Total Hip Arthroplasty in Overweight Patients: Do Obesity and BMI Affect Implant Positioning, Outcomes, and Complications?

Obesity is one of the most problematic issues for health organizations worldwide because of its relationship with several chronic diseases. It is also demonstrated to increase early onset of hip arthritis, consequently leading to early failure of implants of total hip arthroplasty (THA). The aim of the study was to assess the influence of obesity on the positioning of prosthetic components and potential complications. A total of 312 patients underwent THA from 2006 to 2015 at our institute. All procedures were performed by a single surgeon (M.F.S.). As indicated by the World Health Organization (WHO), our population was stratified on the basis of body mass index (BMI): Four underweight, 112 nonobese, 131 overweight, 51 grade-1 obese, 10 grade-2 obese, and 4 grade-3 obese patients were included. No superobese patients were reported. The population was assessed clinically (implant survival, surgery time, blood loss, and complications) as well as radiologically (femoral offset, cup abduction and anteversion, and periacetabular osteolysis). Higher cup inclination (48.70 vs. 45.94 degrees), surgical time (86 vs. 80 min), and total blood losses (1,026 vs. 761 mL) were reported in overweight/obese patients (p < 0.01). Statistical analysis documented a significant relationship between obesity and cup inclination, surgical time, intraoperative and total blood losses, as well as BMI and age at surgery (p < 0.05). The overall correct positioning of prosthetic components is not significantly related to obesity. Although maintained in the “safe zone,” cup abduction, blood loss, and operative time tend to significantly increase with BMI.