Knee and Hip Replacement Pain: A New Approach to Pain Management

Patients undergoing knee or hip replacements recover more quickly when treated with targeted pain-blocking medications that may eliminate the need for general anesthesia during surgery and intravenous narcotics drugs after surgery.

A decade ago, patients undergoing hip or knee replacements were almost exclusively given general anesthesia during surgery and intravenous narcotic pain medications afterward. This approach works for most people and still is commonly practiced. But both general anesthesia and intravenous narcotic drugs can cause nausea, vomiting, grogginess, decreased bowel function and other side effects.

In the early 2000s, Mayo Clinic anesthesiologists began developing new anesthesia protocols for joint replacement surgery that used known anesthetic and pain relief techniques in new combinations. Their goal was to eliminate the need for general anesthesia and intravenous narcotics and the resulting side effects.

The new procedures may vary but typically involve:

A choice: Even with the new protocols, patients may choose regional anesthesia, where the lower half of the body is numbed, or general anesthesia.

Oral pain medications early on: A combination of oral narcotic pain medications are given prior to surgery. Oral narcotics have fewer side effects than narcotics given intravenously. This technique is helpful for recovery whether general or regional anesthesia is used.

Sedation: Sedative drugs given before surgery help patients using regional anesthesia nap during the procedure, but not lose consciousness.

Nerve blocks: Through a catheter, a continuous infusion of numbing medicine is pumped near the surgery site for 48 hours. Nerve blocks are performed in conjunction with general or regional anesthesia.

Oral pain medications after surgery: For more than 95 percent of patients, pain that occurs after the nerve blocks are removed can be managed with oral pain medications such as acetaminophen (Tylenol, others), tramadol (Ultram, others) or oxycodone. Intravenous narcotic medications are used as a last resort.

Patients who receive regional anesthesia report significantly less pain after surgery than those receiving general anesthesia and intravenous narcotics. These patients are out of bed sooner, begin physical therapy sooner and leave the hospital one to two days before patients who were given general anesthesia and intravenous narcotics. With the newer protocols, patients may still experience typical side effects including nausea and vomiting, but to a lesser degree than with the older anesthesia methods.

Another benefit is that regional anesthesia protocols make surgery an option for older adults with more complicated conditions. A decade ago, older adults often were not considered candidates for surgery because they would have fared poorly with older anesthesia techniques.

Doctors report few downsides to these newer pain management approaches. Nerve injury is a rare potential complication. For most people, the regional anesthesia protocols are a change for the better, resulting in less pain, fewer complications and a quicker recovery.

Source: Mayo Clinic (2/10/2010)

X-Ray Often Better and Cheaper than MRI in Knee Diagnostics

A weight-bearing X-ray is a better diagnostic tool and much less expensive than the MRI typically prescribed for patients with knees affected by osteoarthritis, according to a recent study. A patient’s medical history and a routine physical should be the starting point for a primary-care physician, followed by basic diagnostics.

"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 orthopedics 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". Medical imaging now accounts for 10%-15% of Medicare payments to physicians, compares with less than 5% only 10 years ago.

In 2008, Medicare will reimburse doctors more than $400 per MRI. By contrast, a 4-view X-ray which effectively reveals osteoarthritis and is routinely used by most orthopaedic surgeons, reimburses doctors just over $43. It is estimated that these MRI costs will continue to row at an annual rate of 20% or more in 2008. In the United States more than 533,000 total knee replacements were performed in 2005, primarily because of severe pain, swelling of stiffness of the knee caused by osteoarthritis.

A random sample of 50 knee arthroplasty patients found that 32 of the 50 had had a knee MRI within 2 years before surgery, ordered by their primary-care or orthopedic physician. The MRI did not produce any diagnostic information which could not have been provided by an X-ray, and more than 50% did not have any X-rays before 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.

Dr. Goldstein added, "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."

The study was presented at the 75th Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) in March, 2008.

Knee Surgery Recovery and Range of Motion Limited By Obesity

After total knee replacement surgery, obesity limits a patient’s range of motion, makes the recovery period longer and calls for extended physical therapy, according to a recent study. A patient’s body mass index (BMI)—a correlation between height and weight—has a direct relationship on the knee’s range of motion and need for manipulation under anesthesia.

Close to 20% of patients with a BMI of 25 to 30 needed manipulation for improved flexibility and to break up scar tissue, while patients with a BMI of less than 25 needed the manipulation. Said Geoffrey Westrich, MD, lead author of the study and an associate professor of orthopaedic surgery at Hospital for Special Surgery in New York City, "For anyone considering knee replacement surgery, recovery time is always an important consideration". Heavy patients, he continued, need to be advised that their weight will probably slow their recovery.

Data from 309 patients (400 knee replacements) who underwent the procedure at Hospital for Special Surgery was evaluated for the effect of BMI on range of motion and the need for manipulation under anesthesia. Patients with BMI from less than 25 to more than 29.9 were divided into groups: major findings from the study were as follows:

  • The greater a patient’s BMI, the less range of motion they can expect after knee surgery
  • Age was not a predictor for range of motion
  • Gender was a predictor for range of motion and the need for manipulation
  • Regardless of BMI: – Men had a 4.6-degree higher range of motion than women – Less than 10 percent of men needed manipulation six weeks after surgery compared to 18.5 percent for women

"Our study reinforces the drain that obesity is having on the health-care system," Dr. Westrich said. "The obesity epidemic is causing health-care expenditures to grow at a rapid rate. Insurance companies, Medicare, hospital administrators, and patients need to understand that obesity will likely cause different patient outcomes, including more complications that may require further surgical interventions."
Dr. Westrich concludes that "setting realistic expectations prior to surgery is paramount to patient care.". Surgeons performed more than 533,000 knee replacements in 2005.

The study was presented at the 75th Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS) in March, 2008.

Will There Be Enough Orthopedic Surgeons to Meet Joint Replacement Demand?

According to a new study by Dr. Iorio and his colleagues to be presented at the 75th Annual Meeting of the American Academy of Orthopaedic Surgeons (AAOS), the numbers of hip and knee replacement surgeries have increased dramatically in the last 10 years.

Dr. Iorio, senior attending orthopedic surgeon at the Lahey Clinic in Massachusetts said, "We are preparing for an epidemic of serious proportions."

In 2005, 285,000 total hip replacements and 523,000 total knee replacements were performed in the United States. By 2030, these two procedures are expected to jump to 572,000 and 3.4 million, respectively. Said Dr. Iorio: "The demand for these procedures will grow rapidly, and the orthopedic workforce will not be able to keep up. The supply of orthopedic surgeons will only increase 2 percent during 2000 and 2020. What we have on our hands is an access problem."

A 2005 survey of more than 23,000 AAOS members revealed:

  • 30 percent identified themselves as general orthopedic surgeons
  • 13 percent of orthopedic surgeons identified themselves as specialists in sports medicine
  • 10 percent identified themselves as hand surgeons
  • Only 7 percent identified themselves as primary surgical specialists for the adult hip and knee

"Simply put," Iorio added, "there will be a need for services that overwhelms the supply of physicians who will be able to fill that demand. Patient care is of utmost concern to us. Getting arthritic patients back to the quality of life they once had is always first and foremost. If these projections come to life, the access for a joint replacement will negatively impact patient care."