Orthopaedic Specialty Clinic of Spokane, PLLC

Metal insert touted as less invasive option for some osteoarthritis sufferers.

By Carla K. Johnson

Belinda "Polly" Playfair, a Chewalah, Wash., business owner, endured years of pain, multiple surgeries, and increasingly limited mobility after damaging a knee while serving in the military. In the 1982 accident, she says, an engine broke loose from a hoist, knocking her into a 14-foot-deep service pit.

Later on, despite various efforts to repair the knee, "It would stiffen up, and it would give while I was walking. I used a cane for 20 years," Playfair says. Worse yet, the pain steadily increased.

"I just got to the point where I couldn't walk anymore," she says. "To put any weight on the leg was excruciating."

Her frustrating efforts to return to a more normal, active lifestyle took a sharp turn for the better last May, she says. That's when Dr. David Scott, a Spokane orthopedic surgeon, inserted into her failing knee a small, shiny piece of metal called a UniSpacer that had been approved for use in the U.S. only a year earlier.

"I was able to stand on it right away - not feeling any pain," says Playfair, 49, who operates the 49er Motel in Chewelah with her husband, Robert. Although her overall recovery from the procedure was gradual, she considers the wait to have been well worth it.

"I can't even tell that I have something in there. I actually can get down on my knees on the floor with it," she says. "I still have a little bit of swelling once in a while, but the pain that used to be there isn't there any more. I can't say anything bad about it. I feel wonderful."

Scott, a principal with Orthopaedic Specialty Clinic of Spokane PLLC, says he has inserted about 30 UniSpacers in patients' knees over the last 14 months. "I think they've done very well," he says. "I'm very happy with the results. The patients seem to be doing quite will with it."

Made by Centerpulse Orthopedics Inc., of Austin, Texas, the UniSpacer is a kidney-shaped piece of highly polished cobalt chrome that's produced in varying sizes to conform to the weight and size of each patient.

It's designed to decrease pain and improve joint stability for people who suffer from osteoarthritis on the inside half of the knee. The UniSpacer is targeted at people who have exhausted traditional treatments for knee pain, such as drugs and arthroscopic surgery, but are looking for an alternative to total knee replacement.

Wear-and-Tear Damage

Osteoarthritis is a condition that develops over time as the cartilage in the knee cracks and wears away, typically just through active use, which differentiates it from rheumatoid arthritis, a chronic disease. Because cartilage cannot fully repair itself, it may continue to erode over time, causing stiffness at first, then pain as the bones of the joint - the femur and the tibia - begin to rub together.

Intended to fill in for worn-out cartilage and to restore ligament tension, the UniSpacer is a "self-centering" device, which means it conforms to the natural bone structure without bone cement or screws, and adapts to the motion of the patient's knee, Centerpulse says.

Its curved face allows it to interact with the bone somewhat like a cup and ball.

Because it isn't attached in any way, its use doesn't compromise a patient's ability to have total knee replacement surgery performed later if that becomes necessary, the company says.

Contrary to the notion that the procedure might be targeted mostly at the elderly, Scott says it makes the most sense for people ranging in age from their 40s to their 60s who want to remain physically active.

"It's often very healthy people who have been very active in their lives" who need the surgery, he says.

The procedure requires only a three-inch incision and takes only about an hour to perform. Scott says it typically includes removing some damaged cartilage and feathering the bone ends lightly so they'll mate will with the UniSpacer. Patients normally stay in the hospital one night, he says.

Although it is a less invasive procedure than a total knee replacement, recovery can take just as long or longer, requiring three to six months for a patient to feel comfortable with the insert and up to about a year to recover totally, Scott says.

Centerpulse claims that most patients recover 80 percent to 90 percent of their function in eight to 12 weeks, but after that, recovery is much slower.

Scott also emphasizes that, over the long term, the UniSpacer "does not necessarily provide absolutely 100 percent pain relief, but it helps a lot." Total knee replacement is a little more reliable and provides more pain relief, but also obviously has a more dramatic effect on the body's physiology, he says.

Because the UniSpacer still is so new, its useful life span hasn't been determined yet. Still, Scott says, "If we buy a patient five or 10 years of some reasonable activity and relief from their pain, that alone is a huge benefit."

He says he was part of a small group of surgeons who received training on the UniSpacer in October 2001, and believes that until recently he was the only Spokane-area orthopedic surgeon who offered the implant.

Litigation Problems

Centerpulse Orthopedics is a prominent maker of orthopedic implants for hips, knees, shoulders, and elbows. Over the last several years, though, it has been forced to cope with a flurry of litigation over defective hip and knee implants that led its Switzerland-based parent company, Centerpulse, formerly Sulzer Medica, to agree last year to a $725 million class-action settlement in the U.S.

The lawsuits stemmed mostly from a recall Sulzer announced in December 2000 after discovering that machinery oil had contaminated some of the implant parts manufactured by the company's plant in Texas. While many patients weren't affected by the problem, others had to have the part removed because it failed to adhere to the bone and reportedly caused some patients considerable pain.

One of the affected products, which Scott introduced in the Spokane market about three and a half years ago, was the Metasul "metal-on-metal" hip-replacement prosthesis that's touted to be more wear-resistant and long-lasting than earlier metal-on-plastic implants.

Scott is reluctant to discuss the controversy, which he says had regrettable consequences both for many patients and for the manufacturer. He notes, though, that the company after having revised its manufacturing process, is continuing to manufacture and market the ball-and-socket-type hip-replacement product.

He claims that the UniSpacer, because of its differing design and a different manufacturing process, isn't susceptible to potential similar production-related problems.

Scott is one of several orthopedic surgeons who left Spokane Orthopaedic & Fracture Clinic PLLC about four years ago to form Orthopaedic Specialty Clinic of Spokane, also on the city's North Side.

The latter group currently leases space in the Northpointe Medical Building, at 9631 N. Nevada, but plans to move in April into an 8,500-square-foot building that it's developing nearby at the northwest corner of Holland Avenue and Nevada Street.