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Background: There is increasing appreciation of the distinction between gender and sex as well as the importance of accurately reporting these constructs. Given recent attention regarding transgender and gender nonconforming (TGNC) and intersex identities, it is more necessary than ever to understand how to describe these identities in research. This study sought to investigate the use of gender- and sex-based terminology in arthroplasty research., Methods: The 5 leading orthopaedic journals publishing arthroplasty research were reviewed to identify the first twenty primary clinical research articles on an arthroplasty topic published after January 1, 2022. Use of gender- or sex-based terminology, whether use was discriminate, and whether stratification or adjustment based on gender or sex was performed, were recorded., Results: There were 98 of 100 articles that measured a construct of gender or sex. Of these, 15 articles used gender-based terminology, 45 used sex-based terminology, and 38 used a combination of gender- and sex-based terminology. Of the 38 articles using a combination of terminology, none did so discriminately. All articles presented gender and sex as binary variables, and 2 attempted to explicitly define how gender or sex were defined. Of the 98 articles, 31 used these variables for statistical adjustments, though only 6 reported stratified results., Conclusions: Arthroplasty articles infrequently describe how gender or sex was measured, and frequently use this terminology interchangeably. Additionally, these articles rarely offer more than 2 options for capturing variation in sex and gender. Future research should be more precise in the treatment of these variables to improve the quality of results and ensure findings are patient-centered and inclusive., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Stiffness remains a common complication after primary total knee arthroplasty (TKA). Manipulation under anesthesia (MUA) is the gold standard treatment for early postoperative stiffness; however, there remains a paucity of data on the risk of MUA after primary TKA if a prior contralateral TKA required MUA., Methods: We performed a retrospective review of 3,102 patients who had staged primary TKAs between 2016 and 2021. The mean body mass index was 33 (range, 18 to 59) and the mean age was 67 years (range, 24 to 91). The mean preoperative range of motion for the first TKA was 2 to 104°, and for the contralateral TKA was 1 to 107°. The primary outcomes were MUA following first and second primary TKAs. Multivariable Poisson regressions were used to evaluate associations between risk factors and outcomes., Results: The rate of MUA after the first TKA was 2.6% (n = 83 of 3,102) and 1.3% (n = 40 of 3,102) after the contralateral TKA. After adjustment, there was a nearly 14-fold higher rate of MUA after the second TKA if the patient had an MUA after the first TKA (relative risk, 13.80; 95% CI [confidence interval], 7.14 to 26.66). For the first TKA, increasing age (adjusted risk ratio [ARR], 0.65; 95% CI, 0.50 to 0.83) and increasing body mass index (ARR, 0.65; 95% CI, 0.47 to 0.90) were associated with lower risk for MUA. For the second TKA, increasing age was associated with a lower risk of MUA (ARR, 0.60; 95% CI, 0.45 to 0.80)., Conclusions: For patients undergoing staged bilateral TKA, patients who undergo MUA following the first primary TKA are nearly 14-fold more likely to undergo an MUA following the contralateral primary TKA than those who did not have an MUA after their first TKA., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Although the risk of concomitant injury with anterior cruciate ligament (ACL) tears as a function of specific sports participation has been studied in adults, the topic has not been examined in pediatric and adolescent patients., Purpose/hypothesis: The purpose of the study was to determine if certain sports were associated with a higher risk of concomitant injuries in the setting of an ACL tear. It was hypothesized that the risk of concomitant injuries with ACL tears will differ by type of sport participation in the pediatric population., Study Design: Cross-sectional study; Level of evidence, 3., Methods: Patients ≤18 years old from 2 tertiary children's hospitals who had undergone primary ACL reconstruction between 2006 and 2018 were included. Sport at the time of injury, demographic factors, and injury pattern (medial meniscal [MM] tears, lateral meniscal [LM] tears, posterior cruciate ligament [PCL] tears, medial collateral ligament [MCL] tears, lateral collateral ligament [LCL] tears, and any concomitant injury) were identified., Results: A total of 855 patients with a mean age of 15.5 ± 1.7 years (range, 7-22 years) met the inclusion criteria. Of the included patients, 353 (41.3%) had an isolated ACL tear. A concomitant MM tear was identified in 27.6% of patients, LM tear in 42.9%, PCL injury in 0.4%, MCL injury in 3.0%, and LCL injury in 0.5%. There was no difference in the likelihood of concomitant MM injuries by sex (29.3% for male patients vs 26% for female patients; P = .31) or by sex within basketball (29.3% for male patients vs 25.6% for female patients; P = .96) or soccer (32.3% vs 26.3%; P = .06). Boys had higher proportions of LM injuries overall (51.7% for male patients vs 34.6% for female patients; P < .001) but not within the basketball subgroup (50.5% vs 40.0%; P = .86) or the soccer subgroup (59.7% vs 40.0%; P = .19). No statistically significant associations were found between patient age and specific ACL concomitant injury patterns. When stratifying by body mass index, it was found overweight and obese individuals constituted a greater proportion of LM (49.6% vs 39.1%; P = .01) but not MM (29.4% vs 25.5%; P = .28) injuries when compared to normal-weight patients. Using basketball as the comparison group, soccer and football injuries were 18% more likely to result in any concomitant injury, including concomitant MM, LM, PCL, MCL, and LCL injuries., Conclusion: In the pediatric population, soccer and football players were more likely to present with a concomitant injury in addition to ACL injury relative to basketball players. This study aids in understanding sport-associated ACL injury patterns and can help physicians with patient counseling and injury prevention., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: P.D.F. has received consulting fees from WishBone Medical and hospitality payments from Medical Device Business Services. A.G. has received education payments from Rock Medical Orthopedics. R.J.M. has received compensation for services other than consulting from Philips Electronics North America Corp. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2024.)

Injuries in pediatric and adolescent athletes continue to rise in the United States, with increases in year-round sports participation, earlier sport specialization, and inadequate access to neuromuscular training programs. In this setting, the use of magnetic resonance imaging (MRI) provides a critical diagnostic tool. This review article describes the utility of MRI in diagnosing common pediatric and adolescent sports injuries and presents imaging findings associated with these pathologies., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Congenital disorders of glycosylation type I (CDG-I) are a group of autosomal recessive genetic multisystem disorders that arise from defective glycoprotein biosynthesis. Although ocular abnormalities have been described in patients with CDG-I, few ocular abnormalities have been associated with ALG12-CDG (CDG-Ig), a rare subtype of CDG-I. We report a case of Duane syndrome, a congenital strabismus syndrome, in a 17-year-old young woman with ALG12-CDG., (Published by Elsevier Inc.)

Competing Interests: The author certifies that there are no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article related to the author or any immediate family members. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request.

Purpose: The purpose of this study was to investigate the effect of anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) fixation at low versus high flexion angles during anterior cruciate ligament reconstruction (ACLR) on rotation or translational knee stability., Methods: The inclusion criteria for this study were (1) cadaveric study, (2) cadaveric specimens underwent ACLR, (3) cadaveric specimen underwent ALLR or LET and (4) specimen preparation technique described the knee flexion angle at the time of ALLR or LET tensioning and fixation. A priori, 'low flexion' was defined as 0-30° and 'high flexion' was defined as 60-90° at graft fixation. Main outcomes of interest included internal rotation and anterior translation., Results: Data from 92 cadaveric knees (from 9 studies) were extracted and included in the meta-analysis. The mean pooled value for internal rotation was 10.1° (95% confidence interval [CI], 5.7-14.5°) for the low flexion group and 11.5° (95% CI, 7.4-15.7°) for the high flexion group (n.s.). The mean pooled value for anterior translation was 4.3 mm (95% CI, 0.5-8.1 mm) for the low flexion group and 3.0 mm (95% CI, 1.1-5.0 mm) for the high flexion group (n.s.)., Conclusion: This meta-analysis of existing biomechanical research found that the rotational and translational stability of the knee were not significantly different between scenarios in which ALLR or LET fixation was performed at low knee flexion angles (0-30°) versus high knee flexion angles (60-90°)., Level of Evidence: Level IV., Competing Interests: David A. Kolin: Editorial or Governing Boards: Associate Editor: Clinical Orthopedics and Related Research (CORR); Reveiwer: Journal of Bone & Joint Surgery (JBJS). Benton E. Heyworth: Allosource: Other financial or material support; Imagen Technologies, Inc.: Stock or stock Options; Pediatric Orthopaedic Society of North America: Board or committee member; Pediatric Research in Sports Medicine (PRISM): Board or committee member; Springer: Publishing royalties, financial or material support; Vericel: Other financial or material support. Peter D. Fabricant: Editorial or Governing Boards: Associate Editor: Clinical Orthopedics and Related Research (CORR); Consultant: BICMD, Inc.; Ownership Interest: OssoVR; HS2, LLC; HSS ASC Development Network, LLC; Joint Effort Administrative Services Organization, LLC. The remaining authors declare no conflict of interest., (© 2024 The Author(s). Journal of Experimental Orthopaedics published by John Wiley & Sons Ltd on behalf of European Society of Sports Traumatology, Knee Surgery and Arthroscopy.)

The incidence of late displacement among pediatric lateral condyle fractures has been described as 1.3-26%. However, prior studies are limited by small cohort sizes. The aim of this study was to determine the rate of late displacement and delayed union among lateral condyle fractures following immobilization in a large cohort and to establish additional radiographic criteria to help surgeons choose between immobilization and operative fixation for minimally displaced fractures. We performed a dual-center retrospective study of patients with lateral condyle fractures between 1999 and 2020. Patient demographics, injury mechanism, time to orthopedic presentation, duration of cast immobilization, and complications following casting were recorded. There were 290 patients with lateral condyle fractures included. The initial management in 61% of patients (178/290) was nonoperative, of which four had delayed displacement at follow-up and two developed delayed union requiring surgery (failure in 6/178, 3.4%). The mean displacement on the anteroposterior view was 1.3 ± 1.1 mm and the lateral view was 0.50 ± 1.0 mm in the nonoperative cohort. In the operative cohort, the mean displacement on AP was 6.6 ± 5.4 mm and the lateral view was 5.3 ± 4.1 mm. Our analysis found the rate of late displacement in patients treated with immobilization was lower than previously reported (2.5%; 4/178). The mean displacement on the lateral film in the cast immobilization cohort was 0.5 mm, suggesting that necessitating near anatomic alignment on the lateral film to consider nonoperative management may lead to a lower incidence of late displacement than previously reported. Level of evidence: Level III, retrospective comparative study., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Anterolateral ligament reconstruction (ALLR) or lateral extra-articular tenodesis (LET) is being used more frequently in conjunction with anterior cruciate ligament reconstruction (ACLR). However, the knee flexion angle at which fixation of ALLR or LET is performed during the procedure is quite variable based on existing technique descriptions., Purpose/hypothesis: The purpose of this study was to identify whether flexion angle at the time of ALLR/LET fixation affected postoperative outcomes in a clinical population. It was hypothesized that ALLR/LET fixation at low versus high flexion angles would lead to no statistically significant differences in patient-reported outcome measures and graft failure rates., Study Design: Systematic review; Level of evidence, 4., Methods: The PubMed, Embase, and Cochrane Library databases were searched according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to identify published clinical studies of ACLR with ALLR/LET in which the knee flexion angle at the time of ALLR/LET was reported. A priori, low flexion was defined as 0° to 30°, and high flexion was defined as 60° to 90°. Studies were excluded if the flexion angle was between 31° and 59° because these angles constituted neither low nor high flexion angles and including them in an analysis of high versus low flexion angle at fixation would have biased the study results toward the null. The overall risk of bias was assessed using the Newcastle-Ottawa Scale. The pooled results of the studies were analyzed using the International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores, along with reported graft failure rates., Results: A total of 32 clinical studies (5230 patients) met inclusion criteria: 22 studies (1999 patients) in the low-flexion group and 10 studies (3231 patients) in the high-flexion group. The median Newcastle-Ottawa Scale score was 6. Comparisons of patients with a low flexion angle versus a high flexion angle demonstrated no differences in the IKDC ( P = .84), Lysholm ( P = .67), or Tegner ( P = .44) scores or in graft failure (3.4% vs 4.1%, respectively; P = .69)., Conclusion: The results of this review indicated that ACLR performed in conjunction with ALLR/LET provides good to excellent patient-reported outcomes and low graft failure rates when ALLR/LET fixation is performed in either low or high knee flexion., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: P.D.F. has received consulting fees from WishBone Medical and stock options from Osso. B.E.H. has received financial or material support from AlloSource, Springer, and Vericel; education payments from Arthrex; nonconsulting fees from Arthrex; royalties from Springer; and stock options from Imagen Technologies. Y.M.Y. has received consulting fees from Smith & Nephew. D.E.K. has received financial or material support from Arthrex and consulting fees from Johnson & Johnson and Miach. M.S.K. has received financial or material support from Elsevier and Wolters Kluwer Health; consulting fees from Best Doctors, OrthoPediatrics, Ossur, and Smith & Nephew; and royalties from OrthoPediatrics, Ossur, Elsevier, and Wolters Kluwer Health. A.T.P. has received consulting fees from OrthoPediatrics. J.J.N. has received research support from Smith & Nephew and Zimmer Biomet Holdings, consulting fees from Responsive Arthroscopy and Smith & Nephew, nonconsulting fees from Smith & Nephew, and royalties from Responsive Arthroscopy. S.C.W. has received consulting fees from Smith & Nephew. P.L.W. has received research support from AlloSource and Ossur, financial or material support from Elsevier, and royalties from Elsevier. M.M. has received royalties from Elizur. J.E.V. has received consulting fees from Arthrex. D.D.S. has received financial or material support from Elsevier, research support from OrthoPediatrics, and royalties from Elsevier. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2024.)

Competing Interests: The author certifies that there are no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article related to the author or any immediate family members. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request.

Aims: Blood transfusion and postoperative anaemia are complications of total knee arthroplasty (TKA) that are associated with substantial healthcare costs, morbidity, and mortality. There are few data from large datasets on the risk factors for these complications., Methods: We retrospectively reviewed the records of TKA patients from a single tertiary care institution from February 2016 to December 2020. There were a total of 14,901 patients in this cohort with a mean age of 67.9 years (SD 9.2), and 5,575 patients (37.4%) were male. Outcomes included perioperative blood transfusion and postoperative anaemia, defined a priori as haemoglobin level < 10 g/dl measured on the first day postoperatively. In order to establish a preoperative haemoglobin cutoff, we investigated a preoperative haemoglobin level that would limit transfusion likelihood to ≤ 1% (13 g/dl) and postoperative anaemia likelihood to 4.1%. Risk factors were assessed through multivariable Poisson regression modelling with robust error variance., Results: In multivariable analyses, each gram of tranexamic acid reduced transfusion likelihood by 39% (adjusted risk ratio (ARR) 0.61 (95% confidence interval (CI) 0.47 to 0.78)). Risk factors associated with an increased risk of transfusion included operating time (ARR 2.07 (95% CI 1.54 to 2.77)) and drain use (ARR 1.73 (95% CI 1.34 to 2.24))., Conclusion: In this study, we found that increased tranexamic acid dosing, decreased operating time, and decreased drain use may reduce transfusions following TKA. We also established a single preoperative haemoglobin cutoff of 13 g/dl that could help minimize transfusions and reduce postoperative complete blood counts., Competing Interests: M. P. Ast reports IP royalties from OrthAlign, consulting fees from BD, Bioventus, Conformis, OrthAlign, Smith & Nephew, and Surgical Care Affiliates, speaker payments from BD, Convatec, OrthAlign, Smith & Nephew, and Stryker, stock or stock options in ConveyMED, HS2, OrthAlign, Ospitek, Osso VR, and Parvizi Surgical Innovations, and research support from Smith & Nephew, all of which are unrelated to this study. M. P. Ast also reports committee membership, or editorial or governing board membership, on AAOS, AAHKS, Eastern Orthopaedic Association, Journal of Arthroplasty, and Journal of Orthopaedic Innovation and Experience. B. P. Chalmers is on the editorial or governing board of the HSS Journal. A. Gonzalez Della Valle reports IP royalties from Link Orthopaedics, OrthoDevelopment, and OrthoSensor, consulting fees from Johnson & Johnson, Link Orthopaedics, and Naviswiss, stock or stock options in Naviswiss and Wish Bone, research support from Naviswiss, all of which are unrelated to this study. A. Gonzalez Della Valle is also a board or committee member of the Hip Society. J. A. Rodriguez reports IP royalties and consulting fees from ConforMIS, Exatech, Medacta, and Smith & Nephew, stock or stock options in Tracpatch, and research support from DePuy, Exactech, and Smith & Nephew, all of which are unrelated to this study. J. A. Rodriguez is also a board or committee member of AAHKS and the Eastern Orthopaedic Association, and an editorial or governing board member of the Journal of Arthroplasty, Clinical Orthopaedics and Related Research, and the HSS Journal. P. K. Sculco reports consulting fees from Zimmer, Lima Corporate, Intellijoint Surgical, EOS Imaging, and DePuy, speaker payments from DePuy, EOS Imaging, and Intellijoint Surgical, research support from Intellijoint Surgical, and stock or stock options in Intellijoint Surgical and Parvizi Surgical Innovation, all of which are unrelated to this study., (© 2023 The British Editorial Society of Bone & Joint Surgery.)

Background: Idiopathic scoliosis (IS) is a common spinal abnormality, in which orthotic management can reduce progression to surgery. However, predictors of bracing success are still not fully understood. We studied a large patient population treated with the nighttime Providence orthosis, utilizing multivariable logistic regression to assess results and predict future spine surgery., Methods: We retrospectively reviewed patients with IS meeting Scoliosis Research Society inclusion and assessment criteria presenting from April 1994 to June 2020 at a single institution and treated with a Providence orthosis. A predictive logistic regression model was developed utilizing the following candidate features: age, sex, body mass index, Risser classification, Lenke classification, curve magnitude at brace initiation, percentage correction in a brace, and total months of brace use. Model performance was assessed using the area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity. The importance of individual features was assessed using the variable importance score., Results: There were 329 consecutive patients with IS with a mean age of 12.8 ± 1.4 years that met inclusion and assessment criteria. Of these, 113 patients (34%) ultimately required surgery. The model's area under the curve (AUC) was 0.72 on the testing set, demonstrating good discrimination. The initial curve magnitude (Importance score: 100.0) and duration of bracing (Importance score: 82.4) were the 2 most predictive features for curve progression leading to surgery. With respect to skeletal maturity, Risser 1 (Importance score: 53.9) had the most predictive importance for future surgery. For the curve pattern, Lenke 6 (Importance score: 52.0) had the most predictive importance for future surgery., Conclusion: Out of 329 patients with IS treated with a Providence nighttime orthosis, 34% required surgery. This is similar to the findings of the BrAist study of the Boston orthosis, in which 28% of monitored braced patients required surgery. In addition, we found that predictive logistic regression can evaluate the likelihood of future spine surgery in patients treated with the Providence orthosis. The severity of the initial curve magnitude and total months of bracing were the 2 most important variables when assessing the probability of future surgery. Surgeons can use this model to counsel families on the potential benefits of bracing and risk factors for curve progression., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: While transfusion and clinically relevant anemia after elective primary total knee arthroplasty (TKA) are uncommon, there remains a question of who needs postoperative hemoglobin monitoring, especially in the setting of increasing incidence of outpatient TKA. The purpose of this study was to create predictive models for postoperative anemia and blood transfusion to guide clinical decision-making., Methods: The records of consecutive TKA patients were reviewed from February 2016 to December 2020 at a single institution. Two multivariable logistic regression models, for postoperative anemia (hemoglobin < 10 g/dL) and allogeneic blood transfusion included 8 variables: age, sex, body mass index, preoperative hemoglobin level, tranexamic acid total dose, American Society of Anesthesiologists level, operative time, and drain use. Model performance was assessed using accuracy, area under the curve (AUC), sensitivity, and specificity., Results: The records of 14,901 patients were included in this study. Patients had a mean (± standard deviation) age of 67.9 ± 9.2 years and mean body mass index of 31.3 ± 6.5 kg/m 2 . The postoperative anemia model had an accuracy of 88% (95% confidence interval [CI], 87%-89%) and AUC of 0.88 (95% CI, 0.87-0.89). The blood transfusion model had an accuracy of 97% (95% CI, 96%-97%) and AUC of 0.90 (95% CI, 0.87-0.93)., Conclusion: The postoperative anemia and blood transfusion model accurately predicted each outcome. Patients with less than a 5% probability of postoperative anemia may not benefit from a complete blood count at postoperative day 1. Application of these criteria may save the healthcare system hundreds of millions of dollars., Level of Evidence: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Identifying genetic risk factors for spinal disorders may lead to knowledge regarding underlying molecular mechanisms and the development of new treatments., Methods: Cases of lumbar spondylolisthesis, spinal stenosis, degenerative disc disease, and pseudarthrosis after spinal fusion were identified from the UK Biobank. Controls were patients without the diagnosis. Whole-genome regressions were used to test for genetic variants potentially implicated in the occurrence of each phenotype. External validation was performed in FinnGen., Results: A total of 389,413 participants were identified from the UK Biobank. A locus on chromosome 2 spanning GFPT1, NFU1, AAK1, and LOC124906020 was implicated in lumbar spondylolisthesis. Two loci on chromosomes 2 and 12 spanning genes GFPT1, NFU1, and PDE3A were implicated in spinal stenosis. Three loci on chromosomes 6, 10, and 15 spanning genes CHST3, LOC102723493, and SMAD3 were implicated in degenerative disc disease. Finally, 2 novel loci on chromosomes 5 and 9, with the latter corresponding to the LOC105376270 gene, were implicated in pseudarthrosis. Some of these variants associated with spinal stenosis and degenerative disc disease were also replicated in FinnGen., Conclusions: This study revealed nucleotide variations in select genetic loci that were potentially implicated in 4 different spinal pathologies, providing potential insights into the pathological mechanisms., Level of Evidence: Prognostic Level III. 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/H454)., (Copyright © 2023 by The Journal of Bone and Joint Surgery, Incorporated.)

Introduction: There is a paucity of data on patient reported outcome measures (PROMs) associated with surgical treatment of osteochondritis dissecans (OCD). As a result, preoperative patient and family counseling regarding expected outcomes is difficult. The purpose of this study was to compare pre-to post-operative changes in PROMs amongst cohorts of patients with OCD that underwent one of three lesion-specific surgical treatments: 1) transarticular drilling for stable lesions, 2) drilling and fixation for unstable lesions 3) grafting for unsalvageable lesions., Methods: The electronic medical records of pediatric and adolescent patients with knee OCD, at a single institution between January 2017 and August 2019, were reviewed. Patients were categorized into one of three surgical groups, with initial determination confirmed at the time of surgery during diagnostic knee arthroscopy. Differences between groups were assessed with one-way analysis of variance (ANOVA)., Results: Of the 78 patients included in this study, 49 (62.8%) were male with a mean age of 13.5 ± 2.2 years. There was no significant difference between the surgical groups for baseline HSS Pedi-FABS (P = 0.58) or PROMIS Mobility (P = 0.47). There were no significant differences in PROMIS PI scores at baseline (P = 0.32), at latest follow-up (P = 0.72), or in interval change from baseline to follow-up (P = 0.42), between the three surgical groups., Conclusion: Lesion-specific surgical management of OCD led to similar improvements in PROMIS PI at a minimum of one-year follow-up. These results may better allow surgeons to reassure patients and families that outcomes are similar when lesions are treated through a lesion-specific algorithm., Level of Evidence: Level IV: Retrospective cohort study., Competing Interests: DWG: AAOS: Board or committee member. AO Trauma International: Paid presenter or speaker. Arthrex, Inc: IP royalties; Paid consultant; Paid presenter or speaker. Current Opinion in Pediatrics: Editorial or governing board; Publishing royalties, financial or material support New York County Medical Society: Board or committee member. New York state society of orthopedic surgeons: Board or committee member. PatelloFemoral Foundation: Board or committee member. Pediatric Orthopaedic Society of North America: Board or committee member. Pediatric Research in Sport Medicine: Board or committee member. Pega Medical: IP royalties. Wolters Kluwer Health - Lippincott Williams & Wilkins: Publishing royalties, financial or material support PDF: Clinical Orthopaedics and Related Research: Editorial or governing board. Osso VR: Stock or stock Options. WishBone Orthopedics: Paid consultant., (© 2023 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Background : When comparing functional outcomes of patients with unicompartmental knee arthroplasty (UKA) versus total knee arthroplasty (TKA), studies often report the UKA as the preferred procedure; however, recent improvements in the design of modern TKA implants have aimed at narrowing this gap. Purpose : We sought to compare the "feel" of modern TKA implants to that of UKA, using the Forgotten Joint Score (FJS), a validated patient-reported outcome measure. Methods : We performed a retrospective review of patients who underwent TKA and UKA at 2 institutions between 2014 and 2017. All UKA procedures were robotic arm-assisted with a single implant, "traditional TKAs" were performed using traditional posterior-stabilized implants, and "modern TKAs" were performed using posterior-stabilized implants with a modern design. Differences in FJS were assessed using 1-way analysis of variance and independent 2-sample t tests. Results : A total of 600 patients were included in our study, with 200 patients in each surgical subcategory. Mean age was 62.8 ± 10.2 years and mean body mass index was 29.9 ± 4.9. Modern TKA and UKA had similar FJS at 1 year. While modern TKA had a significantly higher FJS than traditional TKA, UKA did not have a significantly higher FJS than traditional TKA. Conclusion : Our retrospective analysis found no significant differences in the FJS of patients who underwent UKA and TKA with a modern design; however, both had superior scores than traditional TKA designs. This finding suggests that modern TKA designs may have the potential to achieve the natural feeling that is typically associated with joint-conserving surgeries such as UKA, although longer follow-up is necessary., Competing Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Michael P. Ast, MD, reports relationships with Smith and Nephew and Orthalign. David J. Mayman, MD, reports relationships with Orthalign, Imagen, Smith and Nephew, and Wishbone. Andrew D. Pearle, MD, reports relationships with Smith and Nephew, Engage, and Stryker. Alvin C. Ong, MD, reports relationships with Smith and Nephew and Stryker. The other authors report no potential conflicts of interest., (© The Author(s) 2022.)

Abstract: Orthopaedic surgery research increasingly utilizes statistical models to adjust for confounding, provide additional precision, and describe complex relationships. Traditionally, a statistical model is termed "multivariable" if it examines the relationship between multiple independent variables (e.g., covariables). The term "multivariate" is used to describe statistical models with multiple dependent variables (e.g., outcomes). The precise use of statistical terminology is important for study appraisal and reproducibility. The term "multivariate" is frequently used incorrectly in the orthopaedic literature to describe statistical models with a single dependent variable. In our analysis, we found that the term "multivariate" was used frequently, and in >90% of cases, the term was used to describe models that contain only a single dependent variable. Consistent with our perception, the terms "multivariable" and "multivariate" are not used with optimal precision. Below, we discuss the impact of the misuse of statistical terminology and present suggestions for improving statistical reporting., 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/H378)., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Adhesive capsulitis of the shoulder involves loss of passive range of motion with associated pain and can develop spontaneously, with no obvious injury or inciting event. The pathomechanism of this disorder remains to be elucidated, but known risk factors for adhesive capsulitis include diabetes, female sex, and thyroid dysfunction. Additionally, transcriptional profiling and pedigree analyses have suggested a role for genetics. Identification of elements of genetic risk for adhesive capsulitis using population-based techniques can provide the basis for guiding both the personalized treatment of patients based on their genetic profiles and the development of new treatments by identification of the pathomechanism., Methods: A genome-wide association study (GWAS) was conducted using the U.K. Biobank (a collection of approximately 500,000 patients with genetic data and associated ICD-10 [International Classification of Diseases, 10th Revision] codes), comparing 2,142 patients with the ICD-10 code for adhesive capsulitis (M750) to those without. Separate GWASs were conducted controlling for 2 of the known risk factors of adhesive capsulitis-hypothyroidism and diabetes. Logistic regression analysis was conducted controlling for factors including sex, thyroid dysfunction, diabetes, shoulder dislocation, smoking, and genetics., Results: Three loci of significance were identified: rs34315830 (in WNT7B; odds ratio [OR] = 1.28; 95% confidence interval [CI], 1.22 to 1.39), rs2965196 (in MAU2; OR = 1.67; 95% CI, 1.39 to 2.00), and rs1912256 (in POU1F1; OR = 1.22; 95% CI, 1.14 to 1.31). These loci retained significance when controlling for thyroid dysfunction and diabetes. The OR for total genetic risk was 5.81 (95% CI, 4.08 to 8.31), compared with 1.70 (95% CI, 1.18 to 2.36) for hypothyroidism and 4.23 (95% CI, 2.32 to 7.05) for diabetes., Conclusions: The total genetic risk associated with adhesive capsulitis was significant and similar to the risks associated with hypothyroidism and diabetes. Identification of WNT7B, POU1F1, and MAU2 implicates the Wnt pathway and cell proliferation response in the pathomechanism of adhesive capsulitis., Level of Evidence: Prognostic Level III . 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/H192 )., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: End-stage knee osteoarthritis (OA) is a highly debilitating disease for which total knee arthroplasty (TKA) serves as an effective treatment option. Although a genetic component to OA in general has been described, evaluation of the genetic contribution to end-stage OA of the knee is limited. To this end, we present a genome-wide association study involving patients undergoing TKA for primary knee OA to characterize the genetic features of severe disease on a population level., Methods: Individuals with the diagnosis of knee OA who underwent primary TKA were identified in the U.K. Biobank using administrative codes. The U.K. Biobank is a data repository containing prospectively collected clinical and genomic data for >500,000 patients. A genome-wide association analysis was performed using the REGENIE software package. Logistic regression was also used to compare the total genetic risk between subgroups stratified by age and body mass index (BMI)., Results: A total of 16,032 patients with end-stage knee OA who underwent primary TKA were identified. Seven genetic loci were found to be significantly associated with end-stage knee OA. The odds ratio (OR) for developing end-stage knee OA attributable to genetics was 1.12 (95% confidence interval [CI], 1.10 to 1.14), which was lower than the OR associated with BMI (OR = 1.81; 95% CI, 1.78 to 1.83) and age (OR = 2.38; 95% CI, 2.32 to 2.45). The magnitude of the OR for developing end-stage knee OA attributable to genetics was greater in patients <60 years old than in patients ≥60 years old (p = 0.002)., Conclusions: This population-level genome-wide association study of end-stage knee OA treated with primary TKA was notable for identifying multiple significant genetic variants. These loci involve genes responsible for cartilage development, cartilage homeostasis, cell signaling, and metabolism. Age and BMI appear to have a greater impact on the risk of developing end-stage disease compared with genetic factors. The genetic contribution to the development of severe disease is greater in younger patients., Level of Evidence: Prognostic Level III . 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/H205 )., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

Introduction: Modern total knee arthroplasty (TKA) using the Journey 2 implant utilizes a bicruciate stabilized (BCS) technique. However, whether bicruciate stabilized TKA is equally effective across weight classes is unknown., Methods: We identified patients who underwent primary bicruciate stabilized TKA during 2016 and 2017, at a single institution. All included patients had, at minimum, 2-year follow-up. Patients were categorized into body-mass index (BMI) groups as follows: underweight, normal, or overweight (<30 kg/m 2 ), obese (≥30 to <35 kg/m 2 ), and severely obese (≥35 kg/m 2 ). Patient reported outcome measures (PROMs) were measured at baseline. Both KSS and KOOS JR, along with the Visual Analogue Scale (VAS), were also recorded at follow-up. Pre-operative, post-operative, and pre-to post-operative changes in PROMs were analyzed using analysis of variance (ANOVA) and linear regression., Results: The 292 patients had a mean age of 64.8 years and mean BMI of 32.3 kg/m 2 . There were 116 (39.7%) patients in the underweight, normal, or overweight group, 88 (30.1%) in the obese category, and 88 (30.1%) in the severely obese group. There were no differences between PROMs at baseline or at follow-up (p > 0.10 for all comparisons). There were also no differences in the improvement from pre-to post-operative KSS (p = 0.21) and KOOS JR (p = 0.62)., Conclusions: Bicruciate stabilized TKA has similar effects on PROMs across BMI groups. These results suggest that bicruciate stabilized TKA is a viable treatment option both for low-weight and high-weight patients., Competing Interests: None., (© 2022 Published by Elsevier B.V. on behalf of Professor P K Surendran Memorial Education Foundation.)

Background: Frequently, patients indicated for total hip arthroplasty (THA) present with low back pain (LBP) and hip pain. The purpose of this study was to compare patients whose back pain resolved after THA with those where back pain did not resolve and identify how to predict this using spinopelvic parameters., Methods: We reviewed a series of 500 patients who underwent THA for unilateral hip osteoarthritis by 2 surgeons. Patients underwent biplanar standing and sitting EOS radiographs pre-operatively. Patients with previous spine surgery or femoral neck fracture were excluded. Demographic data was analyzed at baseline. The Oswestry Disability Index (ODI) scores were calculated pre-operatively and at 1 year postoperatively. Spinopelvic parameters included, pelvic incidence and sacral slope (SS) change from standing to sitting., Results: Two hundred and four patients (41%) had documented LBP before THA. The Oswestry Disability Index (ODI) for patients improved from 38.9 ± 17.8 pre-operatively to 17.0 ± 10.6 at 1 year post-operatively (P < .001). At 1- and 2-year follow-up, resolution of back pain occurred in 168 (82.4%) and 187 (91.2%) patients, respectively. Pelvic incidence was not predictive of back pain resolution. All patients whose back pain resolved had a sacral slope change from standing to sitting of >10°, while those patients whose back pain did not resolve had a change of <10°., Conclusion: This study demonstrates that symptomatic low back pain (LBP) resolves in 82% of patients after THA. The results of this study may be used to counsel patients on back pain and its resolution following total hip replacement., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: As the value of patient-reported outcomes becomes increasingly recognized, minimum clinically important difference (MCID) thresholds have seen greater use in shoulder arthroplasty. However, MCIDs are unique to certain populations, and variation in the modes of calculation in this field may be of concern. With the growing utilization of MCIDs within the field and value-based care models, a detailed appraisal of the appropriateness of MCID use in the literature is necessary and has not been systematically reviewed., Questions/purposes: We performed a systematic review of MCID quantification in existing studies on shoulder arthroplasty to answer the following questions: (1) What is the range of values reported for the MCID in commonly used shoulder arthroplasty patient-reported outcome measures (PROMs)? (2) What percentage of studies use previously existing MCIDs versus calculating a new MCID? (3) What techniques for calculating the MCID were used in studies where a new MCID was calculated?, Methods: The Embase, PubMed, and Ovid/MEDLINE databases were queried from December 2008 through December 2020 for total shoulder arthroplasty and reverse total shoulder arthroplasty articles reporting an MCID value for various PROMs. Two reviewers (DAK, MAM) independently screened articles for eligibility, specifically identifying articles that reported MCID values for PROMs after shoulder arthroplasty, and extracted data for analysis. Each study was classified into two categories: those referencing a previously defined MCID and those using a newly calculated MCID. Methods for determining the MCID for each study and the variability of reported MCIDs for each PROM were recorded. The number of patients, age, gender, BMI, length of follow-up, surgical indications, and surgical type were extracted for each article. Forty-three articles (16,408 patients) with a mean (range) follow-up of 20 months (0.75 to 68) met the inclusion criteria. The median (range) BMI of patients was 29.3 kg/m2 (28.0 to 32.2 kg/m2), and the median (range) age was 68 years (53 to 84). There were 17 unique PROMs with MCID values. Of the 112 MCIDs reported, the most common PROMs with MCIDs were the American Shoulder and Elbow Surgeons (ASES) (23% [26 of 112]), the Simple Shoulder Test (SST) (17% [19 of 112]), and the Constant (15% [17 of 112])., Results: The ranges of MCID values for each PROM varied widely (ASES: 6.3 to 29.5; SST: 1.4 to 4.0; Constant: -0.3 to 12.8). Fifty-six percent (24 of 43) of studies used previously established MCIDs, with 46% (11 of 24) citing one study. Forty-four percent (19 of 43) of studies established new MCIDs, and the most common technique was anchor-based (37% [7 of 19]), followed by distribution (21% [4 of 19])., Conclusion: There is substantial inconsistency and variability in the quantification and reporting of MCID values in shoulder arthroplasty studies. Many shoulder arthroplasty studies apply previously published MCID values with variable ranges of follow-up rather than calculating population-specific thresholds. The use of previously calculated MCIDs may be acceptable in specific situations; however, investigators should select an anchor-based MCID calculated from a patient population as similar as possible to their own. This practice is preferable to the use of distribution-approach MCID methods. Alternatively, authors may consider using substantial clinical benefit or patient-acceptable symptom state to assess outcomes after shoulder arthroplasty., Clinical Relevance: Although MCIDs may provide a useful effect-size based alternative to the traditional p value, care must be taken to use an MCID that is appropriate for the particular patient population being studied., Competing Interests: All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2022 by the Association of Bone and Joint Surgeons.)

Background: Preoperative diagnosis of concomitant meniscal tears in pediatric and adolescent patients with acute anterior cruciate ligament (ACL) deficiency is challenging., Purpose: To investigate the diagnostic performance of magnetic resonance imaging (MRI) in detecting meniscal injuries for pediatric and adolescent patients with acute ACL tears., Study Design: Cohort study (diagnosis); Level of evidence, 2., Methods: The authors retrospectively identified patients aged ≤18 years who underwent acute ACL reconstruction between 2006 and 2018 at 2 tertiary academic hospitals. The primary outcomes were arthroscopically confirmed medial, lateral, or any (defined as medial and/or lateral) meniscal tears. To control for chronically deficient knees, patients must have received their MRI study within 4 weeks of injury and must have undergone surgery no more than 8 weeks after their MRI study. Preoperative MRI reports were compared with the gold standard of arthroscopically confirmed tears to calculate sensitivity, specificity, positive predictive value, and negative predictive value. In a secondary analysis, patients were stratified by age into 2 groups (≤13 or ≥14 years), body mass index-for-age data from the Centers for Disease Control were used to classify patients as obese or nonobese, and differences between sensitivity and specificity proportions were analyzed using chi-square test for homogeneity., Results: Overall, 406 patients with a mean age of 15.4 years (range, 10-18 years) were identified. The sensitivity, specificity, positive predictive value, and negative predictive value were as follows: for lateral meniscal (LM) tears, 51.0%, 86.5%, 78.3%, and 65.0%; for medial meniscal tears, 83.2%, 80.6%, 62.3%, and 92.5%; and for any meniscal tear, 75.0%, 72.1%, 81.5%, and 63.8%, respectively. In the stratified analysis, MRI was less specific for the following diagnoses: any meniscal tear in patients aged ≤13 years ( P = .048) and LM tears in obese patients ( P = .020)., Conclusion: The diagnostic ability of MRI to predict meniscal injuries present at acute ACL reconstruction was moderate. Performance was poorest at the lateral meniscus, where MRI failed to detect 97 tears that were found arthroscopically. Specificity was significantly lower in younger patients for any meniscal tear and in obese patients for LM tears., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: P.D.F. has received hospitality payments from Medical Device Business Services. A.G. has received education payments from Arthrex. M.S. has received consulting fees and royalties from OrthoPediatrics and hospitality payments from Stryker. R.J.M. has received education payments from Arthrex, consulting fees from Medical Device Business Services and OrthoPediatrics, speaking fees from Philips Electronic North America, and hospitality payments from Globus Medical and Medical Device Business Services. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto., (© The Author(s) 2022.)

Background: The purpose of our study was to assess the accuracy of a commercially available wearable sensor in replicating pelvic tilt movement in both the sitting and standing position in patients before total hip arthroplasty., Methods: This prospective study evaluated patients undergoing a primary unilateral total hip arthroplasty by a single surgeon. Patients were excluded if they had a body mass index (BMI) greater than 40 kg/m 2 . Two sensors were adhered directly to patients' skin at S2 and T12. The S2 angle was recorded on the sensor at maximum flexion and extension angles and compared with pelvic tilt measurements on both sitting and standing radiographs. The primary outcomes recorded were patients' pelvic tilts measured using radiographs (PT-RAD) and sensors (PT-SEN), with Pearson correlation coefficients and intraclass correlation coefficients (ICCs) calculated., Results: Sixty-one patients (35 males and 26 females) with an average age of 61.5 ± 8.5 years and BMI of 26.9 ± 4.1 kg/m 2 were analyzed. The mean prestanding PT-RAD and PT-SEN were 1.5 ± 8.3 and 1.0 ± 8.1, respectively, with an ICC of 0.98 (95% confidence interval, 0.96-0.99). The mean presitting PT-RAD and PT-SEN were -21.9 ± 12.5 and -20.9 ± 11.7, respectively, with an ICC of 0.97 (95% confidence interval, 0.95-0.98). The multiple R 2 was 0.95 for the prestanding and presitting comparisons. The R 2 for all comparisons between PT-RAD and PT-SEN was >0.85, regardless of BMI or sex., Conclusions: Although the use of wearable technology may have limitations, based on our results, a wearable sensor is accurate in replicating pelvic tilt movement., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Jonathan M. Vigdorchik, M.D., reports stock ownership in Intellijoint Surgical and Motion Insights, receiving fees and research funding from Corin Group, and receiving fees from Intellijoint Surgical, Medacta, and Zimmer; Seth Jerabek, M.D., reports having stock ownership in Stryker and Imagen and receiving IP royalties, personal fees, and research funding from Stryker; the other authors declare no potential conflicts of interest., (© 2021 The Authors.)

Both clinical and genetic factors drive the risk of venous thromboembolism. However, whether clinically recorded risk factors and genetic variants can be combined into a clinically applicable predictive score remains unknown. Using Cox proportional-hazard models, we analyzed the association of risk factors with the likelihood of venous thromboembolism in U.K. Biobank, a large prospective cohort. We then created a polygenic risk score of 36 single nucleotide polymorphisms and a clinical score determined by age, sex, body mass index, previous cancer diagnosis, smoking status, and fracture in the last 5 years. Participants were at significantly increased risk of venous thromboembolism if they were at high clinical risk (subhazard ratio, 4.37 [95% CI, 3.85-4.97]) or high genetic risk (subhazard ratio, 3.02 [95% CI, 2.63-3.47]) relative to participants at low clinical or genetic risk, respectively. The combined model, consisting of clinical and genetic components, was significantly better than either the clinical or the genetic model alone (P < 0.001). Participants at high risk in the combined score had nearly an eightfold increased risk of venous thromboembolism relative to participants at low risk (subhazard ratio, 7.51 [95% CI, 6.28-8.98]). This risk score can be used to guide decisions regarding venous thromboembolism prophylaxis, although external validation is needed., (© 2021. The Author(s).)

Background: We sought to investigate the relationship between the time from an anterior cruciate ligament (ACL) tear to the surgical procedure and meniscal tears in the pediatric and adolescent population., Methods: Patients who were ≤18 years of age and had undergone an ACL reconstruction from 2006 to 2018 were identified in a retrospective, multicenter cohort. The primary outcomes were arthroscopically confirmed medial meniscal or lateral meniscal tears specifically and, in general, if any meniscal tear was present (medial and/or lateral). A multivariable Poisson regression model was used to determine whether the time from the injury to the surgical procedure was a risk factor for subsequent meniscal injury, after controlling for sex, age, and body mass index (BMI). Multivariable Poisson regression was also used to characterize associations of age, sex, and BMI with meniscal injury., Results: In this study, 546 patients with a mean age (and standard deviation) of 15.3 ± 1.6 years were identified. For each week that the surgical procedure was delayed, there was a 2% increased risk of a medial meniscal tear (adjusted relative risk [ARR], 1.02 [95% confidence interval (CI), 1.01 to 1.03]). The weekly increase in risk of a medial meniscal injury was significant for male patients (ARR, 1.03 [95% CI, 1.01 to 1.05]), but not for female patients (ARR, 1.00 [95% CI, 0.97 to 1.04]), even though the effect modification was not significant (p = 0.24). Obese male patients had a 77.9% increased risk of medial meniscal tear for each 10-week delay (p < 0.001). The use of crutches was associated with a decreased risk of medial meniscal tears (ARR, 0.47 [95% CI, 0.34 to 0.64])., Conclusions: In pediatric and adolescent patients, the risk of meniscal injury is substantial after an ACL tear. A delay from the injury to the surgical procedure was associated with a 3% weekly increased risk of medial meniscal injury for male patients, but not for female patients. The increased risk of medial meniscal injury with delays to the surgical procedure was particularly high for obese male patients., 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/G568)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Purpose: Despite the commonplace use of tranexamic acid in total joint arthroplasty, much of the current data regarding its cost-effectiveness examines savings directly related to its hemostatic properties, without considering its protective effect against periprosthetic joint infections. Using break-even economic modeling, we calculated the cost-effectiveness of routine tranexamic acid administration for infection prevention in total joint arthroplasty., Materials and Methods: The cost of intraoperative intravenous tranexamic acid, the cost of revision arthroplasty for periprosthetic joint infections, and the baseline rates of periprosthetic joint infections in patients who did not receive intraoperative tranexamic acid were obtained from the literature and institutional purchasing records. Break-even economic modeling incorporating these variables was performed to determine the absolute risk reduction in infection rate to make routine intraoperative tranexamic acid use economically justified. The number needed to treat was calculated from the absolute risk reduction., Results: Routine use of intraoperative tranexamic acid is economically justified if it prevents at least 1 infection out of 3125 total joint arthroplasties (absolute risk reduction = 0.032%). Cost-effectiveness was maintained with varying costs of tranexamic acid, infection rates, and periprosthetic joint infection costs., Conclusion: The routine use of intraoperative tranexamic acid is a highly cost-effective practice for infection prevention in primary and revision total joint arthroplasty. The use of tranexamic acid is warranted across a wide range of costs of tranexamic acid, initial infection rates, and costs of periprosthetic joint infection treatment., Competing Interests: Dr. Kavolus declares stock or stock options with Conformis, Histogenics, Neogenomics, Nuvasive, and Vericel. No other author has anything to declare., (© 2021 Published by Elsevier B.V. on behalf of Professor P K Surendran Memorial Education Foundation.)

Background: Femoral component rotation in total knee arthroplasty (TKA) has a significant impact on balance and patellofemoral kinematics. However, normal anatomic relationships between rotational axes are poorly understood. As such, we sought to characterize anatomic femoral rotational axes in patients undergoing primary TKA., Methods: We identified 100 patients who underwent a primary TKA with a preoperative computed tomography scan. The angles between the surgical epicondylar axis (SEA) and the anterior-posterior (AP) axis to the posterior condylar axis (PCA) were measured independently by a musculoskeletal fellowship-trained radiologist and a fellowship-trained arthroplasty surgeon. We simulated an ideal TKA in which the femoral component was placed exactly 3° external to the PCA and measured resulting rotation., Results: The SEA was on average 1.5° externally rotated to the PCA (range 3.1° internal to 7.0° external). The AP axis was on average 4.5° externally rotated to the PCA (range 2.3° internal to 10.3° external). The AP axis was a mean 2.7° externally rotated to the SEA (range 6.3° internal to 10.3° external). Routinely setting femoral rotation 3° external to the PCA would result in only 51 (51%) TKAs within ±2° of the SEA and 23 (23%) femoral components internally rotated relative to the SEA., Conclusion: Normal anatomic rotational axes of arthritic knees are highly variable, with a 10° range in the SEA and 16° range in the AP axis. Routinely setting femoral rotation 3° external to the PCA will yield significant error in aligning the femoral component with either the SEA or AP axis., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: In addition to the significant morbidity and mortality associated with periprosthetic joint infection (PJI), the cost of treating PJI is substantial. Prior high-quality national estimates of the economic burden of PJI utilize data up to 2009 to project PJI growth in the United States through 2020. Now in the year 2020, it is appropriate to evaluate these past projections and incorporate the latest available data to better understand the current scale and burden of PJI in the United States., Methods: The Nationwide Inpatient Sample (2002-2017) was used to identify rates and associated inpatient costs for primary total knee arthroplasty (TKA) and total hip arthroplasty (THA) and PJI-related revision TKA and THA. Poisson regression was utilized to model past growth and project future rates and cost of PJI of the hip and knee., Results: Using the most recent data, the combined annual hospital costs related to PJI of the hip and knee were estimated to be $1.85 billion by 2030. This includes $753.4 million for THA PJI and $1.1 billion for TKA PJI, in that year. Increases in PJI costs are mainly attributable to increases in volume. Although the growth in incidence of primary THA and TKA has slowed in recent years, the incidence of PJI and the cost per case of PJI remained relatively constant from 2002 to 2017., Discussion: Understanding the current and potential future financial burden of PJI for surgeons, patients, and healthcare systems is essential. There is an urgent need for efficacious preventive strategies in reducing rates of PJI after THA and TKA., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background : During the worldwide COVID-19 pandemic, physicians had to improvise and adapt new ways to provide care to patients. Purposes : The purpose of this study was to assess physicians' sentiments regarding telemedicine and its use in orthopedic practices. Methods : We performed a cross-sectional study of attending orthopedic physicians, the majority of whom integrated telemedicine into their practices from March to October 2020. A survey was sent to 517 physicians who had registered for an orthopedics conference. The survey included questions pertaining to various factors regarding telemedicine and each physician's practice. Results : Of the 517 physicians who received the survey, 328 responded, for a 63.4% response rate. Of the 328 respondents, 84.1% did not use telemedicine in their practice prior to the COVID-19 pandemic. Even during the pandemic, the physicians most commonly responded that less than 5% of their practice was conducted by telemedicine (n = 103, 31.4%). The second most common response was that more than 20% of visits were done via telemedicine (n = 72, 22.0%); 43.0% of physicians noted that they would not use telemedicine technology in their practice after the pandemic, but 59.1% of physicians would be willing to do annual visits by telemedicine. Ability to examine the patient (2.0 ± 1.0) was rated worse, overall, than either the experience using the technology (3.2 ± 1.0) or the capacity to communicate with the patient (3.6 ± 1.0). Conclusions : Our survey of orthopedic surgeons demonstrates that while the use of telemedicine technology was minimal prior to the pandemic, its use was widely adopted during the pandemic. Nearly half of physicians said that they will continue to use telemedicine., Competing Interests: Declaration of Conflicting Interests: The author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: David A. Kolin, BA MSc, Kaitlin M. Carroll, BS, and Kevin Plancher, MD, declare that they have no conflicts of interest. Fred Cushner, MD, reports relationships with Acelity, Canary Medical, OrthAlign, and Smith & Nephew, outside the submitted work., (© The Author(s) 2020.)

Background: Coronavirus disease 2019 (Covid-19) has rapidly infected millions of people worldwide. Recent studies suggest that racial minorities and patients with comorbidities are at higher risk of Covid-19. In this study, we analyzed the effects of clinical, regional, and genetic factors on Covid-19 positive status., Methods: The UK Biobank is a longitudinal cohort study that recruited participants from 2006 to 2010 from throughout the United Kingdom. Covid-19 test results were provided to UK Biobank starting on March 16, 2020. The main outcome measure in this study was Covid-19 positive status, determined by the presence of any positive test for a single individual. Clinical risk factors were derived from UK Biobank at baseline, and regional risk factors were imputed using census features local to each participant's home zone. We used robust adjusted Poisson regression with clustering by testing laboratory to estimate relative risk. Blood types were derived using genetic variants rs8176719 and rs8176746, and genomewide tests of association were conducted using logistic-Firth hybrid regression., Results: This prospective cohort study included 397,064 UK Biobank participants, of whom 968 tested positive for Covid-19. The unadjusted relative risk of Covid-19 for Black participants was 3.66 (95% CI 2.83-4.74), compared to White participants. Adjusting for Townsend deprivation index alone reduced the relative risk to 2.44 (95% CI 1.86-3.20). Comorbidities that significantly increased Covid-19 risk included chronic obstructive pulmonary disease (adjusted relative risk [ARR] 1.64, 95% CI 1.18-2.27), ischemic heart disease (ARR 1.48, 95% CI 1.16-1.89), and depression (ARR 1.32, 95% CI 1.03-1.70). There was some evidence that angiotensin converting enzyme inhibitors (ARR 1.48, 95% CI 1.13-1.93) were associated with increased risk of Covid-19. Each standard deviation increase in the number of total individuals living in a participant's locality was associated with increased risk of Covid-19 (ARR 1.14, 95% CI 1.08-1.20). Analyses of genetically inferred blood types confirmed that participants with type A blood had increased odds of Covid-19 compared to participants with type O blood (odds ratio [OR] 1.16, 95% CI 1.01-1.33). A meta-analysis of genomewide association studies across ancestry groups did not reveal any significant loci. Study limitations include confounding by indication, bias due to limited information on early Covid-19 test results, and inability to accurately gauge disease severity., Conclusions: When assessing the association of Black race with Covid-19, adjusting for deprivation reduced the relative risk of Covid-19 by 33%. In the context of sociological research, these findings suggest that discrimination in the labor market may play a role in the high relative risk of Covid-19 for Black individuals. In this study, we also confirmed the association of blood type A with Covid-19, among other clinical and regional factors., Competing Interests: OE reports grants from the National Institutes of Health and the Emerson Research Collective. The funders had no role in any aspect of study design, analysis, writing, or other aspects related to the submitted work. There are no relationships or activities that have influenced the submitted work. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

Background: Hemorrhage is a leading cause of death after trauma and childbirth. In response to severe hemorrhage, bleeding patients often receive transfusions of red blood cells, plasma, platelets, or other blood components. We examined risk factors for transfusion in acute severe bleeding in two trials of over 20,000 patients to better understand factors associated with transfusion likelihood., Study Design and Methods: We conducted a cohort analysis of data from the CRASH-2 and WOMAN trials, two multinational trials that recruited patients with traumatic and postpartum hemorrhage, respectively. For each trial, we examined the effect of 10 factors on blood transfusion likelihood. Univariate and multivariate Poisson regressions were used to analyze the relationship between risk factors and blood transfusion., Results: Of the 20,207 traumatic hemorrhage patients, 10,232 (51%) received blood components. Of the 20,060 women with postpartum hemorrhage, 10,958 (55%) received blood components. For patients who suffered from traumatic hemorrhage, those greater than three hours from injury to hospitalization were more likely to be transfused (ARR 1.37; 95% CI, 1.20-1.56). Postpartum hemorrhage patients had an increased likelihood of transfusion if they gave birth outside the hospital (ARR 1.30; 95% CI 1.22-1.39), gave birth more than three hours before hospitalization (ARR 1.09; 95% CI 1.01-1.17), had a Caesarean section (ARR 1.16; 95% CI 1.08-1.25), and if they had any identifiable causes of hemorrhage other than uterine atony., Conclusion: Several risk factors are associated with an increased likelihood of transfusion in traumatic and postpartum hemorrhage patients. Altering modifiable factors, by reducing time from injury or childbirth to hospitalization, for example, might be able to reduce transfusions and their complications., Trial Registration: CRASH-2 is registered as ISRCTN86750102, ClinicalTrials.gov NCT00375258 and South African Clinical Trial Register DOH-27-0607-1919. WOMAN is registered as ISRCTN76912190, ClinicalTrials.gov NCT00872469, PACTR201007000192283, and EudraCT number 2008-008441-38., Competing Interests: With respect to Pfizer, the commercial funder for this trial, there are no other relevant declarations including any declarations related to employment, consultancy, patents, products in development, marketed products, etc. This does not alter our adherence to PLOS ONE policies on sharing data and materials.

We conducted an analysis of 669 Covid-19 positive patients within the UK Biobank cohort, a prospective cohort including over 500,000 participants. Our analyses led to several findings. We found that black participants in the cohort were over four times more likely to be diagnosed with Covid-19 than white participants. In order to assess for confounding, we produced - to our knowledge - the first multivariable adjusted estimate of the association of racial characteristics with Covid-19. Our adjusted estimates indicated that black participants remained at over threefold increased risk of Covid-19 relative to white participants. Exploratory analyses identified that 22.9% of Covid-19 positive black patients were using either angiotensin converting enzyme inhibitors or angiotensin II receptor blockers, relative to just 6.7% of all black participants. Our genetic analyses confirmed the finding of a previous report noting an association of blood type A with Covid-19, and we discovered a novel genetic association with HLA DQA1&#95;509 that remained significant even after Bonferroni correction.

We report the development and characterization of a method, named reversible association with motor proteins (RAMP), for manipulation of organelle positioning within the cytoplasm. RAMP consists of coexpressing in cultured cells (i) an organellar protein fused to the streptavidin-binding peptide (SBP) and (ii) motor, neck, and coiled-coil domains from a plus-end-directed or minus-end-directed kinesin fused to streptavidin. The SBP-streptavidin interaction drives accumulation of organelles at the plus or minus end of microtubules, respectively. Importantly, competition of the streptavidin-SBP interaction by the addition of biotin to the culture medium rapidly dissociates the motor construct from the organelle, allowing restoration of normal patterns of organelle transport and distribution. A distinctive feature of this method is that organelles initially accumulate at either end of the microtubule network in the initial state and are subsequently released from this accumulation, allowing analyses of the movement of a synchronized population of organelles by endogenous motors., Competing Interests: The authors have declared that no competing interests exist.

We have recently shown that the small proton chemical shift difference in 2-methyl-1-(methyl-d)piperidine supports a long-lived nuclear spin state. To identify additional candidate molecules with CH 2 D groups exhibiting accessible long-lived states, and to investigate the factors governing the magnitude of the shift differences, we report a computational and experimental investigation of methyl rotational equilibria and proton chemical shifts in a variety of 2-substituted 1-(methyl-d)piperidines. The polarity and size of the 2-substituent affect the 1,2-stereoisomeric relationship, and consequently, the strength of the rotational asymmetry within the CH 2 D group. Nonpolar and large 2-substituents prefer the equatorial position, and relatively large shift differences (i.e., > 13 ppb) are observed. Polar and small substituents, however, increasingly prefer the axial position, and medium to small shift differences (i.e., 0 to 9 ppb) are observed. In addition, the diastereotopic CH 2 D proton chemical shift difference for tricarbonyl(1-chloro-2-deuteriomethylbenzene) chromium(0) was computed, showing that reasonable predictions of these small shift differences can be extended to more complex, organometallic species.