Revision THA patients over 80 years old experience more major adverse events

Researchers found an increase of 1 year in the age of a patient undergoing revision THA was associated with a 4% greater risk of major complications.

Issue: March 2011

Karl M. Koenig

Within 3 months of revision total hip arthroplasty, 33% of older patients experienced a procedure-related major adverse event vs. 9.4% to 19.5% of younger patients, based on a retrospective study.

Patients 80 years-old or older had the highest rates of minor adverse events (AEs) at nearly 40%, according to findings of a Stanford University Hospital Study that Karl M. Koenig, MD, MS, (now of Dartmouth-Hitchcock Medical Center in Lebanon, N.H.), presented at the 2011 Orthopaedic Research Society Annual Meeting.

“The main take home message is that patients over 80 have significantly increased risk of experiencing a major AE in the first 90 days after this complex surgery,” he told Orthopedics Today.

Though this finding was not unexpected, Koenig said, “The actual rates of complications were somewhat higher than expected. Our feeling is that complication rates are under-reported in the literature and trying to get some real numbers out there … is important.”

Database study

To get a realistic and current picture of the risks of surgery in elderly individuals who may undergo revision total hip arthroplasty (THA), Koenig and colleagues turned to an Institutional Review Board-approved database of prospectively entered information about total joint arthroplasty patients, retrospectively analyzing cases of THA revisions and hemi-arthroplasties converted to THA between 2001 and 2009.

Analyses

They identified mortality and adverse event rates associated with the surgeries, categorized the AEs as major or minor, and grouped patients according to age less than 65 years (123 hips, 116 patients), age 65 to 79 years (137 hips, 128 patients) and age 80 years or greater (65 hips, 62 patients). Death, re-operation, pulmonary embolism, dislocation and deep infection were classified as major AEs.

Low 90-day morbidity

Using the Charlson Comorbidity Index (CCI) as a surrogate for health, Koenig and colleagues tried to determine how CCI and age affected the ability to withstand these procedures and found significant differences in age, body mass index (BMI), CCI, and ASA scores. They saw higher ASA and CCI scores in the older patients and the lowest BMI among the oldest patients, according to the study.

Concerning revision-related factors, investigators determined the types of revision were similar in all cases, with aseptic loosening the main cause for revision in all three groups.

The overall 90-day mortality rate was low (0.6%). Two deaths occurred in the oldest group.

Koenig and colleagues found that after adjusting for comorbidity, an age increase of 1 year resulted in a 4% rise in risk of a major complication. “Our hypothesis was these rates were going to be somewhat higher, especially when you look carefully for complications, which is one of the things we did in this study with a thorough look at the medical record and follow-up with patients by telephone to ensure we captured all those events,” Koenig said.

After adjusting for age — an independent risk factor predictive of increased major Aes — the researchers associated an increase of 1 point in CCI scored produced a 22% increase in major complications.

“As we go forward with health care reform and quality improvement measures, hospitals and surgeons are going to be held to some standard of what is an acceptable complication rate for certain procedures. We found that this complex procedure in very elderly patients with high comorbidities has a higher complication rate than is currently reported,” Koenig said. – by Susan M. Rapp

Reference:

Koenig KM, et al. Advanced age increases the risk for adverse events after revision total hip arthroplasty. Paper #337. Presented at the 2011 Orthopaedic Research Society Annual Meeting. January 13-16, 2011. Long Beach, Calif.

Karl M. Koenig, MD, MS, can be reached at One Medical Center Drive, Lebanon, NH 03756; 603-650-6626; e-mail: karlkoenig51@hotmail.com.

Disclosure: Koenig has no relevant disclosures.

This is an important paper, the first that I am aware of, that reports a high incidence of major adverse events (33%) in patients 80 years or older who had a revision THA. In fact, the authors also report another striking statistic; a 4% increase in risk of a major complication with each year of advanced age. Orthopedic surgeons are fully aware of the possible complications after THA from their own experiences and from many published reports. The Medicare Patient Safety Monitoring System has also quantified adverse events after THA and Huddleston and colleagues reported at the recent American Academy of Orthopaedic Surgeons Annual Meeting in San Diego that cardiac events are a common cause of readmission after THA.

I think this paper is an additional alert to concerns that orthopedic surgeons already have: Not only is the elderly population increasing; our life expectancy is increasing. Younger patients are getting THAs. Implants need to last longer; the need for implant recalls needs to decrease, if not end. Elderly patients are also more active. The baby boomers, now beginning to reach Medicare age, want to continue their physical activities with little change. The old 65 is said to be the new 75.

And yet medical comorbidities are too high, some increasing: heart disease, hypertension, diabetes, lung disease, obesity, etc. The new important focus in health care – prevention — becomes obvious as orthopedic surgeons increasingly need to operate on the advanced elderly. As the authors recommend, surgeons need to have additional tools to assess operative risk in the elderly, such as the CCI. These risks will need to be reduced, if possible, by aggressive medical management before surgery. Surgeons may have to resort to an earlier revision in selected patients, based on problematic radiographic changes, before the patient’s health status prevents an operation. Importantly before surgery, during hospitalization and before discharge, each elderly patient will need maximum medical treatment to minimize the possibility of an adverse event.

Finally, this paper supports the need for additional data ... similar repeat studies in other institutions ... especially from a much needed national joint registry in the United States.

— James H. Herndon, MD
Boston
Disclosure: He has no relevant financial disclosure.