OBJECTIVES : This study aims to investigate the general trends in hip and knee replacements in Italy.

METHODS : Patients who underwent hip or knee replacement from 2009-2016 in Italy were identified with ICD-9-CM procedures and diagnoses codes recorded in the National Hospital Discharge Records, a database including all hospitalizations in public and private Italian hospitals. Statistical significance between the means of the variables was tested using t-test.

RESULTS : In total 791,507 hip replacements and 539,125 knee replacements were performed in Italy from 2009-2016. Unlike the general declining trend in hospitalizations, hip and knee replacements, traditionally considered profitable interventions, are increasing over time (+16.2% and +28.1% respectively). Private and public hospitals show opposite trends. Private hospitals invested in orthopedics by increasing their bed capacity (+15.5%) and had a sharp growth in the number of implants (+40.9% and +44.8%). They attract younger (mean age 69.0 vs. 74.5, p=0.000 for hip, 69.8 vs. 70.7, p=0.000 for knee) and less severe patients (mean Charlson Comorbidity Index 0.044 vs 0.199, p=0.000 for hip 0.019 vs 0.098, p=0.000 for knee). Patients referred to surgery by general practitioners (GPs) tend to be admitted to private hospitals (64.9% for hip and 77.0% for knee). Only 3% of patients is referred to public hospitals by GPs for hip replacement and 5.8% for knee. Public hospitals decreased the number of orthopedics beds over time (-16.3%) while having a very modest increase in the productivity (+4.2% and +4.4% implants).

CONCLUSIONS : Our results show that public hospitals are disinvesting from hip and knee replacement in Italy and are progressively losing their market share. In order to invert the trend, a key role is played by GPs.