TY - JOUR AU - Brigati, David P.; Navale, Suparna M.; Schiltz, Nicholas K.; Bozic, Kevin J. TI - Increased Total Hip Arthroplasty Utilization, Osteoarthritis Diagnoses, and Comorbidity Burden in Patients Younger Than the Age of 65 Years: National Inpatient Trends 1998 to 2013 SN - 2472-8446 SN - 2472-8454 PY - 2018 JF - The Journal of Hip Surgery LA - EN VL - 02 IS - 01 SP - 015 EP - 021 ET - 2018/02/13 DA - 2018/06/04 KW - total hip arthroplasty KW - Nationwide Inpatient Sample KW - Elixhauser comorbidity KW - young patients AB - Primary total hip arthroplasty (THA) in patients younger than the age of 65 years demands long-term success to minimize lifetime revision surgery risks. Age at implantation, etiology of arthrosis, and comorbidity burden all have associations with revision risk. This study uses Nationwide Inpatient Sample (NIS) data between 1998 and 2013 to (1) report the annual utilization of THA in patients age 18 to 99 years divided into age groups, (2) determine trends in primary diagnoses, and (3) explore Elixhauser comorbidity burden trends. The authors reviewed 5,174,020 THA cases from the NIS. Cases were divided into age groups: 18 to 24, 25 to 34, 35 to 44, 45 to 54, 55 to 64, and 65 to 99 years. The annual utilization rate, primary diagnoses, and average count of Elixhauser comorbidities were plotted. Mann–Kendall's nonparametric tests determined significance with p < 0.05. The mean utilization of primary THA in patients aged 18 to 64 years was 57 cases per 105 persons (cpp). The incidence of utilization increased rapidly in patients age 55 to 64 years (123–240 cpp, p < 0.001) and age 45 to 54 years (46–100 cpp, p < 0.001). The predominant diagnoses were osteoarthritis increasing from 65 to 83% (p < 0.001), avascular necrosis decreasing from 17 to 7% (p < 0.001), and trauma decreasing from 11 to 6% (p < 0.001). The average count of Elixhauser comorbidities increased in all age groups from a minimum of 58% (1.2–1.9, p < 0.001) in patients age 55 to 64 years to a maximum of 200% (0.4–1.2, p = 0.003) in patients age 18 to 24 years. Increases in primary THA utilization are occurring disproportionately among patients age 45 to 64 years. The trends in etiologies and comorbidities show mixed anticipated effects on the risks for revision. Increased osteoarthritis diagnoses may be favorable as the etiology with the longest relative implant survival. However, increasing comorbidities may unfavorably heighten the risks of revision. Primary THA utilization is increasing for patients younger than the age of 65 years with osteoarthritis and rising comorbidity burdens. Current national administrative databases add valuable insights to large THA trends, but lack the granularity to fully characterize the causes behind revisions of primary THA. PB - Thieme Medical Publishers DO - 10.1055/s-0037-1618580 UR - http://www.thieme-connect.com/products/ejournals/abstract/10.1055/s-0037-1618580 ER -