Inpatient Dislocation After Primary Total Hip Arthroplasty

Inpatient dislocation after total hip arthroplasty (THA) is considered a nonreimbursable "never event" by the Centers for Medicare and Medicaid Services. There is extensive evidence that technical procedural factors affect dislocation risk, but less is known about the influence of nontechnical factors. We evaluated inpatient dislocation trends after elective primary THA and identified patient and hospital characteristics associated with the occurrence of dislocation.We used discharge records from the Nationwide Inpatient Sample (2002-2011). Temporal trends were assessed, and multivariable logistic regression modeling was used to identify factors associated with dislocation.The in-hospital dislocation rate increased from 0.025% in 2002 to 0.15% in 2011, despite a downward trend in length of stay (P.001). Patient characteristics associated with the occurrence of dislocation were black or Hispanic race/ethnicity, lower household income, and Medicaid insurance. Comorbidities associated with dislocation included hemiparesis/hemiplegia, drug use disorder, chronic renal failure, psychosis, and obesity. Dislocations were less likely to occur at teaching hospitals and in the South.The in-hospital dislocation rate after elective primary THA is increasing, in spite of shorter stays and surgical advances over time. Given the sociodemographic disparities in dislocation risk documented herein, interventions to address social determinants of health might do as much or more to reduce the occurrence of dislocation than technical improvements.