Biologically regenerated meniscal repair may soon trump resection

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Rheumawire

Mar 16, 2004

Biologically regenerated meniscal repair may soon trump resection

San Francisco, CA - New research is paving the way toward biological

regeneration of the meniscus, according to Dr A Sgaglione

(North Shore University Hospital, Manhasset, NY). Sgaglione made his

comments Friday at the 71st annual meeting of the American Academy of

Orthopaedic Surgeons.

" Currently there are 9 resections to every 1 repair, as an overwhelming

number of physicians continue to remove the meniscus rather than repair

it, but we are on the cusp of an explosion in technology, " he says. " In

5 to 10 years, the solution will be biological. "

This change in thought is predominantly driven by an aging yet

increasingly fit population, he says. " Today patients have great

expectations. They say, 'I am 50 years old, and I really like to ski. I

know that my lifespan might be 25 more years and I want my knee fixed!' "

In the past, 50-year-old patients may have been content to put up with

the problem knee and were more sedentary.

One potential promising solution is using fibrin clots to hold sutures

in place and promote healing.

" The most realistic and promising of the technologies is the use of

autoglous platelet-rich plasma [because] it allows you to carry out a

1-step technique in the operating room at the time of surgery using a

patient's own blood, if [you] somehow concentrate it and amplify

healing, " he tells rheumawire.

This is more practical than genetic engineering, he says.

The blood is spun for about 17 minutes to concentrate the platelets and

then placed in the knee during arthroscopy, he explains.

This technology has an 89% success rate, according to a study of 29

patients with an average age of 22 who were followed for 2 years, he

says.

Another promising meniscal-preservation technology involves borrowing

ideas from the cardiology community.

Instead of coated stents used by cardiologists, orthopedic surgeons can

use sutures coated with angiogenic chemicals to promote healing, he

says.

" If we can borrow [this idea] and use bioactice sutures, we can repair

more tears, " he says.

There is also some work being done in gene-modified tissue engineering

using such bioactive factors as insulinlike growth factor (IGF-1) and

vascular endothelial growth factor (VEGF).

" VEGF is very potent but very difficult to control in a lab or in vivo

because of its half life, and it will cause very exuberant responses

such as excessive tissue formation, which is in essence a scar, " he

says.

Currently surgeons do use allograft tissue, but novel scaffolds can be

improved on, he says.

The collagen meniscal implant (CMI) (ReGen Biologics, lin Lakes,

NJ) and the porcine small intestinal submucosa (SIS) scaffold (DePuy

Biologics, Warsaw, IN) may have a role in the future.

The CMI is approved in Europe, Chile, and Australia, and a ruling is

anticipated from the US FDA in early 2005.

The porcine SIS is behind the CMI in approval status, but " so far in

preclinical models in dog knees, promising results have been seen with

good healing, " he says.

" Despite excitement and novel technologies, there are problems ahead,

including durability with construct, and we are in our infancy in

controlling dosing, scheduling, release, and half life of many

chemicals, " Sgaglione says.

Plus, he says, " With chondoprotection, are we really making a

difference? That is our holy grail. "

Cost-effectiveness, too, needs to be determined.

Mann

I'll tell you where to go!

Mayo Clinic in Rochester

http://www.mayoclinic.org/rochester

s Hopkins Medicine

http://www.hopkinsmedicine.org