Copyright © 2009 by The Journal of Bone and Joint Surgery, Inc.

Commentary & Perspective

Commentary & Perspective on
"The Impact of Glycemic Control and Diabetes Mellitus on Perioperative Outcomes After Total Joint Arthroplasty"
by Milford H. Marchant Jr., MD, et al.

Commentary & Perspective by
John C. Clohisy, MD*,
Washington University School of Medicine, St. Louis, Missouri

Posted July 2009

The number of lower-extremity total joint arthroplasty procedures in the United States is expected to increase markedly over the next twenty years. Kurtz et al. recently estimated that, by 2030, more than 500,000 total hip arthroplasties and approximately 3.5 million total knee arthroplasties will be performed annually1. While these procedures provide excellent pain relief, improved function, and enhanced quality of life for the majority of patients, associated perioperative complications can result in appreciable morbidity or even mortality and can further burden our limited healthcare resources2. Therefore, efforts to minimize perioperative complications and reduce the cost of arthroplasty surgery are critical.

In their study, "The Impact of Glycemic Control and Diabetes Mellitus on Perioperative Outcomes After Total Joint Arthroplasty," in this month's issue of The Journal, Marchant et al. analyzed data from the Nationwide Inpatient Sample (NIS) to determine the effect of preoperative glycemic control on the prevalence of in-hospital perioperative complications following lower-extremity total joint arthroplasty. They also evaluated length of hospital stay and cost associated with these procedures. Patients with uncontrolled diabetes, controlled diabetes, or no diabetes were studied to determine the impact of glycemic control. More than one million patients who were treated between 1988 and 2005 were analyzed. Patients with uncontrolled diabetes had a significantly increased prevalence of perioperative complications, mortality, length of hospital stay, and inflation-adjusted charges (p ≤ 0.001 for all). These data are very notable, and they demonstrate the negative impact of uncontrolled diabetes on the clinical results and cost associated with total hip and total knee arthroplasty.

The strengths of this study include the large number of patients analyzed through the NIS database. This database includes patients with Medicare, Medicaid, and private insurance as well as patients without insurance, and therefore provides information on a diverse and generalizable patient population. The experimental design of this study was excellent, and the statistical analysis of the data was rigorous, thus providing us with clinically important information. This study is particularly timely because the prevalence of both osteoarthritic conditions and diabetes is increasing.

Despite the importance of this work, there remain limitations (as acknowledged by the authors in the Discussion). First, the NIS database is very large, with approximately 1000 participating hospitals. The accuracy of glycemic control documentation, hospital coding, and data entry can all be questioned, yet previous investigations have suggested acceptable accuracy and quality control. Second, the three patient study groups (nondiabetic patients, patients with controlled diabetes, and patients with uncontrolled diabetes) had several differences in demographics and hospital characteristics. This introduces a potential for sampling bias. Third, these data only pertain to in-hospital complications related to the initial total joint arthroplasty. Complications after discharge from the hospital were not evaluated in this study. It is possible that such data could show a more profound effect of uncontrolled diabetes on the safety and efficacy of total joint replacement surgery.

This study presents important data regarding diabetic patients who are undergoing total joint replacement surgery. Uncontrolled diabetes was associated with elevated risks of complications, a longer hospital stay, and increased cost. These findings underscore the importance of preoperative screening and medical management prior to surgery. Specifically, glycemic control should be optimized in diabetic patients to minimize perioperative complications and to reduce the cost associated with these procedures.

*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.

References

1. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007;89:780-5.
2. Kim S. Changes in surgical loads and economic burden of hip and knee replacements in the US: 1997-2004. Arthritis Rheum. 2008;59:481-8.