Following a total hip arthroplasty (THA), early hospital readmission rates of 3–8% are considered as ‘acceptable’ in terms of medical care cost policies. Surprisingly, the impact of readmissions on mortality has not been priorly portrayed. Therefore, we aimed to analyse the mortality of unplanned readmissions after primary THA at a high-volume Argentinian center.

We prospectively analysed 90-day readmissions of 815 unilateral, elective THA patients operated between 2010–2014 whose medical insurance was the one offered by our institution. Mean follow-up was 51 months (range, 37–84). Median age was 69 (IQR, 62–77). We stratified our sample into readmitted and non-readmitted cohorts. Through a Cox proportional hazard model, we compared demographic characteristics, clinical comorbidities, surgical outcomes and laboratory values between both groups in order to determine association with mortality.

We found 37 (4.53%) readmissions at a median time of 40.44 days (IQR: 17.46–60.69). Factors associated with readmission were: hospital stay (p=0.00); surgical time (p=0.01); chronic renal insufficiency (p=0.03); ASA class 4 (p=0.00); morbid obesity (p=0.006); diabetes (p=0.04) and a high Charlson Index (p=0.00). Overall mortality rate of the series was 3.31% (27/815). Median time to mortality was 455.5 days (IQR: 297.58–1170.65). One-third (11/37) of the readmitted patients died, being sepsis non-related to the THA the most common cause of death. After adjusting for confounders, 90-day readmissions remained associated with mortality with an adjusted HR of 3.14 (CI95%: 1.05–9.36, p=0.04).

Unplanned readmissions were an independent risk factor for future mortality, increasing 3 times the risk of a decease eventuality.