Readmissions at Thirty-Days and One-Year for Implant-Associated Complications following Primary Total Hip and Knee Arthroplasty: A Population-Based Study of 34,392 Patients Across Austria.

Abstract

Introduction: The primary aim of this study was to assess 30-day and one-year rates for unplanned readmission due to implant-associated complications following total hip (THA) or total knee arthroplasty (TKA) in Austria. Secondary endpoints were reasons for readmission and differences in revision risk depending on demographics and hospital size.

Methods: Data on patients receiving THA (n = 18,508) or TKA (n = 15,884) in orthopaedic and trauma units across Austria within a one-year period (January 2021 to December 2021) was retrieved from a government-maintained database. The absolute and relative frequencies of unplanned readmissions were calculated. Risk factors for 30-day and one-year readmission following THA or TKA due to implant-associated complications were investigated.

Results: The thirty-day and one-year readmission rates for any implant-associated complication were 1.0% (339 of 34,392) and 3.0% (1,024 of 34,392). Relative to the overall readmission rate for any complication at 30 days (n = 1,952) and one year (n = 12,109), respectively, readmission rates for implant-associated complications were 17.4 and 8.5%. The thirty-day readmission rates were higher in THA (1.2%) than TKA patients (0.8%; P = 0.001), while it was the opposite at one year (THA, 2.7%; TKA, 3.3%; P < 0.001). Mechanical complications (554 of 1,024) were the most common reason for one-year readmission. Prolonged length of in-hospital stay independently associated with increased one-year readmission risk in THA and TKA patients. Treatment at large-sized hospitals was associated with a higher one-year readmission risk in TKA patients.

Conclusions: The thirty-day and one-year readmission rates for implant-associated complications following THA or TKA in Austria are lower than reported in other countries, with similar risk factors and reasons for readmission. Considering that almost 20% of unplanned hospital readmissions following total joint arthroplasty are attributable to implant-associated complications, optimization of in-hospital and post-discharge medical care for these patients is warranted.