BACKGROUND We have previously reported the early clinical results of a modular-neck stem identifying an early 2-year revision rate of 13% due to neck-stem corrosion. This report updates our findings to a midterm mean follow-up of 5 years. METHODS This is a consecutive retrospective review of 186 modular-neck hips in 175 patients with a mean follow-up period was 60.1 ± 22.9 months (range 24-100). We reviewed clinical findings, routine radiographs, detailed imaging (metal artifact reduction software-magnetic resonance imaging, ultrasound), and serum ion levels of cobalt and chromium. We performed a survival analysis with the endpoint defined as revision total hip arthroplasty due to neck-stem corrosion. RESULTS We revised 41 hips (22.0%) for neck-stem corrosion. Clinical symptoms (groin pain ± local swelling) were consistently present in those that came for revision. Mean serum cobalt ion levels increased as time passed in all patients. Detailed image findings showed that larger fluid collections and local soft tissue masses were seen predominately in symptomatic patients. However, 14% of patients who underwent revision did not have positive magnetic resonance imaging or ultrasound findings. The survival rate was 87% (95% confidence interval 81-92) at 3 years postoperatively and 72% (95% confidence interval 64-80) at 7 years postoperatively. CONCLUSION The revision rate for this modular-neck stem due to neck-stem corrosion at mid-term follow-up almost doubled in comparison to previous short-term results. It seems reasonable to consider clinical follow-up alone as symptoms, rather than blood testing for ion levels, seem to be the defining characteristic of failure. BACKGROUND Adverse local tissue reactions (ALTRs) around a modular neck stem at our institution lead to a 13.5% rate of revision. The purpose of this study was to report the clinical results of revision total hip arthroplasty (THA) in this patient population. METHODS We identified 80 hips in 77 patients who underwent revision THA due to neck-stem corrosion. Intraoperative and postoperative complications, clinical outcomes, re-revision rates, and the postoperative ion levels were recorded. RESULTS The mean follow-up period after revision was 45.3 ± 16.3 months (range 24-81 months). There were no intraoperative mechanical complications during the revision surgery. Eight hips (10%) had postoperative complications related to the revision implant, of which 6/8 came to re-revision postoperative implant dislocation in 4 hips-2 treated nonsurgically, aseptic loosening of femoral component in 2 hips, and periprosthetic femoral fracture in 2 hips. No patients had recurrence of ALTR nor the recurrence of groin pain within the follow-up period. With 2 exceptions, ion levels normalized within one year of the revision surgery. The survival rate was 94% (95% confidence interval 84-98) at 32 months and 82% (95% confidence interval 56-93) at 63 months after revision THA (using re-revision THA due to any reason as the endpoint). CONCLUSION Intraoperative complication, postoperative complication, and re-revision rates are equivalent to femoral revision surgeries for other causes (infection, fracture, loosening). We recommend selecting revision-type stems to minimize the risk of femoral loosening or periprosthetic fracture, and larger femoral heads or dual mobility bearings to minimize the risk of dislocation. BACKGROUND At the 2019 Annual Meeting of the American Association of Hip and Knee Surgeons (AAHKS), a survey was conducted to assess current practice management strategies by AAHKS members. METHODS AAHKS members used an audience response system to respond to queries related to a variety of practice management issues. The survey contained multiple-choice and yes or no questions. The answers were collected in a central database and provided to the audience in real time. RESULTS There were a number of surprising findings in this year's survey. A majority of AAHKS members are still in private practice (40%), fee for service is still the most common form of compensation (39%), and there has been a decrease in the number of AAHKS members participating in bundle payment contracts (34%). There has been a dramatic rise in both the use of unicondylar knee arthroplasties and the performance of same-day total joint arthroplasty among AAHKS members. CONCLUSION The survey documents the current practice patterns of AAHKS members and demonstrates the continued evolution of the practice of total joint arthroplasty. Future surveys should continue to monitor practice activity related to private practice, fee for service, and the use of same-day total joint arthroplasty. BACKGROUND Bundled payment models may lead to selection of healthier total joint arthroplasty (TJA) candidates resulting in comorbid patients taken care of in fewer hospitals. We aimed to (1) evaluate hospital-specific TJA comorbidity burden ("casemix") over time and (2) associations with resource utilization. METHODS This retrospective cohort study used 2011 and 2016 New York State data (n = 36,078 hip/knee arthroplasties). Comorbidity burden was estimated by the Charlson-Deyo Index; main outcomes were hospitalization cost and nonhome discharge. Hospitals were categorized into those with a decreased, stable (with a 5% buffer), or increased percentage of comorbidity-free patients (Charlson-Deyo = 0) between 2011 and 2016.  https://www.selleckchem.com/products/alantolactone.html  Mixed-effects models measured the association between Charlson-Deyo Index category and outcomes, by hospital casemix categorization. Odds ratios and 95% confidence intervals (CIs) are reported. RESULTS Overall, 29 (n = 8810), 37 (n = 16,297), and 46 (n = 10,971) hospitals were categorized into the decreased, stable, and increased Charlson-Deyo = 0 categories, respectively, with median annual TJA volumes of 499, 814, and 393 (P less then .0001). Multivariable models demonstrated that-in hospitals with a stable patient casemix-increased patient comorbidity was associated with increased hospitalization costs (maximum 21.8%, CI 18.9-24.9, P less then .0001). However, this effect was moderated (maximum 11.1%, CI 8.0-14.2) in hospitals that took on a more comorbid patient casemix. Similar patterns were observed for nonhome discharge. CONCLUSION Most studied hospitals show an increase in comorbidity-free TJA patients, suggestive of patient selection. This redistribution of comorbid patients to select hospitals may not necessarily be a negative development as our results suggest more efficient resource utilization for comorbid patients in such hospitals.