Movement: How the Brain Communicates with the World.

Voluntary movement is a result of signals transmitted through a communication channel that links the internal world in our minds to the physical world around us. Intention can be considered the desire to effect change on our environment, and this is contained in the signals from the brain, passed through the nervous system to converge on muscles that generate displacements and forces on our surroundings. The resulting changes in the world act to generate sensations that feed back to the nervous system, closing the control loop. This Perspective discusses the experimental and theoretical underpinnings of current models of movement generation and the way they are modulated by external information. Movement systems embody intentionality and prediction, two factors that are propelling a revolution in engineering. Development of movement models that include the complexities of the external world may allow a better understanding of the neuronal populations regulating these processes, as well as the development of solutions for autonomous vehicles and robots, and neural prostheses for those who are motor impaired.

Modulation of the HIF2α-NCOA4 axis in enterocytes attenuates iron loading in a mouse model of hemochromatosis.

Intestinal iron absorption is activated during increased systemic demand for iron. The best-studied example is iron deficiency anemia, which increases intestinal iron absorption. Interestingly, the intestinal response to anemia is very similar to that of iron overload disorders, as both the conditions activate a transcriptional program that leads to a hyperabsorption of iron via the transcription factor hypoxia-inducible factor 2α (HIF2α). However, pathways for selective targeting of intestine-mediated iron overload remain unknown. Nuclear receptor coactivator 4 (NCOA4) is a critical cargo receptor for autophagic breakdown of ferritin and the subsequent release of iron, in a process termed ferritinophagy. Our work demonstrates that NCOA4-mediated intestinal ferritinophagy is integrated into systemic iron demand via HIF2α. To demonstrate the importance of the intestinal HIF2α/ferritinophagy axis in systemic iron homeostasis, whole-body and intestine-specific NCOA4-/- mouse lines were generated and assessed. The analyses revealed that the intestinal and systemic response to iron deficiency was not altered after disruption of intestinal NCOA4. However, in a mouse model of hemochromatosis, ablation of intestinal NCOA4 was protective against iron overload. Therefore, NCOA4 can be selectively targeted for the management of iron overload disorders without disrupting the physiological processes involved in the response to systemic iron deficiency.

Tramadol use before total shoulder arthroplasty: patients have lower risk of complications and resource utilization than those using traditional opioids.

BACKGROUND: Evidence continues to mount for the deleterious effects of preoperative opioid use in the setting of total shoulder arthroplasty (TSA). Tramadol, a synthetic opioid with concomitant neurotransmitter effects, has become a popular alternative to traditional opioids, but it has not been well studied in the preoperative setting of TSA. The purpose of this study is to evaluate postsurgical outcomes in TSA for patients with preoperative tramadol use compared with patients using traditional opioids and those who were opioid naïve. METHODS: Using the IBM Watson Health MarketScan databases, a retrospective cohort study was performed for patients who underwent TSA from 2009 to 2018. Filled pain prescriptions were collected, and prescribing trends were analyzed. Outcomes were compared between 4 patient cohorts defined by preoperative analgesia use-opioid naïve, tramadol, traditional opioids, and combination (opioids and tramadol). Multivariate analysis was used to account for small variations in cohort demographics and comorbidities. Analysis focused on resource utilization and complications. Revision rates at 1 and 3 years postoperatively were also compared. RESULTS: A total of 29,454 TSA patients were studied, with 8959 available for 3-year postoperative follow-up. Of these, 10,462 (35.5%) were prescribed traditional opioids and 2214 (7.5%) tramadol only. From 2009 to 2018, prescribing trends in the United States demonstrated a significant decrease in the number of patients prescribed preoperative narcotics, whereas the number of patients prescribed preoperative tramadol and those who were opioid naïve significantly increased. Compared with opioid-naïve patients, the traditional opioid cohort had significantly increased odds of resource utilization and complications, whereas the tramadol cohort did not. Specifically, the traditional opioid cohort had an increased risk of prosthetic joint infection compared with both opioid-naïve and tramadol cohorts. The traditional opioid cohort had higher revision rates than opioid-naïve patients at 1 and 3 years, whereas the tramadol cohort did not. CONCLUSION: Despite a decrease in opioid prescriptions over the study period, many patients in the United States remain on opioids. Although tramadol is not without its own risks, our results suggest that patients taking preoperative tramadol as an alternative to traditional opioids for glenohumeral arthritic pain had a lesser postoperative risk profile, comparable with opioid-naïve patients.

Age-Adjusted Modified Frailty Index Predicts 30-Day Complications and Mortality in Aseptic Revision Total Hip and Knee Arthroplasty.

BACKGROUND: The age-adjusted modified frailty index (aamFI) has been demonstrated to effectively predict postoperative complications and healthcare resource utilization in patients undergoing primary total joint arthroplasty. The purpose of this study was to evaluate the applicability of aamFI in patients undergoing aseptic revision total hip (rTHA) and knee arthroplasty (rTKA). METHODS: A national database was queried for patients undergoing aseptic rTHA and rTKA from 2015 to 2020. A total of 13,307 rTHA and 18,762 rTKA cases were identified. The aamFI was calculated by adding 1 additional point for age ≥73 years to the previously described 5-item modified frailty index (mFI-5). The area under the curve was calculated and compared to compare predictive accuracy between mFI-5 and aamFI. Logistic regression was used to investigate the relationship between aamFI and 30-day complications. RESULTS: The incidence of incurring any (≥1) complication increased from 15% for aamFI 0 to 45% for aamFI ≥5 after rTHA and from 5 to 55% after rTKA. Patients who had an aamFI ≥3 (reference aamFI = 0) had increased odds (rTHA: odds ratio (OR) 3.5, 95% confidence interval (CI) 2.9 to 4.1, P < .001; rTKA: OR 4.2, 95% CI 4.4 to 5.1, P < .001) of incurring at least 1 complication. The aamFI, compared to mFI-5, was a more accurate predictor of any complication (rTHA P < .001; rTKA P < .001) and 30-day mortality (rTHA P < .001; rTKA P < .003). CONCLUSION: The aamFI is an excellent predictor of complications in patients undergoing rTHA and rTKA. The addition of chronological age to the previously described mFI-5 improves the predictive value of this simple metric.

The Impact of Frailty on Outcomes Following Primary Total Hip Arthroplasty in Patients of Different Sex and Race: Is Frailty Equitably Detrimental?

BACKGROUND: Whether frailty impacts total hip arthroplasty (THA) patients of different races or sex equally is unknown. This study aimed to assess the influence of frailty on outcomes following primary THA in patients of differing race and sex. METHODS: This is a retrospective cohort study utilizing a national database (2015-2019) to identify frail (≥2 points on the modified frailty index-5) patients undergoing primary THA. One-to-one matching for each frail cohort of interest (race: Black, Hispanic, Asian, versus White (non-Hispanic), respectively; and sex: men versus women) was performed to diminish confounding. The 30-day complications and resource utilizations were then compared between cohorts. RESULTS: There was no difference in the occurrence of at least 1 complication (P > .05) among frail patients of differing race. However, frail Black patients had increased odds of postoperative transfusion (odds ratio [OR]: 1.34, 95% confidence interval [CI]: 1.02-1.77), deep vein thrombosis (OR: 2.61, 95% CI: 1.08-6.27), as well as >2-day hospitalization and nonhome discharge (P < .001). Frail women had higher odds of having at least 1 complication (OR: 1.67, 95% CI: 1.47-1.89), nonhome discharge, readmission, and reoperation (P < .05). Contrarily, frail men had higher 30-day cardiac arrest (0.2% versus 0.0%, P = .020) and mortality (0.3 versus 0.1%, P = .002). CONCLUSION: Frailty appears to have an overall equitable influence on the occurrence of at least 1 complication in THA patients of different races, although different rates of some individual, specific complications were identified. For instance, frail Black patients experienced increased deep vein thrombosis and transfusion rates relative to their non-Hispanic White counterparts. Contrarily, frail women, relative to frail men, have lower 30-day mortality despite increased complication rates.

The Impact of Frailty Is Age Dependent in Patients Undergoing Primary Total Knee Arthroplasty: The Age-Adjusted Modified Frailty Index.

BACKGROUND: Frailty is a well-established risk factor in patients undergoing total knee arthroplasty (TKA). How age modifies the impact of frailty on outcomes in these patients, however, remains unknown. In this study, we aimed to describe and evaluate the applicability of a novel risk stratification tool-the age-adjusted modified Frailty Index (aamFI)-in patients undergoing TKA. METHODS: A national database was queried for all patients undergoing primary TKA from 2015 to 2019. There were 271,271 patients who met inclusion criteria for this study. First, outcomes were compared between chronologically young and old frail patients. In accordance with previous studies, the 75th percentile of age of all included patients (73 years) was used as a binary cutoff. Then, frailty was classified using the novel aamFI, which constitutes the 5-item mFI with the addition of 1 point for patients ≥73 years. Multivariable logistic regressions were then used to investigate the relationship between aamFI and postoperative outcomes. RESULTS: Frail patients ≥73 years had a higher incidence of complications compared to frail patients <73 years. There was a strong association between aamFI and complications. An aamFI of ≥3 (reference aamFI of 0) was associated with an increased odds of 30-day mortality (odds ratio [OR] 8.6, 95% CI 5.0-14.8), any complication (OR 3.1, 95% CI 2.9-3.3), deep vein thrombosis (OR 1.5, 95% CI 1.2-1.8), and nonhome discharge (OR 6.1, 95% CI 5.8-6.4; all P < .001). CONCLUSION: Although frailty negatively influences outcomes following TKA in patients of all ages, chronologically old, frail patients are particularly vulnerable. The aamFI accounts for this and represents a simple, but powerful tool for stratifying risk in patients undergoing primary TKA.

Patients Who Have Kellgren-Lawrence Grade 3 and 4 Osteoarthritis Benefit Equally From Total Knee Arthroplasty.

BACKGROUND: Recently, some payers have limited access to total knee arthroplasty (TKA) to patients who have Kellgren-Lawrence (KL) grade 4 osteoarthritis only. This study compared the outcomes of patients who have KL grade 3 and 4 osteoarthritis after TKA to determine if this new policy is justified. METHODS: This was a secondary analysis of a series originally established to collect outcomes for a single, cemented implant design. A total of 152 patients underwent primary, unilateral TKA at two centers from 2014 to 2016. Only patients who had KL grade 3 (n = 69) or 4 (n = 83) osteoarthritis were included. There was no difference in age, sex, American Society of Anesthesiologists score, or preoperative Knee Society Score (KSS) between the groups. Patients who had KL grade 4 disease had a higher body mass index. KSS and Forgotten Joint Score (FJS) were collected preoperatively and at 6 weeks, 6 months, 1 year, and 2 years postoperatively. Generalized linear models were used to compare outcomes. RESULTS: Controlling for demographics, improvements in KSS were comparable between the groups at all time points. There was no difference in KSS, FJS, and the proportion that achieved the patient acceptable symptom state for FJS at 2 years. CONCLUSION: Patients who had KL grade 3 and 4 osteoarthritis experienced similar improvement at all time points up to 2 years after primary TKA. There is no justification for payers to deny access to surgical treatment for patients who have KL grade 3 osteoarthritis and have otherwise failed nonoperative treatment.

Does Order of Operation Matter in Patients Who Have Concomitant Hip and Spine Pathology?

BACKGROUND: In patients, who have coexisting lumbar spine and degenerative hip disease, there remains uncertainty regarding whether hip or spine surgery should be performed first. We hypothesized that undergoing total hip arthroplasty (THA) would protect against subsequent lumbar spine surgery (LSS) in patients who have 'hip-spine syndrome.' METHODS: A retrospective cohort study was performed from 2013 to 2021 on patients who had radiographically-confirmed hip osteoarthritis and degenerative lumbar spine pathology, evaluated separately in spine and arthroplasty clinics prior to surgical intervention. Included patients ultimately underwent THA and/or LSS. The primary outcome was survivorship free of LSS or THA after the other was initially performed. RESULTS: Of 256 patients, 206 (80.5%) underwent THA first. Only 14 of 206 (6.8%) who underwent THA required subsequent LSS, while 31 of 50 (62%) who underwent LSS required subsequent THA, (P < .001). At 5 years, there was 93.9% survivorship-free of LSS in the THA first group, compared to 44.7% survivorship-free of subsequent THA in the LSS group. Multivariate analyses showed that patients who had THA first had lower odds of undergoing subsequent surgery (odds ratio [OR]: 0.61, CI: 0.52-0.70, P < .001) compared to those who underwent LSS first. Additionally, those who have higher initial Kellgren-Lawrence grade hip osteoarthritis had lower odds (OR: 0.94, CI: 0.89-0.99, P = .04), and those who have progressive neurologic deficits (OR: 2.64, CI: 1.89-3.7, P < .001) and neurogenic claudication (OR: 1.15, CI: 1.06-1.24, P = .001) had increased odds of undergoing subsequent LSS. CONCLUSION: Patients with 'hip-spine syndrome' may receive more initial benefit from undergoing THA, potentially reducing the subsequent need for LSS. The exceptions were those patients who had lower-severity hip osteoarthritis and symptoms of major spinal stenosis.

RECENT ADVANCES IN INSTRUMENTAL APPROACHES TO TIME-OF-FLIGHT MASS SPECTROMETRY.

Time-of-flight mass spectrometry (TOFMS) is one of the simplest and most powerful approaches for mass spectrometry. Realization of the advantages inherent in TOFMS requires innovation in the theory and practice of the technique. Instrumental developments, in turn, create new capabilities that enable applications in chemical measurement. This review focuses on the recent advances in TOFMS instrumentation. New strategies for ion acceleration, multiplexed detection, miniaturized TOFMS instruments, approaches to extend the length of ion flight, and novel ion detection technologies are reviewed. Techniques that change the basic paradigm of TOFMS by measuring m/z based on ion flight distance are considered, as are applications at the frontiers of instrumental performance. © 2020 John Wiley & Sons Ltd. Mass Spec Rev.

Distributed processing of movement signaling.

Basic neurophysiological research with monkeys has shown how neurons in the motor cortex have firing rates tuned to movement direction. This original finding would have been difficult to uncover without the use of a behaving primate paradigm in which subjects grasped a handle and moved purposefully to targets in different directions. Subsequent research, again using behaving primate models, extended these findings to continuous drawing and to arm and hand movements encompassing action across multiple joints. This research also led to robust extraction algorithms in which information from neuronal populations is used to decode movement intent. The ability to decode intended movement provided the foundation for neural prosthetics in which brain-controlled interfaces are used by paralyzed human subjects to control computer cursors or high-performance motorized prosthetic arms and hands. This translation of neurophysiological laboratory findings to therapy is a clear example of why using nonhuman primates for basic research is valuable for advancing treatment of neurological disorders. Recent research emphasizes the distribution of intention signaling through neuronal populations and shows how many movement parameters are encoded simultaneously. In addition to direction and velocity, the arm's impedance has now been found to be encoded as well. The ability to decode motion and force from neural populations will make it possible to extend neural prosthetic paradigms to precise interaction with objects, enabling paralyzed individuals to perform many tasks of daily living.

The Age-Adjusted Modified Frailty Index: An Improved Risk Stratification Tool for Patients Undergoing Primary Total Hip Arthroplasty.

BACKGROUND: Frailty and increasing age are well-established risk factors in patients undergoing total hip arthroplasty (THA). However, these variables have only been considered independently. This study assesses the interplay between age and frailty and introduces a novel age-adjusted modified frailty index (aamFI) for more refined risk stratification of THA patients. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried from 2015 to 2019 for patients undergoing primary THA. First, outcomes were compared between chronologically younger and older frail patients. Then, to establish the aamFI, one additional point was added to the previously described mFI-5 for patients aged ≥73 years (the 75th percentile for age in our study population). The association of aamFI with postoperative complications and resource utilization was then analyzed categorically. RESULTS: A total of 165,957 THA patients were evaluated. Older frail patients had a higher incidence of complications than younger frail patients. Regression analysis demonstrated a strong association between aamFI and complications. For instance, an aamFI of ≥3 (compared to aamFI of 0) was associated with an increased odds of mortality (OR: 22.01, 95% confidence interval [CI] 11.62-41.68), any complication (OR: 3.50, 95% CI 3.23-3.80), deep vein thrombosis (OR: 2.85, 95% CI 2.03-4.01), and nonhome discharge (OR 9.61, 95% CI 9.04-10.21; all P < .001). CONCLUSION: Chronologically, older patients are impacted more by frailty than younger patients. The aamFI accounts for this and outperforms the mFI-5 in prediction of postoperative complications and resource utilization in patients undergoing primary THA.

Prosthetic Knee Infection With Coagulase-Negative Staphylococcus: A Harbinger of Poor Outcomes.

BACKGROUND: Coagulase-negative staphylococci (CoNS) are biofilm-producing pathogens whose role in periprosthetic joint infection (PJI) is increasing. There is little data on the prognosis and treatment considerations in the setting of PJI. We sought to evaluate the clinical characteristics, outcomes, and complications in these patients. METHODS: This is a retrospective cohort study of adult patients at a single tertiary medical center from 2009 to 2020 with culture-proven CoNS PJI after total knee arthroplasty, as diagnosed by Musculoskeletal Infection Society criteria. The primary outcome was treatment success, with failure defined as recurrent CoNS PJI, recurrent PJI with a new pathogen, and/or chronic oral antibiotic suppression at one year postoperatively. RESULTS: We identified 55 patients with a CoNS total knee arthroplasty PJI with a mean follow-up of 29.8 months (SD: 16.3 months). The most commonly isolated organism was Staphylococcus epidermidis (n = 36, 65.5%). The overall prevalence of methicillin resistance was 63%. Surgical treatment included surgical debridement, antibiotics, and implant retention in 25 (45.5%) cases and two-stage revision (22 articulating and eight static antibiotic-impregnated spacers). At one-year follow-up, only 47% of patients had successful management of their infection. The surgical debridement, antibiotics, and implant retention cohort had the higher rate of treatment failure (60.0%) compared to two-stage revision (46.7%). CONCLUSION: These results indicate a poor rate of success in treating CoNS PJI. This likely represents the interplay of inherent virulence through biofilm formation and decreased antibiotic efficacy.

Implementation of a practice plan for the outpatient cardiac evaluation of children after acute SARS-CoV-2 infection and a report of outcomes.

SARS-CoV-2 infection has been associated with cardiovascular disease in children, but which children need cardiac evaluation is unclear. We describe our experience evaluating 206 children for cardiac disease following SARS-CoV-2 infection (one of whom had ventricular ectopy) and propose a new guideline for management of these children. Routine cardiac screening after SARS-CoV-2 infection in children without any cardiac signs or symptoms does not appear to be high yield.

Capsular Management in Direct Anterior Total Hip Arthroplasty: A Randomized, Single-Blind, Controlled Trial.

BACKGROUND: The direct anterior approach (DAA) is a popular approach to total hip arthroplasty (THA). Unlike the posterior approach, the importance of anterior capsular management is unknown. This randomized controlled trial compares capsular repair versus capsulectomy. METHODS: This single-surgeon, single-blinded, parallel-group randomized controlled trial occurred between 2013 and 2016. Patients undergoing unilateral, primary THA for osteoarthritis consented to undergo blinded, simple randomization to anterior capsulotomy with repair or anterior capsulectomy. Primary outcome measures included hip range of motion, hip flexion strength, and pain with seated hip flexion. Secondary outcome measures included surgical time, estimated blood loss, postoperative complications, and hip disability and osteoarthritis outcome score. Data were prospectively collected intraoperatively, six weeks, six months, an average of over 5 years postoperatively. RESULTS: Ninety-eight patients were ultimately enrolled in the trial; 50 received capsulectomy and 48 received capsulotomy. No significant differences were seen in preoperative demographics or in primary or secondary outcomes during this study. No difference was seen in pain at final follow-up at average > 5 years postoperatively. CONCLUSION: This study demonstrates that capsular management in DAA THA does not affect postoperative pain or range of motion. The anterior capsule's role in prosthetic stability after DAA THA remains uncertain, but it does not currently appear that repair provides benefit and may lead to increased surgical time and blood loss. As such, capsular management in DAA THA is at surgeon discretion.

New-Onset Depression After Total Knee Arthroplasty: Consideration of the At-Risk Patient.

BACKGROUND: Postoperative new-onset depression (NOD) has gained recent attention as a previously unrecognized complication which may put patients at risk for poor outcomes after elective total hip arthroplasty. We aimed to investigate risk factors for the development of NOD after total knee arthroplasty (TKA) and assess its association with postoperative complications. METHODS: This is a retrospective, population-level investigation of elective TKA patients. Patients with a preoperative diagnosis of depression were excluded from this study. Two groups were compared: patients who were diagnosed with depression within one year after TKA (NOD) and those who did not (control). The association of both preoperative patient factors and postoperative surgical and medical complications with NOD was then determined using multivariate and univariate analyses. RESULTS: Of 196,728 unique TKA patients in our cohort, 5351 (2.72%) were diagnosed with NOD within one year of TKA. Age <54 year old, female gender, preoperative anxiety disorder, drug, alcohol, and/or tobacco use, multiple comorbidities, and opioid use before TKA were all associated with a diagnosis of NOD postoperatively (all P < .001). Postoperative NOD was associated with periprosthetic fracture (OR 2.11; 95% CI 1.29-3.52; P = .033), aseptic failure (OR 1.61; 95% CI 1.24-2.07; P = .020), prosthetic joint infection (OR 1.55, 95% CI 1.30-1.85; P < .001), stroke (OR 1.24; 95% CI 1.09-1.42; P = .006), and venous thromboembolism (OR 1.24; 95% CI 1.12-1.37; P < .001). CONCLUSION: Post-TKA NOD is common and is associated with poor outcomes. This may aid surgeons in developing both anticipatory measures and institute preventative measures for patients at risk for developing NOD.

Preoperative Patient Factors and Postoperative Complications as Risk Factors for New-Onset Depression Following Total Hip Arthroplasty.

BACKGROUND: Depression is known to be a risk factor for complication following primary total hip arthroplasty (THA), but little is known about new-onset depression (NOD) following THA. The purpose of this study is to determine the incidence of NOD and identify risk factors for its occurrence after THA. METHODS: This is a retrospective cohort study of the Truven MarketScan database. Patients undergoing primary THA were identified and separated into cohorts based on the presence or not of NOD. Patients with preoperative depression or a diagnosis of fracture were excluded. Patient demographic and comorbid data were queried, and postoperative complications were collected. Univariate and multivariate regression analysis was then performed to assess the association of NOD with patient-specific factors and postoperative complications. RESULTS: In total, 111,838 patients undergoing THA were identified and 2517 (2.25%) patients had NOD in the first postoperative year. Multivariate analysis demonstrated that preoperative opioid use, female gender, higher Elixhauser comorbidity index, preoperative anxiety disorder, drug or alcohol use disorder, and preoperative smoking were associated with the occurrence of NOD (P ≤ .001). The following postoperative complications were associated with increased odds of NOD: prosthetic joint infection (odds ratio [OR] 1.82, 95% confidence interval [CI] 1.42-2.34, P < .001), aseptic revision surgery (OR 1.47, 95% CI 1.06-2.04, P = .019), periprosthetic fracture (OR 1.72, 95% CI 1.13-2.61, P = .01), and non-home discharge (OR 1.59, 95% CI 1.42-1.77, P < .001). CONCLUSIONS: NOD is common following THA and there are multiple patient-specific factors and postoperative complications which increase the odds of its occurrence. Providers should use this information to identify at-risk patients so that pre-emptive prevention strategies may be employed.

Preoperative Analgesia, Complications, and Resource Utilization After Total Hip Arthroplasty: Tramadol Is Associated With Less Risk Than Other Preoperative Opioid Medications.

BACKGROUND: Preoperative opioid use is known to be detrimental to outcomes after total hip arthroplasty (THA). This is concerning as multiple societies recommend tramadol for the management of arthritis. The purpose of this study was to determine if tramadol is associated with postoperative complications, increased resource utilization, and revision when compared with patients receiving nontramadol opioids (NTOs) and those who are opioid naive (ON). METHODS: This is a retrospective cohort study using the Truven MarketScan databases (Truven Health, Ann Arbor, MI). Adult patients undergoing primary THA were identified and divided into 4 cohorts based on preoperative opioid medications (ie, ON, tramadol-only [TO], or NTOs; ±tramadol). Demographics, comorbidities, and 90-day complications were collected and compared between cohorts. Revision rates were compared at 3 years. Univariate and multivariate analyses were performed. Finally, preoperative prescription patterns were trended during the study period. RESULTS: About 198,357 patients, including 18,694 TO and 106,768 ON, were identified. Compared with ON, TO patients had similar rates of complications and revision surgery (P > .05) but had slightly higher emergency department visits (odds ratio [OR], 1.06; 95% confidence interval [95% CI], 1.01-1.12; P = .027), readmissions (OR, 1.16; 95% CI, 1.09-1.22; P < .001), and nonhome discharges (OR, 1.07; 95% CI, 1.02-1.12; P = .010). TO patients had significantly lower odds of incurring most examined complications, including revision surgery, when compared with NTO (P < .05). From 2009 to 2018, the proportion of patients prescribed preoperative opioids decreased. CONCLUSION: Preoperative TO is associated with less postoperative risk than NTO use and is similar to opioid naivety. Fortunately, the number of patients receiving preoperative NTOs appears to be decreasing. Our results support tramadol as an appropriate pre-THA analgesic.

Surgical Treatment of Talus OCL: Mid- to Long-Term Clinical Outcome With Detailed Analyses of Return to Sport.

Talus osteochondral lesions are a commonly underdiagnosed problem in young athletes. Talus osteochondral lesions surgical algorithm remains controversial. Current metrics suggest that conventional treatment of osteochondral lesions of the talus is promising; yet return to sport is poorly studied. Fifty-seven patients following talus osteochondral lesion surgical intervention were included in this study. About 63.1% were female with mean age 37.1 years, mean lesion size 10 × 12.5 mm, and mean follow-up 79.9 months postoperatively. Patients were divided into 4 groups by surgery performed: antegrade arthroscopic bone marrow stimulation, retrograde arthroscopic drilling, osteochondral autograft transfer, and allograft cartilage implantation. Outcome metrics include Visual Analog Scale for pain and function, Short Form-12, Foot and Ankle Disability Scale, Tegner, Marx activity scores, Naal Sports inventory, and patient satisfaction. Over 77% of patients were satisfied with surgical intervention. Each intervention significantly decreased pain and increased function, except retrograde drilling. All interventions trended toward decreased Tegner score; only antegrade drilling showed significant decrease. Based on Naal's sports inventory, 85.7% of surgically treated patients reported participating in sport activities, on average 3 times/week and 50.6 minutes/session. Traditionally, talus osteochondral lesions present a difficult problem that is marred by unsatisfactory nonoperative outcomes in typically active patients. As our surgical understanding has evolved, we've continued to improve on outcomes. Our patients demonstrated 77.2% overall satisfaction rate, a statistically significant improvement in pain and function, at an average follow-up of 79.9 months postoperatively, and a high rate of return to sport with little difference between surgical interventions.

A genetic mouse model of severe iron deficiency anemia reveals tissue-specific transcriptional stress responses and cardiac remodeling.

Iron is a micronutrient fundamental for life. Iron homeostasis in mammals requires sustained postnatal intestinal iron absorption that maintains intracellular iron concentrations for central and systemic metabolism as well as for erythropoiesis and oxygen transport. More than 1 billion people worldwide suffer from iron deficiency anemia (IDA), a state of systemic iron insufficiency that limits the production of red blood cells and leads to tissue hypoxia and intracellular iron stress. Despite this tremendous public health concern, very few genetic models of IDA are available to study its progression. Here we developed and characterized a novel genetic mouse model of IDA. We found that tamoxifen-inducible deletion of the mammalian iron exporter ferroportin exclusively in intestinal epithelial cells leads to loss of intestinal iron absorption. Ferroportin ablation yielded a robust phenotype of progressive IDA that develops in as little as 3 months following disruption of intestinal iron absorption. We noted that, at end-stage IDA, tissue-specific transcriptional stress responses occur in which the heart shows little to no hypoxic and iron stress compared with other peripheral organs. However, morphometric and echocardiographic analysis revealed massive cardiac hypertrophy and chamber dilation, albeit with increased cardiac output at very low basal heart rates. We propose that our intestine-specific ferroportin knockout mouse model of end-stage IDA could be used in future studies to investigate IDA progression and cell-specific responses to hypoxic and iron stress.

Projections and Epidemiology of Revision Hip and Knee Arthroplasty in the United States to 2030.

BACKGROUND: As the incidence of primary total joint arthroplasty rises in the United States, it is important to investigate how this will impact rates of revision arthroplasty. The purpose of this study was to analyze the incidence and future projections of revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) to 2030. Anticipating surgical volume will aid surgeons in designing protocols to efficiently and effectively perform rTHA/rTKA. METHODS: The national inpatient sample was queried from 2002 to 2014 for all rTHA/rTKA. Using previously validated measures, Poisson and linear regression analyses were performed to project annual incidence of rTHA/rTKA to 2030, with subgroup analyses on modes of failure and age. RESULTS: In 2014, there were 50,220 rTHAs and 72,100 rTKAs. From 2014 to 2030, rTHA incidence is projected to increase by between 43% and 70%, whereas rTKA incidence is projected to increase by between 78% and 182%. The 55-64 and 65-74 age groups increased in revision incidence during the study period, whereas 75-84 age group decreased in incidence. For rTKA, infection and aseptic loosening are the 2 most common modes of failure, whereas periprosthetic fracture and infection are most common for rTHA. CONCLUSION: The incidence of rTHA/rTKA is projected to increase, particularly in young patients and for infection. Given the known risk factor profiles and advanced costs associated with revision arthroplasty, our projections should encourage institutions to generate revision-specific protocols to promote safe pathways for cost-effective care that is commensurate with current value-based health care trends. LEVEL OF EVIDENCE: IV.