After just posting nice registry results for rotator cuff tears treated with the patient’s own stem cells instead of surgery, I thought a paper published this week would be a great segue. The rotator cuff is a series of deep shoulder muscles that help to stabilize the shoulder and move the arm. When there’s a tear in the muscle, the surgical approach is to sew the rotator cuff tear together and hope it heals. However, too often it doesn’t heal-with rates of surgical failure as high as 6 in 10. In addition, big tears fare even more poorly. Why? It’s been thought that many rotator cuff muscles and tendons tear because they have poor blood supply, leading to weak tissue. In addition, all too often, the extensive bracing required causes the rotator cuff muscle to atrophy, making it weaker still. Could there be another reason these tears don’t heal that involves the local repair cells?
In a study published this week, physicians in Norway took muscle biopsies from patients with rotator cuff tears. They then stained the tissue using tags that would identify cells that were actively trying to grow and repair, muscle stem cells, and the byproducts of muscle repair. The result? Patients with full thickness rotator cuff tears had less cellular repair potential than those with partial tears. We’ve theorized this for a while, as many full thickness rotator cuff tears just happen with some unusual activity (not severe trauma). The implication is that the tissue is bad as it failed under slightly higher load than usual. Hence trying to sew together bad tissue isn’t going to be that successful. The tissue first needs to have its regenerative potential restored. This is what we believe stem cell injections accomplish. In fact, based on our clinical experience, many of these tears will heal themselves without the need for surgery once the local repair response is augmented with more stem cells. This fits with the high rates of success seen in our recently published treatment registry data on rotator cuff tears treated with only stem cell injections and without surgery.
The upshot? Your torn rotator cuff may have bigger problems than the tear, it may lack in rotator cuff stem cells and may be incapable of healing and maintaining itself, leaving any attempt at suturing the tear more likely to fail. IMHO, restoring that repair potential is the key to healing many tears.