysis. Secondary outcomes were periacetabular radiolucencies and patient-reported outcomes. The midterm results of the trial at 5 years are presented., Results: The median total proximal head penetration (interquartile range) was -0.04 mm (-0.12 to 0.02) in the intervention group and -0.03 mm (-0.14 to 0.05) in the control group (P = .691). The rates of periacetabular radiolucencies were 1 of 44 and 4 of 42 (P = .197), respectively. Patient-reported hip function and health-related quality of life did not differ between the groups, but participants in the intervention group reported a higher level of activity (median University of California Level of Activity score 7 versus 6, P = .020). There were 5 revisions caused by dislocations (2), periprosthetic fracture (1), stem subsidence (1), or iliopsoas impingement (1)., Conclusions: Large metal heads in thin VEPE liners did not increase liner wear and were not associated with liner failure 5 years after THA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background and Objectives: Pain catastrophizing is associated with acute pain after total knee arthroplasty. However, the association between pain catastrophizing and acute pain after unicompartmental knee arthroplasty (UKA) remains unclear., Methods: We investigated the incidence of predicted high-pain and low-pain responders, based on a preoperative Pain Catastrophizing Scale score >20 or ≤20, respectively, and the acute postoperative pain course in both groups. Patients undergoing UKA were consecutively included in this prospective observational cohort study. Pain at rest and during walking (5 m walk test) was evaluated preoperatively, at 24 hours postoperatively, and on days 2-7 using a pain diary., Results: 125 patients were included, with 101 completing the pain diary. The incidence of predicted high-pain responders was 31% (95% CI 23% to 40%). The incidence of moderate to severe pain during walking at 24 hours postoperatively was 69% (95% CI 52% to 83%) in predicted high-pain responders and 66% (95% CI 55% to 76%) in predicted low-pain responders; OR 1.3 (95% CI 0.5 to 3.1). The incidence of moderate to severe pain at rest 24 hours postoperatively was 49% (95% CI 32% to 65%) in predicted high-pain responders and 28% (95% CI 19% to 39%) in predicted low-pain responders; OR 2.6 (95% CI 1.1 to 6.1; p=0.03). Pain catastrophizing was not associated with increased cumulated pain during walking on days 2-7., Conclusions: The incidence of predicted high-pain responders in UKA was slightly lower than reported in total knee arthroplasty. Additionally, preoperative pain catastrophizing was not associated with acute postoperative pain during walking., Competing Interests: Competing interests: KG and AT have received institutional study funding and honorarium related to educational activities from Zimmer Biomet with no relation to the present study., (© American Society of Regional Anesthesia & Pain Medicine 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Length of hospital stay after hip and knee arthroplasty is about 1 day in Denmark with few patients discharged on the day of surgery. Hence, a protocol for multicenter implementation of discharge on day of surgery has been instituted. We aimed to describe the implementation of outpatient hip and knee arthroplasty in a multicenter public healthcare setting., Methods: We performed a prospective multicenter study from 7 public hospitals across Denmark. Patients were screened using well-defined in- and exclusion criteria and were discharged on day of surgery when fulfilling functional discharge criteria. The study period was from September 2022 to February 2023 with variable start of implementation. Data from the same centers in a 6-month period before the COVID pandemic from July 2019 to December 2019 was used for baseline control., Results: Of 2,756 primary hip and knee arthroplasties, 37% (95% confidence interval [CI] 35-39) were eligible (range 21-50% in centers) and 52% (range 24-62%) of these were discharged on day of surgery. 21% (CI 20-23) of all patients (eligible and non-eligible) were discharged on day of surgery with a range of 10-31% within centers. This was an additional 15% (CI 13-17, P < 0.001) compared with patients discharged in the control period (6% in 2019)., Conclusion: We found it possible to perform outpatient hip and knee replacement in 21% of patients in a public healthcare setting, probably to be increased with further center experience.

Objectives: The minimal important change (MIC) reflects what patients, on average, consider the smallest improvement in a score that is important to them. MIC thresholds may vary across patient populations, interventions used, posttreatment time points and derivation methods. We determine and compare MIC thresholds for the Oxford Knee Score and Oxford Hip Score (OKS/OHS) at 3 months postoperatively to 12- and 24-month thresholds in patients undergoing knee or hip arthroplasty., Study Design and Setting: This cohort study used data from patients undergoing total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA), or total hip arthroplasty (THA) at a public hospital between February 2016 and February 2023. At 3, 12, and 24 months postoperatively, patients responded to the OKS/OHS and a 7-point anchor question determining experienced changes in knee or hip pain and functional limitations. We used the adjusted predictive modeling method that accounts for the proportion improved and the reliability of the anchor question to determine MIC thresholds and their mean differences between time points., Results: Complete data were obtained from 695/957 (73%), 1179/1703 (69%), and 1080/1607 (67%) patients undergoing TKA, 474/610 (78%), 438/603 (73%), and 355/507 (70%) patients undergoing UKA, and 965/1315 (73%), 978/1409 (69%), and 1059/1536 (69%) patients undergoing THA at 3, 12, and 24 months, respectively. The median age ranged from 68 to 70 years and 55% to 60% were females. The proportions improved ranged between 83% and 95%. The OKS/OHS MIC thresholds were 0.1, 4.2, and 5.1 for TKA, 1.8, 5.6, and 3.4 for UKA, and 1.3, 6.1, and 6.0 for THA at 3, 12, and 24 months postoperatively, respectively. The reliability ranged between 0.64 and 0.82, and the MIC values increased between three and 12 months but not between 12 and 24 months., Conclusion: Any absence of deterioration in pain and function is considered important at 3 months after knee or hip arthroplasty. Increasing thresholds over time suggest patients raise their standards for what constitutes a minimal important improvement over the first postoperative year. Besides improving our understanding of patients' views on postoperative outcomes, these clinical thresholds may aid in interpreting registry-based treatment outcome evaluations., Competing Interests: Declaration of competing interest A.T. reports a relationship with Zimmer Biomet that includes: consulting or advisory, speaking and lecture fees, and travel reimbursement; a relationship with Pfizer Denmark that includes: board membership and consulting or advisory; and a relationship with Danish Knee Arthroplasty register that includes: board membership. K.G. reports a relationship with Zimmer Biomet that includes: nonfinancial support. Other 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 Inc. All rights reserved.)

Introduction: Perioperative glycaemic control is important. However, the complexity of guidelines for perioperative diabetes management is complicated due to different and novel antihyperglycaemic medications, limited procedure-specific data and lack of data from implemented fast-track regimens which otherwise are known to reduce morbidity and glucose homeostasis disturbances. Consequently, outcome in patients with diabetes mellitus (DM) after surgery and the influence of perioperative diabetes management on postoperative recovery remains poorly understood., Methods and Analysis: A prospective observational multicentre study involving 8 arthroplasty centres across Denmark with a documented implemented fast-track programme (median length of hospitalisation (LOS) 1 day). We will collect detailed perioperative data including preoperative haemoglobin A1c and antidiabetic treatment in 1400 unselected consecutive patients with DM undergoing hip and knee arthroplasty from September 2022 to December 2025, enrolled after consent. Follow-up duration is 90 days after surgery. The primary outcome is the proportion of patients with DM with LOS >4 days and 90-day readmission rate after fast-track total hip arthroplasty (THA), total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA). The secondary outcome is the association between perioperative diabetes treatment and LOS >2 days, 90-day readmission rate, other patient demographics and Comprehensive Complication Index for patients with DM after THA/TKA/UKA in a fast-track regimen., Ethics and Dissemination: The study will follow the principles of the Declaration of Helsinki and ICH-Good Clinical Practice guideline. Ethical approval was not necessary as this is a non-interventional observational study on current practice. The trial is registered in the Region of Southern Denmark and on ClinicalTrials.gov. The main results and all substudies of this trial will be published in peer-reviewed international medical journals., Trial Registration Number: NCT05613439., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Early postoperative mobilization is essential for early functional recovery but can be inhibited by postoperative orthostatic intolerance (OI). Postoperative OI is common after major surgery, such as total knee arthroplasty (TKA). However, limited data are available after less extensive surgery, such as unicompartmental knee arthroplasty (UKA). We, therefore, investigated the incidence of OI as well as cardiovascular and tissue oxygenation responses during early mobilization after UKA., Methods: This prospective single-centre observational study included 32 patients undergoing primary UKA. Incidence of OI and cardiovascular and tissue oxygenation responses during mobilization were evaluated preoperatively, at 6 and 24 h after surgery. Perioperative fluid balance, bleeding, surgery duration, postoperative hemoglobin, pain during mobilization and opioid usage were recorded., Results: During mobilization at 6 h after surgery, 4 (14%, 95%CI 4-33%) patients experienced OI; however, no patients terminated the mobilization procedure prematurely. Dizziness and feeling of heat were the most common symptoms. OI was associated with attenuated systolic and mean arterial blood pressure responses in the sitting position (all p < 0.05). At 24 h after surgery, 24 (75%) patients had already been discharged, including three of the four patients with early OI. Only five patients were available for measurements, two of whom experienced OI; one terminated the mobilization procedure due to intolerable symptoms. We observed no statistically significant differences in perioperative fluid balance, bleeding, surgery duration, postoperative hemoglobin, pain, or opioid usage between orthostatic intolerant and tolerant patients., Conclusions: The incidence of orthostatic intolerance after fast-track unicompartmental knee arthroplasty is low (~ 15%) and is associated with decreased orthostatic pressure responses. Compared to the previously described orthostatic intolerance incidence of ~ 40% following total knee arthroplasty, early orthostatic intolerance is uncommon after unicompartmental knee arthroplasty, suggesting a procedure-specific component., Trial Registration: Prospectively registered at ClinicalTrials.gov; registration number: NCT04195360, registration date: 13.12.2019., (© 2024. The Author(s).)

Historically, the use of medial unicompartmental knee arthroplasty (mUKA) as treatment for end-stage anteromedial osteoarthritis (AMOA) of the knee was limited by contraindications due to age, weight, and activity level; however, now evidence-based, validated, and less selective criteria are used rendering nearly 50% of end-stage OA patients eligible for mUKA. Recent studies have showcased benefits, such as shorter hospital stays, cost efficiency, and comparable functional outcomes to total knee arthroplasty (TKA). Notably, revision rates have been shown to markedly decrease with increased usage, with an ideal usage of > 30% but an acceptable usage of 20-60%. The usage of unicompartmental knee arthroplasty (UKA) varies among countries, with Denmark achieving a notably higher usage compared to Sweden, the UK, the Netherlands, the USA and Germany. This article investigates potential factors contributing to Denmark having a higher national usage of mUKA, surpassing the recommended threshold of a usage > 20%. We explore the tradition for national alliances and streamlined surgical education as possible explanations of this development. These insights offer valuable perspectives for potentially optimizing surgical approaches and implant choices in the surgical treatment of end-stage AMOA of the knee across diverse healthcare settings, underscoring the impact of collective strategies in advancing knee arthroplasty practices, ultimately benefiting patients., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Aims: This study aimed to investigate patients' attitudes towards day-case hip and knee arthroplasty and to describe patient characteristics associated with different attitudes, with the purpose of providing an insight into the information requirements for patients that surgeons should address when informing patients about day-case surgery., Methods: A total of 5,322 patients scheduled for hip or knee arthroplasty between 2016 and 2022 were included in the study. Preoperatively, patients were asked if they were interested in day-case surgery ('Yes', 'Do not know', 'No'). Patient demographics including age, BMI, sex, and patient-reported outcome measures (PROMs) such as the EuroQol five-dimension three-level questionnaire (EQ-5D-3L) were examined within each attitude group. Additionally, changes in attitude were assessed among patients who had completed the questionnaire in association with prior hip or knee arthroplasty., Results: Of the surveyed patients, 41.8% were interested in day-case surgery (n = 2,222), 20.8% responded 'Do not know' (n = 1,105), and 37.5% were not interested (n = 1,995). Patients who were not interested had a higher mean age ('No', 70.2 years (SD 10.0) vs 'Yes', 65.2 years (SD 10.7)), with a majority being female ('No', 71.9% female (n = 1,434) vs 'Yes', 48.6% female (n = 1,081)). Approximately 20% of patients responded 'Do not know' regardless of age, sex, and PROMs. Patients reporting anxiety/depression based on EQ-5D-3L more frequently answered 'No' (56.9%; 66/116) compared to those not experiencing anxiety/depression (34.9%; 1,356/3,890). Among patients who responded 'Do not know' before their first surgery, over 70% changed their attitude to either 'Yes' (29.9%; 38/127) or 'No' (40.9%; 52/127) at their subsequent surgery., Conclusion: From 2016 to 2022, 58.3% of hip and knee arthroplasty patients expressed uncertainty or no interest in day-case surgery. In connection with current initiatives to increase the number of day-case arthroplasty procedures, there should be a focus on informing patients to address the prevalent negative or uncertain attitude. Further research is needed to investigate what preoperative information patients consider crucial in their decision-making process regarding day-case surgery., Competing Interests: C. H. Halken reports grants or contracts from Novo Nordisk Foundation, unrelated to this study. C. Bredgaard Jensen reports grants or contracts from Novo Nordisk Foundation, unrelated to this study. C. Henkel reports support for attending meetings and/or travel from Zimmer Biomet, unrelated to this study. K. Gromov reports grants or contracts from Zimmer Biomet, unrelated to this study. A. Troelsen reports grants or contracts, consulting fees, and membership of the advisory boards of Zimmer Biomet and Pfizer Denmark, and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Zimmer Biomet, all of which are unrelated to this study., (© 2024 The British Editorial Society of Bone & Joint Surgery.)

Aims: In metal-on-polyethylene (MoP) total hip arthroplasty (THA), large metal femoral heads have been used to increase stability and reduce the risk of dislocation. The increased size of the femoral head can, however, lead to increased taper corrosion, with the release of metal ions and adverse reactions. The aim of this study was to investigate the relationship between the size of the femoral head and the levels of metal ions in the blood in these patients., Methods: A total of 96 patients were enrolled at two centres and randomized to undergo MoP THA using either a 32 mm metal head or a femoral head of between 36 mm and 44 mm in size, being the largest possible to fit the thinnest available polyethylene insert. The levels of metal ions and patient-reported outcome measures (Oxford Hip Score, University of California, Los Angeles Activity Scale) were recorded at two and five years postoperatively., Results: At five years, the median levels of chromium, cobalt, and titanium were 0.5 μg/l (interquartile range (IQR) 0.50 to 0.62), 0.24 μg/l (IQR 0.18 to 0.30), and 1.16 μg/l (IQR 1.0 to 1.68) for the 32 mm group, and 0.5 μg/l (IQR 0.5 to 0.54), 0.23 μg/l (IQR 0.17 to 0.39), and 1.30 μg/l (IQR 1 to 2.05) for the 36 mm to 44 mm group, with no significant difference between the groups (p = 0.825, p = 1.000, p = 0.558). There were increased levels of metal ions at two years postoperatively in seven patients in the 32 mm group, compared with four in the 36 mm to 44 mm group, and at five years postoperatively in six patients in the 32 mm group, compared with seven in the 36 mm to 44 mm group. There was no significant difference in either the OHS (p = 0.665) or UCLA (p = 0.831) scores between patients with or without an increased level of metal ions., Conclusion: In patients who underwent MoP THA, we found no differences in the levels of metal ions five years postoperatively between those with a femoral head of 32 mm and those with a femoral head of between 36 mm and 44 mm, and no corrosion-related revisions. As taper corrosion can start after five years, there remains a need for longer-term studies investigating the relationship between the size of the femoral head size and corrosion in patients undergoing MoP THA., Competing Interests: H. Malchau reports institutional support from Zimmer Biomet for the purpose of this study. H. Malchau also reports institutional support from Stryker, royalties from Mako/Stryker, payment for independent expert testimony related to resurfacing for Smith & Nephew, patents related to antibiotic containing polyethylene, and participation on an advisory board for Stryker Nordics, all of which are unrelated to this study. H. Malchau is also a past president of the International Hip Society. M. Mohaddes reports institutional research funds from Zimmer Biomet, unrelated to this study. A. Troelsen reports research support, consultancy payments, payment for lectures including service on speakers bureaus, and travel/accommodations/meeting expenses from Zimmer Biomet, research support and consultancy payments from Pfizer Denmark, participation on advisory boards for Zimmer Biomet and Pfizer Denmark, and participation on the Danish Knee Arthroplasty Register, all of which are unrelated to this study. G. Tsikandylakis reports institutional grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement (ALFGBG-966203), and from the region of Western Götaland in Sweden for research and development (VGFoUREG-967213), unrelated to this study., (© 2024 The British Editorial Society of Bone & Joint Surgery.)

Background and Purpose: The overall potential pool of day-case candidates on a national level in hip and knee arthroplasty is unknown. We aimed to estimate the proportion of hip and knee arthroplasty patients eligible for day-case surgery based on contemporary widely used criteria and determine whether there has been a change in the proportion of eligible patients over time and, secondarily, to investigate the proportion of eligible patients discharged on the day of surgery., Methods: Based on data from the Danish National Patient Register, we identified all patients undergoing primary unilateral hip or knee arthroplasty from January 2010 to March 2020. Using a modification of day-case eligibility criteria proposed by a national multicenter collaboration, we sorted patients into either day-case eligible or ineligible. A day-case procedure was defined as discharge on the day of surgery., Results: We included patients comprising a total of 166,730 primary total hip (THA), total knee (TKA), and unicompartmental knee arthroplasty (UKA). 48% (95% confidence interval [CI] 48-49) were eligible for day-case surgery, with a decline from 50% (CI 49-51) in 2010 to 46% (CI 46-47) eligible in 2019. More UKA patients were day-case eligible (55%, CI 54-56) than THA (47%, CI 47-48) and TKA patients (49%, CI 48-49). A maximum of 8.0% (CI 7.4-8.5) of eligible patients were discharged on the day of surgery in 2019., Conclusion: 48% of the Danish hip and knee arthroplasty patients were potential day-case candidates, with a small decline in eligibility from 50% in 2010 to 46% in 2019. Day of surgery discharge among day-case eligible patients peaked at 8% in 2019. Thus, the potential for more day-case surgery seems large.

Mobilisation difficulties, due to muscle weakness, and urinary retention are common reasons for prolonged admission following hip and knee arthroplasty procedures. Whether spinal anaesthesia is detrimental to early mobilisation is controversial. Previous studies have reported differences in post-operative recovery between spinal anaesthesia and general anaesthesia; however, up-to-date comparisons in fast-track setups are needed. Our randomized, single-blinded, multi-centre, clinical trials aim to compare the post-operative recovery after total hip (THA), total knee (TKA), and unicompartmental knee arthroplasties (UKA) respectively when using either spinal anaesthesia (SA) or general anaesthesia (GA) in a fast-track setup. Included patients (74 THA, 74 TKA, and 74 UKA patients) are randomized (1:1) to receive either SA (2 mL 0.5% Bupivacaine) or GA (Induction: Propofol 1.0-2.0 mg/kg iv with Remifentanil 3-5 mcg/kg iv. Infusion: Propofol 3-5 mg/kg/h and Remifentanil 0.5 mcg/kg/min iv). Patients undergo standard primary unilateral hip and knee arthroplasty procedures in an optimized fast-track setup with intraoperative local infiltrative analgesia in TKA and UKA, post-operative multimodal opioid sparing analgesia, immediate mobilisation with full weightbearing, no drains and in-hospital only thromboprophylaxis. Data will be collected on the day of surgery and until patients are discharged. The primary outcome is the ability to be safely mobilised during a 5-m walking test within 6 h of surgery. Secondary outcomes include fulfilment of discharge criteria, post-operative pain, dizziness, and nausea as well as patient reported recovery and opioid related side effects. Data will also be gathered on all hospital contacts within 30-days of surgery. This study will offer insights into advantages and disadvantages of anaesthetic methods used in fast-track arthroplasty surgery., (© 2023 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.)

Aims: The aim of this study was to describe the pattern of revision indications for unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) and any change to this pattern for UKA patients over the last 20 years, and to investigate potential associations to changes in surgical practice over time., Methods: All primary knee arthroplasty surgeries performed due to primary osteoarthritis and their revisions reported to the Danish Knee Arthroplasty Register from 1997 to 2017 were included. Complex surgeries were excluded. The data was linked to the National Patient Register and the Civil Registration System for comorbidity, mortality, and emigration status. TKAs were propensity score matched 4:1 to UKAs. Revision risks were compared using competing risk Cox proportional hazard regression with a shared γ frailty component., Results: Aseptic loosening (loosening) was the most common revision indication for both UKA (26.7%) and TKA (29.5%). Pain and disease progression accounted for 54.6% of the remaining UKA revisions. Infections and instability accounted for 56.1% of the remaining TKA revision. The incidence of revision due to loosening or pain decreased over the last decade, being the second and third least common indications in 2017. There was a decrease associated with fixation method for pain (hazard ratio (HR) 0.40; 95% confidence interval (CI) 0.17 to 0.94) and loosening (HR 0.29; 95% CI 0.10 to 0.81) for cementless compared to cemented, and units UKA usage for pain (HR 0.67, 95% CI 0.50 to 0.91), and loosening (HR 0.51; 95% CI 0.37 to 0.70) for high usage., Conclusion: The overall revision patterns for UKA and TKA for the last 20 years are comparable to previous published patterns. We found large changes to UKA revision patterns in the last decade, and with the current surgical practice, revision due to pain or loosening are significantly less likely., Competing Interests: K. Gromov discloses funding for the the organizational set-up for the entire fast-track project, including dedicated research staff at all centres, data monitoring, and follow-up on complications, from Novo Nordisk foundation (Grant no. NNF21SA0073760). In addition, the author also discloses grants or contracts from Zimmer Biomet, which are unrelated to this article. L. E. Rasmussen declares consulting fees from Stryker, which is unrelated. A. Troelsen reports research support, consultig fees, and being an advisory board member for Zimmer Biomet and Pfizer Denmark, and payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Zimmer Biomet, all of which is also unrelated to this work., (© 2023 Mikkelsen et al.)

Background: Machine-learning models may improve prediction of length of stay (LOS) and morbidity after surgery. However, few studies include fast-track programs, and most rely on administrative coding with limited follow-up and information on perioperative care. This study investigates potential benefits of a machine-learning model for prediction of postoperative morbidity in fast-track total hip (THA) and knee arthroplasty (TKA)., Methods: Cohort study in consecutive unselected primary THA/TKA between 2014-2017 from seven Danish centers with established fast-track protocols. Preoperative comorbidity and prescribed medication were recorded prospectively and information on length of stay and readmissions was obtained through the Danish National Patient Registry and medical records. We used a machine-learning model (Boosted Decision Trees) based on boosted decision trees with 33 preoperative variables for predicting "medical" morbidity leading to LOS > 4 days or 90-days readmissions and compared to a logistical regression model based on the same variables. We also evaluated two parsimonious models, using the ten most important variables in the full machine-learning and logistic regression models. Data collected between 2014-2016 (n:18,013) was used for model training and data from 2017 (n:3913) was used for testing. Model performances were analyzed using precision, area under receiver operating (AUROC) and precision recall curves (AUPRC), as well as the Mathews Correlation Coefficient. Variable importance was analyzed using Shapley Additive Explanations values., Results: Using a threshold of 20% "risk-patients" (n:782), precision, AUROC and AUPRC were 13.6%, 76.3% and 15.5% vs. 12.4%, 74.7% and 15.6% for the machine-learning and logistic regression model, respectively. The parsimonious machine-learning model performed better than the full logistic regression model. Of the top ten variables, eight were shared between the machine-learning and logistic regression models, but with a considerable age-related variation in importance of specific types of medication., Conclusion: A machine-learning model using preoperative characteristics and prescriptions slightly improved identification of patients in high-risk of "medical" complications after fast-track THA and TKA compared to a logistic regression model. Such algorithms could help find a manageable population of patients who may benefit most from intensified perioperative care., (© 2023. The Author(s).)

Background and Purpose: Day-case hip and knee arthroplasty has gained in popularity, but there are conflicting results regarding readmissions. We aimed to investigate differences in 30- and 90-day readmission rates between day-case patients and patients with a single overnight stay following primary total hip arthroplasty (THA), total knee arthroplasty (TKA), and unicompartmental knee arthroplasty (UKA)., Patients and Methods: We identified day-case (DC) and overnight (ON) THA, TKA, and UKA patients, operated on between 2010 and 2020, from the Danish National Patient Register. Day-case surgery was defined as discharge on the day of surgery. Overnight readmissions within 30 or 90 days of surgery were considered readmissions. We compared readmission rates between DC and ON patients within arthroplasty types using logistic regression adjusted for patient characteristics and year of surgery. We included 29,486 THAs (1,353 DC and 28,133 ON), 15,116 TKAs (617 DC and 14,499 ON), and 6,440 UKAs (1,528 DC and 4,914 ON)., Results: The 30-day readmission rates were: DC-THA 4.4% vs. ON-THA 4.4% (adjusted odds-ratio [aOR] 1.2, 95% confidence interval [CI] 0.91-1.6), DC-TKA 4.7% vs. ON-TKA 4.4% (aOR 1.1, CI 0.69-1.5), and DC-UKA 3.0% vs. ON-UKA 3.0% (aOR 1.1, CI 0.78-1.5). Similarly, no significant differences were present between DC and ON THA, TKA, and UKA regarding 90-day readmissions or time to readmission., Conclusion: We found no differences in readmission rates between day-case THA, TKA, and UKA patients and patients with a single overnight stay.

Background: Postoperative pain after total hip arthroplasty (THA) may delay postoperative mobilization and discharge. Postoperative pain has been shown to be higher in pain catastrophisers and patients receiving opioids. A single dose of glucocorticoid reduces pain after THA, and an increased dose of glucocorticoids has been found to be effective in patients at high risk of postoperative pain after total knee arthroplasty (TKA), however, the ideal dose in THA remains unknown., Objective: To evaluate the effect of a high dose (1 mg kg -1 ) vs. intermediate dose (0.3 mg kg -1 ) of dexamethasone on pain after THA., Design: A randomized double-blind controlled study., Setting: A two-centre study including two large arthroplasty sites in Denmark was conducted from February 2019 to August 2020., Patients: A total of 160 patients undergoing THA by neuraxial block with multimodal analgesia, having a Pain Catastrophising Scale score >20 and/or preoperative opioid use were included., Intervention: Patients were randomly assigned to receive dexamethasone 1 mg kg -1 or 0.3 mg kg -1 before THA., Main Outcome Measures: Primary outcome was percentage of patients experiencing moderate to severe pain (visual analogue scale, VAS > 30 mm on a 0 to 100 mm scale) on ambulating 24 h after surgery. Secondary outcomes included cumulated pain scores, C-reactive protein (CRP), opioid use, postoperative recovery scores, length of stay, complications, and re-admission within 30 and 90 days., Results: No difference was found in percentage of VAS >30 mm 24 h after surgery in the 5-m walk test (VAS > 30/VAS ≤ 30%); 33/42 (44%) vs. 32/43 (43%), relative risk = 1.04 (95% confidence interval 0.72-1.51; P  = 0.814) in 1 mg kg -1vs. 0.3 mg kg -1 respectively. No differences were found in CRP and opioid use between groups. Also, no intergroup differences were found in recovery scores, re-admissions, or complications., Conclusion: 1 mg kg -1vs. 0.3 mg kg -1 dexamethasone improved neither postoperative pain nor recovery in THA in a cohort of predicted high pain responders., Trial Registration: ClinicalTrials.gov ID-number NCT03763760 and EudraCT-number 2018-2636-25., (Copyright © 2023 European Society of Anaesthesiology and Intensive Care. Unauthorized reproduction of this article is prohibited.)

Introduction: A feared complication after total hip arthroplasty (THA) is prosthetic joint infection (PJI), associated with high morbidity and mortality. Prophylactic antibiotics can reduce the risk of PJI. However, there is no consensus on the dosages and current recommendations are based on a low evidence level. The objective is to compare the effect of a single versus multiple doses of prophylactic antibiotics administered within 24 hours on PJI., Methods and Analysis: The study is designed as a cross-over, cluster randomised, non-inferiority trial. All clinical centres use both antibiotic practices (1 year of each intervention). All Danish orthopaedic surgery departments will be involved: Based on quality databases, 2-year cohorts of approximately 20 000 primary THAs conducted at 39 public and private hospitals, will be included., Inclusion Criteria: age ≥18 years, all indications for THA except patients operated due to acute or sequelae from proximal femoral or pelvic fractures or bone tumour or metastasis. The primary outcome is PJI within 90 days after primary THA. Secondary outcomes include (1) serious adverse events, (2) potential PJI, (3) length of hospitalisation stay, (4) cardiovascular events, (5) hospital-treated infections, (6) community-based antibiotic use, (7) opioid use and (8) use of acetaminophen and non-steroidal anti-inflammatory drugs. All outcome measures will be extracted from national databases. Analyses will be based on the intention-to-treat population. Non-inferiority will be shown if the upper limit of the two-sided 95% CI for the OR is less than 1.32 for the single dose as compared with multiple doses. The results will establish best practice on antibiotic prophylaxis dosages in the future., Ethics and Dissemination: This study has been approved by Committees on Health Research Ethics for The Capital Region of Denmark (21069108) and The Danish Medicines Agency (2021091723). All results will be presented in peer-reviewed medical journals and international conferences., Trial Registration Number: NCT05530551., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Purpose: Venous thromboembolism (VTE) is a serious postoperative complication after total knee arthroplasty (TKA). Use of a tourniquet has shown conflicting results for risk of VTE after TKA. We aimed to investigate the associated risk of VTE after TKA using tourniquet in a fast-track set-up as no previous data exists., Patients and Methods: We performed an observational cohort study from 9 fast-track centers including unilateral primary TKA from 2010-2017 with prospective collection of preoperative risk-factors and complete 90-day follow-up. Use of a tourniquet was registered in the Danish Knee Arthroplasty Register. Postoperative VTE was identified from health records. We performed risk analyses using a mixed-effects logistic regression model adjusting for previously identified risk factors., Results: Of the 16,250 procedures (39% males, mean age 67.9 [SD 10.0] years, median LOS 2 [interquartile range 2-3]) 12,518 (77%) were performed with a tourniquet. The annual tourniquet usage varied greatly between departments from 0% to 100%, but also within departments from 0% to 99%. There was no significant difference between the 2 groups with 52 (0.42%) VTEs in the tourniquet group vs. 25 (0.67%) in the no-tourniquet group (p = 0.06 for cumulative 90-day incidence of VTE). This association remained statistically insignificant for VTE using tourniquet after adjustment for previously identified risk factors., Conclusion: We found no association between the use of a tourniquet and increased risk of 90-day VTE after primary fast-track TKA, irrespective of the length of time for which the tourniquet was applied.

Background and Purpose: In existing studies on fasttrack unicompartmental knee arthroplasty (UKA), the majority of surgeries are medial. There are substantial differences between lateral and medial UKA, which is why outcomes cannot automatically be compared. To gain information on the feasibility and safety of fast-track protocols in lateral UKAs, we investigated length of stay (LOS) and early complications after lateral UKA, performed using a fast-track protocol in well-established fast-track centers., Patients and Methods: We retrospectively evaluated prospectively collected data on patients undergoing lateral UKA in a fast-track setup from 2010 to 2018 at 7 Danish fast-track centers. Data on patient characteristics, LOS, complications, reoperations, and revisions was analyzed using descriptive statistics. Safety and feasibility were defined as complication and reoperation rates within 90 days comparable to non-fast track lateral UKA or fast-track medial UKA., Results: We included 170 of patients with a mean age of 66 (SD 12) years. Median LOS was 1 day (interquartile range 1-1), which was unchanged from 2012-2018. 18% were discharged on the day of surgery. Within 90 days, 7 patients experienced medical complications and 5 patients experienced surgical complications. 3 patients underwent reoperation, 2 were soft tissue revisions and the third was removal of an exostosis due to catching of the patella. 1 patient was revised due to a bearing dislocation., Conclusion: Our findings suggest that lateral UKA in a fast-track setting is feasible and safe.

Aims: Medial unicompartmental knee arthroplasty (mUKA) is an advised treatment for anteromedial knee osteoarthritis. While long-term survival after mUKA is well described, reported incidences of short-term surgical complications vary and the effect of surgical usage on complications is less established. We aimed to describe the overall occurrence and treatment of surgical complications within 90 days of mUKA, as well as occurrence in high-usage centres compared to low-usage centres., Methods: mUKAs performed in eight fast-track centres from February 2010 to June 2018 were included from the Lundbeck Foundation Centre for Fast-track Hip and Knee Replacement Database. All readmissions within 90 days of surgery underwent chart review and readmissions related to the surgical wound or the prosthesis were recorded. Centres were categorized as high-usage centres when using mUKA in ≥ 20% of annual knee arthroplasties. The occurrence of complications between high- and low-usage centres were compared using Fisher's exact test., Results: We included 3,757 mUKAs: 2,377 mUKAs from high-usage centres and 1,380 mUKAs from low-usage centres. Surgical complications within 90 days occurred in 69 cases (1.8%), 45 (1.9%) in high-usage centres and 24 (1.7%) in low-usage centres (odds ratio (OR) 1.1 (95% confidence interval (CI) 0.65 to 1.8)). The most frequent complications were periprosthetic joint infections (PJIs) (n = 18; 0.48%), wound-related issues (n = 14; 0.37%), and periprosthetic fractures (n = 13; 0.35%). Bearing dislocations (n = 7; 0.19%) occurred primarily in procedures from high-usage centres. In high-usage centres, seven periprosthetic fractures (0.29%) occurred compared to six (0.43%) in low-usage centres (OR 0.68 (95% CI 0.20 to 2.0)). In high-usage centres, nine PJIs (0.38%) occurred compared to nine (0.65%) in low-usage centres (OR 0.58 (95% CI 0.22 to 1.6))., Conclusion: Surgical complications are rare after fast-track mUKA surgery and with no difference in overall occurrence of surgical complications between high- and low-usage centres, although the risk of some specific surgical complications may favour high-usage centres., Competing Interests: K. Gromov reports grants or contracts from Zimmer Biomet, unrelated to this study. A. Troelsen reports grants or contracts, consulting fees, and leadership or fiduciary role in other board, society, committee or advocacy group, paid or unpaid from Zimmer Biomet and Pfizer Denmark, payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Zimmer Biomet, and participation on a Data Safety Monitoring Board or Advisory Board for Danish Knee Arthroplasty Register, all of which are unrelated to this study., (© 2023 Authors et al.)

Background: Patient-reported outcome measures such as the Oxford Hip Score (OHS) can capture patient-centered perspectives on outcomes after total hip arthroplasty (THA). The OHS assesses hip pain and functional limitations, but defining interpretation threshold values for the OHS is warranted so that numerical OHS values can be translated into whether patients have experienced clinically meaningful changes. Therefore, we determined the minimal important change (MIC), patient acceptable symptom state (PASS), and treatment failure (TF) threshold values for the OHS at 12 and 24-month follow-up in patients undergoing THA., Methods: This cohort study used data from patients undergoing THA at 1 public hospital between July 2016 and April 2021. At 12 and 24 months postoperatively, patients provided responses for the OHS and for 3 anchor questions about whether they had experienced changes in hip pain and function, whether they considered their symptom state to be satisfactory, and if it was not satisfactory, whether they considered the treatment to have failed. The anchor-based adjusted predictive modeling method was used to determine interpretation threshold values. Baseline dependency was evaluated using a new item-split method. Nonparametric bootstrapping was used to determine 95% confidence intervals (CIs)., Results: Complete data were obtained for 706 (69%) of 1,027 and 728 (66%) of 1,101 patients at 12 and 24 months postoperatively, respectively. These patients had a median age of 70 years, and 55% to 56% were female. Adjusted OHS MIC values were 6.3 (CI, 4.6 to 8.1) and 5.2 (CI, 3.6 to 6.7), adjusted OHS PASS values were 30.6 (CI, 29.0 to 32.2) and 30.5 (CI, 29.3 to 31.8), and adjusted OHS TF values were 25.5 (CI, 22.9 to 27.7) and 27.0 (CI, 25.2 to 28.8) at 12 and 24 months postoperatively, respectively. MIC values were 5.4 (CI, 2.1 to 9.1) and 5.0 (CI, 1.9 to 8.7) higher at 12 and 24 months, respectively, in patients with a more severe preoperative state., Conclusions: The established interpretation threshold values advance the interpretation and clinical use of the OHS, and may prove especially beneficial for registry-based evaluations of treatment quality., Level of Evidence: Prognostic Level IV . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H467 )., (Copyright © 2023 by The Journal of Bone and Joint Surgery, Incorporated.)

Music is increasingly being used as a therapeutic tool in the field of rehabilitation medicine and psychophysiology. One of the main key components of music is its temporal organization. The characteristics of neurocognitive processes during music perception of meter in different tempo variations technique have been studied by using the event-related potentials technique. The study involved 20 volunteers (6 men, the median age of the participants was 23  years). The participants were asked to listen to 4 experimental series that differed in tempo (fast vs. slow) and meter (duple vs. triple). Each series consisted of 625 audio stimuli, 85% of which were organized with a standard metric structure (standard stimulus) while 15% included unexpected accents (deviant stimulus). The results revealed that the type of metric structure influences the detection of the change in stimuli. The analysis showed that the N200 wave occurred significantly faster for stimuli with duple meter and fast tempo and was the slowest for stimuli with triple meter and fast pace., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Radchenko, Demareva, Gromov, Zayceva, Rulev, Zhukova and Demarev.)

Pain after total knee arthroplasty (TKA) is a well-known clinical problem potentially delaying ambulation and recovery. Perioperative glucocorticoids reduce pain and facilitate early recovery, but the optimal timing and dose are still unknown. High pain catastrophizers have an increased risk of poorly controlled postoperative pain, and moderate to severe pain at 24 h is associated with a risk of pain relapse at 48 h. To evaluate the effect of a repeat moderate dose of glucocorticoids after TKA in high pain catastrophizers presenting with moderate to severe pain 24 h postoperatively, having received preoperative high-dose glucocorticoids. High pain catastrophizers (Pain Catastrophizing Scale > 20) undergoing TKA are screened 24 h postoperatively and are included if they experience moderate to severe pain (VAS > 30) during a 5 m walk test. The included patients will receive either oral 24 mg dexamethasone (n = 55) or placebo (n = 55) on the evening of Day 1 (~30-37 h) after surgery. In addition, patients receive a standard multimodal analgesic regimen, including paracetamol, celecoxib, local infiltration analgesia, and preoperative dexamethasone (1 mg/kg). Patients will fill out a pain diary for 7 days after surgery. The primary outcome is moderate to severe pain (VAS > 30) during a 5 m walk test on the morning of Day 2 after surgery. The secondary outcomes include cumulated pain at rest and during ambulation, cumulated use of rescue analgesics, quality of sleep, lethargy, dizziness, nausea, satisfaction with the analgesic regimen, length of stay, morbidity, mortality, and reasons for readmissions. Follow-up is at 8 and 30 days. The data from this study will provide evidence for the effect of a repeated dose of dexamethasone as an analgesic adjuvant in patients undergoing TKA with a high risk of postoperative pain., (© 2023 Acta Anaesthesiologica Scandinavica Foundation.)

Background and Purpose: No previous studies have investigated the use of day-case arthroplasty in Denmark on a national scale. We investigated the frequency of day-case surgery in total hip (THA), total knee (TKA), and unicompartmental knee arthroplasty (UKA) from 2010 to 2020 in Denmark., Patients and Methods: Primary unilateral THAs, TKAs, and UKAs performed for osteoarthritis were identified in the Danish National Patient Register using procedural and diagnosis codes. Day-case surgery was defined as discharge on the day of surgery. 90-day readmissions were defined as any overnight admissions following discharge., Results: From 2010 to 2020 Danish surgical centers performed 86,070 THAs, 70,323 TKAs, and 10,440 UKAs. From 2010 to 2014, less than 0.5% of THAs and TKAs were day-case procedures. They increased to 5.4% (95% confidence interval [CI] 4.9-5.8) of THAs and 2.8% (CI 2.4-3.2) of TKAs in 2019. From 2010 to 2014, 11% of UKAs were day-case procedures, but they increased to 20% (CI 18-22) in 2019. This increase was driven by a few surgical centers (3-7 centers). In 2010, readmission rates within 90 days of surgery were 10% after THAs and 11% after TKAs, and 9.4% for both THAs and TKAs in 2019. Readmission rates after UKA fluctuated between 4% and 7%., Conclusion: From 2010 to 2020 the use of day-case surgery in THA, TKA, and UKA increased in Denmark, driven by only a few centers. During the same period readmissions did not increase.

Background and Purpose: Limited data exists on the implementation process and safety of discharge on the day of surgery after primary hip and knee arthroplasty in a multicenter setting. We report our study protocol on the investigation of the feasibility, safety, and socioeconomic aspects following discharge on day of surgery after hip and knee arthroplasty across 8 fast-track centers., Patients and Methods: This is a study protocol for a prospective cohort study on discharge on day of surgery from the Center for Fast-track Hip and Knee Replacement. The collaboration includes 8 centers covering 40% of the primary hip and knee arthroplasty procedures undertaken in Denmark. All patients scheduled for surgery are screened for eligibility using well-defined inclusion and exclusion criteria. Eligible patients fulfilling discharge criteria will be discharged on day of surgery. We expect to screen 9,000 patients annually. Duration and outcome: Patients will be enrolled over a 3-year period from September 2022 and reporting of results will run continuously until December 2025. We shall report the proportion of eligible patients and patients discharged on day of surgery as well as limiting factors. Readmissions and complications within 30 days are recorded with real-time follow-up by research staff. Furthermore, patient-reported information on willingness to repeat discharge on day of surgery, contacts with the healthcare system, complications, and workability is registered 30 days postoperatively. EQ-5D, Oxford Knee Score, and Oxford Hip Score are completed preoperatively and after 3 months and 1 year. Finally, outcome data will be used in the development of a prediction model for successful discharge on the day of surgery.

Objectives: Osteoarthritis is a common and severe, multifactorial disease with a well-established genetic component. However, little is known about how genetics affect disease progression, and thereby the need for joint placement. Therefore, we aimed to investigate whether the genetic associations of knee and hip osteoarthritis differ between patients treated with joint replacement and patients without joint replacement., Methods: We included knee and hip osteoarthritis cases along with healthy controls, altogether counting >700 000 individuals. The cases were divided into two groups based on joint replacement status (surgical vs non-surgical) and included in four genome-wide association meta-analyses: surgical knee osteoarthritis (N = 22 525), non-surgical knee osteoarthritis (N = 38 626), surgical hip osteoarthritis (N = 20 221) and non-surgical hip osteoarthritis (N = 17 847). In addition, we tested for genetic correlation between the osteoarthritis groups and the pain phenotypes intervertebral disc disorder, dorsalgia, fibromyalgia, migraine and joint pain., Results: We identified 52 sequence variants associated with knee osteoarthritis (surgical: 17, non-surgical: 3) or hip osteoarthritis (surgical: 34, non-surgical: 1). For the surgical phenotypes, we identified 10 novel variants, including genes involved in autophagy (rs2447606 in ATG7 ) and mechanotransduction (rs202127176 in PIEZO1 ). One variant, rs13107325 in SLC39A8 , associated more strongly with non-surgical knee osteoarthritis than surgical knee osteoarthritis. For all other variants, significance and effect sizes were higher for the surgical phenotypes. In contrast, genetic correlations with pain phenotypes tended to be stronger in the non-surgical groups., Conclusions: Our results indicate differences in genetic associations between knee and hip osteoarthritis depending on joint replacement status., Competing Interests: Competing interests: The authors US, GT, LS, GB, TET and KS are employed by deCODE genetics/Amgen Inc., (© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)

Aim: To investigate the effect of femoral head size on blood metal-ion levels caused by taper corrosion in metal-on-polyethylene total hip arthroplasty, comparing 36- to 44-mm heads with 32-mm heads., Methods: In a randomised, controlled, single-blinded trial, 96 patients were allocated to receive either a 32-mm metal head or the largest possible metal head (36-44 mm) that could be accommodated in the thinnest available vitamin E, cross-linked polyethylene insert. Blood metal ion levels were collected at 1- and 2-year follow-ups., Results: At 1-year, metal-ion levels did not differ between the groups. The median (interquartile range) blood-ion levels for the 32-mm versus the 36- to 44-mm group were 0.11 µg/L (0.08-0.15) versus 0.12 µg/L (0.08-0.22), p  = 0.546, for cobalt, 0.50 µg/L (0.50-0.59) versus 0.50 µg/L (0.50-1.20), p  = 0.059, for chromium and 1.58 µg/L (1.38-2.05) versus 1.48 µg/L (1.14-1.87), p  = 0.385, for titanium. At 2 years, there was no difference either and the corresponding values were 0.15 µg/L (0.12-0.24) versus 0.18 µg/L (0.12-0.28), p  = 0.682 for cobalt, 0.50 µg/L (0.50-0.50) versus 0.50 µg/L (0.50-0.57), p  = 0.554, for chromium and 1.54 µg/L (1.16-1.87) versus 1.42 µg/L (1.01-1.72), p  = 0.207 for titanium., Conclusions: The use of the largest possible metal head (36-44 mm) compared to a 32-mm head in metal-on-polyethylene bearings does not appear to elevate blood metal-ion levels up to 2 years postoperatively. As taper corrosion is probably time-dependent, longer-term reports are needed to evaluate the association between large metal heads and blood metal ion levels.Trial registration: ClinicalTrials.gov (reg. ID NCT0231 6704).

Background: Postoperative pain after total knee arthroplasty (TKA) is a continuing problem despite optimised multimodal analgesia. Previous studies have shown preoperative glucocorticoids to reduce postoperative pain, but knowledge about specific doses and effects in specific patient groups is lacking., Methods: A two-centre, double-blind, two-arm study comparing preoperative dexamethasone (1 mg kg -1 vs 0.3 mg kg -1 i.v.) on postoperative pain in 160 planned TKA subjects with low preoperative pain catastrophising and no opioid use. Subjects received multimodal analgesia with paracetamol, cyclooxygenase-2 inhibitors, local anaesthetic infiltration analgesia, and rescue opioids. The primary outcome was percentage of subjects experiencing moderate to severe pain (visual analogue scale >30 mm) upon ambulation at 24 h. Secondary outcomes included pain scores, postoperative inflammation (C-reactive protein), opioid and antiemetics use, and 'Quality of Recovery-15' and 'Opioid-Related Symptom Distress Scale', length of stay, readmissions, and complications up to Day 90., Results: A total of 157 subjects (80 vs 77) were included. No difference was found between groups in the incidence of subjects experiencing visual analogue scale >30 on ambulation 24 h after surgery (56% vs 53%, relative risk =1.07, confidence interval: 0.8-1.4, P=0.65). No differences in other pain outcomes or use of rescue opioids and antiemetics, in Quality of Recovery-15 and Opioid-Related Symptom Distress Scale, length of stay, readmissions, or complications. C-reactive protein values were comparable at 24 h (13 [6-25] mg L -1 vs 16 [9-38] mg L -1 , P = 0.07), but lower at 48 h (26 [9-52] mg L -1 vs 50 [30-72] mg L -1 , P<0.01) in the high-dose group., Conclusion: Use of 1 mg kg -1 vs 0.3 mg kg -1 i.v. dexamethasone in low pain responders after TKA did not improve early postoperative pain or other outcomes in contrast to benefits in a high pain responder population., Clinical Trial Registration: NCT03758170 (first registration 29-11-2018)., (Copyright © 2022 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: In this study, we examined the association between obesity and patient-reported outcome measures after medial unicompartmental knee arthroplasty (MUKA), assessed through score changes, Patient Acceptable Symptom State (PASS), and minimal important change (MIC). Second, the association between obesity and early readmissions was examined., Methods: A total of 450 MUKAs (mean body mass index [BMI] 30.3, range, 19.6-53.1), performed from February 2016 to December 2020, were grouped using BMI: <30, 30-34.9, and >34.9. Oxford Knee Score (OKS), Forgotten Joint Score (FJS), and Activity and Participation Questionnaire (APQ) were assessed preoperatively and at 3, 12, and 24 months, postoperatively. The 12-month PASS and MIC were also assessed, defining PASS as OKS = 30, MIC-OKS as change in OKS = 8, and MIC-FJS as change in FJS = 14., Results: No significant differences in OKS change were found between BMI groups. After 12 months, patients who had a BMI of 30-34.9 had lower change in FJS (estimate -8.1, 95% CI -14.9 to -1.4) and were less likely to reach PASS (odds ratio 0.4, 95% CI 0.2-0.7) as well as MIC-FJS (odds ratio 0.5, 95% CI 0.2-0.9). Both obese groups had lower change in APQ after 12 months. Differences in 90-day readmission rates were nonsignificant between groups., Conclusion: Our findings of no differences in OKS improvement between BMI groups and achieving MIC for BMI > 34.9 suggest good improvements in obese patients despite lower preoperative scores, supporting contemporary indications for MUKA. Lower APQ development and achievement of 12-month PASS may be used when addressing expectations of recovery., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Peripheral nerve blocks (PNB) have recently been recommended in total hip (THA) and knee (TKA) arthroplasty as they may reduce pain, morphine consumption, length of stay (LOS) and complications. However, whether PNBs are associated with early discharge within an enhanced recovery protocol including multimodal analgesia is uncertain., Methods: An observational multicenter study from January to August 2017 in six Danish Arthroplasty Centers with established fast-track protocols. Prospective recording of preoperative characteristics and information on PNB, LOS and readmissions through the Danish National Patient Registry and medical records. Multiple logistic regression was used to investigate associations between PNB and a LOS >1 day, LOS >4 days, and 30-days readmissions. We also reported on mobilization, pain, opioid and fall-related complications leading to LOS >4 days or readmissions., Results: A total of 2027 (58.6%) THA and 1432 (41.4%) TKAs with a median LOS of 1 day (IQR 1-2) and 5.3% (CI:4.6-6.1) 30-days readmission rate were identified. PNB was used in 40.7% (CI:38.2-43.3) of TKA and 2.7% (CI:2.0-3.5) of THA, but with considerable interdepartmental variation (0.0-89.0% for TKA). There was no association between PNB and LOS >1 day (OR:1.19 CI:0.82-1.72; p = .354), LOS >4 days (OR:1.4 CI:0.68-2.89; p = .359) or 30-days readmissions (OR:1.02 CI:0.63-1.65; p = .935) in TKA. Logistic regression in THA was not possible due to limited use of PNB. In TKA there were 12 (2.1% CI:1.2-3.6) with and 1 (0.1% CI:0.02-0.7) without a PNB, who had mobilization, pain or opioid-related complications, and 5 (0.9% CI:0.4-2.0) versus 4 (0.5% CI:0.2-1.2) who fell. Correspondingly, 2 (3.7% CI:1.0-12.6) and 11 (0.6% CI:0.3-1.0) of THA patients had these complications, while 0 (0.0% CI:0.0-6.6) and 17 (0.8% CI:0.5-1.3) fell., Conclusion: Routine use of peripheral nerve blocks was not associated with early discharge or 30-days readmissions in fast-track THA and TKA. Future studies should focus on benefits of PNB in high-risk patients., (© 2022 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.)

Background: Early postoperative mobilization can be hindered by orthostatic intolerance (OI) due to failed orthostatic cardiovascular regulation. The underlying mechanisms are not fully understood and specific data after total knee arthroplasty (TKA) are lacking. Therefore, we evaluated the incidence of OI and the cardiovascular response to mobilization in fast-track TKA., Methods: This prospective observational cohort study included 45 patients scheduled for primary TKA in spinal anesthesia with a multimodal opioid-sparing analgesic regime. OI and the cardiovascular response to sitting and standing were evaluated with a standardized mobilization procedure preoperatively, and at 6 and 24 h postoperatively. Hemodynamic variables were measured non-invasively (LiDCO™ Rapid). Perioperative bleeding, fluid balance, surgery duration, postoperative hemoglobin, opioid use, and pain during mobilization were recorded., Results: Eighteen (44%) and 8 (22%) patients demonstrated OI at 6 and 24 h after surgery, respectively. Four (10%) and 2 (5%) patients experienced severe OI and terminated the mobilization procedure prematurely. Dizziness was the most common OI symptom during mobilization at 6 h. OI was associated with decreased orthostatic responses in systolic, diastolic, mean arterial pressures, and heart rate (all p < .05), while severe OI patients demonstrated impaired diastolic, mean arterial pressures, heart rate, and cardiac output responses (all p < .05). No statistically significant differences in perioperative bleeding, fluid balance, surgery duration, postoperative hemoglobin, pain, or opioid use were observed between orthostatic tolerant and intolerant patients., Conclusion: Early postoperative OI is common following fast-track TKA. Pathophysiologic mechanisms include impaired orthostatic cardiovascular responses. The progression to severe OI symptoms appears to be primarily due to inadequate heart rate response., (© 2022 Acta Anaesthesiologica Scandinavica Foundation.)

Background and Purpose: Developing meaningful thresholds for the Oxford Knee Score (OKS) advances its clinical use. We determined the minimal important change (MIC), patient acceptable symptom state (PASS), and treatment failure (TF) values as meaningful thresholds for the OKS at 3-, 12-, and 24-month follow-up in patients undergoing unicompartmental knee arthroplasty (UKA)., Patients and Methods: This is a cohort study with data from patients undergoing UKA collected at a hospital in Denmark between February 2016 and September 2021. The OKS was completed preoperatively and at 3, 12, and 24 months postoperatively. Interpretation threshold values were calculated with the anchor-based adjusted predictive modeling method. Non-parametric bootstrapping was used to derive 95% confidence intervals (CI)., Results: Complete 3-, 12-, and 24-month postoperative data was obtained for 331 of 423 (78%), 340 of 479 (71%), and 235 of 338 (70%) patients, median age of 68-69 years (58-59% females). Adjusted OKS MIC values were 4.7 (CI 3.3-6.0), 7.1 (CI 5.2-8.6), and 5.4 (CI 3.4- 7.3), adjusted OKS PASS values were 28.9 (CI 27.6-30.3), 32.7 (CI 31.5-33.9), and 31.3 (CI 29.1-33.3), and adjusted OKS TF values were 24.4 (CI 20.7-27.4), 29.3 (CI 27.3-31.1), and 28.5 (CI 26.0-30.5) at 3, 12, and 24 months postoperatively, respectively. All values statistically significantly increased from 3 to 12 months but not from 12 to 24 months., Interpretation: The UKA-specific measurement properties and clinical thresholds for the OKS can improve the interpretation of UKA outcome and assist quality assessment in institutional and national registries.

Background: Patients undergoing lower limb arthroplasty who are severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive at the time of surgery have a high risk of mortality. The National Institute for Health and Clinical Care Excellence and the British Orthopaedic Association advise self-isolation for 14 days preoperatively in patients at a high risk of adverse outcomes due to COVID-19. The aim of the study is to assess whether preoperative polymerase chain reaction (PCR) for SARS-CoV-2 could be performed at between 48 and 72 hours preoperatively with specific advice about minimizing the risk of SARS-CoV-2 restricted to between PCR and admission., Methods: A multicentre, international, observational cohort study of 1,000 lower limb arthroplasty cases was performed. The dual primary outcomes were 30-day conversion to SARS-CoV-2 positive and 30-day SARS-CoV-2 mortality. Secondary outcomes included 30-day SARS-CoV-2 morbidity., Results: Of the 1,000 cases, 935 (94%) had a PCR between 48 and 72 hours preoperatively. All cases were admitted to and had surgery through a COVID-free pathway. Primary knee arthroplasty was performed in 41% of cases, primary hip arthroplasty in 40%, revision knee arthroplasty in 11%, and revision hip arthroplasty in 9%. Six percent of operations were emergency operations. No cases of SARS-CoV-2 were identified within the first 30 days., Conclusion: Preoperative SARS-CoV-2 PCR test between 48 and 72 hours preoperatively with advice about minimizing the risk of SARS-CoV-2 restricted to between PCR and admission in conjunction with a COVID-free pathway is safe for patients undergoing primary and revision hip and knee arthroplasty. Preoperative SARS-CoV-2 PCR test alone may be safe but further adequately powered studies are required. This information is important for shared decision making with patients during the current pandemic., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Background and Purpose: Despite increased attention to and acceptance of fast-track procedures, there is a lack of studies concerning discharge on the day of surgery (DOS) following total knee arthroplasty (SD-TKA). We evaluated the feasibility of SD-TKA, and compared safety and patient-reported outcomes (PROs) between patients undergoing SD-TKA and patients undergoing standard TKA., Patients and Methods: A SD-TKA group (n = 101) was matched 1:1 to a standard TKA group (n = 101) on age, sex, and ASA score. Feasibility (being discharged on DOS), safety (unplanned contacts and complications evaluated by telephone calls (2 weeks), outpatient visits (2 weeks), and readmission (90 days)) were assessed. Further, Oxford Knee Score (OKS) and Visual Analogue Scale (VAS) (pain at rest and activity) were reported (90 days)., Results: 89 of 101 SD-TKA patients were discharged on DOS. The number of telephone calls (≤ 83) and outpatient visits (12) were similar in the 2 groups. The number of readmissions was ≤ 3 in both groups, and only 1 of the readmissions was related to TKA surgery. No differences were found at 90-day follow-up in terms of OKS (34 in both groups) or VAS (rest: SD-TKA = 7 and standard TKA = 8; activity: SD-TKA = 17 and standard TKA = 15)., Interpretation: SD-TKA is feasible in a selected group of patients, and safety and PROs are comparable to patients undergoing standard TKA.

Introduction: The coronavirus outbreak causes postponement of elective surgery. We evaluated how pain, function and general health were impacted by postponing elective knee and hip arthroplasty in patients with knee and hip osteoarthritis with no known surgery rescheduling date due to the coronavirus outbreak., Methods: This study included 194 patients from a Danish public hospital with postponed elective primary knee or hip arthroplasty due to the lockdown. Patients responded to questionnaires when their surgery was cancelled and before surgery. Changes in pain and function were evaluated with the Oxford Knee and Hip Scores (OKS, OHS) and their general health with the EuroQol 5-dimension scale (EQ5D). Additionally, we asked about the patients' concerns and whether they felt improved, unchanged or deteriorated during the waiting period., Results: Complete data were obtained for 110 (57%) patients, 59 and 51 awaiting knee or hip arthroplasty (median age 71 years, 62% were female), respectively. Arthroplasty was postponed for a median (range) 98 (63-161) days. A total of 34% were concerned that the postponement would lead to a poorer outcome. Mean OKS and OHS differences were 0 (95% confidence interval (CI): -1-1) and -1 (95% CI: -2-0) from surgery cancellation to re-scheduled surgery. The mean EQ5D index difference was 0.0 (95% CI: 0.0-0.1) for both groups. A total of 75 (68%) patients felt an important deterioration of their condition., Conclusions: Pre-operatively, patients worried about experiencing an altered treatment outcome due to postponed surgery and felt that their condition had deteriorated during the waiting period although this was not reflected in patient-reported outcome measures., Funding: Department of Orthopaedic Surgery., Trial Registration: not relevant., (Articles published in the DMJ are “open access”. This means that the articles are distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits any non-commercial use, distribution, and reproduction in any medium, provided the original author(s) and source are credited.)

Aims: Treatment of end-stage anteromedial osteoarthritis (AMOA) of the knee is commonly approached using one of two surgical strategies: medial unicompartmental knee arthroplasty (UKA) or total knee arthroplasty (TKA). In this study we aim to investigate if there is any difference in outcome for patients undergoing UKA or TKA, when treated by high-volume surgeons, in high-volume centres, using two different clinical guidelines. The two strategies are 'UKA whenever possible' vs TKA for all patients with AMOA., Methods: A total of 501 consecutive AMOA patients (301 UKA) operated on between 2013 to 2016 in two high-volume centres were included. Centre One employed clinical guidelines for the treatment of AMOA allowing either UKA or TKA, but encouraged UKA wherever possible. Centre Two used clinical guidelines that treated all patients with a TKA, regardless of wear pattern. TKA patients were included if they had isolated AMOA on preoperative radiographs. Data were collected from both centres' local databases. The primary outcome measure was change in Oxford Knee Score (OKS), and the proportion of patients achieving the patient-acceptable symptom state (PASS) at one-year follow-up. The data were 1:1 propensity score matched before regression models were used to investigate potential differences., Results: The matched cohort included 400 patients (mean age 67 years (SD 9.55), 213 (53%) female, mean BMI 30.2 kg/m 2 , 337 (84%) American Society of Anesthesiologists grade ≤ 2). We found a mean adjusted difference in change score of 3.02 points (95% confidence interval (CI) 1.41 to 4.63; p < 0.001) and a significantly larger likeliness of achieving PASS (odds ratio 3.67 (95% CI 1.73 to 8.45); p = 0.001) both in favour of the UKA strategy., Conclusion: UKA and TKA are both good strategies for treating end-stage AMOA. However, when compared as a strategy, UKA achieved larger improvements in OKS, and were more likely to reach the PASS value at one-year follow-up. Cite this article: Bone Jt Open  2022;3(5):441-447.

Background and Purpose: Unicompartmental knee arthroplasty (UKA) has increased in use. We investigated changes to UKA revision risk over the last 20 years compared with total knee arthroplasty (TKA), examined external and patient factors for correlation to UKA revision risk, and described the survival probability for current UKA and TKA practice., Patients and Methods: All knee arthroplasties reported to the Danish Knee Arthroplasty Register from 1997 to 2017 were linked to the National Patient Register and the Civil Registration System for comorbidity, emigration, and mortality information. All primary UKA and TKA patients with primary osteoarthritis were included and propensity score matched 4 TKAs to 1 UKA. Revision and mortality were analyzed using competing risk cox regression with a shared gamma frailty component., Results: The matched cohort included 48,195 primary knee arthroplasties (9,639 UKAs). From 1997-2001 to 2012-2017 the 3-year hazard ratio decreased from 5.5 (95% CI 2.7-11) to 1.5 (CI 1.2-1.8) due to increased UKA survival. Cementless fixation, a high percentage usage of UKA, and increased surgical volume decreased UKA revision risk, and increased in occurrence parallel to the decreasing revision risks. Current UKA practice using cementless fixation at a high usage unit has a 3-year implant survival of 96% (CI 97-95), 1.1% lower than current TKA practice., Interpretation: UKA revision risk has decreased over the last 20 years, nearing that of TKA surgery. High usage rates, surgical volume, and the use of cementless fixation have increased during the study and were associated with decreased UKA revision risks.

Background and Purpose: Data on application of fasttrack/enhanced recovery protocols in revision hip arthroplasty (R-THA) surgery is scarce. We report length of stay (LOS), risk of LOS > 5 days, and readmission ≤ 90 days after revision hip arthroplasty in centers with a well-established fast-track protocol in both primary and revision procedures., Patients and Methods: This is an observational cohort study from the Centre for Fast-track Hip and Knee Replacement and the Danish Hip Arthroplasty Register. Consecutive elective aseptic major component revision hip arthroplasties from 6 dedicated fast-track centers from 2010 to 2018 were included., Results: 1,345 R-THAs were analyzed, including 23% total revisions, 52% acetabular component revisions, and 25% femoral component revisions. Mean age was 70 years (SD 12) and 61% were female. Median LOS was 3 days (interquartile range [IQR] 2-6), decreasing from median 6 (IQR 3-10) days in 2010 to 2 (IQR 1-4) days in 2018. The 90-day readmission rate was 20%, but showed a fluctuating and increasing trend from 13% in 2010 to 28% in 2018. Risk factors for LOS > 5 days and readmission were use of walking aid, preoperative hemoglobin ≤ 13 g/dL, pharmacological treated psychiatric disorder, age ≥ 80 years, age 70-79 years (only LOS > 5 days), cardiac disease (only LOS > 5 days), pulmonary disease (only readmission), BMI ≥ 35 (only LOS > 5 days) and ≥ 1 previous revision (only LOS > 5 days)., Interpretation: LOS decreased to median 2 days at the end of the study period, but the 90 days readmission risk remained high (> 20%). Several risk factors for postoperative complications were identified, suggesting that at-risk patients should be treated using an extended fast-track/enhanced recovery protocol focusing on preoperative optimization and postoperative monitoring as well as surgical techniques to reduce hip dislocations.

Background: Total knee arthroplasty (TKA) is associated with moderate-to-severe postoperative pain despite multimodal opioid-sparing analgesia. Pain catastrophising or preoperative opioid therapy is associated with increased postoperative pain. Preoperative glucocorticoid improves pain after TKA, but dose-finding studies and benefit in high pain responders are lacking., Methods: A randomised double-blind controlled trial with preoperative high-dose intravenous dexamethasone 1 mg kg -1 or intermediate-dose dexamethasone 0.3 mg kg -1 in 88 patients undergoing TKA with preoperative pain catastrophising score >20 or regular opioid use was designed. The primary outcome was the proportion of patients experiencing moderate-to-severe pain (VAS >30) during a 5 m walk 24 h postoperatively. Secondary outcomes included pain at rest during nights and at passive leg raise, C-reactive protein, opioid use, quality of sleep, Quality of Recovery-15 and Opioid-Related Symptom Distress Scale, readmission, and complications., Results: Moderate-to-severe pain when walking 24 h postoperatively was reduced (high dose vs intermediate dose, 49% vs 79%; P<0.01), along with pain at leg raise at 24 and 48 h (14% vs 29%, P=0.02 and 12% vs 31%, P=0.03, respectively). C-reactive protein was reduced in the high-dose group at both 24 and 48 h (both P<0.01). Quality of Recovery-15 was also improved (P<0.01)., Conclusions: When compared with preoperative dexamethasone 0.3 mg kg -1 i.v., dexamethasone 1 mg kg -1 reduced moderate-to-severe pain 24 h after TKA and improved recovery in high pain responders without apparent side-effects., Clinical Trial Registration: NCT03763734., (Copyright © 2021 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Limited data exist on fast-track protocols in relation to revision knee arthroplasty. Hence, the aim of this study was to report length of stay (LOS), risk of LOS > 5 days and readmission ≤ 90 days after revision knee arthroplasty in centers with a well-established fast-track protocol in both primary and revision surgery., Methods: An observational cohort study from the Centre for Fast-track Hip and Knee Replacement and the Danish Knee Arthroplasty Register. We included elective aseptic major component revision knee arthroplasties consecutively from 6 dedicated fast-track centers from 2010 to 2018., Results: 1439 revision knee arthroplasties were analyzed, including 900 total revisions, 171 large partial revisions (revision of either femoral or tibia component) and 368 revisions of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA). Mean age was 65 years (SD 10.9) and 66% were females. Mean LOS was 3.7 days (SD 3.9) in the study period, but decreased to 2.4 days (SD 1.3) in 2018. Risk factors for LOS > 5 days was ≥ 1 previous revision, use of walking aid, BMI > 35, ages < 50, 70-79 and ≥ 80 years, whereas revision of UKA to TKA and large partial revision were negatively associated. The 90-day readmission and mortality risk was 9.1% and 0.5%. Cardiac disease and use of walking aid were associated with increased risk of readmission ≤ 90 days., Conclusion: Elective aseptic major component revision knee arthroplasty using similar fast-track protocols as in primary TKA is safe with short and decreasing LOS., 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 © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)