Predictors of reoperation and survival experience for primary total knee arthroplasty in young patients with degenerative and inflammatory arthritis.

INTRODUCTION: While total knee arthroplasty (TKA) is typically implemented in patients > 65 years old, young patients may need to undergo TKA for pain relief and functional improvement. Current data are limited by older cohorts and short-term survival rates. This study aimed to examine a large sample size of patients with degenerative and inflammatory conditions who underwent primary TKA at a young (≤ 40) age to identify predictors of reoperation, as well 15-year survivorship. MATERIALS AND METHODS: A retrospective study was performed on 77 patients (92 surgeries) who underwent primary TKA at ≤ 40 years old, between January 1990 and January 2020. Patient charts were reviewed and a multivariable logistic regression model identified independent predictors of reoperation. Kaplan-Meier analysis was employed to build survival curves and log-rank tests analyzed survival between groups. RESULTS: Of the 77 patients, the median age at the time of surgery was 35.7 years (IQR: 31.2-38.7) and median follow-up time was 6.88 years. Twenty-one (22.8%) primary TKAs underwent 24 reoperations, most commonly due to stiffness (n = 9, 32.1%) and infection (n = 13, 46.4%) more significantly in the OA group (p = 0.049). There were no independent predictors of reoperation in multivariable analysis, and 15-year revision-free survivorship after TKA did not differ by indication (77.3% for OA/PTOA vs. 96.7% for autoimmune, p = 0.09) or between ≤ 30 and 31-40 year age groups (94.7% vs. 83.6%, p = 0.55). CONCLUSIONS: In this cohort of patients ≤ 40 years old, revision-free survival was comparable to that reported in the literature for older TKA patients with osteoarthritis/autoimmune conditions (81-94% at 15-years). Though nearly a quarter of TKAs required reoperation and causes of secondary surgery differed between degenerative and inflammatory arthritis patients, there were no significant predictors of increased reoperation rate. Very young patients ≤ 30 years old did not have an increased risk of revision compared to those aged 31-40 years.

Association of Pharmacologic Treatment of Depression/Anxiety With Initial Patient-Reported Outcome Measures in Patients With Hip and Knee Osteoarthritis.

INTRODUCTION: Depression and anxiety are common comorbidities that may exacerbate osteoarthritis (OA)-related pain. We aim to evaluate the effect of pharmacologic treatment of depression/anxiety on hip and knee patient-reported outcome measures (PROMs). METHODS: A multi-institutional PROMs database was queried for patients with depression or anxiety and hip or knee OA who completed a PROMs questionnaire at an initial orthopaedic visit between January 2015 and March 2023. Data on demographics, comorbidities, and duration of pharmacologic treatment of depression/anxiety were obtained. Patients were stratified into three cohorts based on treatment duration. PROMs were compared across cohorts. RESULTS: Two thousand nine hundred sixty patients who completed PROMs at their initial orthopaedic visit had both OA and depression/anxiety. One hundred thirty-four (4.5%) received pharmacologic treatment of depression/anxiety for < 1 year, versus 196 (6.6%) for more than 1 year. In unadjusted analyses, patients with pharmacologic treatment had significantly lower Patient-Reported Outcomes Measurement Information System (PROMIS)-Physical (39.8 [IQR 34.9, 44.9] vs 42.3 [37.4, 47.7], P < 0.001) and PROMIS-Mental (43.5 [36.3, 50.8] vs 48.3 [41.1, 53.3], P < 0.001) scores than those without treatment. After adjusting for demographics and comorbidities, only differences in PROMIS-Mental scores remained statistically significant, with pharmacologic treatment associated with lower scores (ß = -2.26, 95% CI, [-3.29, -1.24], P < 0.001). On secondary analysis including duration of pharmacologic treatment, < 1 year of treatment was associated with significantly lower PROMIS-Mental scores than those not treated (ß = -4.20, 95% CI [-5.77, -2.62], P < 0.001) while scores of patients with more than 1 year of treatment did not differ significantly from those without treatment. CONCLUSION: :Our results indicate that pharmacologic treatment of depression/anxiety is associated with improved psychological health but not with improved physical symptoms related to OA. We observed a nonsignificant trend that patients with depression/anxiety who warrant pharmacologic treatment tend to have worse physical symptoms than those who do not; however, unadjusted analyses suggest this is a complex relationship beyond the isolated effect of pharmacologic treatment.

Racial and Ethnic Minority Patients Have Increased Complication Risks When Undergoing Surgery While Not Meeting Clinical Guidelines.

BACKGROUND: Clinical guidelines for performing total joint arthroplasty (TJA) have not been uniformly adopted in practice because research has suggested that they may foster inequities in surgical access, potentially disadvantaging minority sociodemographic groups. The aim of this study was to assess whether undergoing TJA without meeting clinical guidelines affects complication risk and leads to disparities in postoperative outcomes. METHODS: This retrospective cohort study evaluated the records of 11,611 adult patients who underwent primary TJA from January 1, 2010, to December 31, 2020, at an academic hospital network. Based on self-reported race and ethnicity, 89.5% of patients were White, 3.5% were Black, 2.9% were Hispanic, 1.3% were Asian, and 2.8% were classified as other. Patients met institutional guidelines for undergoing TJA if they had a hemoglobin A1c of <8.0% and a body mass index of <40 kg/m2 and were not currently smoking. A logistic regression model was utilized to identify factors associated with complications, and a mixed-effects model was utilized to identify factors associated with not meeting guidelines for undergoing TJA. RESULTS: During the study period, 11% (1,274) of the 11,611 adults who underwent primary TJA did not meet clinical guidelines. Compared with the group who met guidelines, the group who did not had higher proportions of Black patients (3.2% versus 6.0%; p < 0.001) and Hispanic patients (2.7% versus 4.6%; p < 0.001). An increased risk of not meeting guidelines at the time of surgery was demonstrated among Black patients (odds ratio [OR], 1.60 [95% confidence interval (CI), 1.22 to 2.10]; p = 0.001) and patients insured by Medicaid (OR, 1.75 [95% CI, 1.26 to 2.44]; p = 0.001) or Medicare (OR, 1.22 [95% CI, 1.06 to 1.41]; p = 0.007). Patients who did not meet guidelines had a higher risk of reoperation than those who met guidelines (7.7% [98] versus 5.9% [615]; p = 0.017), including a higher risk of infection-related reoperation (3.1% [40] versus 1.4% [147]; p < 0.001). CONCLUSIONS: We found that patients who underwent TJA despite not meeting institutional preoperative criteria had a higher risk of postoperative complications. These patients were more likely to be from racial and ethnic minority groups, to have a lower socioeconomic status, and to have Medicare or Medicaid insurance. These findings underscore the need for surgery-related shared decision-making that is informed by evidence-based guidelines in order to reduce complication burden. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Reverse Fragility Index: Comparing Revision Rates Between Direct Anterior and Other Approaches in Total Hip Arthroplasty. A Systematic Review of Randomized Controlled Trials.

BACKGROUND: Despite increasing adoption of the direct anterior (DA) approach in total hip arthroplasty (THA), uncertainty persists regarding its outcomes beyond the 1-year mark in comparison to other approaches. We used the reverse fragility index (RFI) to evaluate the robustness of reported findings in the literature. METHODS: We conducted a systematic review of randomized controlled trials (RCTs) comparing implant revision rates between DA and other approaches in THA, defined as all those different from DA. Our primary outcome was the RFI, which gauges the number of events needed for a nonsignificant result to become significant, in the revision rate between DA and other approaches. We also calculated the reverse fragility quotient by dividing the RFI by each study's sample size. Median values and interquartile ranges (IQRs) were displayed. RESULTS: A total of 10 RCTs with a total of 971 patients were included. The median RFI was 5 (IQR, 4 to 5), indicating the study's results would be statistically significant if the outcomes of 5 patients in 1 treatment arm were reversed. The median reverse fragility quotient was 0.049 (IQR, 0.04 to 0.057), indicating that a change of outcome in 4.9% of patients would render the revision rate significant. The median number of patients lost to follow-up was 4 (IQR, 0 to 7). Of the 10 RCTs, 6 had more patients lost to follow-up than their respective RFI values. CONCLUSIONS: Notable fragility was evidenced in most studies comparing DA to other approaches for THA. Surgeons should not solely rely on the P value to determine clinical significance and instead use multiple metrics. LEVEL OF EVIDENCE: II.

The Association of Sacro-Femoro-Pubic Angle and Postoperative Dislocation Following Total Hip Arthroplasty.

BACKGROUND: Spino-pelvic orientation may affect dislocation risk following total hip arthroplasty (THA). It can be measured on lateral lumbo-pelvic radiographs. The sacro-femoro-pubic (SFP) angle, measured on an antero-posterior (AP) pelvis radiograph, is a reliable proxy for pelvic tilt, a measurement of spino-pelvic orientation measured on a lateral lumbo-pelvic radiograph. The purpose of this study was to investigate the relationship between SFP angle and dislocation following THA. METHODS: An Institutional Review Board-approved retrospective case-control study was conducted at a single academic center. We matched 71 dislocators (cases) to 71 nondislocators (controls) following THA performed by 1 of 10 surgeons between September 2001 and December 2010. Two authors (readers) independently calculated SFP angle from single preoperative AP pelvis radiographs. Readers were blinded to cases and controls. Conditional logistic regressions were used to identify factors differentiating cases and controls. RESULTS: The data did not show a clinically relevant or statistically significant difference in SFP angles after adjusting for gender, American Society of Anesthesiologists classification, prosthetic head size, age at time of THA, measurement laterality, and surgeon. CONCLUSION: We did not find an association between preoperative SFP angle and dislocation following THA in our cohort. Based on our data, SFP angle as measured on a single AP pelvis radiograph should not be used to assess dislocation risk prior to THA.

Short-to Mid-Term Survivorship of a Patient-specific Unicompartmental Knee Arthroplasty Implant Cast from a Three-Dimensional Printed Mold.

The purpose of this study was to determine early survivorship and complication rates associated with the implantation of a new patient-specific unicompartmental knee implant cast from a three-dimensional (3D) printed mold, introduced in 2012. We retrospectively reviewed 92 consecutive patients who underwent unicompartmental knee arthroplasty (UKA) with a patient-specific implant cast from a 3D printed mold between September 2012 and October 2015. The early results of a patient-specific UKA implant were favorable in our cohort, with survivorship free from reoperation of 97% at an average 4.5 years follow-up. Future studies are necessary to investigate the long-term performance of this implant. Survivorship of a patient-specific unicompartmental knee arthroplasty implant cast from a 3D printed mold.

Are There More Radiolucent Lines in Patients Who Underwent Total Knee Arthroplasty With or Without a Tourniquet During Cementation at 5 to 8 Years After Surgery?

BACKGROUND: This study investigated the presence and progression of radiolucent lines (RLLs) after cemented total knee arthroplasty (TKA) with or without tourniquet use. METHODS: There were 369 consecutive primary cemented TKAs with 5 to 8 years of follow-up. A tourniquet was used during component cementation in patients who underwent surgery from January 3, 2006, to March 31, 2010. No tourniquet was used from August 14, 2009, to October 14, 2014. There were 192 patients in the tourniquet group (TQ) and 177 patients in the no tourniquet group (NQ). Patient demographics, reoperations, and complications were recorded. RLLs were identified on anteroposterior, lateral, and skyline x-rays at 1, 2, and 5 to 8 years postoperatively using the modern knee society radiographic evaluation system. Demographics, reoperations, complications, and RLLs were compared. Age, sex, and body mass index were similar between groups. Mean tourniquet time in TQ was 11 minutes (range, 8 to 25). RESULTS: The presence of RLLs differed between groups, with 65% of TQ knees having RLLs under any part of the prostheses versus 46% of NQ knees (P < .001). The progression of RLL >2 mm occurred in 26.0% of knees in TQ and 16.7% of knees in NQ (P = .028). There were 13 TKAs that underwent subsequent revision surgery. There was no statistically or clinically significant difference in revision rate between groups (7 revisions in TQ, 6 in NQ, P = .66). CONCLUSION: Less RLLs were identified in NQ versus TQ. There were no statistically or clinically significant differences in revision rates between the NQ and TQ groups at 5 to 8 years.

Patient-Specific Safe Zones for Acetabular Component Positioning in Total Hip Arthroplasty: Mathematically Accounting for Spinopelvic Biomechanics.

BACKGROUND: Despite a growing understanding of spinopelvic biomechanics in total hip arthroplasty (THA), there is no validated approach for executing patient-specific acetabular component positioning. The purpose of this study was to (1) validate quantitative, patient-specific acetabular "safe zone" component positioning from spinopelvic parameters and (2) characterize differences between quantitative patient-specific acetabular targets and qualitative hip-spine classification targets. METHODS: From 2,457 consecutive primary THA patients, 22 (0.88%) underwent revision for instability. Spinopelvic parameters were measured prior to index THA. Acetabular position was measured following index and revision arthroplasty. Using a mathematical proof, we developed an open-source tool translating a surgeon-selected, preoperative standing acetabular target to a patient-specific safe zone intraoperative acetabular target. Difference between the patient-specific safe zone and the actual component position was compared before and after revision. Hip-spine classification targets were compared to patient-specific safe zone targets. RESULTS: Of the 22 who underwent revision, none dislocated at follow-up (4.6 [range, 1 to 6.9]). Patient-specific safe zone targets differed from prerevision acetabular component position by 9.1 ± 4.2° inclination/13.3 ± 6.7° version; after revision, the mean difference was 3.2 ± 3.0° inclination/5.3 ± 2.7° version. Differences between patient-specific safe zones and the median and extremes of recommended hip-spine classification targets were 2.2 ± 1.9° inclination/5.6 ± 3.7° version and 3.0 ± 2.3° inclination/7.9 ± 3.5° version, respectively. CONCLUSION: A mathematically derived, patient-specific approach accommodating spinopelvic biomechanics for acetabular component positioning was validated by approximating revised, now-stable hips within 5° version and 3° inclination. These patient-specific safe zones augment the hip-spine classification with prescriptive quantitative targets for nuanced preoperative planning.

Patterns and Persistence of Perioperative Plasma and Cerebrospinal Fluid Neuroinflammatory Protein Biomarkers After Elective Orthopedic Surgery Using SOMAscan.

BACKGROUND: The neuroinflammatory response to surgery can be characterized by peripheral acute plasma protein changes in blood, but corresponding, persisting alterations in cerebrospinal fluid (CSF) proteins remain mostly unknown. Using the SOMAscan assay, we define acute and longer-term proteome changes associated with surgery in plasma and CSF. We hypothesized that biological pathways identified by these proteins would be in the categories of neuroinflammation and neuronal function and define neuroinflammatory proteome changes associated with surgery in older patients. METHODS: SOMAscan analyzed 1305 proteins in blood plasma (n = 14) and CSF (n = 15) samples from older patients enrolled in the Role of Inflammation after Surgery for Elders (RISE) study undergoing elective hip and knee replacement surgery with spinal anesthesia. Systems biology analysis identified biological pathways enriched among the surgery-associated differentially expressed proteins in plasma and CSF. RESULTS: Comparison of postoperative day 1 (POD1) to preoperative (PREOP) plasma protein levels identified 343 proteins with postsurgical changes ( P < .05; absolute value of the fold change [|FC|] > 1.2). Comparing postoperative 1-month (PO1MO) plasma and CSF with PREOP identified 67 proteins in plasma and 79 proteins in CSF with altered levels ( P < .05; |FC| > 1.2). In plasma, 21 proteins, primarily linked to immune response and inflammation, were similarly changed at POD1 and PO1MO. Comparison of plasma to CSF at PO1MO identified 8 shared proteins. Comparison of plasma at POD1 to CSF at PO1MO identified a larger number, 15 proteins in common, most of which are regulated by interleukin-6 (IL-6) or transforming growth factor beta-1 (TGFB1) and linked to the inflammatory response. Of the 79 CSF PO1MO-specific proteins, many are involved in neuronal function and neuroinflammation. CONCLUSIONS: SOMAscan can characterize both short- and long-term surgery-induced protein alterations in plasma and CSF. Acute plasma protein changes at POD1 parallel changes in PO1MO CSF and suggest 15 potential biomarkers for longer-term neuroinflammation that warrant further investigation.

Is It the Back or the Hip? Differentiating Lumbar Spine From Hip Pathologies: Key Points of Evaluation and Treatment.

Disorders of the hip and spine commonly coexist and are difficult to disentangle. When they do occur together, the pathology is often referred to as hip-spine syndrome. When hip-spine syndrome is suspected, it is critically important to properly identify the relative contributions that the hip and spine each provide to a patient's overall clinical presentation. To focus on the incorrect anatomic site would be a disservice to the patient. The interconnectivity of hip and spine pathology, the various clinical presentations of the most commonly seen hip and spine disorders, the broad differential and suggested workup that should be considered for such patients, the various treatment modalities available, and the clinical predictors and expected outcomes for patients with hip-spine syndrome are important factors for review.

Linking the KOOS-PS to PROMIS Physical Function in Knee Patients Evaluated for Surgery.

INTRODUCTION: The Knee Injury and Osteoarthritis Outcome Score-Physical Function Short-form and the Patient-Reported Outcomes Measurement Information System Physical Function are widely used patient-reported outcome measures in orthopaedic practice and research. It would be helpful for clinicians and researchers to compare scores obtained on one instrument with those collected on another. To achieve this goal, this study conducted a linking analysis and computed a crosswalk table between these two scales. DATA: The data of this study were collected as part of the clinical care of total knee arthroplasty patients in a large urban and suburban health system. The sample was a mix of responses from nonsurgical (no surgery performed), preoperative (before surgical intervention), and postoperative (after surgical intervention) groups. METHODS: This study applied five linking methods: the item response theory (IRT)-based linking methods including fixed-parameter calibration, separate-parameter calibration with Stocking-Lord constants, and calibrated projection; and the equipercentile methods with log-linear smoothing and nonsmoothing approaches. Before conducting the linking analysis, we checked the linking assumptions including the similar content of the two scales, the unidimensionality of the combined scales, and the population invariance. The results of the five linking methods were evaluated by mean difference, SD, root-mean-squared deviation, intraclass correlation coefficient of the observed T scores and the crosswalk-derived T scores. RESULTS: The linking assumptions were all met. T scores generated from the Stocking-Lord crosswalk had the smallest mean difference (= -0.03) and relatively small SD (= 4.91) and root-mean-squared deviation (= 4.91) among the five linking methods. We validated this crosswalk in a larger sample with the nonsurgical, preoperative, and postoperative groups and in an external sample. DISCUSSION: This study provides clinicians and researchers a practical tool (ie, a crosswalk table) to link scores from two popular physical function measures. Given the diversity of patient-reported outcome measures in use for knee conditions, these crosswalk tables would accelerate clinical and research interpretation of aggregating functional outcomes among the patients evaluated for knee surgery each year.

SLAMF7 engagement superactivates macrophages in acute and chronic inflammation.

Macrophages regulate protective immune responses to infectious microbes, but aberrant macrophage activation frequently drives pathological inflammation. To identify regulators of vigorous macrophage activation, we analyzed RNA-seq data from synovial macrophages and identified SLAMF7 as a receptor associated with a superactivated macrophage state in rheumatoid arthritis. We implicated IFN-γ as a key regulator of SLAMF7 expression and engaging SLAMF7 drove a strong wave of inflammatory cytokine expression. Induction of TNF-α after SLAMF7 engagement amplified inflammation through an autocrine signaling loop. We observed SLAMF7-induced gene programs not only in macrophages from rheumatoid arthritis patients but also in gut macrophages from patients with active Crohn's disease and in lung macrophages from patients with severe COVID-19. This suggests a central role for SLAMF7 in macrophage superactivation with broad implications in human disease pathology.

Reliability and Reproducibility of Sacro-Femoro-Pubic Angle Measurements on Anteroposterior Pelvis Radiographs.

BACKGROUND: The sacro-femoro-pubic (SFP) angle is a surrogate measurement for pelvic tilt obtained on anteroposterior (AP) pelvis radiographs. It is unknown whether the SFP angle can be measured reliably by senior surgeons and trainees alike. METHODS: We conducted an intrareader and interreader reliability study using preoperative AP pelvis radiographs. Using our hospital electronic database, we randomly selected 31 subjects undergoing primary total hip arthroplasty. An attending orthopedic surgeon and two orthopedic surgery residents performed two separate SFP angle measurements for each subject. Intrareader and interreader agreement were measured using intraclass correlation coefficients (ICC). RESULTS: Pairwise intrareader and interreader ICCs ranged from 0.91 to 0.99. Overall ICC was 0.94. Interreader ICCs between the attending surgeon and each orthopedic resident were 0.93 and 0.98, and the ICC between orthopedic residents was 0.91. Interreader mean differences for SFP angle measurements were 2.32 degrees or less: -2.03 (standard deviation: 2.23) and 0.29 (1.64) between the attending surgeon and each orthopedic resident, and 2.32 (2.44) between orthopedic residents. CONCLUSION: SFP angle may be measured reliably on AP pelvis radiographs by senior clinicians and trainees. SFP angle measurement may prove helpful as an alternative to pelvic tilt measurements when lateral pelvic radiographs are not available.

Correlation Between Patient-Reported Outcome Measures and Health Insurance Provider Types in Patients with Hip Osteoarthritis.

BACKGROUND: Patient-reported outcome measures (PROMs) are frequently utilized to assess patient perceptions of health and function. Numerous factors influence self-reported physical and mental health outcome scores. The purpose of this study was to examine if an association exists between insurance payer type and baseline PROM scores in patients diagnosed with hip osteoarthritis. METHODS: We retrospectively reviewed the baseline PROM scores of 5,974 patients diagnosed with hip osteoarthritis according to the International Classification of Diseases, Tenth Revision (ICD-10) code within our institutional database from 2015 to 2020. We examined Hip disability and Osteoarthritis Outcome Score-Physical Function Short-form (HOOS-PS), Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function Short Form 10a (PF10a), PROMIS Global-Mental, and PROMIS Global-Physical scores. Descriptive analyses, analysis of variance (ANOVA), analysis of covariance (ANCOVA), and post hoc analyses were utilized to assess variations in PROM scores across insurance type. RESULTS: The mean age (and standard deviation) of the study population was 63.5 ± 12.2 years, and 55.7% of patients were female. The Medicaid cohort had a comparatively higher percentage of Black, Hispanic, and non-English-speaking patients and a lower median household income. The Charlson Comorbidity Index was highest in the Medicare and Medicaid insurance cohorts. Patients utilizing commercial insurance consistently demonstrated the highest baseline PROMs, and patients utilizing Medicaid consistently demonstrated the lowest baseline PROMs. Subsequent analyses found significantly poorer mean scores for the Medicaid cohort for all 4 PROMs when compared with the commercial insurance and Medicare cohorts. These score differences exceeded the minimal clinically important differences (MCIDs). For the PROMIS Global-Mental subscore, a significantly lower mean score was observed for the Workers' Compensation and motor vehicle insurance cohort when compared with the commercial insurance and Medicare cohort. This difference also exceeded the MCID. CONCLUSIONS: PROM scores in patients with hip osteoarthritis varied among those with different insurance types. Variations in certain demographic and health indices are potential drivers of these observed baseline PROM differences. For patients with hip osteoarthritis, the use of PROMs for research, clinical, or quality-linked payment metrics should acknowledge baseline variation between patients with different insurance types. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

HIV-Positive Patients Are at Increased Risk of Venous Thromboembolism After Total Joint Replacement.

BACKGROUND: Antiretroviral therapy has improved the life expectancy of HIV patients, leading to an increase in total joint replacement for age-related osteoarthritis. HIV patients are inherently hypercoagulable at baseline. The goal of our study was to compare the incidence of venous thromboembolism (VTE) in HIV patients with HIV-negative controls after total joint replacement. METHODS: A multicenter, retrospective cohort study of 110 HIV patients (85 hips and 25 knees) and 240 HIV-negative controls (180 hips and 85 knees) between 2000 and 2018. Prophylactic anticoagulation was used in 98% of patients postoperatively-low-molecular weight heparin (73%), warfarin (19%), aspirin (6%), and clopidogrel (1%). RESULTS: The VTE rate was 3.6% in the HIV-positive group (2.5% total hip arthroplasty [THA] and 8.0% total knee arthroplasty [TKA]) and 0.4% in the control group (0% THA and 1.7% TKA). VTEs occurred at the median (interquartile range) time of 40 days (1 to 52) post-op in the HIV group and 3 days post-op in the one control. Multivariable logistic regression adjusting for sex, smoking, history of VTE, and joint replaced identified HIV as an independent predictor of VTE (odds ratio 10.9, 95% confidence interval 1.1 to 114.0, P = 0.046). All patients with VTE were treated with warfarin (5 to 9 months); two cases were complicated by hemarthrosis and excessive bleeding at the insulin injection site. CONCLUSION: We observed increased rates of symptomatic VTE in HIV patients after THA (2.5%) and TKA (8%) compared with HIV-negative control patients (0% and 1.7%, respectively). HIV positivity was identified as an independent predictor of perioperative VTE. Our data suggests that HIV patients may be at higher risk for post-op VTE than HIV-negative patients. Surgeons may want to consider the use of more potent anticoagulation (ie, warfarin or novel anticoagulants) for a longer duration in HIV-positive patients. However, further studies are necessary to form evidence-based guidelines regarding this practice. LEVEL OF EVIDENCE: Level III, prognostic.

Weight loss before total joint arthroplasty using a remote dietitian and mobile app: study protocol for a multicenter randomized, controlled trial.

BACKGROUND: The months prior to elective surgery may present an opportunity for patients to initiate behavior changes that will simultaneously ready them for surgery and improve their overall health status. An upcoming elective total joint arthroplasty (TJA) may serve as motivation for patients with severe obesity (body mass index [BMI]> 40 kg/m2) to lose weight, as it may optimize clinical outcomes following TJA and help them become eligible for TJA since some surgeons use a BMI of 40 kg/m2 as a cut-off for offering surgery in an effort to optimize outcomes. METHODS: The purpose of this multicenter randomized, controlled trial is to assess the feasibility and efficacy of a 12-week remote dietitian (RD) supervised dietary and physical activity weight loss intervention and mobile app for 60 patients with severe obesity prior to undergoing TJA. Intervention participants will receive access to a smartphone app and connect with an RD who will contact these participants weekly or bi-weekly via video calls for up to nine video calls. Together, participants and RDs will set goals for lifestyle modifications, and RDs will check on progress towards achieving these goals using in-app tools such as food logs and text messages between video calls. All patients will be encouraged to lose at least 20 pounds with a goal BMI < 40 kg/m2 after 12 weeks. Individuals randomized to the control group will receive clinical standard of care, such as nutritionist and/or physical therapy referrals. Outcome and demographic data will be collected from blood serology, chart review, mobile app user data, pre- and postintervention surveys, and phone interviews. The primary outcome measure will be weight change from baseline. Secondary outcome measures will include percentage of patients eligible to undergo TJA, number of sessions completed with dietitians, self-reported global health status (PROMIS Global Health scale), self-reported joint-specific pain and function (Knee injury and Osteoarthritis Outcome Score (KOOS) or Hip disability and Osteoarthritis Outcome Score (HOOS)), and serologies such as hemoglobin A1c, total lymphocyte count, albumin, and transferrin. Qualitative responses transcribed from phone interviews about the intervention will also be analyzed. DISCUSSION: This will be the first study to assess pre-operative weight loss in patients with severe obesity anticipating orthopaedic surgery using an RD and mobile app intervention aimed at helping patients become eligible for TJA. TRIAL REGISTRATION: Registered on 1 April 2020 at Clincialtrials.gov. Trial number is NCT04330391 .

Association Between Preoperative Radiographic Severity of Osteoarthritis and Patient-Reported Outcomes of Total Knee Replacement.

BACKGROUND: The goal of this study was to investigate the association between preoperative radiographic severity of knee osteoarthritis (OA) and patient-reported outcomes following total knee replacement. METHODS: We used data from a prospective cohort study of individuals who underwent total knee replacement at a high-volume medical center. Patient-reported outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score and the Knee injury and Osteoarthritis Outcome Score (KOOS) activities of daily living (ADL) subscore, assessed preoperatively and 2 years postoperatively. We measured preoperative radiographic OA severity using the Osteoarthritis Research Society International (OARSI) Atlas score, dichotomized at the median. We assessed the association between radiographic OA severity and postoperative patient-reported outcomes in bivariate analyses and in multivariable linear regression, with adjustment for age, sex, body mass index, and comorbidity score. RESULTS: The analytic cohort included 240 patients with a mean age at surgery of 66.6 years (standard deviation, 8 years); 61% were female. The median total OARSI radiographic severity score was 10 (range, 3 to 17). The cohort improved substantially at 2 years following total knee replacement, with WOMAC pain and KOOS ADL score improvements on the order of 30 points. We did not observe significant or clinically important differences in pain relief or functional improvement between patients with milder and more severe radiographic OA. Sensitivity analyses using other radiographic assessment measures yielded similar findings. CONCLUSIONS: Total knee replacement offers substantial symptomatic relief and functional improvement regardless of preoperative radiographic OA severity. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Notch signalling drives synovial fibroblast identity and arthritis pathology.

The synovium is a mesenchymal tissue composed mainly of fibroblasts, with a lining and sublining that surround the joints. In rheumatoid arthritis the synovial tissue undergoes marked hyperplasia, becomes inflamed and invasive, and destroys the joint1,2. It has recently been shown that a subset of fibroblasts in the sublining undergoes a major expansion in rheumatoid arthritis that is linked to disease activity3-5; however, the molecular mechanism by which these fibroblasts differentiate and expand is unknown. Here we identify a critical role for NOTCH3 signalling in the differentiation of perivascular and sublining fibroblasts that express CD90 (encoded by THY1). Using single-cell RNA sequencing and synovial tissue organoids, we found that NOTCH3 signalling drives both transcriptional and spatial gradients-emanating from vascular endothelial cells outwards-in fibroblasts. In active rheumatoid arthritis, NOTCH3 and Notch target genes are markedly upregulated in synovial fibroblasts. In mice, the genetic deletion of Notch3 or the blockade of NOTCH3 signalling attenuates inflammation and prevents joint damage in inflammatory arthritis. Our results indicate that synovial fibroblasts exhibit a positional identity that is regulated by endothelium-derived Notch signalling, and that this stromal crosstalk pathway underlies inflammation and pathology in inflammatory arthritis.