There is ongoing discussion about whether preoperative obesity is negatively associated with
inpatient outcomes of total hip arthroplasty (THA). The aim was to investigate the interaction
between obesity and muscle strength and the association with postoperative inpatient recovery
Preoperative obesity (body mass index (BMI)>30 kg/m2) and muscle weakness (hand grip
strength <20 kg for woman and <30 kg for men) were measured about 6 weeks before THA.
Patients with a BMI<18.5 kg/m2 were excluded. Outcomes were delayed inpatient recovery of
activities (>2 days to reach independence of walking) and prolonged length of hospital stay (LOS,
>4 days and/or discharge to extended rehabilitation). Univariate and multivariable regression
analyses with the independent variables muscle weakness and obesity, and the interaction
between obesity and muscle weakness, were performed and corrected for possible confounders.