Background:National projections of future joint arthroplasties are useful for understanding the changing burden of surgery and related outcomes on the health system. The aim of this study is to update the literature by producing Medicare projections for primary total joint arthroplasty (TJA) procedures until 2040 and 2060.Methods:The present study used data from the Centers for Medicare & Medicaid Services (CMS) Medicare/Medicaid Part B National Summary and combined procedure counts with use of Current Procedural Terminology (CPT) codes to identify whether the procedure was a primary total hip arthroplasty (THA) or total knee arthroplasty (TKA) procedure. In 2019, the annual volume of primary TKA was 480,958 and that of primary THA was 262,369. These values formed a baseline from which we generated point forecasts for 2020-2060 and 95% forecast intervals (FIs).Results:Between 2000 and 2019, the estimated annual volume of THA increased by 177% and that of TKA increased by 156% on average. Regression analysis projected an annual growth rate of 5.2% for THA and 4.44% for TKA. Based on these yearly projected increases, an estimated increase of 28.84% and 24.28% is expected for each 5-year period after 2020 for THA and TKA, respectively. By 2040, the number of THAs is projected to be 719,364 (95% FI, 624,766 to 828,286) and the number of TKA is projected to be 1,222,988 (95% FI, 988,714 to 1,512,772). By 2060, the number of THAs is projected to be 1,982,099 (95% FI, 1,624,215 to 2,418,839) and the number of TKAs is projected to be 2,917,959 (95% FI, 2,160,951 to 3,940,156). In 2019, Medicare data showed that THA constituted approximately 35% of TJA procedures performed.Conclusions:Based on 2019 total volume counts, our model forecasts an increase in THA procedures of 176% by 2040 and 659% by 2060. The estimated increase for TKA is projected to be 139% by 2040 and 469% by 2060. An accurate projection of future primary TJA procedure demands is important in order to understand future health-care utilization and surgeon demand. This finding is only applicable to a Medicare population and demands further analysis to see if this extends to other population groups.Level of Evidence:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND: To determine the frequency, characteristics, and use of resources related to electric scooter (e-scooter) injuries in the emergency department (ED) of a major metropolitan area hospital. METHODS:We performed a retrospective review of all ED presentations related to e-scooter injuries at a level-I trauma center between May 2017 and February 2020. We identified ED presentation data, injury-related data, patients' clinical course after evaluation, injury diagnosis, surgical procedures, and ED readmissions.RESULTS: A total of 3,331 patients with e-scooter injuries presented to the ED over a 34-month period. There was a 6-fold increase in e-scooter-related injuries presenting to the ED, from an average of 26.9 injuries per month before the introduction of shared e-scooter services in August 2018 to an average of 152.6 injuries per month after its introduction. The average injury rate during weekdays was 3.27 per day, with the majority of injuries occurring in the afternoon. The most common mechanism of injury was rider fall (79.1%). There were a total of 2,637 orthopedic injuries, of which 599 (22.7%) were fractures. A total of 296 (8.9%) patients were hospitalized following the initial ED admission, and 462 surgeries were performed within seven days of ED arrival. CONCLUSIONS:The introduction of the shared e-scooter services is associated with a dramatic increase in e-scooter injuries presenting to the ED. E-scooter use carries considerably underestimated injury risks of high-energy trauma and misunderstood mechanisms of injuries. These injuries challenge the healthcare system, with a major impact on both EDs and surgical departments.

Background: The use of electric scooters (e-scooters) has dramatically increased as they become an attractive alternative for public transportation in busy metropolitan areas worldwide. Despite their benefits, e-scooters challenge the health-care system with poorly understood forms of injuries, mainly orthopaedic fractures. To our knowledge, this study is the first to investigate e-scooter-related orthopaedic fracture patterns, mechanisms of injury, and management.Methods: Data on 3,331 e-scooter-related admissions were retrospectively collected between May 2017 and February 2020 in a level-I trauma center. These admissions were analyzed for demographic variables, orthopaedic fracture diagnosis (using the AO/OTA classification), associated injuries, and surgical treatment.Results: During the study period, a total of 716 fractures were diagnosed in 563 patients, with 46.4% of the patients requiring hospitalization. Of 492 upper-limb fractures, 89.2% occurred in a rider fall mechanism; and of 210 lower-limb fractures, 15.7% occurred in rider-vehicle collisions. Fifty-nine percent of long bone fractures were complex fragmentary and/or intra-articular fractures. Orthopaedic surgeons recommended that 225 fractures undergo surgical treatment. The most common upper-limb fracture was AO/OTA class 2R1A, with open reduction and internal fixation of the distal part of the radius being the most common upper-limb procedure (n = 58). The most common lower-limb fracture was AO/OTA class 41C, with open reduction and internal fixation of the proximal part of the tibia being the most common procedure (n = 28). A total of 22 patients (3.9%) required reoperation within 1 year. Conclusions:This investigation provides unique information on demographic characteristics, patterns, and treatment of orthopaedic fractures secondary to the high-energy mechanism of e-scooter injuries. These new in-depth data are important, first, for health-care system preparedness with regard to management and resource allocation to treat these challenging injuries and, second, for legislators promoting safety and injury prevention strategies.T he introduction of electric scooters (e-scooters) and the e-scooter rideshare services have revolutionized commuting throughout the world 1,2 . These low-cost and environmentally friendly vehicles have become an attractive alternative for public transportation 3 , despite the fact that their configuration does not offer protection to the rider, leading to high rates of injuries 4 .The first e-scooter rideshare service was introduced in Israel in August 2018 5 . Several other companies quickly followed, increasing to thousands of e-scooters available throughout the cities 6 . In 2019, a year after the rideshare launch, our center's surrounding metropolitan area had the highest per-capita rate of shared e-scooter users worldwide, with approximately 7.5% of commuters using rideshare services on a daily basis 7 . Per company policy, no official driving permit is required, but riders should be at least 18 years of age and ...