Journal Logo

Institutional members access full text with Ovid®

Effect of Body Mass Index on Complications and Reoperations After Total Hip Arthroplasty

Wagner, Eric R., MD1,a; Kamath, Atul F., MD1,b; Fruth, Kristin M., BS1,c; Harmsen, William S., MS1,d; Berry, Daniel J., MD1,e

doi: 10.2106/JBJS.O.00430
Scientific Articles
Buy
Disclosures

Background: High body mass index (BMI) is associated with increased rates of complications after total hip arthroplasty. Studies to date have evaluated risk mainly as a dichotomous variable according to BMI thresholds. The purpose of this paper was to characterize the risk of complications and implant survival according to BMI as a continuous variable.

Methods: Using prospectively collected data from our institutional total joint registry, we analyzed 21,361 consecutive hips (17,774 patients) treated with primary total hip arthroplasty between 1985 and 2012 at a single institution. The average BMI at the time of surgery was 28.7 kg/m2 (range, 15 to 69 kg/m2). Estimates of revision surgery and common complications associated with BMI were analyzed using the Kaplan-Meier method of assessing survivorship, with associations of outcomes assessed using a Cox model.

Results: Utilizing smoothing spline parameterization, we found that reoperation (p < 0.001) and implant revision or removal rates (p = 0.002) increased with increasing BMI. Increasing BMI was associated with increased rates of early hip dislocation (p = 0.02), wound infection, and, most strikingly, deep periprosthetic infection (a hazard ratio of 1.09 per unit of BMI >25 kg/m2; p < 0.001). However, we found no association between increasing BMI and any revision for mechanical failure of the implant or between increasing BMI and revision for aseptic implant loosening. There was an inverse correlation between increasing BMI and risk of revision for bearing wear.

Conclusions: The rates of reoperation, implant revision or removal, and common complications after total hip arthroplasty were strongly associated with BMI.

Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

1Departments of Orthopedic Surgery (E.R.W., A.F.K., and D.J.B.) and Biostatistics and Health Sciences Research (K.F. and W.S.H.), Mayo Clinic, Rochester, Minnesota

aE-mail address for E.R. Wagner: wagner.eric@mayo.edu

bE-mail address for A.F. Kamath: akamath@post.harvard.edu

cE-mail address for K. Fruth: fruth.kristin@mayo.edu

dE-mail address for W.S. Harmsen: harmsen.william@mayo.edu

eE-mail address for D.J. Berry: berry.daniel@mayo.edu

Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated
You currently do not have access to this article

To access this article: