By Tom Keppeler, Knee1 Staff
A new device that enables a surgeon to quickly suture together tears in the meniscus—the thin pad of cartilage that cushions the knee—will debut this week, bringing hope for shorter surgeries, and, with luck, shorter recoveries.
At the top of your shinbone, or tibia, lie two half-moon shaped pads of cartilage known as menisci (singular: meniscus). When they are torn, which often accompanies other injuries such as tears of the Anterior Cruciate Ligament, the knee loses its natural shock absorber. Studies have proven that meniscal tears can lead to pain, swelling, and early-onset arthritis. Many surgeons used to think (and some continue to do so) that a torn meniscus can not be fixed; it must instead be removed before the tear becomes larger. However, developments in the last 10 years have enabled surgeons to repair torn menisci with great results.
In the early 1990s, surgeons found that suturing, or stitching, the meniscus together was an effective way to repair the meniscus. The stitches were flexible, which allowed the meniscus to bear weight while it healed. In addition, sutures held the discs together tighter, creating a good repair site. The surgery was done through an open incision, however, making for an invasive procedure and a large surgical wound.
In 1996, the meniscal arrow was invented, according to Nick Sgaglione, MD, a Long Island-based orthopedic surgeon. The arrow (like a straight pin) was passed through one side of the tear and into the other. Although it did not hold the site together as tightly as sutures, the device could be delivered in an arthroscopic manner—with just one 3-millimeter hole, rather than a long incision—making it less invasive and allowing for a quicker healing time. As a result, most surgeons dropped the suture technique and turned, instead, to arrows. The device, which still remains the state of the art, was bioabsorbable, meaning that it broke down over time and was eventually washed out of the body. However, the absorbable aspect of arrows made for an additional worry: a soft-tissue reaction may occur inside the knee as the device is implanted. In addition, because the arrow is more like a straight pin and less like stitches, it may rub against the other tissues in the joint, especially the sensitive articular cartilage that surrounds the ends of the bones.
Sgaglione compares repairing a torn meniscus with arrows to a quick repair job for a torn suit. "The pin can dislodge, it can poke your skin when you're at a party, you may have a reaction to the material it's made out of, et cetera," Sgaglione says. Instead, Sgaglione recommends that you take it to a tailor, who would sew the tear together with stitches (or sutures) in the quickest way possible. Enter FasT-Fix, Smith & Nephew Endoscopy's latest innovation, which allows a surgeon to do just that: suture—not pin—a tear in the meniscus in a quick, simple procedure. The device combines the best of both worlds: it can be delivered arthroscopically like arrows, but with a tighter hold and fewer potential complications.
Here's how it works:
- First, a surgeon makes small cuts through which he will pass the arthroscope and tools. The FasT-Fix needle and tools—wrapped in a protective sheath so as not to damage the tissues inside the knee, are pushed toward the torn meniscus.
- Once near the meniscus, the surgeon pulls the sheath back, exposing a needle with two prongs (called suture anchors, since they will later hold the stitches to the tissue) attached to it. Between the prongs runs a thin, strong thread, the suture.
- The needle is passed through one side of the meniscal tear, leaving behind the first suture anchor. To visualize this, think of a button being sewed to a shirt. As the needle passes through the shirt, it leaves the button, or anchor, behind.
- A site three to five millimeters away is then selected to receive the other stitch and, thus, the other anchor. The surgeon makes the second stitch, placing the anchor at the site.
- The surgeon loops the thread around and pulls the thread. A preformed knot in the FasT-Fix suture slides down toward the repair site as the surgeon pulls the thread.
- A "knot pusher" device is then brought to the area. The surgeon uses the tool to push the knot—making it tighter—and cut off any excess thread. The tools are then removed, and the surgery is completed.
Sgaglione calls FasT-Fix the "third generation" of meniscal repair. The device is a marvel, he says—not because of the materials, which have been used in many patients and have been proven to work—but because of the delivery, which makes it easy for the surgeon to produce a better, more solid repair arthroscopically. A less-invasive, yet stronger approach would allow patients to heal more quickly with less worry that their repair will not heal.
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