Amy Norton

Repair or Reconstruction: What's Best for ACL Tears? (usnews.com)

ACL injuries are often treated with surgery, and the "gold standard" is ACL reconstruction: A surgeon removes the torn ligament remnant and replaces it with a portion of a tendon from elsewhere in the body, or with donated tissue from a cadaver.

Reconstruction has been the preferred choice over repairing the tear in the existing ligament for many years. Studies going several decades back showed that those repaired ligaments often did not hold up over time, but repair techniques have improved and there is growing interest in offering ACL repair to at least some patients.

Both ACL reconstruction and repair are minimally invasive procedures, but repair is thought to have some potential advantages in that 1) it avoids borrowing tissue (usually a tendon connecting to the kneecap or one of the hamstring muscles) and 2) it might allow a faster recovery.

A study was conducted that compared 75 patients who had undergone ACL repair vs. 75 patients who had basic reconstruction. Each repair patient was "matched" with a reconstruction patient of the same age, sex, body weight, sports participation, and general physical activity level.

The study found repair patients did better in certain respects:

1. Better hamstring strength six months post-surgery.

2. Better scores on a "forgotten joint" scale (they were giving less thought to their injured knee, 

    possibly because it felt normal again) 2.5 years post-surgery.

However, there was a significant downside as 5% of the repair patients were more likely to reinjure the knee whereas none of the reconstruction patients ruptured their ligament replacement.

Age did seem to make a significant difference in that risk: Many repeat tears were among patients younger than 22 because high school and college athletes -  eager to get back into the game - may simply have more chances at a re-rupture. Add to that the higher risk might partly stem from the biology of those younger knees.

Regarding whether repair led to a faster recovery, the study found no clear proof of that because 75% of repair patients had returned to their pre-injury level of sports participation as opposed to 60% of the reconstruction group. However, that difference was not significant in statistical terms.

It was cautioned that the risk of re-injury in young patients should be taken seriously because for young athletes going the repair route was considered an unacceptable revision rate. A repeat rupture can damage other tissue in the knee, including cartilage cushioning the joint.

On the other hand, for adults who are not heavily into "cutting" sports like soccer and basketball, ACL repair can be an option. Further, another option for the relatively older, non-athletic people simply physical therapy without surgery because the knee joint is stable enough for their usual activities, even without an ACL.

A question the new findings do not address is how ACL repair compares to physical therapy alone for relatively older patients age 30+. Currently, many who suffer an ACL tear may find their surgeon does not suggest repair as an option and they may be better off taking the physical therapy option, especially if the older person is active but not to the extent an athlete is.