Not all patients benefit equally from hip or knee replacement: Study finds

(Press-News.org) TORONTO, ON, April 5, 2013 — Only half of people with arthritis who had a hip or knee replacement reported a significant improvement in pain and mobility after surgery, according to a new study led by Women's College Hospital and the Institute for Clinical and Evaluative Sciences (ICES).

"Many patients with hip and knee arthritis have the condition in more than one of their hip or knee joints," said the study's lead author Dr. Gillian Hawker. "So it's not surprising that replacing a single joint doesn't alleviate all their pain and disability — patients may need subsequent surgeries to maximize the benefits of joint replacement."

The study, published in the journal Arthritis & Rheumatism, followed a cohort of 2,400 patients with osteoarthritis and inflammatory arthritis in Ontario. Nearly 480 had a hip or knee replacement and of the 202 patients included in the study, only half reported a meaningful improvement in their overall hip and knee pain and disability one to two years after surgery. What's more, researchers found the patients who had worse knee or hip pain to begin with but fewer general health problems and no arthritis outside of the replaced joint were more likely to report benefits.

According to the study authors, nearly 83 per cent of study participants had at least two troublesome hips and or knees. In general, an estimated 25 per cent of patients who undergo a single joint replacement will have another joint replacement — usually the other hip or knee — within two years.

"While demand for joint replacement surgery has increased as our population ages, physicians lack a set of established criteria to help determine what patients will benefit from surgery and at what point during the course of the disease," said Dr. Hawker, physician-in-chief at Women's College Hospital and a senior scientist at ICES. "As physicians, we need to do a better job of targeting treatments to the right patient at the right time by the right provider."

Arthritis is a leading cause of disability in men and women in Canada. According to the Arthritis Society, joint damage from osteoarthritis is responsible for more than 80 per cent and 90 per cent of hip replacement and knee surgeries in Canada, respectively.

### About Women's College Hospital For more than 100 years, Women's College Hospital (WCH) has been dedicated to groundbreaking advances in health care. Today, this legacy continues. WCH is delivering health system solutions by creating new models of ambulatory care and improving access. As a teaching hospital affiliated with the University of Toronto, Women's College Hospital is also training the health professionals of the future to work in ambulatory settings.

About ICES ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of health care issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting health care needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy.