Sometimes tears of the rotator cuff tendon (RCT) are so severe, they can’t be repaired. Trying to bring the two torn ends together puts too much pressure on the tissue.
In this study, researchers from Seoul, Korea report on a way to bridge the gap and obtain complete healing of the RCT. They used the biceps tendon as an interposition repair.
The surgery was done on 31 shoulders with massive, irreparable RCT tears. The same surgeon performed all the surgeries. Half the group had an open procedure with a five-centimeter (two inches) incision. The deltoid muscle was split in half in the process. The other half had arthroscopic surgery. Small puncture holes were made for the scope to pass through the skin into the joint. The deltoid muscle was left intact.
The long head of the biceps tendon was cut close to its attachment at the glenoid labrum. The labrum is a dense ring of fibrous cartilage. It goes around the rim of the acetabulum (shoulder socket) to increase the depth and stability of the shoulder joint.
The surgeon used a suture retriever to reach in and pull the ends of the RCT back together as closely as possible. The biceps tendon was then used as a graft. It was placed between the two torn ends of the RCT and stitched in place (interposition repair).
This bundle of soft tissue was then attached to the bone in a procedure called a tenodesis (tendon-to-bone attachment). Braided sutures and suture anchors were used to hold everything together while it healed.
Everyone in both groups had six-to-eight weeks of rehab. Passive motion was allowed right from the start. Active motion was allowed when the patient had full passive range-of-motion (or six weeks after the surgery). Muscle strengthening exercises were slowly added at six weeks post-op. Any stressful activities or positions weren’t allowed for the first six months.
Results were measured using pain, range-of-motion, and strength. Several tools such as the University of California at Los Angeles (UCLA) score, the Simple shoulder Test (SST), and the Constant Score were used to measure function. A myometer was used to measure muscle strength.
The results showed reduced pain at rest and during exercise in both groups. Improvements in motion and strength were also observed in both groups. Overall, the clinical results between the open and arthroscopic groups were the same.
Magnetic resonance imaging (MRI) was used to assess post-operative tendon healing. The radiologist knew the patients had surgery for a torn RCT. But he did not know the size or location of the repaired RCT tear. There was complete healing in 64 per cent of the arthroscopic group. The remaining patients in the arthroscopic group had partial or complete retears. There was only one case of retear in the open group.
The authors report the 64 per cent rate of success is much better than rates reported in other studies using other repair methods. The advantage of the biceps interposition repair is that the graft serves as an internal splint while healing occurs.
By performing a tenodesis (tendon-to-bone attachment), tension is taken off the repaired (healing) site. At the same time, there is enough tendon-to-bone contact to restore normal biomechanics. This may help prevent re-rupture and a failed surgery. The patient experiences pain relief and does not have any obvious cosmetic deformity.
In summary, the biceps interposition graft for massive rotator cuff tears had good results. The study was not conducted with comparison groups, so it was not possible to say the interposition technique was superior to other methods of repair. More research is needed to identify the best way to assure repair integrity.