Morbid Obesity in Total Hip Arthroplasty: Redefining Outcomes for Operative Time, Length of Stay, and Readmission

The incidence of obesity among patients presenting for elective total hip arthroplasty (THA) has increased in the last decade, and the relationship between obesity and the need for joint arthroplasty has been demonstrated. This study evaluates the effects of morbid obesity on outcomes after primary THA by comparing short-term outcomes in THA between a morbidly obese (body mass index [BMI] ≥40) and a normal weight (BMI, 18.5 to <25) cohort at our institution between January 2003 and December 2010.

Thirty-nine patients included in the morbidly obese group were compared with 186 in the normal weight group. Operative time, length of stay, complications, readmission, and length of readmission were compared.

Operative time was increased in the morbidly obese group at 122 minutes compared with 100 minutes (P = .002). Postoperatively, there was an increased 30-day readmission rate related to surgery of 12.8% associated with BMI ≥40 compared with 2.7% (P = .005) as well as a 5.1-fold increase in surgery-related readmitted bed days—0.32 bed days per patient for normal weight compared with 1.64 bed days per patient for the morbidly obese (P = .026).

Morbidly obese patients present a technical challenge and likely this, and the resultant complications are underestimated. More work needs to be performed to enable suitable allocation of resources.