High Failure Rate for Repair of Meniscal Tears

Meniscus (plural: menisci) in the knee depend on an intact and healthy anterior cruciate ligament (ACL). Without the ACL, forces on the meniscus increase up to 200 per cent. Protecting the meniscus is one reason why ACL tears are repaired.

The meniscus is a moon or crescent-shaped fibrocartilaginous structure present on both sides of the knee (medial and lateral). Both menisci provide structural integrity and support to the knee when it undergoes tension and torsion. Athletes involved in pivoting, cutting, or sudden changes in direction are most likely to sustain an ACL/medial meniscus tear. This commonly includes soccer and basketball players and skiers.

Treatment of meniscal tears has changed over the years from removal to preservation. Surgeons use arthroscopic methods to check the meniscus for damage. Any frayed edges are smoothed. Holes may be drilled with a tiny meniscus repair needle to stimulate bleeding and speed up recovery. The process of putting holes in the cartilage is called trephination.

The focus today is more on finding the best way to repair this structure. In this study, theFas-T-Fix device was used to repair vertical unstable medial meniscal tears in 27 patients. The Fas-T-Fix is an all-inside suture repair technique (different from the standard inside-out suture method). The sutures are easy to handle for the surgeon. Each suture has two attachment sites, which forms a closed loop. There are no sharp edges and they have excellent holding power.

Results are reported over a period of two to five years. Failure of the meniscal repair was counted as any patient who ended up with knee pain or problems and who had an arthroscopic exam confirming another tear of the meniscus where it had been repaired. There were six total failures out of the 27 patients (22 per cent). Anyone with a second meniscal tear was then treated with a partial meniscectomy (removal of the damaged cartilage).

The authors weren’t just looking at the final outcomes using the Fas-T-Fix. They also collected enough data about each patient to look for any trends or factors that might predict who would have a successful result and who would not. Failure was more common in acutely injured knees. In this case, acute described patients who had surgery within the first six months after the injury. Chronic injuries were defined as those that were repaired six months (or more) after the original injury.

They also took a look at the condition of the joint cartilage and joint surfaces while doing the arthroscopic exam and repair. Injuries in this area did not seem to have any connection with success or failure. The biggest factor appeared to be location of the meniscal tear. Most of the failures (four out of five) were located in the red-white vascular zone. That’s an 80 per cent failure rate for that zone.

There are three zones in the meniscus that correspond to blood supply to the area. The outermost zone is the red-red zone. Here there is the greatest amount of blood flow and the best chance for success. The middle zone (between the red-red and white zones) is the red-white zone. The inner zone is called the red-white zone. Healing potential is the poorest for tears in this central zone as this study confirmed.

The authors conclude that there are many things yet to consider in finding the best approach to ACL-associated meniscal tears. Failure of meniscal repairs increases with time from surgery. Patients who remain active after surgery figure into that factor. There are other suture repair devices besides the Fas-T-Fix. But the ease of intraoperative use with the Fas-T-Fix may result in more surgeons using this approach and with patients who should not be repaired with this device (e.g., red-white zone tears).

The patients in this study will be followed longer and results will be reported again later. In the meantime, more study on the problem of meniscal repairs and repair failures is warranted by the current high rate of failure reported in this and other studies.