New Study Finds MRI Unnecessary For Diagnosing Osteoarthritis Of The Knee

Main Category: Bones / Orthopaedics
Also Included In: Arthritis;  MRI / PET / Ultrasound
Article Date: 11 Mar 2008 - 2:00 PDT

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Osteoarthritis (OA) is known as the "wear and tear" arthritis, effecting millions of people. Patients seeking relief from this disease are often sent for a magnetic resonance image (MRI) to diagnose their problem. A new study revealed today at the 75th Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS), found that patients seeking treatment for arthritic knees should be given a weight-bearing X-ray first. X-rays are a better diagnostic tool and much less expensive. The study highlights the need for the primary-care physician to start with a patient's medical history, after that, a routine physical and then focus on basic diagnostic skills.

"MRIs are being used in excess. Many doctors no longer talk to or examine their patients. Instead, they are going right for the technology," said Wayne Goldstein, MD. Dr. Goldstein, lead author on the study, is a clinical professor of orthopaedics at the University of Illinois at Chicago College of Medicine and chairman of the Illinois Bone and Joint Institute.

"This is another example of over-utilization of the health-care system. It has become easier to go for the high-cost imaging. On average, an X-ray can cost less than $150, while an MRI can cost around $2,500. Many physicians are ordering MRIs for osteoarthritis of the knee, when all they need to make the diagnosis is that X-ray."

Utilization of medical imaging is rising rapidly:

- It now consumes 10 percent to 15 percent of Medicare payments to physicians, compared with less than 5 percent only 10 years ago.

- These costs are expected to continue growing at an annual rate of 20 percent or more.

In 2008, Medicare will reimburse doctors more than $400 per MRI. A four-view X-ray, which works more effectively in showing osteoarthritis and is what most orthopaedic surgeons use, will reimburse doctors just over $43.

Reimbursement for each procedure is as follows:

MRI X-Ray (4-view) 2008 $457.33 $43.39 2007 $470.91 $42.46

In 2005, more than 533,000 total knee replacements (also known as total knee arthroplasties or TKA) were performed in the United States. The most common reasons for this surgery are:

- Severe pain

- Swelling and/or stiffness in the knee frequently caused by osteoarthritis, which cannot be satisfactorily treated with medications or other therapies

Researchers in this study reviewed a random sample of 50 patients who had total knee arthroplasty for osteoarthritis to see if they had an MRI of the knee within the two years before surgery. They found that 32 of the 50 patients did have an MRI which was ordered by their primary-care or orthopaedic physician and that the MRI did not provide any additional diagnostic information that could not be provided by an X-ray. More than half did not have any X-rays performed before their surgical consultation.

"There are some indications for MRI, such as suspicion of avascular necrosis [in which blood loss to the area causes bones to break down, something which may not be seen on early X-rays], but that is not a common condition," Dr. Goldstein said.

Dr. Goldstein and his co-authors believe that the main reason for this over-utilization of the MRI is a lack of education on this diagnostic technique, especially with family and primary-care physicians. "We fix this problem through educating physicians on the appropriate use of MRIs. We also need to educate our patients. Virtually every adult experiencing a knee problem should first have an appropriate set of X-rays before considering an MRI, which has been marketed as the premier diagnostic tool, so patients often come into the office expecting, even demanding, an MRI. Physicians need to look at why they are ordering an MRI and consider whether it is truly necessary."

American Academy of Orthopaedic Surgeons