New surgical techniques are helping to improve treatment of a lesser-known type of knee ligament injury, according to a research review.

The ligament in question is called the posterior cruciate ligament, or PCL - a band of strong tissue that connects the shinbone to the thighbone and prevents the shinbone from moving too far backward.

When it comes to knee injuries, the anterior cruciate ligament (ACL) gets most of the attention, as ACL tears are far more common. However, the PCL can be torn when a heavy force strikes the front of the knee - if, for instance, the knee hits the dashboard in a car accident, or an athlete falls hard onto a bent knee.

Partial tears to the PCL are generally treated with rest, physical therapy or other non-invasive measures. When it is completely torn, though, surgery may be recommended.

The new review, published in the Journal of the American Academy of Orthopedic Surgeons, charts the recent progress that has been made in reconstructing damaged PCLs.

The traditional surgical method is to replace the ligament with a so- called “one-bundle” graft taken from another part of the patient’s body or from a cadaver. The graft is passed through a “tunnel” in the front of the shinbone and attached to the bone at a single site.

Newer methods have been developed, however - one being the “two- bundle” approach, which uses thinner individual tissue grafts that are attached to the bone at two sites. The other option is known as in-lay reconstruction, where instead of using a tunnel in the shinbone, the surgeon screws the new tissue directly into the shinbone.

Lab research suggests that the newer methods may be more effective than traditional surgery, according to Dr. Matthew Matava, an orthopedic surgeon at the Washington University School of Medicine in Chesterfield, Missouri, and the lead researcher on the review.

With in-lay reconstruction, the tissue graft is likely to fray or become stretched out, as it is not wound around the shinbone tunnel, Matava explained in a news release from the American Academy of Orthopedic Surgeons (AAOS).

The evidence, however, comes from biomechanical studies, and clinical trials have not yet shown the newer methods to be superior.

“Although we believe the newer treatments are better,” Matava said, “we still must prove it.”

According to the AAOS, some surgeons believe that the new means of PCL reconstruction are more complex, and therefore more risky. The group advises patients who need the procedure to find an orthopedic surgeon with specific experience in PCL reconstruction.

SOURCE: Journal of the American Academy of Orthopedic Surgeons, July 2009.