Disability management news briefs
Single-dose drug provides superior pain relief
Study finds COX-2 better than morphine
Researchers found that a single dose of injectable COX-2 specific analgesic provides superior pain relief for total knee replacement patients, according to results of a Phase III study presented at the recent American Academy of Orthopaedic Surgeons Annual Meeting in San Francisco.
The multi-center, double-blind, placebo- controlled study included 208 patients with moderate to severe post-surgical pain. After discontinuing patient-controlled analgesia on the first post-surgical day, patients were randomly assigned to receive either:
- a single intravenous dose of parecoxib sodium (COX-2, 20 mg or 40 mg);
- ketorolac (30 mg);
- morphine sulfate (4 mg);
- placebo.
Additional analgesics, or rescue medications, were administered as needed, and pain and safety were assessed over the next 24 hours.
Researchers found that parecoxib sodium, ketorolac, and morphine sulfate each had a similar onset of action with a median time of 11 to 15 minutes. However, patients treated with the 40 mg dose of parecoxib sodium continued without additional analgesics significantly longer than patients treated with morphine sulfate. Specific time until patients requested additional analgesics were:
- Parecoxib patients had a median duration of five hours and 10 minutes prior to requesting additional analgesics.
- Morphine sulfate patients had a median duration of two hours and seven minutes prior to requesting additional analgesics.
- Ketorolac patients had a median duration of four hours and 35 minutes prior to requesting additional analgesics.
In addition to longer median duration of pain relief, 80% of patients who received the 40-mg dose of parecoxib rated their pain medication as good or excellent compared to 70% of ketorolac patients and 45% of morphine patients.
"Total knee replacement is a very painful procedure," Evan Ekman, MD, an orthopedic surgeon and director of Southern Orthopaedic Sports Medicine in Columbia, SC, told attendees. "Keeping pain in check following knee replacement surgery can be very challenging, given the side effects of analgesics like morphine and ketorolac," he noted. "This study suggests that parecoxib may become an effective and well-tolerated option, which is an exciting prospect, since no new injectable analgesics have been introduced in the United States in more than a decade."
Technology improves knee implants
Implants last longer, say researchers
Active, younger patients who suffer from arthritis or chronic injury may soon have access to knee replacement surgery much earlier in life, thanks to a new implant technology introduced at the recent American Academy of Orthopaedic Surgeons Annual Meeting in San Francisco.
Orthopedic surgeons have traditionally delayed joint replacement surgery in patients younger than 65 because the implant materials used rarely withstood the wear placed on them for longer than 10 to 15 years. Smith & Nephew’s Orthopedic Division in Memphis has developed oxidized zirconium — a metallic alloy with a ceramic surface — in response to the orthopedic community’s concerns over implant wear. The U.S. Food and Drug Administration in Rockville, MD, recently approved oxidized zirconium for use in knee implants.
"Oxidized zirconium addresses one of the most critical issues in clinical orthopedics today, which is the generation of wear debris," notes Leo Whiteside, MD, of the Missouri Bone and Joint Center in St. Louis. "The bottom line is the lower the amount of wear debris generated, the longer the implant will last."
Most implants on the market are made from a cobalt-chrome alloy that slides against a plastic bearing. The motion and friction caused by daily living can damage the implant’s surface and cause metal and plastic wear debris leading to bone loss and the need for replacement implants. Compared to cobalt chromium oxidized zirconium, in knee wear simulation testing, reduced the rate of plastic wear by 85%.
"We’ve been evaluating the new knee implant in patients for the past two years," says Richard Laskin, MD, of the Hospital for Special Surgery in New York City. "The exciting part is that this is not an externally applied coating. The metal component is heated and infused with oxygen until the outer surface naturally turns into a ceramic."
Implants made of oxidized zirconium also contain nondetectable traces of nickel, providing a solution for the more than 20,000 candidates for total knee replacement each year identified as acutely allergic to nickel.
For information on product availability by region, visit the company web site at www.oxidizedzirconium.com.
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