Tendon transfers are a newer treatment for irreparable rotator cuff tears. They’re a less-common treatment, but are becoming a useful tool in the armamentarium for orthopedic shoulder surgeons.
The rotator cuff is made up of four muscles and four tendons, which are there to hold the humeral head into its very vertical and otherwise unstable socket and to initiate motion in the first 45 degrees in every direction.
In a rotator cuff tear, the rotator cuff tendon has torn off the bone or has torn right before it attaches to the bone. It can cause pain, weakness or a combination of both.
Rotator cuff tears can be the result of trauma such as dislocating your shoulder; a repetitive overuse injury; chronic shoulder instability; or wear and tear. There is some genetics involved: if your parents had rotator cuff tears without having trauma, you’re more likely to have issues as well.
Not everyone who has a rotator cuff tear needs to be fixed. If someone has no pain or weakness, they don’t need treatment.
How Rotator Cuffs Are Repaired
More and more, surgeons are leaning toward arthroscopic repairs done with tiny incisions, a camera and arthroscopic tools to place small anchors in the bone and repair the torn tendon back down to the bone. It’s more like farming than carpentry. We’re trying to induce the body to heal the tendon back down to the bone. After surgery, most people are in a sling for six or more weeks so that the rotator cuff tissue heals back down to the bone.
Repairing the tissue down to the bone relies on several things.
- Good enough tissue to bring back down to the bone.
- Tissue strong enough for the suture material to grab it.
- The body’s ability to heal the tissue down to the bone.
If you don’t have good tissue or it’s so contracted that it’s not able to be brought back down to the bone, the traditional repair won’t work well.
In those cases, there are a few options:
- Debride those painful tissues through a scope or in an open manner.
- Do a superior capsular reconstruction, which provides a bumper between the humeral head (top of the ball) and the underside of the acromion, the little bone on the top of the shoulder.
- Do a tuberoplasty, which is similar to the superior capsular reconstruction and puts a bumper in place between the humeral head and acromion.
- Do a reverse shoulder replacement.
- Do a tendon transfer.
Tendon Transfers for Rotator Cuff Repairs
Who are tendon transfers for?
Tendon transfers are beneficial for those patients who are too functionally active and too young for a reverse shoulder replacement. Reverse shoulder replacements were developed for patients who had poor functioning rotator cuff pathology. They work very well and are one of the biggest and most powerful tools the shoulder surgeons have in their armamentarium for restoring patient function, but they carry some restrictions like a lifetime 30-pound weight limit. Like other joint replacements, they include restrictions so you don’t dislocate your shoulder, and they can wear out over time.
Tendon transfers were developed to help patients who are young, who have irreparable rotator cuff tears and who need to be highly functional: somebody who needs to swing a hammer for a living, somebody who needs to carry their kids or grandkids, or just somebody who is very active and needs to lift more than that 30-pound weight limit.
How do tendon transfers work?
Muscles move bones. A muscle has to cross a joint in order to move that joint. In many ways, human bodies are overengineered. More than 70 years ago, hand surgeons realized that in patients who had nerve problems, traumatic injuries or muscle problems, they could borrow some muscle-tendon units and move that tendon slightly to restore function that had been lost.
It sounds scarier than it is. Tendon transfers are a technique that has been done in the hand, forearm and foot for more than 70 years. In the world of orthopedics, it’s very, very common. In the world of shoulder surgery in adults it’s less common but is taking off rapidly because patients are doing so well.
Who is a tendon transfer for?
It’s for people who have recurrent rotator cuff tears or muscles that don’t really work for multiple reasons, including from nerve compression and previous infection.
If you have very bad arthritis, an active infection, or are unable or unwilling to follow the post-operative restrictions, you cannot have a tendon transfer.
Types of Tendon Transfer
There are two muscle-tendon units that we use to restore function that’s lost in the rotator cuff that does not result in dysfunction for the rest of the shoulder.
Latissimus Dorsi Tendon Transfer
The first of the two workhorses is the latissimus dorsi, the muscle that people who are doing lat pull downs and pull ups are trying to make. It’s a very powerful internal rotator. We have a lot of internal rotators for the shoulder to turn your arm in, but the only external rotators are the rotator cuff muscles. If you’ve torn all of your rotator cuff muscles, you can have strong internal rotation but nothing to bring the arm out. We can move the latissimus dorsi to the outside of the arm to help recreate that.
The latissimus dorsi can be moved higher up or just moved to the outside of the humerus and become an external rotator instead of an internal rotator. After the surgery, it’s easy to learn how to use it with physical therapy.
A recent study looking at 70 patients with latissimus dorsi transfers showed that all patients had an improvement in their shoulder scores, a decrease in their pain, an increase in their forward flexion, and an increase in their external range of motion.
Lower One-Third Trapezius Transfer
The second common method is the lower one-third trapezius transfer, which can be very useful in a massive non-repairable rotator cuff tear, including tears of the supraspinatus, which is on top; the infraspinatus, on top but toward the back; or the teres minor, on the backside of the humerus. This type of tendon transfer can help restore both external rotation and forward flexion.
A study in the Journal of Shoulder and Elbow a couple of years ago looked at 33 patients with lower one-third trapezius transfers. All of the patients improved in their subjective shoulder value, a rating a patient gives of their shoulder’s use from 0% to 100%; DASH score, a measure of the function of daily living; shoulder range of motion; forward flexion; and external range of motion.
The lower third of the trapezius is on the back and is in the same line of pull as the other rotator cuff tendons, so it works well as a tendon transfer. Since it is already on the back and in line with the rotator cuff muscles, there is almost no education needed from a therapy standpoint for you to use the muscle after it is transferred.
The tendon is harvested in an open procedure and lengthened using an allograft, which is donated tissue, and then the procedure becomes arthroscopic. The tendon is inserted into place using the same type of bone anchors used for regular rotator cuff surgery.
Summary
Tendon transfers are a good option for restoring the function of rotator cuff tissue in the setting of irreparable tears. They’re not for patients who have infection, bad arthritis or those who can’t follow the post-operative therapy protocols. They’re becoming more common as a tool to restore shoulder function and may provide a benefit for patients who have an irreparable rotator cuff tear but who are not yet ready for a reverse shoulder replacement.
Frequently asked questions
Does it matter if the tear occurred recently?
Tissue quality matters, not when the tear occurred. Oftentimes we can tell the tissue quality on the MRI scan ahead of time. Sometimes the plan with a patient will be to repair the rotator cuff, but if the tissue may not hold the anchors the preoperative plan may change to a tendon transfer.
How long does it take for the tendon to heal after the tendon transfer?
The bench science tells us that it takes six to eight weeks for tendon-to-bone healing to start, which is why people are placed in an immobilizer or sling for six to eight weeks after surgery. Then the tendon-to-bone healing has to become oriented in a way that is meaningful and provides strength to the repair, which is why after the time in the sling, the next six to eight weeks are spent working on gentle range of motion and then strengthening.
How are the donated tissues used?
Donated cadaver tissue is treated before surgery so that the cells that made up the tissue are gone, so there’s no transmission of any kind of disease nor any way to have symptoms of graft vs host. The material that is used is the matrix or the building blocks of that tendinous material to give your cells a place to join on, to migrate new cells into it and replace and rebuild it.
Is there an age limit on having a tendon transfer?
No, there is not. During my fellowship one patient I had for this procedure was three years old. The oldest patient I’ve had for a tendon transfer was 92.
Might it tear again after a tendon transfer?
Absolutely. If we do something silly or have another accident, it can break again. However, tendon transfers are pretty robust. The tendon material that we use to extend the length of the tendons is primarily an Achilles tendon allograft, which is a very thick tissue. I have not personally had a tendon transfer fail, but it’s certainly possible and I will never say never.
If somebody has a second rotator cuff tear in the same shoulder is a tendon transfer an option or does it have to be a reverse shoulder replacement?
It depends on the degree of arthritis. In grades one, two and maybe three, tendon transfer is a viable possibility with a long conversation with your surgeon. If you have grade four arthritis, and changes around the joint that are significant with end stage arthritis, doing a tendon transfer without resurfacing that joint with a reverse shoulder replacement would be ill advised.
Do the tendon grafts always come from donated material or do they sometimes come from elsewhere in your body?
For this type of tendon transfer, they always come from donated material. In ACL reconstruction, we have several types of autografts that can be used, which are tendons that come from our body: hamstring, patella tendon, quadriceps tendon. These grafts are not big enough for the tendon transfers in and around the shoulder. Instead, we use allograft, which is donated material. Additionally, the allograft that is used is an Achilles tendon allograft, which is a large, thick tendon. You can’t have your own Achilles tendon removed or you would struggle to walk. Nobody has made a synthetic version that is workable at this point in time.