If we want to reduce hospital readmissions and limit complications, we have to know what they are,” said William L. Healy, MD, at the 2014 Specialty Day program of the Hip Society and the American Association of Hip and Knee Surgeons (AAHKS). “Although we all think we know what a complication is and deal with it, there’s very little consensus definition of complications of hip replacement.”

Dr. Healy, who is associated with Newton Wellesley Hospital in Newton, Mass., noted that complication reporting has been evolving over the past two decades and that complication rates are being used as a proxy for quality.

“In total hip arthroplasty (THA),” he said, “complication reporting can identify problems in patient selection, clinical pathways, implants used, surgical technique, and follow-up care. However, reporting of THA complications is not standardized and different investigators report different complications with different definitions.”

To address this problem, the Hip Society established a work group in 2011 to develop a minimum necessary list of complications and adverse events required for accurate reporting of THA outcomes. They also sought to develop standardized definitions that were simple, clear, and consistent with ICD-9 codes and Hip Society scores. Once the list and the definitions were developed, the workgroup surveyed members of the Hip Society to test their applicability and reasonableness.

“We were pleased that every clinical member of the Hip Society responded to the survey,” said Dr. Healy, who then presented the list of complications (Table 1).

“Keep in mind that not all complications are equal in either the clinical or research realm,” he continued. “Stratification of complications increases the clinical applicability and improves clarity of research when complications are being considered.”

The workgroup developed four levels of complications, ranging from those that require no treatment or change in routine care to those that are associated with a life- or limb-threatening event and require immediate invasive treatment. Death was included as a fifth level.

“We are now working on validation of these definitions and stratifications,” reported Dr. Healy. “If we do not define and standardize THA complications, someone else will do it for us—probably without the same diligence and concern for patient care that we have.”

Understanding the data
“Hip and knee replacement collectively comprise the single largest line item for Medicare,” reported Vincent D. Pellegrini Jr., MD, of the University of Maryland School of Medicine. “Not only that, they have the most rapidly increasing rate of utilization of any procedure in the United States.”

Dr. Pellegrini reviewed administrative data, including utilization rates, costs, complication rates, and readmission rates on both a national and selected states basis. He cautioned that administrative databases are purely observational tools and that it would be presumptuous to draw conclusions based on them.

“The National Inpatient Sample provides longitudinal trends over time and state inpatient databases show interesting regional variations,” said Dr. Pellegrini. Longitudinal observations indicate that the cost of hospitalization for THA is on the decline. However, the number of patients with no comorbidities is also diminishing, so THA patients are sicker, which drives readmissions.

“A multivariate risk analysis for pulmonary embolism (PE)/venous thromboembolism (VTE) shows that, that despite a 40 percent reduction in inpatient PE/VTE, VTE was the single adverse event associated with the greatest increase in index hospital cost,” noted Dr. Pellegrini.

Data also show that the average age of a THA patient is about 66 years, and slightly more females than males have the procedure. Underserved, unrepresented minorities continue to have a disproportionately small percentage of THAs (less than 10 percent compared to more than 85 percent white).

Dr. Pellegrini noted that surgical-site related complications—such as superficial wound infection, periprosthetic joint infections, bleeding, dislocation, and mechanical failure—collectively have a 4 percent readmission rate. Systemic issues—such as PE/VTE, myocardial infarction, pneumonia, and septicemia—have a slightly lower readmission rate (3.5 percent). All cause readmission rates are about 15 percent.

“Why is this important?” he asked. “Under the Hospital Readmission Reduction Program, hospitals will be subject to a penalty of up to 2 percent of reimbursement for readmissions that exceed the ‘expected’ ratio, which is based on a 3-year prior readmission data set.”

Managing the surgical wound
Wound complications are fairly common, noted Kevin L. Garvin, MD, of the University of Nebraska Medical Center. “To decrease problems related to the surgical wound, we need to first identify reasons for hospital readmission, define the risk factors associated with readmission diagnosis, and if possible, correct and reevaluate,” he said.

Dr. Garvin identified the following top three risk factors for infection and wound problems:

• obesity
• hematoma, bleeding, anticoagulation
• staph infection

“Obesity is an epidemic in total joint patients,” he said, noting that patients with a body mass index (BMI) higher than 40 have a high likelihood of infection and readmission. He has heard that many insurance companies are now denying THA for patients with a BMI of 40 or more. “We need to do a better job of helping these people with their problem,” he said, “including offering nutritional consults, weight-loss programs, and consultation with a bariatric surgeon.”

Next is the problem of bleeding. Citing a 2012 study on compliance with the Joint Commission’s Surgical Care Improvement Project (SCIP) measures and hospital-associated infections following THA, Dr. Garvin noted that hospital compliance with SCIP antibiotic measures increased, but was not associated with a significant reduction in infection. In fact, a separate study showed that high compliance with VTE measures significantly increased the risk of infection.

“We know surgical site infections (SSI) are potentially preventable adverse events, said Dr. Garvin. “They significantly increase healthcare costs, length of stay, readmission rates, and mortality rates. The question is whether nasal decolonization or glycopeptide antibiotic prophylaxis reduces SSI caused by gram-positive bacteria.” He cited several studies on the issue.

In summary, he advised attendees to carefully consider the risks and benefits of VTE chemoprophylaxis and mechanical prophylaxis for patients. He noted the strong evidence for routine decolonization and selective anti-MRSA prophylaxis. He encouraged attendees to help patients address modifiable risk factors such as obesity and diabetes to help lower infection rates and readmissions, and he supported a team approach and pathway to improve outcomes.

Additional presenters during the symposium included Paul F. Lachiewicz, MD, and Richard Iorio, MD. The symposium is available for online viewing (registration fee required) at http://www.prolibraries.com/aaos/events/2014hipsoc/event

Disclosure information: Dr. Healy—DePuy, A Johnson & Johnson Company. Dr. Pellegrini— DePuy, A Johnson & Johnson Company; ACGME RRC in Orthopaedic Surgery; American Orthopaedic Association (AOA); Association of American Medical Colleges; Health Volunteers Overseas/Orthopaedics Overseas; Hip Society. Dr. Garvin—Wolters Kluwer Health–Lippincott Williams & Wilkins; AOA; Hip Society; Knee Society.

Mary Ann Porucznik is managing editor of AAOS Now. She can be reached at porucznik@aaos.org

References:

1. Wang Z, Chen F, Ward M, Bhattacharyya T. Compliance with Surgical Care Improvement Project Measures and Hospital-Associated Infections Following Hip Arthroplasty. J Bone Joint Surg Am, 2012 Aug 01;94(15):1359-1366. http://dx.doi.org/10.2106/JBJS.K.00911
2. Mont M, Jacobs J, Lieberman J, et al. Preventing venous thromboembolic disease in patients undergoing elective total hip and knee arthroplasty. J Bone Joint Surg Am 2012;94(8):673.