Q: I was just informed that my retorn meniscus is not all that uncommon. Yet I thought having the surgery to repair it would protect my knee and prevent early arthritis. It never crossed my mind that it might break again. Is this common?

A: Unfortunately, yes -- meniscal tears are common and reinjury is common. In fact, there is evidence of a 24 per cent failure rate for meniscal repairs five years after the operation. This figure is based on a systematic literature review and meta-analysis conducted by researchers at the Washington University School of Medicine in St. Louis.

The study was done by the Sports Division of their Department of Orthopaedic Surgery. By pooling the data from 13 high-quality studies, the authors were able to provide a five-year perspective for the modern arthroscopic repairs used most often.

Although they hypothesized (and hoped) that short-term results (after two years) that were previously reported would be maintained long-term, that was not the actual fact. Instead, nearly one-fourth of all patients continued to experience mechanical symptoms (knee pain, clicking, locking) or recurrent tears requiring additional surgery.

This large failure rate was consistent for open surgery as well as arthroscopic procedures (using all types of surgical repair techniques). The rate was similar no matter what type of rehab program was used (nonweight-bearing for four weeks, early weight-bearing, early range, of motion, or immobilization with cast, splint, or brace).

And it was true whether there was a medial or lateral repair. The rates were the same if patients had an intact or damaged anterior cruciate ligament (ACL). And the five-year outcomes are the same if the damaged ACL is repaired or reconstructed.

That is different than what has been believed all along. Meniscus tears accompanied by ACL injury were routinely both repaired with the notion that without all soft tissues being reconstructed, the patient would be at increased risk of failure. Further studies are definitely needed to resolve this issue.

Reference: Jeffrey J. Nepple, MD, et al. Meniscal Repair Outcomes at Greater Than Five Years. A Systematic Literature Review and Meta-Analysis. In The Journal of Bone and Joint Surgery. December 19, 2012. Vol. 94. No. 24. Pp. 2222-2227.