Introduction. Bundled Payments (BP) were a revolutionary new experiment for CMS that tested whether risk sharing for an episode of care would improve quality and reduce costs. The initial success of BP accelerated their growth as evidence by the launch of both mandatory and commercial bundles. Success in BP is dependent on the target price and the opportunity to reduce avoidable costs during the episode of care. There is concern that the aggressive target pricing methodology in the new model (BPCI-Advanced) penalizes high performing groups that already achieved low episode costs through prior experience and investment in BP. We hypothesize that this methodology incorporates unsustainable downward trends on target prices to a point beyond reasonableness for efficient groups to reduce additional costs and will lead to a large percentage of groups opting out of BPCI-A in favor of a return to fee for service (FFS) reimbursement. Methods. Using CMS data, we compared the target price factors for hospitals that participated in both BPCI classic (2013 –2018) and BPCI Advanced (beginning 10/2018), referred to as “legacy hospitals”, with hospitals that only participated in BPCI Advanced (beginning 10/2018). With the rebasing of BPCI-A target prices in Jan 2020 and the opportunity for participants to drop out of individual episode types or the program all together, we compared the retention of episode types that hospitals initially enrolled at the onset of BPCI-A with the current enrollment in 2020. Locally, we analyzed the BPCI-A target price factors across hospitals for a large orthopaedic practice that participated in BPCI Classic and the impact it had on the financial incentive/disincentive to remain in the lower extremity joint replacement episode type in 2020. Results. At its peak in July 2015, 423 acute care hospitals participated in one or more episode type in BPCI Classic. At its peak in March 2019, 715 acute care hospitals participated in one or more episode types in BPCI-Advanced. 130 (18%) of the hospitals in BPCI Advanced were also legacy participants in BPCI Classic, enrolling in 414 of the same episode types during both programs. In 2020, 251 (61%) of the episode types that hospitals were in enrolled in for both BPCI Classic and BPCI Advanced were dropped, suggesting prior experience in BPCI influences a participant's opportunity for success in BPCI Advanced. Furthermore, an analysis of the target price factors for episode types enrolled in by legacy hospitals during both programs suggests that prior participation in BPCI Classic is correlated with more aggressive target prices. A comparison of target price factors of similar hospitals reveals that legacy BPCI Classic hospitals that participated in lower extremity joint replacement (LEJR) BPCI Advanced received a larger negative adjustment on the target price (0.11 lower on average as a product of the Peer Adjusted Trend factor and ACH Efficiency factor) than non-legacy hospitals that participated in BPCI Advanced. Furthermore, analysis of the hospital targets for a large, high-performing legacy Physician Group Practice in BPCI Classic for LEJR revealed even greater negative adjustment on the target price than non-legacy participants. Comparing participants of similar peer groups on the Peer Adjusted Trend and ACH Efficiency factors suggests that CMS expects costs to decline more for legacy hospitals that have achieved efficiency than hospitals with no prior BP experience and higher baseline spend. Conclusions. BPCI Advanced provides little to no opportunity for a reduction in cost for already efficient TJA providers, as evident by the 55% dropout rate for BPCI-A participants in LEJR between model years 1 and 3. Efficient TJA providers in BPCI Advanced are challenged by the program's utilization of a peer adjusted trend factor and efficiency factor that presumes their costs will decline at the same aggressive rate or more than nonefficient TJA providers. It remains to be seen if reverting to Medicare fee for service will support the same level of care coordination, cost and quality achieved in historical TJA bundled payment programs

Background. The Comprehensive Care for Joint Replacement (CJR) model was implemented in April-2016 to standardize cost and improve quality of care for two of the most commonly billed inpatient procedures for Medicare patients, total knee and total hip arthroplasty. The purpose of this study is to compare one institution's predicted savings and losses under the CJR model with actual savings and losses after two years of implementation and discuss new methods to maintain savings. Methods. Using our institution's data, we calculated the mean cost per episode of care. We calculated the percent reduction in target price and percent savings or losses per case for the CJR and Bundle Payment Care Initiative (BPCI) for each Medicare Severity Diagnosis Related Group (MS-DRG) using mean cost per episode and CJR and BPCI target prices. We compared the target prices, annual savings, and losses per episode of care for both CJR and BPCI. All CJR savings, projected and actual, were computed by comparing CJR savings to that of 2018 BPCI savings. Results. We found an average savings of 2.32% under CJR compared to the projected loss of −11.6% for MS-DRG 469 with fracture. There was a 7.97% savings for MS-DRG 470 without fracture compared to the projected 1.9%, a 20.94% savings for MS-DRG 470 with fracture compared to the projected 23.7%, and a loss of −3.98% for MS-DRG 469 without fracture compared to the projected 2.5% savings. Conclusions. The CJR target prices are lower than that of BPCI and this makes maintaining an episode of care at or below the target price increasingly difficult. Discharge disposition and readmission are well established factors that increase hospital cost [7]. However, reduction of these does not seem enough to maintain savings under the CJR model. New cost savings mechanisms such as identification of patients eligible for SDD, and reduction of unnecessary home services resulted in smaller losses of positive margins, though these were still significantly less for CJR than BPCI

Introduction. The Comprehensive Care for Joint Replacement (CJR) initiative was implemented to address the two most commonly billed inpatient surgical procedures, total hip and knee arthroplasty. The primary purpose of this manuscript is to review the economic implications of one institution's mandatory involvement in CJR in comparison to prior involvement in Bundled Payment for Care Improvement (BPCI). Methods. The average cost per episode of care (EOC) was calculated using our institution's historical data. The target prices, projected savings or losses per EOC, and the projected annual savings for both BPCI and CJR were established and comparatively analyzed. Results. The CJR target prices will decrease in comparison to BPCI target prices by: 24% for MS-DRG 469 without fracture, 22.8% for 469 with fracture, 26.1% for 470 without fracture, 27.7% for 470 with fracture; resulting in a reduction in savings per EOC by: 92.8% for MS-DRG 469 without fracture, 166.0% for 469 with fracture, 94.9% for 470 without fracture, 61.7% for 470 with fracture (Table 1). This institution's projected annual savings under CJR will decrease by 83.3%. Conclusion. These results suggest that the margin for savings in CJR will be substantially reduced compared to those in BPCI. Hospitals resources previously devoted will have far less impact in CJR and hospitals new to CJR who have not made these investments previously, will require even greater resources for developing cost-reduction and quality control strategies to remain financially solvent. The statements contained in this document are solely those of the authors and do not necessarily reflect the views or policies of CMS. The authors assume responsibility for the accuracy and completeness of the information contained in this document. For any tables or figures, please contact the authors directly

Introduction. Current CMS reimbursement policy for total joint replacement is aligned with more cost effective, higher quality care. Upon implementation of a standardized evidenced-based care pathway, we evaluated overall procedural costs and clinical outcomes over the 90-day episode of care period for patients undergoing TKA with either conventional (Conv.) or robotic-assisted (RAS) instrumentation. Methods. In a retrospective review of the first seven consecutive quarters of Bundled Payment for Care Improvement (BPCI) Model 2 participation beginning January 2014, we compared 90-day readmission rates, Length of Stay (LOS), discharge disposition, gains per episode in relation to target prices and overall episode costs for surgeons who performed either RAS-TKA (3 surgeons, 147 patients) or Conv. TKA (3 surgeons, 85 patients) at a single institution. All Medicare patients from all surgeons performing more than two TKA's within the study period were included. An evidence-based clinical care pathway was implemented prior to the start of the study that standardized pre-operative patient education, anesthesia, pain management, blood management, and physical/occupational therapy throughout the LOS for all patients. Physician specific target prices were established from institutional historical payment data over a prior three year period. Results. RAS and Conv-TKA procedures exhibited an average gain per episode of $7,600 and $5,579, respectively. The average total cost per 90-day episode was $2,085 lower for patients receiving RAS-TKA ($28,943 versus $31,028), with the majority of cost savings in reduced SNF usage ($1,481) and readmissions ($944). Discharge to home versus Sub-acute Rehabilitation Facilities (SAR's) was 14% higher in the RAS group (62% vs 48%, p<0.05). Conclusions. Implementation of a standardized care pathway across all service departments and physicians resulted in a reduction in overall episode of care costs, with further reductions in cost and discharge to SARs observed with the use of RAS

Introduction. The Comprehensive Care for Joint Replacement (CJR) model for total hip arthroplasty (THA) involves a target reimbursement set by the Center for Medicare and Medicaid Services (CMS). Many patients exceed these targets, but predicting risk for incurring these excess costs remains challenging, and we hypothesized that select patient characteristics would adequately predict CJR cost overruns. Methods. Demographic factors and comorbidities were retrospectively reviewed in 863 primary unilateral CJR THAs performed between 2013 and 2017 at a single institution. A predictive model was built from 31 validated comorbidities and a base set of 5 patient factors (age, gender, BMI, ASA, marital status). A multivariable logistic regression model was refined to include only parameters predictive of exceeding the target reimbursement level. These were then assigned weights relative to the weakest parameter in the model. Results. The overall cost of care for 225 patients (26.1%) exceeded the target price, and a comprehensive model containing all 36 parameters demonstrated adequate discrimination (AUC: 0.748). This model was narrowed to 12 parameters retained for their statistical value in predicting excess cost, without substantial loss of predictive ability (AUC: 0.735). A single score formed from the sum of each patient's weighted parameters also showed adequate discrimination (AUC: .732), with predicted risk for exceeding CJR targets ranging from 10% for a patient score of 10 to 80% for a score of 30. Average scores for patients exceeding the target price were significantly higher than those who did not (19.5 vs 15.0, p < 0.0001). Conclusions. A model composed of weighted comorbidities and base demographics provides adequate discrimination in predicting whether THA costs will exceed CJR targets. This not only helps identify patients who may benefit from further pre-operative optimization, but also allows health systems to predict the likely minimum incurred costs for select patients scheduled for surgery

Introduction. Hip fractures are a common pathology treated by Orthopaedic surgeons. The Comprehensive Care for Joint Replacement (CJR) model utilizes risk stratification to set target prices for these patients undergoing hemiarthroplasty or total hip arthroplasty (THA). We hypothesized that sub-specialty arthroplasty surgeons would be able to treat patients at a lower cost compared to surgeons of other specialties during cases performed while on call. Methods. Patients with hemiarthroplasty or THA for hip fractures were retrospectively collected from June, 2013, to May, 2017, from a single tertiary referral center. Demographic information and outcomes based on length of stay (LOS), net payment, and target payment were collected. Patients were then stratified by surgeon subspecialty (arthroplasty trained vs. other specialty). Univariable and multivariable analysis for payment based on treating surgeon was then performed. Results. 197 hip fracture patients were included through the collection period. 40 patients were treated by arthroplasty surgeons and 157 patients were not. There was no difference in LOS, however, when treated by arthroplasty trained surgeons, they were significantly more likely to have a lower net payment (32,507 vs. 42,518; p=0.001) with cost of care below the target payment (80.0% vs 51.6%; p=0.001), partially stemming from decreased discharges to skilled nursing facilities (p=0.008). In multivariable regression controlling for age, sex, BMI, ASA score, and procedure, arthroplasty surgeons were more likely to perform under the target price, which approached statistical significance (OR 2.177; 95% CI 0.866–5.474; p=0.098). Discussion and Conclusion. Hip fracture patients are commonly treated by on-call surgeons given the need to expedite their care. However, given the bundled payment model implemented by CJR, there must be special consideration to fracture stratification, implant selection, and surgeon experience. If feasible, our data suggests that an arthroplasty surgeon may contribute to decreased cost of care; a larger multicenter study is required

Introduction. The purpose of bundled payment programs is to reduce cost via risk sharing, while still maintaining quality. If savings are achieved under a historic target price, the orthopedic surgeon will receive a monetary bonus. If costs are higher, a portion is deducted from payment to the orthopedic surgeon. The purpose of this study was to evaluate our experience with the Bundled Payments for Care Improvement Program (BPCI) when run by an orthopedic surgeon group to determine patient safety and who benefited the most financially. Methods. This program ran from January 2015 through September 2018. 3,186 Medicare total hip and knee replacements, elective (DRG 470) and for fracture (DRG 469), performed by our group were included. 90 day hospital and all postoperative expenditures were reconciled against our historic cost. All patients were medically optimized with discharge plans established preoperatively. We developed preferred skilled nursing facilities and home health care agencies with synergistic medical providers so that discharges were recommended as soon as appropriate. We hired two full-time case managers to have direct contact with patients pre-and post-operatively. Waiver assistance such as house and pet sitters were used if necessary at our expense. 35% of savings went to the convener, who acted as a liaison between our group and CMS. Expenditures for the 90-day period for all patients were calculated to determine where savings occurred and which entity benefitted financially. Results. There was an average 9.2% reduction in hospital readmissions. An estimated total savings of $5,100,000 occurred. There was a 17% reduction in hospital costs, a 12.1% reduction in admissions to skilled nursing facilities with a 34% reduction in length of stay, and a 5% reduction in admissions to inpatient rehabilitation facilities. There was a 35% reduction in home health visits, but no change in outpatient physical therapy visits. After group expenses, final bonus to the orthopedic provider was on average $262 per patient. Conclusion. The physician managed program was very successful from Medicare's standpoint, achieving significant monetary savings without reducing quality of care. However, the bonus to the providing and managing physicians was nominal. It also does not take into consideration the 50 plus hours spent in meetings to develop this program. Participation could be considered a defensive posture so as not to lose more reimbursement. However, experience was gained which will be valuable for future gain sharing programs. Physicians and physician organizations need to sit at the head of the table to manage future payment bundles and perhaps also act as the convener. We deserve this, as a result of demonstrating high safety and cost savings. For figures, tables, or references, please contact authors directly

Background. In surgeon controlled bundled payment and service models, the goal is to reduce cost but preserve quality. The surgeon not only takes on risk for the surgery, but all costs during 90 days after the procedure. If savings are achieved over a previous target price, the surgeon can receive a monetary bonus. The surgeon is placed in a position to optimize the patients preoperatively to minimize expensive postoperative readmissions in a high risk population. Traditionally, surgeons request that primary care providers medically clear the patient for surgery with cardiology consultation at their discretion, and without dictating specific testing. Our participation in the Bundled Payments for Care Improvement (BPCI) program for total hip and knee replacement surgeries since 1/1/15 has demonstrated a significant number of patients having costly readmissions for cardiac events. Objective. To determine the medical effectiveness and cost savings of instituting a new innovative cardiac screening program (Preventive Cardio-Orthopaedics) for total hip and knee replacement patients in the BPCI program and to compare result to those managed in the more traditional fashion. Methods. The new screening program was instituted on 11/1/17 directed by an advanced cardiac imaging cardiologist (EH). Testing included an electrocardiogram, echocardiogram, carotid and abdominal ultrasound, and coronary computed tomography angiography (CCTA). If needed, a 3 day cardiac rhythm monitor was also performed. Four of the ten physicians in our group performing hip and knee replacement surgeries participated. Charts of readmitted patients were reviewed to determine past medical history, method of cardiac clearance, length and cost of readmission. Results. 2,459 patients had total hip or knee replacement in the BPCI program between 1/1/15 and 10/31/17 prior to instituting the new program. All had complete 90 day postoperative readmission data supplied by the CMS, with 25 (1%) of these patients having readmissions for cardiac events for a total cost of readmissions of %149,686. 14 of 25 had a preoperative clearance by a cardiologist. In 19 of the 25 patients, the only preoperative cardiac screening tool performed was an electrocardiogram. Since instituting the new program, 842 additional surgeries were performed, 463 by the four surgeons involved. 126 patients were agreeable to be evaluated through the Preventive Cardio-Orthopaedics program. 4 patients of the four physicians still screened via the traditional cardiac program had a cardiac event readmission. The average readmission hospital stay was 3.33 days at a total cost of %42,321. 2 patients of the four physicians evaluated by the Preventive Cardio-Orthopaedics program had a cardiac related readmission, at an average hospital stay of 2 days, and at a total cost of %10,091. Conclusions. Risk sharing programs have forced surgeons to take a more active role in optimizing their patients medically; otherwise they will be penalized with a decreased reimbursement. Traditionally, we have abdicated this responsibility to primary care and cardiology physicians but have noted a high cardiac readmission risk. In response, we have begun using a unique cardiac screening model. Our preliminary experience predicts fewer cardiac readmissions thereby improving care, and at a lower cost

Introduction. Bundle payment models have clinical and economic impacts on providers. Despite efforts made to improve care, experience has shown that a few episodes with costs well above a target (bundle busters) can reduce or negate positive performances. The purpose of this study was to identify both the primary episode drivers of cost and patient factors that led to episodes above target. Methods. A retrospective study of 10,000 joint replacement episodes from a large healthcare system in CJR and a private orthopedic practice in BPCI was conducted. Episodes with costs greater than target price (TP) were designated as bundle busters and sub-divided into 4 groups:. 1). < 1 standard deviation (SD) above TP (n=1700). 2). > 1 to 2 SD above TP (n=240). 3). > 2 to 3 SD above TP (n=70). 4). > 3 SD above TP (n=70). Bundle busters were compared to the control that were at/below the TP (n= 7500). For the CJR/BPCI cohorts, one SD was defined as $10,700/$13,000, respectively. Two linear regressions assessed the likelihood of factors predicting a bundle buster and the total episode cost. These variables included demographics, acuity classifications, comorbidities, length of stay, readmissions, discharge disposition, post-acute utilization, and episode costs. Results. Group 1 had 66% higher total episode costs than the control group, 13% higher hospital costs, and 144% higher SNF costs. Costs for Group 2 were at least double that of Group 1. Significant predictors for bundle busters included, race, age, comorbidities, BMI, and LOS. (P<0.01) Significant predictors for total episode costs included, gender, age, ROM, SOI, comorbidities, and BMI. (P<0.1). Discussion. Age, Comorbidities, and BMI are among significant predictors of higher total episode costs. Identifying drivers and factors that impact bundle busters supports the importance of care model improvements that mitigate risks associated with these patients

Background. The Bundled Payments for Care Improvement (BPCI) was developed by the US Center for Medicare and Medicaid (CMS) to evaluate a payment and service delivery model to reduce cost but preserve quality. 90 day postoperative expenditures are reconciled against a target price, allowing for a monetary bonus to the provider if savings were achieved. The surgeon is placed in a position to optimize the patients preoperatively to minimize expensive postoperative cardiovascular readmissions in a high risk population. Traditionally, surgeons request that primary care providers medically clear the patient for surgery with or without additional cardiology consultation, without dictating specific testing. Typical screening includes an EKG, occasionally an echocardiogram and nuclear stress test, and rarely a cardiac catheterization. Our participation in the BPCI program for total hip and knee replacement surgeries since 1/1/15 has demonstrated a significant number of patients having readmissions for cardiac events. Objective. To determine the medical effectiveness and cost savings of instituting a new innovative cardiac screening program (Preventive Cardio-Orthopaedics) for total hip and knee replacement patients in the BPCI program and to compare result to those managed in the more traditional fashion. Methods. The new screening program was instituted on 11/1/17 directed by an advanced cardiac imaging cardiologist (EH). Testing included an electrocardiogram, echocardiogram, carotid and abdominal ultrasound, and coronary computed tomography angiography (CCTA). If needed, a 3 day cardiac rhythm monitor was also performed. Four of the ten physicians in our group performing hip and knee replacement surgeries participated. Charts of readmitted patients were reviewed to determine past medical history, method of cardiac clearance, length and cost of readmission. Results. 1,361 patients had total hip or knee replacement in the BPCI program between 1/1/15 and 1/28/18 and all had complete 90 day postoperative readmission data supplied by the CMS, with 25 of these patients evaluated through the Preventive Cardio- Orthopaedics program. 12 (0.90%) screened via the traditional cardiac program had a cardiac event readmission. The average readmission hospital stay was 3.67 days at a total cost of $69,378. 7 of 12 had a preoperative clearance by a cardiologist. In 9 of the 12 patients, the only preoperative cardiac screening tool performed was an electrocardiogram. None of these 25 patients evaluated through the new program has been readmitted. 84 more patients have been evaluated in this program since 1/28/18, but 90 day readmission data is still incomplete. Preliminary data suggests that the highest risk in these patients is not severe coronary artery disease, but atrial fibrillation, hypertension with left ventricular hypertrophy, and cardiac plaques with ulceration. Conclusions. Risk sharing programs have forced joint replacement surgeons to take a more active role in optimizing their patients medically; otherwise they will be penalized with a decreased reimbursement. Traditionally, we have abdicated this responsibility to primary care and cardiology physicians but have noted a high readmission risk with a cardiac event. In response, we have begun using a unique cardiac screening model. Our preliminary experience predicts fewer cardiac readmissions thereby improving care, and at a lower cost

The unparalleled events of the year 2020 continue to evolve and challenge the worldwide community on a daily basis. The COVID-19 pandemic has had a major impact on all aspects of our lives, and has caused major morbidity and mortality around the globe. The impact of COVID-19 on the practice of orthopedic surgery has been substantial with practice shutdowns, elective surgery restrictions, heightened utilization of telemedicine platforms and implementation of precautionary measures for in-person clinic visits. During this transition period the scholarly and educational pursuits of academic surgeons have been de-emphasized as the more immediate demands of clinical practice survivorship have been the priority. This unavoidable focus on clinical practice has heightened the importance of orthopedic subspecialty societies in maintaining an appropriate level of attention on research and educational activities. Under the outstanding presidential leadership of Robert Barrack, MD, The Hip Society adapted to the profound challenges of 2020, and maintained strong leadership in the realms of education and research. The recent 2020 summer meeting of the Hip Society was a testimonial to the resilience and dedication of the Society members to ongoing innovation in research and education. Due to travel and social distancing restrictions the 2020 summer meeting was transitioned from an in-person to a virtual meeting format. Dr Barrack and Program Chair Dr John Clohisy assisted with oversight of the meeting, while Olga Foley and Cynthia Garcia ensured the success of the meeting with remarkable planning and organization. These collaborative efforts resulted in an organized, well-attended, high level scientific meeting with engaging discussion and a remarkable virtual conference environment. The Bone & Joint Journal is very pleased to partner with The Hip Society to publish the proceedings of this very unique virtual meeting. The Hip Society is based in the United States and membership is granted to select individuals for leadership accomplishments in education and research related to hip disease. The Society is focused on the mission of advancing the knowledge and treatment of hip disorders to improve the lives of patients. The vision of the Hip Society is to lead in the discovery and dissemination of knowledge related to disorders of the hip. The annual closed meeting is one of the most important events of the society as this gathering highlights timely, controversial and novel research contributions from the membership. The top research papers from The Hip Society meeting will be published and made available to the wider orthopedic community in The Bone & Joint Journal. This partnership with The Bone & Joint Journal enhances the mission and vision of The Hip Society by international dissemination of the meeting proceedings. Given the far-reaching circulation of The Bone & Joint Journal the highest quality work is available to an expanding body of surgeons, associated healthcare providers and patients. Ultimately, this facilitates the overarching Hip Society goal of improving the lives of our patients. The 2020 virtual Hip Society meeting was characterized by outstanding member attendance, high quality paper presentations and robust discussion sessions. The meeting was held over two days and encompassed 58 open paper presentations divided into ten sessions with moderated discussions after each session. All papers will be presented in this issue in abstract form, while selected full papers passing our rigorous peer review process will be available online and in The Bone & Joint Journal in a dedicated supplement in 2021. The first session of the meeting focused on issues related to complex primary THA and osteonecrosis of the femoral head. Dr Gross presented on the conversion of hip fusion to THA in 28 patents at a mean 7 years. He reported a high clinical success rate, yet complications of heterotopic ossification and neurologic injury were relatively common. Consideration of heterotopic ossification prophylaxis and the selective use of a constrained liner were recommended. Dr Pagnano summarized the use of various contemporary porous acetabular components in 38 hips in the setting of prior pelvic radiation. The mean follow-up was 5 years and 10 year survivorship was 100% with all implants radiographically fixed. Dr Bolognesi's study demonstrated that THA in solid organ transplant patients is associated with higher risk for facility placement, transfusions and readmissions. This patient population also has increased mortality risk (4.3% risk at 1 year) especially lung transplant patients. The second group of papers focused on femoral head osteonecrosis. Dr Iorio presented single center data demonstrating that CT scan was a useful adjunct for diagnosis in the staging work-up for cancer, yet was not useful for ARCO staging and treatment decision-making. On the basic science side, Dr Goodman utilized a rabbit model of steroid-induced femoral head osteonecrosis to determine that immunomodulation with IL-4 has the potential to improve bone healing after core decompression. The session was concluded by Dr Nelson's study of ceramic-on-ceramic THA in 108 osteonecrosis patients. The median 12 year results were outstanding with marked increases in PROs, maintenance of high activity levels, and a 3.7% revision rate. In the second session attention was directed to THA instability and spinopelvic mobility. Dr Sierra presented a machine learning algorithm for THA dislocation risk. Two modifiable variables (anterior/lateral approach, elevated liner) were most influential in minimizing dislocation risk. Dr Taunton's study demonstrated a deep learning artificial intelligence model derived from postoperative radiographs to predict THA dislocation risk. High sensitivity and negative predictive value suggest that this model may be helpful in assessing postoperative dislocation risk. In reviewing a large single-center, multiple surgeon cohort of 2,831 DAA procedures, Dr Moskal noted a very low dislocation rate (0.45%) at minimum 2 years. Importantly, spinopelvic pathology or prior spinal instrumentation was not associated with an increased dislocation risk (0.30%). Dr Huo and colleagues analyzed pelvic tilt during functional gait in patients with acetabular dysplasia. They detected variable pelvic tilt on different surfaces with the data suggesting that patients with more anterior pelvic tilt while standing tend to have greater compensatory posterior pelvic tilt during gait. Dr Lamontagne reported on the sagittal and axial spinomobility in patients with hip OA, and highlighted reductions in pelvic tilt, pelvic-femoral-angle, lumbar lordosis and seated maximal trunk rotation when compared to controls. Dr Dennis showed that differences in spinopelvic mobility may explain the variable accuracy of acetabular version measurements on the cross-table lateral radiographs. Dr Gwo-Chin presented on a comprehensive functional analysis of 1,592 patients undergoing THA and observed that spinopelvic abnormalities are not infrequent (14%) in THA patients. Consistent with these findings Dr Murphy and collaborators identified a low prevalence of previous spinal instrumentation (1.5%), yet a high prevalence of spine stiffness (27.6%) in 149 patients undergoing THA. Session three highlighted various aspects of treating hip disease in young patients. Dr Peters investigated the need for subsequent hip arthroscopy in 272 patients treated with an isolated PAO. Only 4.8% of these patients required subsequent arthroscopy calling into question the routine use of combined arthroscopy and PAO. Three papers addressed questions related to THA in young patients. Dr Berend's study of 2532 hips demonstrated that high activity level was not associated with an increased risk of midterm aseptic or all cause failure. Dr Nunley presented on 43 young patients with an average age of 52 years treated with a cementless stem and modular dual mobility articulation. Stress shielding was minimal and no concerning metal ion release detected. Dr Garvin summarized minimum 15 year data of THA with highly cross-linked polyethylene in patient less than 50 years. These hips performed exceptionally well with no mechanical loosening or radiographic osteolysis. Dr Engh examined 10 year results of the Birmingham Hip Resurfacing implant and reported a 92.9 % overall survivorship, with males less than 55 years achieving a 98.3% survivorship. The session was concluded by long-term data on the Conserve Plus hip resurfacing arthroplasty. Dr Amstutz presented an impressive dataset depicting an 83.1% 20 year survivorship for this early resurfacing cohort. Direct anterior approach total hip arthroplasty was the focus of session four. Dr Meneghini reported on the anesthesia and surgical times of direct anterior and posterior approaches from a large healthcare system database. These data suggested longer OR and surgical times for the DAA both in the inpatient and ASC environments. Dr Clohisy introduced the technique and early outcomes of lateral decubitus position DAA. In a learning curve experience of 257 hips. 96% of acetabular components were in the Lewinneck safe zone, the aseptic revision rate was 0.9% and there were no dislocations. Dr Beaule analyzed femoral stem cement mantle with the DAA and posterior approaches by comparing two matched cohorts. Stem alignment and cement mantle quality were equivalent with both approaches. Similarly, Dr Emerson demonstrated technical feasibility and fewer cemented femoral stem failures when compared to cementless stems in a series of 360 DAAs THAs. The final paper of the session presented by Dr Hamilton examined the impact of surgical approach on dislocation after isolated head and liner exchange. Neither the posterior nor the anterior approach was superior in reducing the dislocation rate for these high dislocation risk procedures. The fifth session explored contemporary topics related to anesthesia and pain management. Dr Byrd opened the session with a comparative study evaluating general versus spinal anesthesia for hip arthroscopy. This preliminary study was provoked by the desire to minimize aerosolized exposure early in the COVID-19 pandemic by transitioning to spinal anesthesia. Both anesthetic methods were effective. Dr Austin presented a randomized, double-blind controlled trial comparing spinal anesthetic with mepivacaine, hyperbaric bupivacaine and isobaric bupivacaine. Mepivacaine patients ambulated earlier and were more likely to be discharged the same day. Dr Mont provided a very timely study on the effects of “cannabis use disorder” and THA outcomes. This administrative database study of 44,154 patients revealed this disorder to be associated with longer hospital stays, increased complications rates and higher costs. Dr Bedair investigated whether a highly porous acetabular component submerged in an analgesic solution could enhance perioperative pain management. Interestingly, this novel strategy was associated with a reduction of postoperative pain scores and opioid consumption in 100 experimental patients compared to 100 controls. The concluding paper of the session by Dr Della Valle examined whether decreased discharge opioids led to increased postoperative opioid refills. A large single-center study of 19,428 patients detected a slight increase (5%) in opioid refills but a reduction in total refill morphine milligram equivalents. The final, sixth session of day one considered various challenging aspects of revision hip arthroplasty. Dr Nam started the session with review of preliminary results from a randomized control trial comparing closed incision negative-pressure therapy with a silver-impregnated dressing for wound management in 113 hips undergoing revision arthroplasty. Unlike previous reports, the negative pressure therapy was associated with a higher reoperation rate for wound-related complications. Dr Bostrom highlighted the potential clinical impact of basic biological interventions by establishing the presence of Neutrophil Extracellular Traps (NETS) in fibrotic tissue from human aseptic loosening specimens and in a murine model of unstable tibial implantation. NET inhibition in the murine model prevented the expected tibial implant osseointegration failure. Dr Lombardi presented early 3.3 year clinical results of a highly porous Ti6al4v acetabular component in complex primary and revision arthroplasty. Survivorship for aseptic loosening was 96.6 % and 95.3% for the primary and revision cases, respectively. Dr Schwarzkopf and colleagues explored the impact of time to revision arthroplasty on clinical outcomes. Analysis of 188 revision cases revealed early revisions (less than 2 years from primary) were associated with worse outcomes, longer hospitalizations and higher reoperation rates. Mid-term results for modular dual mobility implants in revision arthroplasty were reviewed by Dr Lachiewicz who reported on 126 hips at a mean 5.5 years. 11% of hips dislocated and the 6 year survival was 91%. An outer head diameter of 48mm or greater was associated with a lower risk of dislocation. Dr Berry concluded the session by discussing the outcomes of treating the challenging problem of interprosthetic femur fractures. A single-center study of 77 cases treated over 32 years demonstrated a 79% success rate free of reoperation at 2 years with 95% of patients being ambulatory. The second day commenced with the seventh session evaluating recent strategies to improve short-term THA outcomes. Dr Bozic and colleagues investigated the association of quality measure public reporting with hip/knee replacement outcomes. Annual trend data from 2010–2011 and 2016–2017 indicate that hospital-level complication and readmission rates decease after the start of public reporting, yet it is difficult to prove a direct effect. Dr Slover reviewed his institutions experience with the Comprehensive Care for Joint Replacement (CJR) model and emphasized that lower CJR target prices make it increasingly difficult for programs to meet target price thresholds. Cost saving strategies including same day discharge and reduction of home health services may result in smaller losses of positive margins. Dr Barsoum reported on the influence of patient and procedure-related risk factors of length of stay after THA. Patient-related risk factors provided substantial predictive value yet procedure-related risk factors (hospital site and surgical approach) remain the main drivers of predicting length of stay. Dr Hozack reviewed an impressive, single surgeon cohort of 3,977 DAA THAs and analyzed adverse events and 90 day perioperative outcomes. Simultaneous bilateral DAA THA was comparable with unilateral or staged bilateral procedures in regards to complications, readmission rate and home discharge rate but with an increased risk of transfusion. To examine the risk of complications with outpatient joint arthroplasty, Dr Della Valle performed a single-surgeon matched cohort analysis comparing outpatient and inpatient hip and knee arthroplasties. Outpatient procedures were not associated with an increased risk of any postoperative complications and actually experienced fewer emergency department visits. The eighth session covered various contemporary challenges in hip arthroplasty care. Dr Griffin began the session with an analysis of the timing of complications associated with two-stage exchange procedures for periprosthetic joint infection (PJI). Of the 189 hips included, 41.6% had a complication and the mortality was 14.1% at 2.5 years, highlighting the morbidity of this treatment method. Dr Fehring provided data assessing the fate of two-stage reimplantation after failed debridement, antibiotics and implant retention (DAIR) for a prosthetic hip infection. This analysis of 114 hips yielded concerning results demonstrating a 42.9% treatment failure of patients treated with a previous DAIR compared to a 12.3% failure rate in patients treated with an initial 2-stage procedure. Dr Jacobs reviewed the analysis of 106 femoral heads with severe corrosion and identified a chemically dominated etching process termed “column damage” to be a detrimental damage mode within CoCr femoral heads that is directly linked to banding within its microstructure. These data indicate that implant alloy microstructure must be optimized to minimize the release of fretting-corrosion products. Simon Mears presented retrospective data from 184 THAs with a dual modular femoral stem. A subgroup of hips with a modular, cobalt chromium femoral neck had a pseudotumor visualized in 15% with only 55% of these having elevated CoCr levels. These findings may support the use of routine follow-up MARS MRI for modular CoCr femoral neck prostheses. The final two studies explored timely issues related to viral illness and hip surgery. Dr Browne analyzed three large administrative databases to elucidate whether patients are at increased risk for viral illnesses following total joint replacement. The incidence of postoperative influenza after total joint replacement was not increased compared to patients not undergoing total joint replacement surgery suggesting that arthroplasty procedures may not heighten the risk of viral illness. In the final paper of the session Dr Haddad presented important data regarding perioperative complications in coronavirus positive patients undergoing surgical treatment of femoral neck fractures. In this multicenter cohort study from the United Kingdom 82 coronavirus positive patients were shown to have longer hospital stays, more critical care unit admissions, higher risk of perioperative complications and an increased mortality compared to 340 coronavirus negative patients. The eighth session had two papers on alternative femoral stem designs and three presentations more focused on femoral fracture treatments. Dr Mihalko focused on the European and US experiences with the Metha femoral neck retaining stem. The US experience mirrored the encouraging results from Europe with a 94% all cause femoral survivorship and a 99.1% femoral aseptic loosening survivorship at 5 years. Dr Kraay summarized dual energy x-ray absorptiometry (DEXA) evaluation of 16 low modulus composite femoral components at long-term follow-up of a mean 22 years. The bone mineral density associated with the implant increased in Gruen zones 2–6 and showed limited decreases in zones 1 and 7. These data support the concept that a low modulus femoral stem may more effectively load the proximal femur. Dr Springer provided data from the American Joint Replacement Registry (AJRR) and by evaluating outcomes of exact matched cohorts of 17,138 patients treated with cementless or cemented femoral implants for femoral neck fractures. Cemented implants were associated with marked reduction in early revision and periprosthetic fractures. However, cemented fixation was associated with an increased mortality at 90 days and 1 year. Additional data from the AJRR was presented by Dr Huddleston who investigated the risk factors for revision surgery after arthroplasty in a cohort of 75,333 femoral neck fractures. THA when compared to hemiarthroplasty was associated with higher early and overall revision rates. Cementless femoral fixation and increased age were also associated with higher rates of any revision. Both of these studies from the AJRR suggest that further consideration should be given to femoral fixation preferences in the femoral neck fracture population. Dr Vail summarized his institution's experience with an interdisciplinary hip fracture protocol for patients undergoing arthroplasty for acute femoral neck fractures. His study compared 157 cases prior to protocol implementation with 114 patients treated after the protocol was established. The impact of the interdisciplinary protocol was impressive as evidenced by a reduced time to operative treatment, length of stay, complication rate and one-year mortality. All being achieved without an increase in readmissions or facility discharges. The final session of the meeting addressed innovations in perioperative care of THA patients. Dr Barrack started the session with an interesting study examining the feasibility and patient preferences regarding telemedicine. A cross-sectional telephone survey of 163 arthroplasty patients indicated that 88% of patients use the internet and 94% own a device capable of videoconferencing. Nevertheless, only 18% of patients preferred a video visit over an in-person clinic visit due to concerns of inferior care. Dr Barnes quantified preoperative optimization work in 100 arthroplasty patients by using EMR activity logs and determined the surgical team spends an average 75 minutes per case on preoperative work activities. Dr Duwelius reported the early outcomes of primary THA with a smartphone-based exercise and educational platform compared to standard of care controls. A randomized control trial design with 365 patients demonstrated similar outcomes and non-inferiority of the smartphone platform relative to complications, readmissions, emergency room/urgent care visits. The association of controlled substance use with THA outcomes was assessed by Dr Higuera Rueda. A quantitative assessment using the NarxCare score identified 300 and above as a score associated with adverse outcomes after THA. Dr Macaulay reviewed data from a large retrospective study of 1,825 THAs indicating that discontinuation of intermittent pneumatic compression devices does not increase the risk of venous thromboembolism in standard risk patients being treated with 81mg ASA BID as prophylaxis. Dr Antoniou presented the final paper of the meeting investigating potential changes in patient health status as an indication for surgery over time. Data from this large systematic review of the literature found patients undergoing THA at similar health status to the past with no influence form patient age, gender, year of enrollment or geographic region. As summarized above, the 2020 virtual Hip Society Summer Meeting was rich in scientific content, productive discussion and a collaborative spirit. This collective body of work will result in impactful scientific contributions and will serve as a foundation for future innovation and advancements in the treatment of hip disease