Shift from inpatient to outpatient treatment in all age groups of anterior cruciate ligament surgery in Germany: An analysis of the public healthcare system.

Abstract

Ruptures of the anterior cruciate ligament (ACL) are among the most common orthopaedic diagnoses with severe short- and long-term consequences for patients. The aim of the study was to analyze trends of inpatient and outpatient treatment of ACL injuries in Germany. All ACL reconstructions in Germany in public health insurance patients between 2019 and 2024 were included. The data of the Institute for the hospital remuneration system (InEK) were used for inpatient cases, while data of the Central Institute for Statutory Health Insurance Physicians in Germany (ZI) were used for outpatient treatments. Between 2019 and 2024, a total of 242,423 operatively treated ACL ruptures were identified in Germany, corresponding to an overall annual incidence of 48.39 ± 6.63 per 100,000 inhabitants. While the overall incidence declined slightly by 5.5% over the study period, substantial shifts in treatment setting were observed: outpatient cases increased by 70.8%, whereas inpatient cases decreased by 26.8%. Across all age groups, inpatient incidence rates declined, especially among younger and middle-aged adults, while outpatient incidence increased significantly, most notably in working-age populations (18-65 years). The relative difference between inpatient and outpatient care narrowed over time (RR 4.99 in 2019 vs. 2.35 in 2024), indicating a pronounced shift towards outpatient management. This nationwide move towards outpatient ACL reconstruction signifies a fundamental change in care delivery, offering potential benefits in efficiency and resource use. However, it also emphasizes the importance of careful patient selection, standardized perioperative protocols and ongoing outcome monitoring to make sure clinical safety and effectiveness are maintained. Level IV.