The repair of meniscal tears is significantly improved when performed in conjunction with reconstruction of the anterior cruciate ligament (ACL), according to research presented here at the American Orthopaedic Society for Sports Medicine 2011 Annual Meeting.

It is generally believed that meniscal repairs heal more successfully when they are performed along with ACL reconstruction; however, success rates even when the ACL is stable have not previously been demonstrated, according to lead author David Wasserstein, MD, MSc, from the University of Toronto in Ontario, Canada.

"Many surgeons believe that meniscal repairs are more successful when performed with ACL reconstructions. This is most likely true in an unstable knee because repairing the meniscus and not repairing a torn ACL leaves high stress on the repair and likely results in a higher failure rate," he explained.

"What we don't know is if meniscal repair is as successful in ACL-intact or stable knees, compared to an unstable knee, when done with ACL reconstruction."

For the retrospective case-control population-level study, Dr. Wasserstein and his team identified 1298 patients who underwent meniscal repair in conjunction with ACL reconstruction (combined group), and compared them with the same number of patients in the same study period who underwent meniscal repair alone (control group).

The two groups were matched for age and sex.

The results showed the rate of meniscal reoperation to be 4.5% when the repair was performed with ACL reconstruction, and as high as 20.7% when performed alone (P < .0001), Dr. Wasserstein told meeting attendees.

The researchers also looked at the number of meniscal repair procedures performed by the surgeon in the year prior to the event. The results showed that significantly more repairs in the combined group were performed by the highest-volume surgeons, compared with those performed in control group (42% vs 14%;P < .0001).

"In general, meniscal repair is statistically and clinically significantly improved when performed in conjunction with ACL reconstruction," the researchers conclude.

Dr. Wasserstein said the results were somewhat unexpected. "We were a bit surprised by the results, because our hypothesis was that there would be no difference," he said.

He added that possible explanations for the differences between groups could be the type or pattern of the tear, mechanical factors (such as limb malalignment or occult instability), and the potential healing benefit of postoperative hemarthrosis from drilling bony tunnels in ACL surgery.

"Many experts have postulated that this may occur because of either mechanical or biological factors," he said. "Some have advocated doing a notchplasty (i.e., drilling the notch to get some bleeding into the joint) when doing meniscal repairs in isolation; however, there is no strong evidence to support this."

According to session moderator Wayne J. Sebastianelli, MD, professor of orthopedic surgery and director of athletic medicine at Hershey/Penn State Orthopedics in State College, Pennsylvania, even when the knee is stable, the nature of the injury to the meniscus could justify a combination with ACL reconstruction.

"The key thing is that if a meniscus repair that is done in an isolated way without a ligament injury, it means the meniscus itself probably has some sort of collagen damage, which makes the healing process statistically less probable than if the meniscus was injured when the ligament was torn," explained Dr. Sebastianelli.

"The structure fundamentally has a flaw in it, whether it's based on alignment of the limb or repetitive microtrauma that just sort of weakens that meniscus....Even though we try to stitch that and repair it, the underlying weakness or mechanical alignment problem still exists," he said.

The chances of such a repair lasting is not as likely "as if the meniscus repair is associated with an ACL tear, because that meniscus was completely normal and never had a problem until the ligament was injured."

The findings help underscore the importance of surgical technique and postop care in preventing the need for reconstruction, Dr. Sebastianelli added.

"I think it just drives home the fact that to get a meniscus to heal after you repair it, you need to have a meticulous technique and to treat the patient appropriately postop so there isn't any inappropriate stress applied to the meniscus before it is healed," he said, "and that could take 6 months."

"I think a lot of people are probably not recognizing the fact that it's attention to detail — not only on the repair side, but also on the rehabilitation side — that leads to the success of meniscus repair."

Dr. Wasserstein and Dr. Sebastianelli have disclosed no relevant financial relationships.

American Orthopaedic Society for Sports Medicine (AOSSM) 2011 Annual Meeting: Abstract 7. Presented July 7, 2011.

Nancy A. Melville • Medscape Medical News © 2011 WebMD, LLC