Surgeons continue to look for ways to repair rotator cuff tears (RCTs) that yield better long-term results. Studies have been done of the open repair, mini-open cuff repair, and arthroscopic repair. Results have been compared of short-term, mid-term, and long-term outcomes. Pain relief and improved function are the main measures used.
In this study, the multi-suture technique for rotator cuff repair is compared with open cuff repair. The authors wanted to test the idea that using multiple groups of sutures would disperse the force of the repair.
For a successful rotator cuff repair, the repair site must be stronger than the maximal muscle contraction force. Dividing the force across a larger portion of the rotator cuff tendon might reduce the total force across the rotator cuff crescent.
Three groups of cadavers were used. Cadavers are human bodies preserved after death for study. The surgeons cut a three-centimeter section of the supraspinatus tendon where it attached to the bone. This created an equal RCT in each shoulder.
Group one had the multi-suture method of repair. Three groups of four to five sutures were used to repair the torn cuff. Group two was treated with a three-suture technique. And group three was the control group with a normal rotator cuff. All three groups were equal in terms of age and gender.
A special DEXA scan was done to measure bone mineral density on all specimens. Previous studies have shown that a strong bridge of bone helps decrease the chances of the sutures pulling out of the bone. All cadavers had similar (adequate) density.
A special machine was used to apply an equal load to the rotator cuff tendon. The machine loaded the shoulder for two seconds over 3500 cycles. The load used was equal to two-thirds of the maximal force exerted by the rotator cuff muscles. The number of cycles mimics an average person’s daily activities involving the shoulder.
Results were measured by observing for failure of the cuff repair. A gap at the site of the repair was a sign of failure. A five-millimeter gap was a 50 per cent failure. A 10 mm (or larger) gap was defined as a 100 per cent failure.
The results showed that the multi-suture method is superior to the three-suture technique. A favorable environment for tendon healing is provided by the multi-suture approach. The technique is as strong as a normal rotator cuff tendon and stronger than provided by an open rotator cuff repair.
When failure occurred in the multi-suture group, it was for a variety of reasons. In some cases, the sutures pulled through the bone. In other specimens, the sutures failed at the tendon. In a small number of cases, fracture of the humeral neck occurred during the surgery.
The authors point out that the multi-suture technique is best suited for massive rotator cuff tears. It is not used in routine arthroscopic repairs. A strong enough bridge of bone is needed at the greater tuberosity of the humerus. This gives a stable base for the tunnels that must be drilled through the bone for the sutures to go through.
Finally, with the multi-suture method, the sutures must not be crossed but they should be tied to each other. This helps prevent a decrease in the strength of the repair site.
Using the multi-suture technique gives the patient a fixation strength equal to or greater than an undamaged rotator cuff. This may mean less time immobilized during healing and faster recovery. If the risk of fixation failure can be decreased in this way, the patient will have less shoulder stiffness. Faster return to normal activities and return to work or sports can be expected.