Orthopedic surgeons are making rotator cuff repairs using arthroscopic techniques. Studies show that this method produces results similar to the standard open incision or mini-open repairs.
But the failure rate is much higher for arthroscopic shoulder repairs compared to mini-open and open repairs. And other studies have shown that repair failure occurs most often during the first two months.
In this study, sutures used to repair a torn rotator cuff are compared using three different techniques. The hope was to understand immediate repair strength as it relates to early failures. The goal is to find ways to reduce failures caused by suture failure.
Thirty human shoulders from cadavers were used in this study. All shoulders were free of any rotator cuff tears. The cadavers were matched as closely as possible for age and bone quality. A defect in the supraspinatus tendon of the rotator cuff was then surgically created and repaired.
Repair techniques included Mason-Allen sutures, the knotless anchor method, and the corkscrew suture anchor method. These are all double-row suture techniques. The medial row was always done with two suture anchors. The lateral row used one of the techniques just mentioned. The authors describe the formation and placement of each type of suture.
Cyclic load was then applied to the repairs until 5,000 cycles or failure occurred (whichever came first). Five thousand cycles is equal to 50 loading cycles during daily activities for the first 12 weeks after surgery. This type of biomechanical testing is common in studies of this kind.
Here’s what the researchers found:
longer than the two other methods
lateral (second) row of stitches
The authors concluded that there are major differences in failure rates of double-row rotator cuff repair techniques. These are the methods used most often when performing arthroscopically versus through a mini-open approach.
Immediate repair strength is less using anchor techniques compared with bone tunnel techniques. Failure was more likely to occur where the suture attached to the bone rather than at the tendon. And more tendon versus anchor failures occurred.
These findings suggest a need to improve anchor and suture designs. Reducing the friction between the suture and the anchor and strengthening the suture from repeated rubbing are important goals. Improving surgical techniques may be able to help reduce the failure rate of rotator cuff repairs.