Hip and knee replacement is one of the fastest growing areas of surgery. In 1980 there were only about 100,000 knee and hip replacements in the U.S., compared to about one million in 2013. Estimates are for that number to grow fourfold to four million surgeries by 2030.
“Certainly it is the fastest growing type of orthopaedic surgery,” said C. Lowry Barnes, MD, chair of the University of Arkansas for Medical Sciences (UAMS) Orthopaedic Surgery Department. “The aging of baby boomers and trauma increase the need for hip and knee replacements. Fortunately, we have good treatment for those who need joint replacement. The success rate is very good now, and patients return to near normal activity very quickly. As results continue to improve, the popularity of the operation increases.”
Barnes said currently there is not a significant mismatch in need for surgical treatment and surgeons available to deliver that care. However, the projected increases in joint replacement over the next couple of decades will make this a real challenge, he said.
In the past physicians would recommend patients wait until later in life to have joint replacement because the artificial joints lasted on average only 15 years. But now joint replacement is offered earlier in life.
“Although artificial joints have a limited life expectancy, we think the life expectancy of implants is getting longer because implants and materials are better,” Barnes said. “Everything suggests the newer implants will have longer life expectancy because wear is less. Time will tell.”
The other reason surgeons are now operating on younger adults than in the past is that it is best to keep people active. “The problem is if you wait too long for someone who has significant arthritis, and people are inactive as a result, the patient can develop other illnesses such as diabetes and heart disease that are not only a problem in themselves, but also increase the risk of having complications with joint replacement surgery,” Barnes said.
There is a new trend around country looking at outpatient joint replacement. Currently it is not done in Arkansas. Barnes said while almost all patients go home the day following surgery, and most could be done on an outpatient basis, Medicaid and private payers in Arkansas don’t recognize it as an outpatient procedure.
One of the most significant risks for joint replacement surgery is post-operative infections, but that risk is less than one percent. Barnes said studies have shown there are fewer complications with surgeons who do the surgeries more frequently.
“Surgeons who do a lot of joint replacements are quicker at doing the operation and have developed techniques to decrease the infection risk,” Barnes said. “The same is true related to hospitals. Those hospitals that do higher volumes have lower complication risks, including infections.”
Terry Sites, MD, an orthopaedic surgeon who is chief of orthopaedic surgery with Advanced Orthopaedic Specialists, Fayetteville, said there has been ongoing work in reducing the complication risk of total joint arthroplasty.
“Smoking, diabetes and obesity have all been shown to increase the risk of wound healing problems and deep infection,” Sites said. “Delaying total joint arthroplasty to lose weight and achieve a BMI of less than 30 has been shown to significantly decrease the surgical risks of infection, deep vein thrombosis, and death. Delaying surgery to lose weight has no deleterious effects on total joint arthroplasty outcomes.”
For diabetics, it has been shown that HbA1c levels of greater than or equal to 10 gave patients an increased risk for surgical site infection, delayed wound healing, mortality, pulmonary and neurologic complications, increased the length of the hospital stay, and resulted in greater pain as compared with non-diabetic patients.
“Therefore, in patients with co-morbidities, the risks associated with total joint replacement can be significantly reduced by addressing these co-morbidities and maximizing their improvement prior to surgical intervention,” Sites said.
There has also been increased interest in the biologic treatment or solution for some arthritic changes.
“These include cartilage restoration techniques such as autologous chondrocyte implantation where a small amount of cartilage can be removed from an individual patient and grown to millions of cells in the laboratory and then surgically re-implanted into the joint to restore the articular surface,” Sites said. “These types of techniques are currently being used today and hold even more promise for the future. In some situations, these techniques can be used to prevent the young to middle-aged person from needing joint replacement.”
Sites said there has also been ongoing focus on the nonsurgical management of osteoarthritis of the knee which include low-impact aerobic exercise, weight loss, pharmacologic agents and intra-articular injections.
Sites said improvements have been made in terms of pain management at the time of total knee arthroplasty utilizing multi-modal pain protocols that include peripheral nerve blocks, intravenous acetaminophen and others to decrease the need for postoperative narcotics.
“These multi-modal pain protocols also allow for earlier and more efficient rehabilitation in the first couple of days following surgery,” Sites said.
Gordon Newbern, MD, an orthopaedic surgeon with Arkansas Specialty Orthopaedics, Little Rock, said the best results from total joint replacement occur when narcotics are avoided and minimized. Patients have best and most rapid recovery when they require fewer narcotics.
“Less narcotic means patients are much more alert and mobile, have much less nausea, constipation and urinary retention,” Newbern said. “Patients on long-term narcotic therapy often exhibit ‘opioid-induced hyperalgesia’ with amplified and difficult-to-control pain after surgery. Studies have shown this to lead to poorer functional recovery and poorer overall success of the surgery. Even reducing the long term narcotic user narcotic dose by 50 percent for two weeks before the surgery can greatly reduce this effect. Due to the problems that narcotic pain pills cause for patients, we recommend narcotics not be used to manage long-term arthritic conditions.”
Newberg said with increased training and experience, hip and knee replacements are quicker than in years past, now taking 50-90 minutes to perform.
“Pain control and mobility are much better than just three to four years ago and now 95 percent of patients go home the day following their surgery,” Newbern said. “People with hip replacements are fairly sore for seven to ten days, but well recovered in six to eight weeks. Knee replacements are more painful and slower to recover, taking three to four weeks to get past the more significant pain and stiffness and then 10-12 weeks to near recovery. Hip replacement patients can do their own therapeutic exercises, but knee replacement patients require outpatient physical therapy for several weeks after surgery.”
Related Links:
University of Arkansas for Medical Sciences Orthopaedic Surgery Department