The wider use of knee replacement, on one hand, is good news for the rapidly aging population. But while knee surgery eases pain from severe arthritis and improves quality of life, the improvements "can be viewed as another strain on government, individuals,and businesses struggling with unremitting growth in health care costs,'' the authors report in the Journal of the American Medical Association. "People are living longer and want to be active," says lead author Peter Cram. "They feel great after this surgery. They can hike in the mountains and ski. They can be active with their grandchildren." The challenges, he adds, are how to address post-surgery problems that can develop from shorter hospital stays and in patients with other conditions such as diabetes and obesity, and how to ensure doctors are not overusing a "highly reimbursed procedure."
A knee replacement costs Medicare about $15,000, costs that would be higher, the authors find, had Medicare not taken cost-lowering measures of shortening hospital stays and relocating many rehabilitations from in-patient clinics into the patients' homes. However, those strategies can lead to problems down the road for some patients and add costs and longer recovery times. The study is the first to evaluate trends and outcomes linked to total knee replacement, the authors write, and includes a breakdown of expensive factors that can lead to rehospitalizations and additional surgeries. From 1991 to 2010, 3.27 million patients ages 65 and older had total knee replacements and 318,563 had knee revisions, additional surgery to fix problems.
The researchers found the number of primary replacements among Medicare patients increased from 93,230 in 1991 to 243,802 in 2010 (an increase of 161.5%). The number of revisions increased from 9,650 to 19,871. Total knee replacement surgeries increased 99.2% (31.2 procedures per 10,000 Medicare enrollees in 1991 to 62.1 procedures per 10,000 in 2010.) "We not only have more people aging than we did 20 years ago, but we have more of these surgeries being performed,'' says Cram, a physician at the University of Iowa Carver College of Medicine in Iowa City.
During the same time period, length of hospital stay decreased from 7.9 days to 3.5 days for total knee replacement and from 8.9 to five days for revisions. However, re-admissions have increased slightly for total knee replacements but have increased more than 100% for revisions. "Revisions are a much more complicated surgery,'' says Cram, "and we need to be thinking more about which patients are suited for them and which ones aren't." In an accompanying editorial, the authors say the yearly demand for total knee replacements could be as high as 3.48 million procedures by 2030 and can potentially "decrease the allocation of health care resources used by patients." Yet the surgeries also "will be a driver of health care costs,'' and steps need to be taken to address "predisposing modifiable factors such as obesity and to advance efforts at early intervention strategies to treat mild arthritis and to prevent progression'' requiring surgery.
But that was the explanation Kelly O'Sullivan was eventually given for her two-year-old daughter Blaze's unusual symptoms - a rash that covered her body and swollen joints which stopped her wanting to walk. Kelly, from Bolton, says Blaze had a normal birth and developed normally, walking when she was a year old. But Blaze became ill in January this year when she was 18 months old. Kelly says: "At first she got a rash all over her and a high temperature and she didn't want to walk. "I took her to the doctor and she was given lots of different medicines, antibiotics. "Then she started walking with a limp, and it got progressively worse and her knee swelled up to the size of a tennis ball."
Doctors thought Blaze's symptoms were caused by a viral infection, but then she began to experience stiffness in her neck and this time was referred to her local hospital. Kelly said: "They still thought it was a viral infection. She was in there for about four weeks, and given intravenous antibiotics. Lots of doctors from different specialties saw her." However there was still no diagnosis - and Blaze was moved to Manchester Children's Hospital where another raft of tests, including a lymph node biopsy and a bone marrow test, were carried out. Finally - in March - she was diagnosed with systemic juvenile idiopathic arthritis (JIA).
'She shouldn't miss out'
JIA refers to a group of arthritic conditions which affect children. All cause inflammation, but relatively little is known about them and how they will progress. Any problem usually starts before a child is five, and affects more girls than boys. An estimated 12,000 children in the UK have a form of arthritis. Some only have a short-term illness, while around a third continue to have symptoms into adulthood - but it is hard to predict how an individual's illness will progress. Kelly said she was pleased that Blaze had a diagnosis at last - but surprised. "I didn't know a two-year-old could get arthritis. It's not something you think they can have."
Blaze now has to have daily and weekly injections and takes steroids to control her symptoms. Kelly, who also has a two-week-old baby, says the medication is helping but Blaze cannot lead a normal toddler's life. "She should be able to run around like any normal toddler. And I can't get her into a nursery because one of the drugs she takes, methotrexate, affects the immune system and they won't take her. "I'm trying to get her a place though, because she shouldn't have to miss out."