Joint surgery more common

By JOSH MCLEAN

REVIEW-JOURNAL

According to the American Academy of Orthopaedic Surgeons, total knee replacement surgery was the top most common procedure for musculoskeletal-related hospitalizations in 2004 at 478,000 while total hip replacement ranked third on the list at 324,000. With the number of hip and knee joint replacement surgeries more than doubling in the last decade -- the stereotype that only the aged and inactive undergo the procedure is now being challenged.

WHAT IS JOINT REPLACEMENT SURGERY?

Joint replacement surgery, otherwise known as arthroplasty, is considered one of the most successful treatments for patients with osteoarthritis, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The two most common joints are the knee and hip. The surgery is done on patients whose joints have become damaged by disease or injury.

Joints are formed by two ends of bone connected by a soft, protected cushion called cartilage. If cartilage tissue becomes damaged, it does not allow the joints to move in a smooth manner. Initially, the inflammation of the tissue causes pain, but as the cartilage wears away the bones begin to rub against one another and cause even more pain.

Sometimes surgeons may be able to replace or repair just damaged parts of the joint, but when the entire joint is injured a total joint replacement is necessary. When this procedure is done, the doctor removes the diseased and damaged portions of the joint and replaced them with implants.

There are various prosthetic options, which are all regulated by the U.S. Food and Drug Administration. The most commonly used prostheses for hips and knees are made of metal and plastic, however, there are also other options. Usually the metal is titanium or a mix of chromium and cobalt, and the plastic is a polyethylene. According to the FDA, the doctor considers the patient's gender, age, weight, anatomy, general health, activity level and medical history when choosing the right prosthesis.

The AAOS reports the average length of stay for patients who underwent total hip replacement surgery was about four days and had a price tag of approximately $35,000 in 2003. Knee arthroplasty patients stayed the same amount of time in the hospital, but paid less at $31,000.

It is also important to consider that surgery is only the first hurdle for knee and hip replacements. Afterward, much rehabilitation is necessary to restore function to the joint.

WHO HAS JOINT REPLACEMENT SURGERY?

Though the number of knee replacement patients under age 60 has increased in recent years, the average age of patients in 2004 was about 67, according to the National Hospital Discharge Survey. Surprisingly, the average age of hip replacement patients was a year younger, at about 66 years. While the stereotype that joint replacement surgery is for the elderly, rock star Eddie Van Halen is among a growing number of younger adults who are undergoing the surgery when he had his hip replaced in 1999 at the age of 43. Not only is age a factor, but gender also seems to play a role. Women account for approximately two-thirds of knee and hip joint replacement surgeries. This is because women are more prone to conditions that require the procedure and on average they live longer than men.

COMMON PROBLEMS

Despite the growing number of success stories associated with the surgery, there are still a few drawbacks. Complications associated with the surgery, such as blood clots can occur. In addition, the knee or hip replacements don't always hold up throughout the patient's lifetime. About 80 percent of implants last at least 20 years, according to the AAOS. When they fail, revision surgery is then necessary. In spite of many technological advancements in the area, the AAOS reports the proportion of knee revision replacement surgeries to primary procedures has continued to hover around eight percent over recent years. Revision hip procedures account for about one in every six hip replacement surgeries, according to the National Hospital Discharge Survey.

The success of the joint replacement surgery depends on several factors: patient's age at the time of the surgery, the patient's lifestyle and activity and any complications as a result of the surgery.

Complications can include infection, blood clots in the veins of the leg (venous thromboembolism), joint dislocation, loosening of the implant, nerve damage and the formation of normal bone in the soft tissues (heterotopic ossification). While most of these complications are relatively rare, doctors take many precautions directly after surgery and during rehabilitation to avoid them.

"I like to tell my patients that the chances of complications happening are below one percent," said Dr. Christopher Browne, M.D., an orthopedic surgeon with Eastern Oklahoma Orthopedic Center. "With the therapy these days and how aggressive we are as to getting patients up and moving, a lot of complications are reduced."

NEW TECHNOLOGY

When it comes to hip replacement surgery, much progress has been made in the last ten years thanks to "minimally invasive surgery" or MIS. Though not all patients qualify for MIS, those who do have fewer complications, have less pain and recover faster. With this new procedure, there is only one scar measuring about two inches in comparison to the large incisions of open surgery that can be up to six inches in length. However, the downfall is that doctors trained in MIS estimate that only about 17 to 20 percent of hip replacement candidates are eligible for the procedure despite the high demand from patients.

John J. Callaghan, M.D., Professor of the Departments of Orthopaedic Surgery and Biomedical Engineering at the University of Iowa College of Medicine and spokesperson for the American Academy of Orthopaedic Surgeons warns MIS is not the perfect surgery for all patients.

"It is very important that we have the good surgical candidates with correct fixation of the parts in hip replacement surgery," said Callaghan.

For example obese patients are not good candidates. In addition, because of the nature of the surgery, it takes more time and therefore, more anesthesia. Unfortunately, the surgery also has more incidences of need for surgical revisions due to problems associated with the original surgery, according to Callaghan. This is due to the increased restriction on the visual field.

For knee replacement, there has been a technological advance called computer-assisted total knee replacement surgery that allows for greater durability of the replaced joints. The surgery uses image-guided technology to perfectly align the knee implant. The computer-assisted procedure does not use the intramedullary rod necessary in the standard surgery. This reduced the risk of acute respiratory distress caused by fat embolization and allows surgeons to experience the same success with smaller incisions.

"Computer-assisted surgery is a navigational tool to help align the implants," Browne said. "It's like using a GPS system. I map in the patient's anatomy and it takes that information and makes a computer model of it.

"I'm still doing the implant, but the computer guides me and I get more precise in how I align things," he said. "It's like with the tires on your car. If you have perfect alignment your tires tend to wear more evenly, while if the alignment's off, there's uneven wear and they'll need replacement sooner. The big thing is the long-term benefit to the patient."

Dr. Daniel J. Berry, professor and chairman of Orthopedics and the Mayo Clinic said the new procedure is making great progress and has a high level of success with those experience with the surgery."Current efforts are focused on making the process simpler, more efficient, and more cost effective," Berry said. "As these methods evolve, it seems likely some form of computer assistance will eventually become a routine part of total knee arthroplasty."Because the surgery is still quite new, computer-assisted total knee replacement is more difficult and takes extra time for the surgeon.

HOW DO YOU KNOW IT'S TIME FOR SURGERY?

The Arthritis Foundation suggests that if you have any of these signs, you should speak to your rheumatologist or orthopedic surgeon about the possibility of joint replacement:

* You are unable to sleep at night because of the pain.

* You have tried different medications and they don't help the pain, or the medication you have been taking is no longer effective.

* You feel that the pain from your arthritis is keeping you from regular activities, such as visiting friends, going shopping or even taking a vacation.

* Your activity is restricted to the point where you have difficulty getting out of a chair, going up the stairs, getting off the toilet, or getting up from the floor.

WHAT DO I ASK THE SURGEON?

The Arthritis Foundation suggests these questions to ask your surgeon before undergoing joint replacement:

* What makes a person a good candidate for joint surgery?

* What are the risks involved with joint surgery?

* Are there be any other non-surgical treatments I haven't yet tried that would alleviate my pain and help me move more easily?

* What type of procedure would you recommend for me?

* How would joint replacement help my particular problem?

What is not going to change after the operation?

* How long will recovery take?

* What is involved in the recovery process?

* Can you tell me what the outcome (decreased pain, improved function) has been for the majority of the patients?

* Can you provide the names of several people I could contact to talk about what they experienced with surgery?

JOINT REPLACEMENT FACTS

According to the Centers for Disease Control and Prevention:

* Hospital discharges for total hip replacement increased by one-third and knee replacements by 70 percent from 1996-2006.

* The most common reason for joint replacement is pain and decreased quality of life from osteoarthritis. With an aging population and one-third of Americans obese, prevalence of osteoarthritis is expected to increase.

* Demand for joint replacements will grow an estimated 175 percent for total hip replacements and six-fold for total knee replacements by 2030.

* Advances in surgical techniques, such as minimally-invasive methods and use of computer-assisted surgical systems, aim to reduce post-operative pain, shorten recovery time and improve surgical accuracy.