Patient expectations prior to TKR not influenced by function of knee

Issue: November 2010

The most disconcerting finding of a recent study surveying patient expectations prior to primary total knee replacement is that patients did not tailor their expectations of postoperative outcomes based on the preoperative function and pain of the knee.

“We thought people would realistically modify their expectations, understanding that the fact that they had not walked a mile in years might keep them from easily returning to walking a mile. But we found no association between preoperative knee pain/function and expectations of postoperative results,” said senior author Matthew S. Hepinstall, MD, an orthopedic surgeon and the orthopaedic basic science coordinator at Lenox Hill Hospital in New York City.

Few demographic associations

The study was inspired by the authors’ experience with the variability of patient expectations before and after knee replacement and the influence of those expectations on the patient’s perception of the relative success of the surgery.

A total of 1,943 patients were administered the Hospital for Special Surgery (HSS) expectation survey prior to surgery. Baseline scores were also obtained for the SF-36 Health Survey, Knee injury and Osteoarthritis Outcome Score (KOOS) and Lower- Extremity Activity Scale (LEAS).

Several previous studies assessing patient expectations have found relationships between demographic factors, such as age, gender and race or ethnicity. “But we found fewer associations with these demographic factors than we anticipated, based on smaller studies,” Hepinstall told Orthopedics Today.

Prior joint replacement

One of the strong associations in the current study was history of prior joint replacement surgery, which was linked to “slightly lower, and what we would consider more reasonable expectations,” Hepinstall said. The median expectation score of patients who had previously undergone joint replacement surgery was comparable to the findings of a previous study gauging the expectations of arthroplasty surgeons for patients undergoing primary TKR: roughly 78 on the expectation score from HSS, where both studies were performed.

“However, when we looked at the patients who had never had prior joint replacement surgery, their expectations were somewhat higher on average, suggesting that people with experience – both surgeons and patients who have had surgery – develop more realistic expectations, or at least somewhat lower expectations, than people who do not have specific experience with joint replacement,” Hepinstall said.

Age and expectations

The survey results, which were presented at the 2010 annual meeting of the American Academy of Orthopaedic Surgeons (AAOS) in New Orleans, also found a correlation between patient age and expectation. “Older people had lower expectations, which we predicted; however, the magnitude of that association was not as robust as we might expect,” Hepinstall said. “Older people did not have much lower expectations than younger patients.”

Unrealistic expectations might be attributed to a failure of the preoperative education process, according to Hepinstall. “A prior study, using the same expectation survey, found that introducing a preoperative education module for providing patients more accurate expectations resulted in slightly lower, more appropriate expectations,” he said.

A multivariate regression analysis revealed that demographics, pre-operative knee pain/function and overall general physical and mental health, only accounted for about 10% of the variability in patient expectations.

“The remaining 90% was accounted by things we could not measure or predict, presumably including the patient’s prior experience with medical intervention, and its success or failure; the patient’s experience with family members who have joint replacement; and the patient’s general level of trust in the health care system,” Hepinstall said.

“The bottom line is that we can’t predict expectations based on measurable quantities. We actually have to ask the patient: What are you looking for? What do you hope joint replacement will allow you do?” By probing, “we are likely to know if we can meet the patient’s desired outcome with our intervention,” he said. – by Bob Kronemyer

Reference:

Hepinstall MS, Rutledge J, Bornstein L, et al. Factors that impact expectations prior to total knee replacement. Paper 682. Presented at the 2010 Annual Meeting of the American Academy of Orthopaedic Surgeons. March 9-13. New Orleans.

Matthew S. Hepinstall, MD, can be reached at 130 E. 77th St., 11t h Floor, New York, New York 10075; 212-434-6880; e-mail: matthepinstall@yahoo.com.

John M. Cuckler

With the need to understand the factors that impact expectations for TKR, this paper is an important reminder to the knee replacement surgeon of the difficulty in assessing patient expectations for a TKR. Commonly used metrics, such as the SF-36, KOOS, or LEAS had only mild correlations with patient expectations.

The critical conclusion from this study is that each patient should be assessed individually with regard to preoperative expectations for the outcome of knee arthroplasty. The surgeon should take the time to listen carefully to the patient with regard to his or her hope for the outcome of the procedure, and counsel each patient accordingly. As indicated in this study’s abstract, “unreasonably high expectations are not confined to young, active patients.”

– John M. Cuckler, MD
Orthopedics Today Editorial Board member
Birmingham, Ala.

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