Aims. We compared the outcome of total hip arthroplasty (THA) in obese
patients who previously underwent bariatric surgery and those who
did not, in a matched cohort study. Patients and Methods. There were 47 THAs in the bariatric group (42 patients), and
94 THAs in the comparison group (92 patients). The mean age of the
patients was 57 years in both groups (24 to 79) and 57% of the patients
in both groups were women. The mean time between bariatric surgery
and THA was five years (four months to 12 years) in the bariatric group.
The mean follow-up after THA was three years (2 to 9). . Results. The mean BMI improved from 49.7 kg/m. 2. (35 to 75) prior
to bariatric surgery to 35.3 kg/m. 2 . (21 to 49) at the
time of THA (p <
0.001). Patients in the comparison group had
an increased risk of re-operation (Hazard Ratio (HR) 3.2; 95% confidence
intervals (CI) 1.3 to 9.5, p = 0.01) and revision (HR 5.4; 95% CI
1.5 to 34.5, p = 0.01) when compared with the bariatric group. Conclusion. Patients had a dramatic improvement in BMI after bariatric surgery
and those with