You may be referring to the Grutter and Petersen article in The American Journal of Sports Medicine on using the flexor carpi radialis (FCR) tendon graft. They developed this method of AC repair that doesn't use any wires or screws.

They say the tendon graft restores the joint to its normal position and function. They used the FCR tendon graft to replace three of the ligaments holding the AC joint together.

If this is the study you saw, it's important to note they used cadavers, not live patients. The results were encouraging since cadavers don't have the "live" and dynamic muscles around the joint to assist with motion and stability. The models used were all from older adults, too.

Most likely this technique will be studied on live subjects before it's adopted as a standard operation for AC repair.