Muscle Transplantation: Specialists & Information

A muscle transplant is a treatment option in reconstructive surgery. It is also referred to as a muscle transfer. During the procedure, muscles are rerouted to stabilize a joint, or donor muscles are implanted. The procedure is a type of motor replacement surgery and is frequently used in shoulder surgery following severe muscle injuries. 

Muscle transplantation is intended to reduce pain and improve joint function. It is a relatively complex procedure and is indicated only when other treatments have not been successful.

For a muscle transfer to be successful, the rerouted muscle must be long enough and well-perfused.

The origins of muscle transplantation lie in surgical procedures involving the latissimus dorsi muscle due to significant defects in the rotator cuff of the shoulder joint. In this context, muscle transplantation offers significant advantages. Consequently, it has been used successfully and increasingly in this setting since 1988.

Due to its large surface area, this muscle allows for sufficient mobility during the transfer. The healing of the transferred tendon is also relatively unproblematic.

Eight muscles are primarily responsible for the stability and function of the shoulder joint. They must work together precisely so that the shoulder is fully functional.

With the exception of the latissimus dorsi muscle, all muscles of the shoulder joint originate at the shoulder girdle. Each shoulder muscle is responsible for a specific movement. The four muscles closest to the joint form the rotator cuff.

If one of these muscles does not function properly, the entire joint becomes less mobile and unstable. A muscle transfer is not always necessary, but in severe cases, it may be the only option.

Most tears in the shoulder muscles are caused by wear and tear. The age-related, chronically narrowed space under the acromion, as well as genetically poor-quality tendon and muscle tissue, contribute to such muscle tears.

Over time, the tendons and muscles slowly deteriorate, and the defects become increasingly larger. Falls onto the arm and shoulder or one-sided strain in throwing athletes also contribute to muscle tears. These tears require both a donor muscle and a donor nerve.

In such severe cases, defects in the shoulder’s rotator cuff can no longer be repaired with sutures. In these instances, a muscle transplant can generally restore shoulder function effectively. 

Muscle transplantation is performed when the torn tendon and the affected muscle have retracted to such an extent that fixation to the humeral head is no longer possible.

In some cases, it may be helpful to relocate a muscle to a different site © adimas | AdobeStock

Ideally, the surgeons should specialize in

• shoulder and elbow surgery,
• hand surgery, and
• sports traumatology

.

As a rule,

• trauma surgeons,
• orthopedic surgeons, and
• sports medicine physicians with surgical training

perform such surgeries. These procedures are often performed at specialized orthopedic clinics and university hospitals with surgical centers.

Plastic surgeons also specialize in the microsurgical reconstruction of lesions in peripheral nerves. This enables them to perform muscle and tendon transfers as well.

Two surgical methods for joint centering are standard:

• the L’Episcopo method and
• the Herzberg transfer.

Both methods achieve good functional results.

During the procedure, the patient usually lies on their side, though the surgery can also be performed with the patient in a reclining position. In the first step, performed on the upper part of the shoulder, the surgeon exposes the rotator cuff and checks whether any defects can be repaired. If this is still possible, a muscle transplant is unnecessary.

If not, the surgeon makes a second incision on the back of the shoulder and transposes the latissimus dorsi muscle.

This surgery is also increasingly being performed with endoscopic assistance. Because this approach minimizes tissue trauma, the burden on the patient is significantly reduced.

The back muscle transfer (latissimus dorsi transfer)

Only severe defects of the rotator cuff warrant such a major operation.

The surgeon detaches the latissimus dorsi muscle from the back of the upper arm and transplants it, along with its tendon, to the back of the humeral head. In this way, the surgeon closes defects in the rotator cuff.

Instead of its previous role as an internal rotator, the muscle now functions as an external rotator.

The pectoralis major transfer

In this procedure, the pectoralis major muscle is transferred. This shoulder surgery is performed for orthopedic reasons, not plastic surgery reasons.

A prerequisite for this surgery is that

• mobility of the shoulder joint is significantly restricted and
• a standard suture cannot repair the defect in the rotator cuff.

If the serratus anterior muscle is paralyzed, this also indicates the need for a pectoralis major transfer. This muscle is located on the lateral wall of the chest and is often damaged in accidents or by tumors. Affected individuals can no longer extend their arms properly or can do so only with severe pain, nor can they perform boxing movements.

During the operation, portions of the pectoralis major are detached and pulled backward along the chest wall through the armpit. The surgeon then attaches the muscle to the outer edge of the scapula.

Free Functional Muscle Transfer (FFMT)

A free functional muscle transfer (FFMT) may be necessary if

• there is no donor muscle available for the transfer, or
• restoration of nerve supply is no longer possible.

The following muscles are suitable for such a muscle transfer:

• the gracilis muscle, located on the medial side of the thigh,
• the large back muscle, the latissimus dorsi, and
• the rectus femoris muscle, located at the front of the thigh.

The optimal selection of the donor nerve is also important for the success of the surgery and the postoperative recovery process.

As with any surgery, there are risks associated with anesthesia and wound healing. These include

• thrombosis,
• bleeding,
• infections,
• nerve and vascular damage, or
• embolisms.

The transplanted tendon may also tear or fail to heal properly. This risk is particularly high if the shoulder is subjected to premature or improper stress.

The treating physician supports the patient from the preparation for the procedure through to comprehensive follow-up care. 

It is standard practice to immobilize the shoulder for six weeks with a splint or cast, followed by physical therapy.

Passive physical therapy exercises are recommended as early as one to two weeks after surgery. This is followed by a phase of active exercises, as the muscle must learn its new functions.

After about twelve weeks, patients can resume normal daily activities. Sports that place strain on the pectoral muscle should not be resumed until four to six months have passed.

Recovery takes several months and always depends on the individual’s specific situation.