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Surgical repair of hip fracture carries substantial short-term risks of mortality and complications. The risk-reward calculus for most patients with hip fractures favors surgical repair. However, some patients have low prefracture functioning, frailty, and/or very high risk of postoperative mortality, making the choice between surgical and nonsurgical management more difficult. The importance of high-quality informed consent and shared decision-making for frail patients with hip fracture has recently been demonstrated. A tool to accurately estimate patient-specific risks of surgery could improve these processes.With this study, we sought (1) to develop, validate, and estimate the overall accuracy (C-index) of risk prediction models for 30-day mortality and complications after hip fracture surgery; (2) to evaluate the accuracy (sensitivity, specificity, and false discovery rates) of risk prediction thresholds for identifying very high-risk patients; and (3) to implement the models in an accessible web calculator.In this comparative study, preoperative demographics, comorbidities, and preoperatively known operative variables were extracted for all 82,168 patients aged 18 years and older undergoing surgery for hip fracture in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) between 2011 and 2017. Eighty-two percent (66,994 of 82,168 ) of patients were at least 70 years old, 21% (17,007 of 82,168 ) were at least 90 years old, 70% (57,260 of 82,168 ) were female, and 79% (65,301 of 82,168 ) were White. A total of 5% (4260 of 82,168) of patients died within 30 days of surgery, and 8% (6786 of 82,168) experienced a major complication. The ACS-NSQIP database was chosen for its clinically abstracted and reliable data from more than 600 hospitals on important surgical outcomes, as well as rich characterization of preoperative demographic and clinical predictors for demographically diverse patients. Using all the preoperative variables in the ACS-NSQIP dataset, least absolute shrinkage and selection operator (LASSO) logistic regression, a type of machine learning that selects variables to optimize accuracy and parsimony, was used to develop and validate models to predict two primary outcomes: 30-day postoperative mortality and any 30-day major complications. Major complications were defined by the occurrence of ACS-NSQIP complications including: on a ventilator longer than 48 hours, intraoperative or postoperative unplanned intubation, septic shock, deep incisional surgical site infection (SSI), organ/space SSI, wound disruption, sepsis, intraoperative or postoperative myocardial infarction, intraoperative or postoperative cardiac arrest requiring cardiopulmonary resuscitation, acute renal failure needing dialysis, pulmonary embolism, stroke/cerebral vascular accident, and return to the operating room. Secondary outcomes were six clusters of complications recently developed and increasingly used for the development of surgical risk models, namely: (1) pulmonary complications, (2) infectious complications, (3) cardiac events, (4) renal complications, (5) venous thromboembolic events, and (6) neurological events. Tenfold cross-validation was used to assess overall model accuracy with C-indexes, a measure of how well models discriminate patients who experience an outcome from those who do not. Using the models, the predicted risk of outcomes for each patient were used to estimate the accuracy (sensitivity, specificity, and false discovery rates) of a wide range of predicted risk thresholds. We then implemented the prediction models into a web-accessible risk calculator.The 30-day mortality and major complication models had good to fair discrimination (C-indexes of 0.76 and 0.64, respectively) and good calibration throughout the range of predicted risk. Thresholds of predicted risk to identify patients at very high risk of 30-day mortality had high specificity but also high false discovery rates. For example, a 30-day mortality predicted risk threshold of 15% resulted in 97% specificity, meaning 97% of patients who lived longer than 30 days were below that risk threshold. However, this threshold had a false discovery rate of 78%, meaning 78% of patients above that threshold survived longer than 30 days and might have benefitted from surgery. The tool is available here: https://s-spire-clintools.shinyapps.io/hip_deploy/ .The models of mortality and complications we developed may be accurate enough for some uses, especially personalizing informed consent and shared decision-making with patient-specific risk estimates. However, the high false discovery rate suggests the models should not be used to restrict access to surgery for high-risk patients. Deciding which measures of accuracy to prioritize and what is "accurate enough" depends on the clinical question and use of the predictions. Discrimination and calibration are commonly used measures of overall model accuracy but may be poorly suited to certain clinical questions and applications. Clinically, overall accuracy may not be as important as knowing how accurate and useful specific values of predicted risk are for specific purposes.Level of Evidence Level III, therapeutic study.

Direct data abstraction from a patient's chart by experienced medical professional data abstractors has been the historical gold standard for quality and accuracy in clinical medical research. The limiting challenge to population-wide studies for quality and public health purposes is the high personnel costs associated with very large-scale efforts of this type. Two historically related programs that are at least partially able to successfully circumvent this problem and provide high-quality data relating to surgical procedures and the early postoperative period are reviewed in this article. Both utilize similar data abstraction efforts by specially trained and qualified medical abstractors of a sample subset of the total procedures performed at participating hospitals.The Veterans Affairs Surgical Quality Improvement Program (VASQIP), detailed by Nicholas J. Giori, MD, PhD, in the first section of this article, makes use of trained abstractors and has undergone recent additions and updates, including the development of an associated total hip registry for the VA system. The data elements and data integrity provided by both of these programs establish important benchmarks for other "big data" efforts, which often attempt to use alternative less-expensive methods of data collection in order to achieve more widespread or even nationwide data collection.In the second section, Elizabeth B. Habermann, PhD, MPH, provides a detailed review of the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP), the data elements collected, and examples of the range of quality improvement and outcomes studies in orthopaedic surgery that it has made possible, along with information on data that have not been collected and the resulting limitations. The ACS NSQIP was actually modeled after the very similar earlier effort started by the United States Department of Veterans Affairs (VA).

Hydroxyapatite (HA) coatings were introduced to improve uncemented implant osteointegration and to prevent loosening and osteolysis. However, data regarding these implants have been inconsistent. We studied the effect of HA coating of femoral stems and acetabular cups on component revision after primary total hip arthroplasty (THA) in the veteran population.We identified patients who underwent uncemented primary THA at any Veterans Health Administration (VHA) hospital from 2000 to 2017 and who had implants that were available as either HA-coated or non-HA-coated models. The endpoint was removal of the component of interest for any reason. For each individual stem and shell, unadjusted and adjusted (for age and body mass index) Cox proportional hazards models were used to estimate hazard ratios for the risk of explantation between HA-coated and non-HA-coated implants of the same type.A total of 262 HA-coated cups, 4580 non-HA-coated cups, 4767 HA-coated stems, and 9397 non-HA-coated stems were available for analysis. The mean follow-up time was 9.01 years (43,627 total implant-years) for cups and 7.13 years (101,004 total implant-years) for stems. One of the two shells reviewed had significantly lower survivorship and an elevated hazard ratio for explantation with HA coating. Among the five implant pairs of stems, and the other shell, implant survival and hazard ratios for explantation were not affected by HA coating.HA coating did not improve THA implant survival in our veteran population. Although HA-coated versions of hip implants tend to be more costly than their noncoated counterparts, these results do not support their general use.

ImportanceRecent legislation expanded veterans’ access to Veterans Health Administration (VA)-purchased care. Quality should be considered when choosing where to get total knee arthroplasty (TKA), but currently available quality metrics provide little guidance.ObjectiveTo determine whether an association exists between the proportion of TKAs performed (vs purchased) at each VA facility and the quality of care provided (as measured by short-term complication rates).Design, Setting, and ParticipantsThis 3-year cohort study used VA and community care data (fiscal year 2017 to fiscal year 2019) from the VA’s Corporate Data Warehouse. Complications were defined following the Centers for Medicare and Medicaid Services’ methodology. The setting included 140 VA health care facilities performing or purchasing TKAs. Participants included veterans who had 43 371 primary TKA procedures that were either VA-performed or VA-purchased during the study period.ExposuresOf the 43 371 primary TKA procedures, 18 964 (43.7%) were VA-purchased.Main Outcomes and MeasuresThe primary outcome was risk-standardized short-term complication rates of VA-performed or VA-purchased TKAs. The association between the proportion of TKAs performed at each VA facility and quality of VA-performed and VA-purchased care was examined using a regression model. Subgroups were also identified for facilities that had complication rates above or below the overall mean complication rate and for facilities that performed more or less than half of the facility’s TKAs.ResultsAmong the study sample’s 41 775 veterans who underwent 43 371 TKAs, 38 725 (89.3%) were male, 6406 (14.8%) were Black, 33 211 (76.6%) were White, and 1367 (3.2%) had other race or ethnicity (including American Indian or Alaska Native, Asian, and Native Hawaiian or other Pacific Islander); mean (SD) age was 66.9 (8.5) years. VA-performed and VA-purchased TKAs had a mean (SD) raw overall short-term complication rate of 2.97% (0.08%). There was no association between the proportion of TKAs performed in VA facilities and risk-standardized complication rates for VA-performed TKAs, and no association for VA-purchased TKAs.Conclusions and RelevanceIn this cohort study, surgical quality did not have an association with where veterans had TKA, possibly because meaningful comparative data are lacking. Reporting local and community risk-standardized complication rates may inform veterans’ decisions and improve care. Combining these data with the proportion of TKAs performed at each site could facilitate administrative decisions on where resources should be allocated to improve care.

There are growing concerns that Veterans' increased use of Veterans Health Administration (VA)-purchased care in the community may lead to lower quality of care.We compared rates of hospital readmissions following elective total knee arthroplasties (TKAs) that were either performed in VA or purchased by VA through community care (CC) at both the national and facility levels.Three-year cohort study using VA and CC administrative data from the VA's Corporate Data Warehouse (October 1, 2016-September 30, 2019). We obtained Medicare data to capture readmissions that were paid by Medicare. We used the Centers for Medicare and Medicaid Services (CMS) methods to identify unplanned, 30-day, all-cause readmissions. A secondary outcome, TKA-related readmissions, identified readmissions resulting from complications of the index surgery. We ran mixed-effects logistic regression models to compare the risk-adjusted odds of all-cause and TKA-related readmissions between TKAs performed in VA versus CC, adjusting for patients' sociodemographic and clinical characteristics.Nationally, the odds of experiencing an all-cause or TKA-related readmission were significantly lower for TKAs performed in VA versus CC (eg, the odds of experiencing an all-cause readmission in VA were 35% of those in CC. At the facility level, most VA facilities performed similarly to their corresponding CC providers, although there were 3 VA facilities that performed worse than their corresponding CC providers.Given VA's history in providing high-quality surgical care to Veterans, it is important to closely monitor and track whether the shift to CC for surgical care will impact quality in both settings over time.

BACKGROUND: Recently, impingement between the femoral stem and ceramic liner, which appears as a notch in the stem neck on radiographs, has emerged as a new complication. However, the proportion of impingement, potential risk factors, and related complications are poorly elucidated. QUESTION/PURPOSES: In patients who underwent ceramic-on-ceramic (CoC) THA and had at least 10 years of follow-up, we asked: (1) What proportion had radiographic evidence of stem neck–ceramic liner impingement (notching of the stem), and what implant design, implantation factors, or complications such as ceramic fracture or metallosis are associated with impingement? (2) How common are the complications of noise and ceramic fracture? (3) What are the radiologic changes (including fixation of femoral and acetabular components, osteolysis, and heterotopic ossification) and clinical outcomes as determined by the modified Harris hip score (mHHS) for this cohort? (4) What is the survivorship with implant revision as the endpoint and with reoperation for any reason as the endpoint after CoC THA using a thick-neck stem design? METHODS: Between May 2003 and April 2010, 643 patients underwent primary THA at a tertiary referral hospital. After excluding patients with metal-on-polyethylene and with ceramic-on-polyethylene implants, 621 patients were considered eligible for this study. All patients received the same hemispherical titanium cup, a standard-length tapered titanium stem, and a CoC bearing. Of those, 19% (115) were lost to follow-up before 10 years, and 8% (50) were excluded because they died before the minimum follow-up duration of 10 years, leaving 73% (456) for analysis. Patients had a mean age of 50 ± 14 years and were followed for a median (range) of 13 years (10 to 17). The mean cup abduction was 38° ± 5°, and the mean cup anteversion was 26° ± 7°. To determine the proportion of patients with the neck-liner impingement, we analyzed the plain radiographs of every patient during follow-up to detect notches around the stem. The detection of stem neck notches on the radiographs was reliable (intraobserver reliability: κ = 0.963; p < 0.001 and interobserver reliability: κ = 0.975; p < 0.001). To evaluate factors related to notching, we compared the possible confounding factors including gender, age, BMI, implant position, neck length, and head diameter. Complications such as ceramic fracture, noise, dislocation, and periprosthetic joint infection were recorded. Noise was evaluated via interview and with the Hip Noise Assessment Questionnaire, which assessed the noise qualitatively. For clinical outcome, we assessed the mHHS, which includes pain and function scales (0 [worst] to 100 [best]), every visit. Tilting of at least 4° or migration of at least 4 mm was the criteria for cup loosening; subsidence more than 3 mm, any change in position, or a continuous radiolucent line greater than 2 mm was the criteria for stem loosening. To evaluate osteolysis, we performed CT scans in 57% (262 of 456) of patients. Kaplan-Meier survivorship analysis was performed using the endpoints of survivorship free from implant revision and survivorship free from reoperation for any cause. RESULTS: The proportion of stem neck notching was 11% (49 of 456). There were no differences in cup abduction and anteversion between hips with notches and those without notches. Notched hips were more likely to have 28-mm than 32-mm heads (90% [44 of 49] versus 70% [285 of 407]; odds ratio 3.77 [95% CI 1.46 to 9.73]; p = 0.004). None of the 49 notched hips had a ceramic head or liner fracture or evidence of metallosis. A ceramic head fracture was reported in 2% (9 of 456); all fractures occurred in 28-mm short neck heads. A ceramic liner fracture occurred in 0.2% (1 of 456), and noise was noted in 6% (27 of 456). Acetabular osteolysis developed in 2% (7 of 456). The mHHS was 91 ± 12 points at the final follow-up. The survivorship free from implant revision was 97% (95% CI 96% to 99%), and the survivorship free from reoperation for any cause was 96% (95% CI 95% to 98%) at 13 years. CONCLUSION: The proportion of stems with neck–ceramic liner impingement and ceramic component fracture were unacceptably high after the use of a thick-neck stem design, especially when a 28-mm head was used. We have discontinued the use of this stem design and we recommend that such stems should not be used when CoC bearings are used. As these findings might be generalized to other bearing couples, further studies focused on polyethylene liner wear and local metallosis due to thick stem neck are warranted. LEVEL OF EVIDENCE: Level III, therapeutic study.

The Department of Veterans Affairs (VA) both delivers health care in its own facilities and, increasingly, purchases care for veterans in the community. Policy makers, administrators, health care providers, and veterans frequently face decisions about which services should be delivered versus purchased by the VA. Comparisons of quality across settings are essential if veterans are to receive care that is consistently accessible, patient centered, effective, and safe. We compared risk-adjusted major postoperative complication rates for total knee arthroplasties that were delivered in VA facilities versus purchased from community providers. Overall, adjusted complication rates were significantly lower for arthroplasties delivered by the VA compared with those that were purchased. However, hospital-level comparisons revealed five locations where VA-purchased care outperformed VA-delivered care. As the amount of VA-purchased care continues to increase under the Veterans Access, Choice, and Accountability Act of 2014 and the VA Maintaining Internal Systems and Strengthening Integrated Outside Networks Act of 2018, these results support VA monitoring of overall and local comparative hospital performance to improve the quality of the care that the VA delivers while ensuring optimal outcomes in VA-purchased care.

Background Lewinnek’s recommendation for orienting the cup in THA is criticized because it involves a static assessment of the safe zone and because it does not consider stem geometry. A revised concept of the safe zone should consider those factors, but to our knowledge, this has not been assessed. Questions/purposes (1) To determine the shape, size, and location of target zones for combined cup and stem orientation for a straight stem/hemispheric cup THA to maximize the impingement-free ROM and (2) To determine whether and how these implant positions change as stem anteversion, neck-shaft angle, prosthetic head size and target range of movements are varied. Methods A three-dimensional computer-assisted design model, in which design geometry was expressed in terms of parameters, of a straight stem/hemispheric cup hip prosthesis was designed, its design parameters modified systematically, and each prosthesis model was implanted virtually at predefined component orientations. Functional component orientation referencing to body planes was used: cups were abducted from 20° to 70°, and anteverted from -10° to 40°. Stems were rotated from -10° to 40° anteversion, neck-shaft angles varied from 115° to 143°, and head sizes varied from 28 to 40 mm. Hip movements up to the point of prosthetic impingement were tested, including simple flexion/extension, internal/external rotation, ab/adduction, combinations of these, and activities of daily living that were known to trigger dislocation. For each combination of parameters, the impingement-free combined target zone was determined. Maximizing the size of the combined target zone was the optimization criterion. Results The combined target zones for impingement-free cup orientation had polygonal boundaries. Their size and position in the diagram changed with stem anteversion, neck-shaft angle, head size, and target ROM. The largest target zones were at neck-shaft angles from 125° to 127°, at stem anteversions from 10° to 20°, and at radiographic cup anteversions between 17° and 25°. Cup anteversion and stem anteversion were inverse-linearly correlated supporting the combined-anteversion concept. The range of impingement-free cup inclinations depended on head size, stem anteversion, and neck-shaft angle. For a 127°-neck-shaft angle, the lowest cup inclinations that fell within the target zone were 42° for the 28-mm and 35° for the 40-mm head. Cup anteversion and combined version depended on neck-shaft angle. For head size 32-mm cup, anteversion was 6° for a 115° neck-shaft angle and 25° for a 135°-neck-shaft angle, and combined version was 15° and 34° respectively. Conclusions The shape, size, and location of the combined target zones were dependent on design and implantation parameters of both components. Changing the prosthesis design or changing implantation parameters also changed the combined target zone. A maximized combined target zone was found. It is mandatory to consider both components to determine the accurate impingement-free prosthetic ROM in THA. Clinical Relevance This study accurately defines the hypothetical impingement-free, design-specific component orientation in THA. Transforming it into clinical precision may be the case for navigation and/or robotics, but this is speculative, and as of now, unproven.

Objective This retrospective cohort study tested the hypothesis that implementing a multidisciplinary patient-specific discharge protocol for prescribing and tapering opioids after total hip arthroplasty (THA) will decrease the morphine milligram equivalent (MME) dose of opioids prescribed. Methods With institutional review board approval, we analyzed a Perioperative Surgical Home database and prescription data for all primary THA patients three months before (PRE) and three months after (POST) implementation of this new discharge opioid protocol based on patients’ prior 24-hour inpatient opioid consumption. The primary outcome was total opioid dosage in MME prescribed and opioid refills for six weeks after surgery. Secondary outcomes included the number of tablets and MME prescribed at discharge, in-hospital opioid consumption, length of stay, and postoperative complications. Results Forty-nine cases (25 PRE and 24 POST) were included. Total median (10th–90th percentiles) MME for six weeks postoperatively was 900 (57–2082) MME PRE vs 295 (69–741) MME POST (mean difference = 721, 95% confidence interval [CI] = 127–1316, P = 0.007, Mann-Whitney U test). Refill rates did not differ. The median (10th–90th percentiles) initial discharge prescription in MME was 675 (57–1035) PRE vs 180 (18–534) POST (mean difference = 387, 95% CI = 156–618, P = 0.003, Mann-Whitney U test) MME. There were no differences in other outcomes. Conclusions Implementation of a patient-specific prescribing and tapering protocol decreases the mean six-week dosage of opioid prescribed by 63% after THA without increasing the refill rate.

Evidence is limited regarding cannabinoid use among total joint arthroplasty (TJA) patients, despite increased availability and popularity for treating chronic pain. The authors hypothesized that preoperative cannabinoid use increased and opioid use decreased during a 6-year interval in total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients, and also asked whether complications were associated with use of these substances. This retrospective, single-institution study reviewed electronic medical records and the Veterans Affairs Surgical Quality Improvement Program (VASQIP) database for TJA cases from 2012 through 2017. Primary outcomes were the prevalence and trends of active cannabinoid and opioid use, as determined by routine preoperative urine toxicology screening. Multivariable regression analyses were conducted to investigate a secondary outcome, whether there was an association between cannabinoid or opioid use and postoperative complications. A total of 1778 operations (1161 TKAs and 617 THAs) performed on 1519 patients were reviewed. The overall prevalence of pre-operative cannabinoid and opioid use was 11% and 23%, respectively. Comparing 2012 with 2017, cannabinoid use increased from 9% to 15% ( P =.049), and opioid use decreased from 24% to 17% ( P =.040). Cannabinoid users were more likely to be taking opioids than nonusers ( P =.002). Controlling for age, sex, surgery type, and American Society of Anesthesiologists score, cannabinoid use was not associated with 90-day readmission, infection, reoperation, or other VASQIP-captured complications. Laboratory testing indicated a much higher prevalence of cannabinoid use among TJA patients than previously reported. During a 6-year period, cannabinoid use increased more than 60%, and opioid use decreased approximately 30%. These findings indicate that cannabinoid use did not appear to be associated with perioperative complications. [ Orthopedics . 2021;44(1):e101–e106.]

Objective The optimal continuous peripheral nerve block (CPNB) technique for total hip arthroplasty (THA) that maximizes both analgesia and mobility is unknown. Continuous erector spinae plane (ESP) blocks were implemented at our institution as a replacement for fascia iliaca (FI) catheters to improve our THA clinical pathway. We designed this study to test the hypothesis that this change will increase early postoperative ambulation for elective primary THA patients. Methods We identified all consecutive primary unilateral THA cases six months before and six months after the clinical pathway change to ESP catheters. All other aspects of the THA clinical pathway and multimodal analgesic regimen including perineural infusion protocol did not change. The primary outcome was total ambulation distance (meters) on postoperative day 1. Other outcomes included total ambulation on postoperative day 2, combined two-day ambulation distance, pain scores, opioid consumption, inpatient length of stay, and minor and major adverse events. Results Eighty-eight patients comprised the final sample (43 FI and 45 ESP). Postoperative day 1 total ambulation distance was greater for the ESP group compared with the FI group (median [10th–90th percentiles] = 24.4 [0.0–54.9] vs 9.1 [0.7–45.7] meters, respectively, P = 0.036), and two-day ambulation distance was greater for the ESP group compared with the FI group (median [10th–90th percentiles] = 68.6 [9.0–128.0] vs 46.6 [3.7–104.2] meters, respectively, P = 0.038). There were no differences in pain scores, opioid use, or other outcomes. Conclusions Replacing FI catheters with continuous ESP blocks within a clinical pathway results in increased early ambulation by elective primary THA patients.

In 2012, we reported on the prevalence of hepatitis C virus (HCV) infection in Veterans Affairs (VA) patients undergoing total joint arthroplasty (TJA) at our center. In this patient population, 8.4% were antibody positive and 4.5% were viremic with HCV. In 2014, the first all-oral direct-acting antiviral treatment for hepatitis C became available. The Department of Veterans Affairs then underwent an aggressive program to eradicate hepatitis C from the veteran population. The purpose of this report is to provide updated information on the prevalence of HCV viremia among patients undergoing primary TJA at the same center.A retrospective review was performed of all patients undergoing primary TJA at a single VA medical center in 2019. Anti-HCV antibody and HCV viremia prevalence were calculated. Comparisons were made to data from a previously reported cohort of patients who had undergone TJA at the same center from 2007 to 2009.Thirty-three (11.6%) of 285 patients screened preoperatively were positive for the hepatitis C antibody. Only one of the 33 anti-HCV-positive patients was viremic at the time of screening for an overall viremic prevalence of 0.4%. We found no statistically significant difference in the birth year, or anti-HCV antibody-positive rate from the prior cohort, but the prevalence of HCV viremia decreased significantly.Because direct-acting antiviral HCV treatment has become available, HCV viremia among VA patients undergoing TJA has been reduced from 4.5% to 0.4%. Surgeons are still advised to minimize the risk of sharps injury.

BACKGROUND Both neuraxial and peripheral regional analgesic techniques offer postoperative analgesia for total hip arthroplasty (THA) patients. While no single technique is preferred, quadriceps muscle weakness from peripheral nerve blocks may impede rehabilitation. We designed this study to compare postoperative ambulation outcome in THA patients who were treated with a new ultrasound-guided fascia iliaca catheter (FIC) technique or intrathecal morphine (ITM). METHODS We reviewed the electronic health records of a sequential series of primary unilateral THA patients who were part of a standardized clinical pathway; apart from differences in regional analgesic technique, all other aspects of the pathway were the same. Our primary outcome was total ambulation distance (meters) combined for postoperative days 1 and 2. Secondary outcomes included daily opioid consumption (morphine milligram equivalents) and analgesic-related side effects. We examined the association between the primary outcome and analgesic technique by performing crude and adjusted ordinary least-squares linear regression. A P value < 0.05 was considered statistically-significant. RESULTS The study analyzed the records of 179 patients (fascia iliaca, n = 106; intrathecal, n = 73). The primary outcome (total ambulation distance) did not differ between the groups (P = 0.08). Body mass index (BMI) was the only factor (β = -1.7 [95% CI -0.5 to -2.9], P < 0.01) associated with ambulation distance. Opioid consumption did not differ, while increased pruritus was seen in the intrathecal group (P < 0.01). CONCLUSIONS BMI affects postoperative ambulation outcome after hip arthroplasty, whereas the type of regional analgesic technique used does not. An ultrasound-guided FIC technique offers similar analgesia with fewer side effects when compared with ITM.

Background Approximately 15%-20% of total knee arthroplasty (TKA) patients do not experience clinically meaningful improvements. We sought to compare the accuracy and parsimony of several machine learning strategies for developing predictive models of failing to experience minimal clinically important differences in patient-reported outcome measures (PROMs) 1 year after TKA. Methods Patients (N = 587) in 3 large Veteran Health Administration facilities completed PROMs before and 1 year after TKA (92% follow-up). Preoperative PROMs and electronic health record data were used to develop and validate models to predict failing to experience at least a minimal clinically important difference in Knee Injury and Osteoarthritis Outcome Score (KOOS) Total, KOOS JR, and KOOS subscales (Pain, Symptoms, Activities of Daily Living, Quality of Life, and recreation). Several machine learning strategies were used for model development. Ten-fold cross-validation and bootstrapping were used to produce measures of overall accuracy (C-statistic, Brier Score). The sensitivity and specificity of various predicted probability cut-points were examined. Results The most accurate models produced were for the Activities of Daily Living, Pain, Symptoms, and Quality of Life subscales of the KOOS (C-statistics 0.76, 0.72, 0.72, and 0.71, respectively). Strategies varied substantially in terms of the numbers of inputs required to achieve similar accuracy, with none being superior for all outcomes. Conclusion Models produced in this project provide estimates of patient-specific improvements in major outcomes 1 year after TKA. Integrating these models into clinical decision support, informed consent and shared decision making could improve patient selection, education, and satisfaction. Level of Evidence Level III, diagnostic study.

Background Social determinants of health (SDOH) are the conditions in which people are born, grow, live, work, and age. They are associated with disparities in outcomes following total joint arthroplasty (TJA). These disparities occur even in equal-access healthcare systems such as the Veterans Health Administration (VHA). Our goal was to determine whether SDOH affect patient-reported outcome measures (PROMs) following TJA in VHA patients. Methods Patients scheduled to undergo total hip or knee arthroplasty at VHA Hospitals in Minneapolis, MN, Palo Alto, CA, and San Francisco, CA, prospectively completed PROMs before and 1 year after surgery. PROMs included the Hip disability and Osteoarthritis Outcome Score, the Knee injury and Osteoarthritis Outcome Score, and their Joint Replacement subscores. SDOH included race, ethnicity, marital status, education, and employment status. The level of poverty in each patient’s neighborhood was determined. Medical comorbidities were recorded. Univariate and multivariate analyses were performed to determine whether SDOH were significantly associated with PROM improvement after surgery. Results On multivariate analysis, black race was significantly negatively correlated with knee PROM improvement and Hispanic ethnicity was significantly negatively correlated with hip PROM improvement compared to whites. Higher baseline PROM scores and lower age were significantly associated with lower PROM improvement. Significant associations were also found based on education, gender, comorbidities, and neighborhood poverty. Conclusion Minority VHA patients have lower improvement in PROM scores after TJA than white patients. Further research is required to identify the reasons for these disparities and to design interventions to reduce them.

Introduction Patients with complete spinal cord injury (SCI) may develop concurrent sequalae that interact and share symptoms; thus, a careful approach to diagnosis and management of new symptoms is crucial. Case presentation A patient with prior T4 complete SCI presented with progressive autonomic nervous system (ANS) dysfunction. The initial differential diagnosis included syringomyelia and lumbar Charcot arthropathy. He had comorbid heterotopic ossification (HO) of the left hip. Surprisingly, his autonomic symptoms resolved following resection of the HO. In hindsight, loss of motion through the hip caused by HO may have led to hinging through a previously asymptomatic lumbar Charcot joint, causing dysautonomia. Discussion ANS dysfunction is a disabling sequela of complete SCI and has a broad differential diagnosis. Hip immobility may be an indirect and overlooked cause due to the mechanical relationship between the hip and the lumbar spine.

Hospital-related factors associated with mortality and morbidity after hip fracture surgery are not completely understood. The Veterans Health Administration (VHA) is the largest single-payer, networked healthcare system in the country serving a relatively homogenous patient population with facilities that vary in size and resource availability. These characteristics provide some degree of financial and patient-level controls to explore the association, if any, between surgical volume and facility resource availability and hospital performance regarding postoperative complications after hip fracture surgery.(1) Do VHA facilities with the highest complexity level designation (Level 1a) have a disproportionate number of better-than-expected performance outliers for major postoperative complications compared with lower-complexity level facilities? (2) Do VHA facilities with higher hip fracture surgical volume have a disproportionate number of better-than-expected performance outliers for major postoperative complications compared with lower-volume facilities?We explored the Veterans Affairs Surgical Quality Improvement Project (VASQIP) database from October 2001 to September 2012 for records of hip fracture surgery performed. Data reliability of the VASQIP database has been previously validated. We excluded nine of the 98 VHA facilities for contributing fewer than 30 records. The remaining 89 VHA facilities provided 23,029 records. The VHA designates a complexity level to each facility based on multiple criteria. We labeled facilities with a complexity Level 1a (38 facilities)-the highest achievable VHA designated complexity level-as high complexity; we labeled all other complexity level designations as low complexity (51 facilities). Facility volume was divided into tertiles: high (277 hip fracture procedures during the sampling frame), medium (204 to 277 procedures), and low (204 procedures). The patient population treated by low-complexity facilities was older, had a higher prevalence of severe chronic obstructive pulmonary disease (26% versus 22%, p0.001), and had a higher percentage of patients having surgery within 2 days of hospital admission (83% versus 76%, p0.001). High-complexity facilities treated more patients with recent congestive heart failure exacerbation (4% versus 3%, p0.001). We defined major postoperative complications as having at least one of the following: death within 30 days of surgery, cardiac arrest requiring cardiopulmonary resuscitation, new q-wave myocardial infarction, deep vein thrombosis and/or pulmonary embolism, ventilator dependence for at least 48 hours after surgery, reintubation for respiratory or cardiac failure, acute renal failure requiring renal replacement therapy, progressive renal insufficiency with a rise in serum creatinine of at least 2 mg/dL from preoperative value, pneumonia, or surgical site infection. We used the observed-to-expected ratio (O/E ratio)-a risk-adjusted metric to classify facility performance-for major postoperative complications to assess the performance of VHA facilities. Outlier facilities with 95% confidence intervals (95% CI) for O/E ratio completely less than 1.0 were labeled "exceed expectation;" those that were completely greater than 1.0 were labeled "below expectation." We compared differences in the distribution of outlier facilities between high and low-complexity facilities, and between high-, medium-, and low-volume facilities using Fisher's exact test.We observed no association between facility complexity level and the distribution of outlier facilities (high-complexity: 5% exceeded expectation, 5% below expectation; low-complexity: 8% exceeded expectation, 2% below expectation; p = 0.742). Compared with high-complexity facilities, the adjusted odds ratio for major postoperative complications for low-complexity facilities was 0.85 (95% CI, 0.67-1.09; p = 0.108).We observed no association between facility volume and the distribution of outlier facilities: 3% exceeded expectation and 3% below expectation for high-volume; 10% exceeded expectation and 3% below expectation for medium-volume; and 7% exceeded expectation and 3% below expectation for low-volume; p = 0.890). The adjusted odds ratios for major postoperative complications were 0.87 (95% CI, 0.73-1.05) for low- versus high-volume facilities and 0.89 (95% CI, 0.79-1.02] for medium- versus high-volume facilities (p = 0.155).These results do not support restricting facilities from treating hip fracture patients based on historical surgical volume or facility resource availability. Identification of consistent performance outliers may help health care organizations with multiple facilities determine allocation of services and identify characteristics and processes that determine outlier status in the interest of continued quality improvement.Level III, therapeutic study.

Total joint arthroplasty (TJA) in a homeless patient is generally considered contraindicated. Here, we report our known medical and social (housing and employment) results of homeless veterans who had TJA. Thirty-seven TJAs were performed on 33 homeless patients (31 men) at our hospital between November 2000 and March 2014. This was 1.2% of all TJAs. Average age was 54 years. Average hospital stay was 4.1 days. There were no major inpatient complications. Thirty-four cases had at least 1-year follow-up in any clinic within the Veterans Affairs health care system. There were no known surgery-related reoperations or readmissions. At final follow-up, 24 patients had stable housing and 9 were employed. The extensive and coordinated medical and social services that were provided to veterans from the Department of Veterans Affairs contributed to our positive results. Keywords: Homeless, Veteran, Joint replacement, Total hip, Total knee, Employment

Multimodal analgesic clinical pathways for joint replacement patients often include perineural catheters, but long-term adherence to these pathways has not yet been investigated. Our primary aim was to determine adherence rate to a knee arthroplasty clinical pathway for patients undergoing staged bilateral procedures.This study was performed at a hospital with a Perioperative Surgical Home program and knee arthroplasty clinical pathway using multimodal analgesia and adductor canal catheters. Data were examined for all orthopedic surgery patients over a 4-year period. We included patients who had staged bilateral knee arthroplasty electively scheduled on 2 separate dates. The primary outcome was rate of adductor canal catheter utilization as a measure of adherence to the clinical pathway. Other outcomes included rates of neuraxial anesthesia and minor and major perioperative complications.We analyzed data for 103 unique patients. The interval between surgeries was a median of 261 days (10th-90th percentile, 138-534 days). All 103 patients had adductor canal catheters for both the first and second surgeries (P0.999). Forty-one percent of patients had the same surgeon for both surgeries, but only 2% had the same anesthesiologist (P0.001). From the first to the second surgery, utilization of neuraxial anesthesia increased from 51% to 68%, respectively (P = 0.005). There were no differences in minor or major complications.For staged bilateral knee arthroplasty patients, 100% clinical pathway adherence including perineural catheters and multimodal analgesia is feasible despite multiple variables. We believe that patient-centered acute pain management requires consistent and reliable delivery of care.

Biomechanical studies with reliable clinical applicability are challenging to carry out. The results can be heavily dependent on the materials being tested (condition and ages of specimens), environmental conditions (temperature, moisture), magnitude and direction of loading, loading characteristics (static, dynamic), loading cycles and frequency, and how one measures and defines failure. The interested reader gains more confidence in the results and recommendations of a biomechanics study if the methodology reasonably models real-world scenarios and multiple studies from different labs all come to the same general conclusion.

Osteoarthritis (OA) is the leading cause of joint failure, yet the underlying mechanisms remain elusive, and no approved therapies that slow progression exist. Dysregulated integrin function was previously implicated in OA pathogenesis. However, the roles of integrin α(V)β(3) and the integrin-associated receptor CD47 in OA remain largely unknown. Here, transcriptomic and proteomic analyses of human and murine osteoarthritic tissues revealed dysregulated expression of α(V)β(3), CD47, and their ligands. Using genetically deficient mice and pharmacologic inhibitors, we showed that α(V)β(3), CD47, and the downstream signaling molecules Fyn and FAK are crucial to OA pathogenesis. MicroPET/CT imaging of a mouse model showed elevated ligand-binding capacities of integrin α(V)β(3) and CD47 in osteoarthritic joints. Further, our in vitro studies demonstrated that chondrocyte breakdown products, derived from articular cartilage of individuals with OA, induced α(V)β(3)/CD47-dependent expression of inflammatory and degradative mediators, and revealed the downstream signaling network. Our findings identify a central role for dysregulated α(V)β(3) and CD47 signaling in OA pathogenesis and suggest that activation of α(V)β(3) and CD47 signaling in many articular cell types contributes to inflammation and joint destruction in OA. Thus, the data presented here provide a rationale for targeting α(V)β(3), CD47, and their signaling pathways as a disease-modifying therapy.

Objective Among Veterans Health Administration (VHA) patients who undergo total knee arthroplasty (TKA) nationally, what are the underlying readmission rates and associations with perioperative opioid use, and are there associations with other factors such as preoperative health care utilization? Methods We retrospectively examined the records of 5,514 TKA patients (primary N = 4,955, 89.9%; revision N = 559, 10.1%) over one fiscal year (October 1, 2010–September 30, 2011) across VHA hospitals nationwide. Opioid use was classified into no opioids, tramadol only, short-acting only, or any long-acting. We measured readmission within 30 days and the number of days to readmission within 30 days. Extended Cox regression models were developed. Results The overall 30-day hospital readmission rate was 9.6% (N = 531; primary 9.5%, revision 11.1%). Both readmitted patients and the overall sample were similar on types of preoperative opioid use. Relative to patients without opioids, patients in the short-acting opioids only tier had the highest risk for 30-day hospital readmission (hazard ratio = 1.38, 95% confidence interval = 1.14–1.67). Preoperative opioid status was not associated with 30-day readmission. Other risk factors for 30-day readmission included older age (≥66 years), higher comorbidity and diagnosis-related group weights, greater preoperative health care utilization, an urban location, and use of preoperative anticonvulsants. Conclusions Given the current opioid epidemic, the routine prescribing of short-acting opioids after surgery should be carefully considered to avoid increasing risks of 30-day hospital readmissions and other negative outcomes, particularly in the context of other predisposing factors.

There has been an increased interest in the role of corrosion in total hip arthroplasty. This is based on reports of early implant failures and adverse local tissue reaction resulting from excessive corrosion at the modular interfaces of some implant designs. Orthopedic alloys are not selected based solely on their mechanical properties of strength, but rather because they possess the best balance between material properties of corrosion resistance and mechanical properties of strength. The passive layer of a metal oxide that develops on a surface of a metal serves a critical role in preventing corrosion. However, this protective layer is a dynamic structure. Aggressive corrosion occurs on implants when the kinetics of this oxide layer’s destruction dominates over its generation. There is a spectrum of different types of corrosion defined by the environment and stability of the passive layer. Pitting is the localized dissolution of this protective metal oxide film. Crevice corrosion occurs with a similar mechanism but in an isolated environment that promotes corrosion. Fretting corrosion or mechanically assisted crevice corrosion (MACC) occurs with the addition of mechanical oscillating loads at the modular junction that disrupts this protective layer. Understanding this process is important to improve implant designs, surgical technique, and assessment of patients.

Post-market medical device surveillance is a challenge facing manufacturers, regulatory agencies, and health care providers. Electronic health records are valuable sources of real-world evidence for assessing device safety and tracking device-related patient outcomes over time. However, distilling this evidence remains challenging, as information is fractured across clinical notes and structured records. Modern machine learning methods for machine reading promise to unlock increasingly complex information from text, but face barriers due to their reliance on large and expensive hand-labeled training sets. To address these challenges, we developed and validated state-of-the-art deep learning methods that identify patient outcomes from clinical notes without requiring hand-labeled training data. Using hip replacements—one of the most common implantable devices—as a test case, our methods accurately extracted implant details and reports of complications and pain from electronic health records with up to 96.3% precision, 98.5% recall, and 97.4% F1, improved classification performance by 12.8–53.9% over rule-based methods, and detected over six times as many complication events compared to using structured data alone. Using these additional events to assess complication-free survivorship of different implant systems, we found significant variation between implants, including for risk of revision surgery, which could not be detected using coded data alone. Patients with revision surgeries had more hip pain mentions in the post-hip replacement, pre-revision period compared to patients with no evidence of revision surgery (mean hip pain mentions 4.97 vs. 3.23; t = 5.14; p

BACKGROUND: Existing universal and procedure-specific surgical risk prediction models of death and major complications after elective total joint arthroplasty (TJA) have limitations including poor transparency, poor to modest accuracy, and insufficient validation to establish performance across diverse settings. Thus, the need remains for accurate and validated prediction models for use in preoperative management, informed consent, shared decision-making, and risk adjustment for reimbursement. QUESTIONS/PURPOSES: The purpose of this study was to use machine learning methods and large national databases to develop and validate (both internally and externally) parsimonious risk-prediction models for mortality and complications after TJA. METHODS: Preoperative demographic and clinical variables from all 107,792 nonemergent primary THAs and TKAs in the 2013 to 2014 American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) were evaluated as predictors of 30-day death and major complications. The NSQIP database was chosen for its high-quality data on important outcomes and rich characterization of preoperative demographic and clinical predictors for demographically and geographically diverse patients. Least absolute shrinkage and selection operator (LASSO) regression, a type of machine learning that optimizes accuracy and parsimony, was used for model development. Tenfold validation was used to produce C-statistics, a measure of how well models discriminate patients who experience an outcome from those who do not. External validation, which evaluates the generalizability of the models to new data sources and patient groups, was accomplished using data from the Veterans Affairs Surgical Quality Improvement Program (VASQIP). Models previously developed from VASQIP data were also externally validated using NSQIP data to examine the generalizability of their performance with a different group of patients outside the VASQIP context. RESULTS: The models, developed using LASSO regression with diverse clinical (for example, American Society of Anesthesiologists classification, comorbidities) and demographic (for example, age, gender) inputs, had good accuracy in terms of discriminating the likelihood a patient would experience, within 30 days of arthroplasty, a renal complication (C-statistic, 0.78; 95% confidence interval [CI], 0.76-0.80), death (0.73; 95% CI, 0.70-0.76), or a cardiac complication (0.73; 95% CI, 0.71-0.75) from one who would not. By contrast, the models demonstrated poor accuracy for venous thromboembolism (C-statistic, 0.61; 95% CI, 0.60-0.62) and any complication (C-statistic, 0.64; 95% CI, 0.63-0.65). External validation of the NSQIP- derived models using VASQIP data found them to be robust in terms of predictions about mortality and cardiac complications, but not for predicting renal complications. Models previously developed with VASQIP data had poor accuracy when externally validated with NSQIP data, suggesting they should not be used outside the context of the Veterans Health Administration. CONCLUSIONS: Moderately accurate predictive models of 30-day mortality and cardiac complications after elective primary TJA were developed as well as internally and externally validated. To our knowledge, these are the most accurate and rigorously validated TJA-specific prediction models currently available (http://med.stanford.edu/s-spire/Resources/clinical-tools-.html). Methods to improve these models, including the addition of nonstandard inputs such as natural language processing of preoperative clinical progress notes or radiographs, should be pursued as should the development and validation of models to predict longer term improvements in pain and function. LEVEL OF EVIDENCE: Level III, diagnostic study.

Osteoarthritis is characterized by articular cartilage breakdown, and emerging evidence suggests that dysregulated innate immunity is likely involved. Here, we performed proteomic, transcriptomic, and electron microscopic analyses to demonstrate that mast cells are aberrantly activated in human and murine osteoarthritic joint tissues. Using genetic models of mast cell deficiency, we demonstrate that lack of mast cells attenuates osteoarthritis in mice. Using genetic and pharmacologic approaches, we show that the IgE/FcεRI/Syk signaling axis is critical for the development of osteoarthritis. We find that mast cell-derived tryptase induces inflammation, chondrocyte apoptosis, and cartilage breakdown. Our findings demonstrate a central role for IgE-dependent mast cell activation in the pathogenesis of osteoarthritis, suggesting that targeting mast cells could provide therapeutic benefit in human osteoarthritis.Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).

Question 1: Does the use of a tourniquet influence the rates of surgical site infections/periprosthetic joint infections (SSIs/ PJIs) in primary or revision TKA? Recommendation: The literature is inconclusive regarding the use of tourniquet during total knee arthroplasty and its potential to increase the risks for surgical site infections/periprosthetic joint infections (SSIs/PJIs) in TKAs. Tourniquet times and pressures should be minimized to reduce this risk. Level of Evidence: Limited Delegate Vote: Agree: 89%, Disagree: 9%, Abstain: 2% (Super Majority, Strong Consensus) Rationale: The use of a pneumatic tourniquet during total knee arthroplasty (TKA) has long been a standard for this procedure. However, concerns have arisen over the ischemic injury that can occur from tourniquet use. This has prompted many authors to conduct studies evaluating the use and nonuse of a tourniquet and its effect on perioperative blood loss, postoperative pain and function, and postoperative complications [1e7]. However, many of these studies are small, randomized, controlled trials that lack the power to definitively state the influence of tourniquet use of surgical site infections (SSIs) and periprosthetic joint infections (PJIs). Liu et al [8] showed in a randomized controlled trial of 52 patients undergoing simultaneous bilateral TKA that tourniquet use was associated with greater wound ooze and blistering, as well as the only deep infection in the cohort occurring in a TKAcase that had been performed while using a tourniquet. In a 31- patient randomized controlled trial, Clarke et al [9] demonstrated that increased tourniquet pressures led to sustained wound hypoxia up to 1 week after surgery. A meta-analysis by Yi et al [6] evaluated 13 randomized controlled trials of tourniquet use comprising 859 patients. Of these 13 studies, 3 evaluated infection risk, SSI, and PJI together, and they found that tourniquet use was significantly associated with an increased risk of infection. A meta-analysis by Zhang et al [10] found a similar pooled result with tourniquet use associated with a greater risk of nonthrombotic complications, infection included. Longer tourniquet times, and by virtue longer surgical times, have been associated with an increased risk for both SSI and PJI [11-13]. Willis-Owen et al [11] in a series of 3449 consecutive TKA found that patients who went on to have a SSI/PJI had significantly longer tourniquet times than noninfected patients. Ricciardi et al [12] found a similar result in their analysis of perioperative variables affecting 30-day readmission. Na et al [14] evaluated early release of the tourniquet following cementation of components vs reinflation of the tourniquet after controlling bleeding in 206 patients and found that the increased tourniquet time for patients in the reinflation group did not affect the rate of wound complications, SSI, or PJI. However, none of these studies were able to propose a cutoff for tourniquet time over which the risk of SSI and PJI begins to increase. These studies also did not differentiate between operative time and tourniquet time. As increased surgical time is a known risk factor for SSI and PJI, the confounding effect of increased surgical time may be influencing the relationship between tourniquet time and postoperative infections. There is still much debate over the efficacy of tourniquet use to decrease perioperative blood loss. Ledin et al [15] conducted a randomized controlled trial on 50 consecutive TKAs on the use of a tourniquet and found no difference in calculated perioperative blood loss. The meta-analysis by Zhang et al [10] found that calculated blood loss was greater without the use of a tourniquet ; however, this did not result in a greater transfusion requirement. Conversely, a meta-analysis by Jiang et al [16] found that tourniquet use did decrease transfusion requirement in the pooled analysis of 1450 knees. As allogeneic blood transfusion is a known risk factor for SSI and PJI, limiting blood loss is an important aspect of infection prevention [17e20]. Another concern with the use of a tourniquet during TKA is whether appropriate antibiotic prophylaxis is administered to the surgical site. Friedman et al [21] evaluated soft tissue and bone concentrations of antibiotics given 1 minute, 2 minutes, and 5 minutes before tourniquet inflation and found the highest concentrations when antibiotics were administered 5 minutes before inflation. Yamada et al [22] found that when cefazolin was administered 15 minutes before inflation, the concentration in the bone and soft tissue at the surgical site was above the MIC90 for methicillin-sensitive Staphylococcus aureus, but below the MIC90 for cephazolin-resistant coagulase-negative staphylococcal species. Young et al [23] found that by administering antibiotic prophylaxis intraosseously, higher regional antibiotic concentrations could be achieved ; however, the clinical efficacy of this in reducing the rates of SSI and PJI still need to be evaluated. The effect that the use of a tourniquet has on the incidence of SSIs and PJIs after TKA has not been fully evaluated. The randomized controlled trials of this subject have been of small cohorts of patients that lack the power to evaluate these complications. The meta-analyses on this topic also have not been able to definitively comment, as many studies did not report the incidence of SSI and PJI in their cohorts. Moving forward, studies evaluating the use of a tourniquet during TKA should consider SSI and PJI as a secondary end point so that future pooled analyses may be better able to elucidate a connection, if one exists.

Key Points Question Are the data in a large US electronic health record (EHR) complete and accurate enough to track trends in implant use and to assess the durability of implants (hereafter referred to as implant survivorship)? Findings In this cohort study, EHR records of patients who had total hip arthroplasty in all Veterans Health Administration hospitals since 2000 were automatically reviewed using novel software; 80% to 95% of hip replacement components used since 2014 were accurately identified, trends in implant use matched known national trends, and known poor implants were found to be negative outliers. Meaning Automated analysis of the EHR provides a low-cost, low-overhead method to assess implant use and performance., Importance Implant registries provide valuable information on the performance of implants in a real-world setting, yet they have traditionally been expensive to establish and maintain. Electronic health records (EHRs) are widely used and may include the information needed to generate clinically meaningful reports similar to a formal implant registry. Objectives To quantify the extractability and accuracy of registry-relevant data from the EHR and to assess the ability of these data to track trends in implant use and the durability of implants (hereafter referred to as implant survivorship), using data stored since 2000 in the EHR of the largest integrated health care system in the United States. Design, Setting, and Participants Retrospective cohort study of a large EHR of veterans who had 45 351 total hip arthroplasty procedures in Veterans Health Administration hospitals from 2000 to 2017. Data analysis was performed from January 1, 2000, to December 31, 2017. Exposures Total hip arthroplasty. Main Outcomes and Measures Number of total hip arthroplasty procedures extracted from the EHR, trends in implant use, and relative survivorship of implants. Results A total of 45 351 total hip arthroplasty procedures were identified from 2000 to 2017 with 192 805 implant parts. Data completeness improved over the time. After 2014, 85% of prosthetic heads, 91% of shells, 81% of stems, and 85% of liners used in the Veterans Health Administration health care system were identified by part number. Revision burden and trends in metal vs ceramic prosthetic femoral head use were found to reflect data from the American Joint Replacement Registry. Recalled implants were obvious negative outliers in implant survivorship using Kaplan-Meier curves. Conclusions and Relevance Although loss to follow-up remains a challenge that requires additional attention to improve the quantitative nature of calculated implant survivorship, we conclude that data collected during routine clinical care and stored in the EHR of a large health system over 18 years were sufficient to provide clinically meaningful data on trends in implant use and to identify poor implants that were subsequently recalled. This automated approach was low cost and had no reporting burden. This low-cost, low-overhead method to assess implant use and performance within a large health care setting may be useful to internal quality assurance programs and, on a larger scale, to postmarket surveillance of implant performance., This cohort study quantifies the extractability and accuracy of registry-relevant data from the electronic health record (EHR) and assesses the ability of these data to track trends in implant use and implant survivorship, using data stored since 2000 in the EHR of the largest integrated health care system in the United States.

Background Obesity exacerbates pre-existing musculoskeletal disease and joint pain. This may limit physical activity in obese individuals. Objectives We sought to identify the disease burden and impact of osteoarthritis of the lumbar back, hip, knee, and ankle in veterans undergoing bariatric surgery. Setting Veterans Affairs medical center. Methods Retrospective review of a prospective bariatric database of operations performed at a single Veterans Affairs medical center. Patients with osteoarthritis of the lumbar spine, hip, knee, or ankle were identified and diagnosis confirmed by electronic health record review of prior radiographic reports. Analysis was performed using χ 2 test for continuous variables. Student's t test and one-way analysis of variance were used to compare qualitative variables. Results Of 254 bariatric surgical patients, 83.9% had preoperative musculoskeletal pain before bariatric surgery and 59.1% had a confirmed diagnosis of osteoarthritis of the lumbar spine, hips, knees, and/or ankles. Follow-up rate was 97.4%, 85.4%, and 82.6% at 1, 3, and 5 years respectively. Of patients with osteoarthritis, 58.6% had knee involvement and 46% had multiple sites involved. In the cohort without osteoarthritis, percent excess body mass index loss was 66.9% at 1 year versus 58.5% in the cohort with osteoarthritis ( P = .009), 66.1% versus 51.9% ( P = .001) at 3 years, and 64.3% versus 50.1% ( P = .002) after 5 years. Percent total weight loss was 28.4% versus 25.2%, 28.0% versus 22.8%, and 27.1% versus 22.4%, respectively, at 1, 3, and 5 years. Conclusions Osteoarthritis is common among veterans undergoing bariatric surgery. It is associated with significantly less weight loss compared to veterans who do not have osteoarthritis, up to 5 years after bariatric surgery.

Background The American Joint Replacement Registry (AJRR) Total Joint Risk Calculator uses demographic and clinical parameters to provide risk estimates for 90-day mortality and 2-year periprosthetic joint infection (PJI). The tool is intended to help surgeons counsel their Medicare-eligible patients about their risk of death and PJI after total joint arthroplasty (TJA). However, for a predictive risk model to be useful, it must be accurate when applied to new patients; this has yet to be established for this calculator. Questions/purposes To produce accuracy metrics (ie, discrimination, calibration) for the AJRR mortality calculator using data from Medicare-eligible patients undergoing TJA in the Veterans Health Administration (VHA), the largest integrated healthcare system in the United States, where more than 10,000 TJAs are performed annually. Methods We used the AJRR calculator to predict risk of death within 90 days of surgery among 31,214 VHA patients older than 64 years of age who underwent primary TJA; data was drawn from the Veterans Affairs Surgical Quality Improvement Project (VASQIP) and VA Corporate Data Warehouse (CDW). We then used VHA mortality data to evaluate the extent to which the AJRR calculator estimates distinguished individuals who died compared with those who did not (C-statistic), and graphically depicted the relationship between estimated risk and observed mortality (calibration). As a secondary evaluation of the calculator, a sample of 39,300 patients younger than 65 years old was assigned to the youngest age group available to the user (65-69 years) as might be done in real-world practice. Results C-statistics for 90-day mortality for the older samples were 0.62 (95% CI, 0.60-0.64) and for the younger samples they were 0.46 (95% CI, 0.43-0.49), suggesting poor discrimination. Calibration analysis revealed poor correspondence between deciles of predicted risk and observed mortality rates. Poor discrimination and calibration mean that patients who died will frequently have a lower estimated risk of death than surviving patients. Conclusions For Medicare-eligible patients receiving TJA in the VA, the AJRR risk calculator had a poor performance in the prediction of 90-day mortality. There are several possible reasons for the model's poor performance. Veterans Health Administration patients, 97% of whom were men, represent only a subset of the broader Medicare population. However, applying the calculator to a subset of the target population should not affect its accuracy. Other reasons for poor performance include a lack of an underlying statistical model in the calculator's implementation and simply the challenge of predicting rare events. External validation in a more representative sample of Medicare patients should be conducted to before assuming this tool is accurate for its intended use. Level of evidence Level I, diagnostic study.

Background Statistical models to preoperatively predict patients' risk of death and major complications after total joint arthroplasty (TJA) could improve the quality of preoperative management and informed consent. Although risk models for TJA exist, they have limitations including poor transparency and/or unknown or poor performance. Thus, it is currently impossible to know how well currently available models predict short-term complications after TJA, or if newly developed models are more accurate. We sought to develop and conduct cross-validation of predictive risk models, and report details and performance metrics as benchmarks. Methods Over 90 preoperative variables were used as candidate predictors of death and major complications within 30 days for Veterans Health Administration patients with osteoarthritis who underwent TJA. Data were split into 3 samples—for selection of model tuning parameters, model development, and cross-validation. C-indexes (discrimination) and calibration plots were produced. Results A total of 70,569 patients diagnosed with osteoarthritis who received primary TJA were included. C-statistics and bootstrapped confidence intervals for the cross-validation of the boosted regression models were highest for cardiac complications (0.75; 0.71-0.79) and 30-day mortality (0.73; 0.66-0.79) and lowest for deep vein thrombosis (0.59; 0.55-0.64) and return to the operating room (0.60; 0.57-0.63). Conclusions Moderately accurate predictive models of 30-day mortality and cardiac complications after TJA in Veterans Health Administration patients were developed and internally cross-validated. By reporting model coefficients and performance metrics, other model developers can test these models on new samples and have a procedure and indication-specific benchmark to surpass.

Morbidly obese patients with severe osteoarthritis benefit from successful total joint arthroplasty. However, morbid obesity increases the risk of complications. Because of this, some surgeons enforce a body mass index (BMI) eligibility criterion above which total joint arthroplasty is denied. In this study, we investigate the trade-off between avoiding complications and restricting access to care when enforcing BMI-based eligibility criteria for total joint arthroplasty.In this retrospective cohort study, the Veterans Health Administration (VHA) Corporate Data Warehouse (CDW) and Veterans Affairs Surgical Quality Improvement Program (VASQIP) databases were reviewed for patients undergoing total joint arthroplasty from October 2011 through September 2014. We determined, if various BMI eligibility criteria had been enforced over that period of time, how many short-term complications would have been avoided, how many complication-free surgical procedures would have been denied, and the positive predictive value of BMI eligibility criteria as tests for major complications. To provide a frame of reference, we also determined what would have happened if eligibility for total joint arthroplasty were arbitrarily determined by flipping a coin.In this study, 27,671 total joint arthroplasties were reviewed. With a BMI criterion of ≥40 kg/m, 1,148 patients would have been denied a surgical procedure free of major complications, and 83 patients would have avoided a major complication. The positive predictive value of a complication using a BMI of ≥40 kg/m as a test for major complications was 6.74% (95% confidence interval [CI], 5.44% to 8.33%). The positive predictive value of a complication using a BMI criterion of 30 kg/m was 5.33% (95% CI, 4.99% to 5.71%). Flipping a coin had a positive predictive value of 5.05%.A 30 kg/m criterion for total joint arthroplasty eligibility is marginally better than flipping a coin and should not determine surgical eligibility. With a BMI criterion of ≥40 kg/m, the number of patients denied a complication-free surgical procedure is about 14 times larger than those spared a complication. Although the acceptable balance between avoiding complications and providing access to care can be debated, such a quantitative assessment helps to inform decisions regarding the advisability of enforcing a BMI criterion for total joint arthroplasty.Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background The use of chemoprophylaxis to prevent thromboembolic disease after primary THA and TKA can be associated with postoperative bleeding complications. Mechanical prophylaxis has been studied as an alternative to chemoprophylaxis with greater safety in patients undergoing THA, but no data have been published comparing the safety of chemoprophylaxis versus mechanical methods for patients undergoing TKA. The risk of readmission resulting from bleeding and venous thromboembolism (VTE) has also not been determined for patients undergoing THA or TKA when treated with low-molecular-weight heparin (LMWH) alone compared with mechanical prophylaxis plus aspirin (ASA). Question/purposes We sought to answer four questions: For the THA and TKA cohorts, respectively, (1) was the incidence of readmission resulting from VTE and bleeding complications higher with LMWH than mobile compression plus ASA; and (2) was the incidence of wound bleeding complications higher with LMWH than mechanical compression plus ASA? For the TKA cohort specifically, (3) was the frequency of systemic bleeding events and complications related to chemical prophylaxis higher with LMWH compared with mechanical compression plus ASA? (4) Was there a difference in symptomatic VTEs between LMWH and mechanical compression plus ASA? Methods Between November 2008 and April 2011, 632 patients underwent primary THA and TKA. Seventy-two patients (11%) were identified before surgery as being at high risk for VTE (31 patients) or bleeding (41 patients) and were excluded from the study. Five hundred sixty patients (89%) were considered to be at standard risk for VTE and bleeding and comprise the study cohort. Between November 2008 and November 2009, 252 patients (76 THAs, 176 TKAs) underwent THA and TKA and were treated with LMWH (5 mg dalteparin given subcutaneously daily for 14 days) and in-hospital nonmobile mechanical compression. Between November 2009 and April 2011, a total of 308 patients undergoing THA and TKA (108 THAs, 200 TKAs) were treated using a mobile compression device plus oral aspirin once daily for 2 weeks after surgery. All complications and readmissions that occurred within 6 weeks of surgery were noted. There were no differences between the VTE treatment groups with regard to age, sex, or body mass index. Results For the THA cohort, there was no difference in the frequency of readmission for a bleeding complication (wound or systemic) between the two groups (2.6% for LMWH versus 0.9% for mobile compression; p = 0.57; odds ratio [OR], 2.9). Patients undergoing TKA treated with LMWH had higher readmission rates within 6 weeks of surgery because of a bleeding complication, a wound infection, or the development of a VTE (6.8% for LMWH versus 1.5% for mobile compression; p = 0.015; OR, 4.8). For the THA cohort, there was higher wound bleeding complication frequency with LMWH (9.2% for LMWH versus 0.9% for mechanical compression; p = 0.009; OR, 10.9). Patients undergoing TKA treated with LMWH had a higher frequency of wound bleeding complications or infection (3.9% for LMWH versus 0.5% for mobile compression; p = 0.028; OR, 8.2). Patients undergoing TKA treated with LMWH had higher rates of systemic bleeding or a complication secondary to LMWH administration (2.8% for LMWH versus 0% for mobile compression; p = 0.022; OR, 12.8). No difference was noted in the rate of symptomatic VTEs between either group (for THA: 2.6% for the LMWH group versus 1.9% for the mechanical compression group; p = 1; for TKA: 1.1% versus 0%, respectively; p = 0.22). Conclusions Based on these results, we advocate for routine use of mobile mechanical compression devices in the prevention of VTEs and complications associated with more potent chemical anticoagulants. However, more focused randomized clinical trials are needed to validate these findings. Level of evidence Level III, therapeutic study.

BACKGROUND: Some studies have revealed an increased risk of early aseptic loosening of cementless stems in THA when inserted through an anterior or anterolateral approach compared with a posterior approach, whereas approach does not appear to be a risk factor in others. Stem design, whether “anatomic” (that is, stems with a curved lateral profile or an obtuse angle at the proximal-lateral portion of the stem) or “shoulder” (that is, straight with a proximal shoulder), may also be associated with a differential risk of aseptic loosening in cementless THA depending on the surgical approach used, but if so, this risk is not well characterized. QUESTIONS/PURPOSES: In this national registry study, we investigated the association between surgical approach and early aseptic loosening of (1) cementless femoral stems with a proximal angular shape (shoulder); and (2) anatomically shaped femoral stems. METHODS: The Dutch Arthroplasty Registry is a nationwide population-based register recording data on primary and revision hip arthroplasty. We selected all primary THAs (n = 63,354) with a cementless femoral stem inserted through an anterior, anterolateral, or posterior approach from 2007 to 2013 with a minimal followup of 2 years. Femoral stems were classified as “anatomic,” “shoulder,” or “other” (that is, not classifiable as anatomic or shoulder). From the 47,372 THAs with an anatomic or shoulder stem (mean followup, 3.5 years; SD, 1.8 years), 340 (0.7%) underwent revision surgery as a result of aseptic loosening of the femoral stem, 1195 (2.5%) were revised for other reasons, and 1558 patients (3.3%) died. We used Cox proportional hazard models to determine hazard ratios for aseptic loosening of anatomic and shoulder stems for the anterolateral and anterior approaches compared with the posterior approach. RESULTS: After controlling for relevant confounding variables such as sex, American Society of Anesthesiologists score, previous surgery, and coating and material of the femoral stem, we found that there was a stem-approach interaction. Separate analysis showed that shoulder stems had a greater likelihood of early aseptic loosening when the anterolateral approach (hazard ratio [HR], 2.28; 95% confidence interval [CI], 1.43–3.63; p < 0.001) or anterior approach (HR, 10.47; 95% CI, 2.55-43.10; p = 0.001) was used compared with the posterior approach. Separate analysis of the anatomic stems yielded no association with approach (anterolateral: HR, 1.07, 95% CI, 0.70–1.63, p = 0.77; anterior: HR, 1.31, 95% CI, 0.91-1.89, p = 0.15). CONCLUSIONS: In THA, cementless femoral stems with a proximal shoulder are associated with early aseptic loosening when inserted through an anterior or anterolateral approach compared with a posterior approach. An anatomically shaped stem may be preferred with these approaches, although further analysis with larger registry volumes should confirm our results, in particular for shouldered stems when implanted through an anterior approach. LEVEL OF EVIDENCE: Level III, therapeutic study.