What are Upper Extremity Tendon Transfers?
An upper extremity tendon transfer is a surgical procedure to restore the lost functions of the upper extremity or arm (the upper arm, forearm, and hand). The procedure involves transferring a functional muscle-tendon unit (MTU) from its original attachment to the new location to replace a non-functioning MTU in order to restore balance or motion to the arm. Tendons are bands of connective tissue fibers that connect muscle to bone. Tendon transfers involve separating a tendon from muscle and reattaching it to a new site. The tendon is usually obtained from a donor muscle.
There are certain prerequisites for the surgery to be successful, including:
- The muscle attached to the tendon should be functional.
- The soft tissue that will receive the tendon should be functional. Scarring or skin damage makes the process of transfer difficult.
- The joints through which the tendon will pass should be mobile and stable.
- Near or normal motor strength in donor muscle
- Full passive mobility of the joint
Principle of Tendon Transfers
During a tendon transfer surgical procedure, the muscle’s origin, its nerve supply, and blood supply are kept intact but the tendon is detached from its place of insertion (attachment) on the bone and sutured back into a different bone or tendon. After the tendon is transferred, when a muscle contracts it will produce a new action depending on its place of insertion.
Upper extremity movements that can be restored using tendon transfer surgery include:
- Wrist extension
- Elbow extension
- Finger flexion
- Thumb flexion
It should be noted that each tendon transfer can only replace one movement and sufficient donor muscles are required to power multiple non-functioning MTU’s in the arm, such as the wrist and/or hand, to improve function.
Indications for Upper Extremity Tendon Transfer Surgery
Tendon transfer surgery is effective in the restoration of upper limb function for patients with several indications, including:
- Tendon transfer surgery is done to restore certain functions that are lost as a result of nerve injury. Some of the common nerve injuries that can be treated with tendon transfer surgery include spinal cord, peripheral nerve, radial nerve, ulnar nerve, or median nerve injury.
- Muscle and tendon injuries such as tendon ruptures due to rheumatoid arthritis or fractures, irreparable muscle and tendon lacerations.
- Nervous system disorders such as cerebral palsy, stroke, traumatic brain injuries, and spine muscle atrophy.
- Congenital conditions such as hypoplastic thumbs and birth brachial plexopathy (paralyzed nerves) in which certain muscle functions are absent can be treated with tendon transfer surgery.
- Persistent pain and upper extremity dysfunction with limitations in elevation and external rotation.
- Young, active, and motivated patient who is amenable to intensive physical therapy and postoperative immobilization along with a full passive range of motion.
- Failed conservative treatment
Preparation for Upper Extremity Tendon Transfer Surgery
Preparation for upper extremity tendon transfer surgery may involve the following steps:
- A review of your medical history and a physical examination are performed to check for any medical issues that need to be addressed prior to surgery.
- Depending on your medical history, social history, and age, you may need to undergo tests such as blood work and imaging to help detect any abnormalities that could compromise the safety of the procedure.
- You will be asked if you have allergies to medications, anesthesia, or latex.
- You should inform your doctor of any medications or supplements you are taking or any conditions you have such as heart or lung disease.
- You may be asked to stop taking blood-thinners, anti-inflammatories, aspirin, or other supplements for a week or two.
- You should refrain from alcohol and tobacco at least a few days prior to surgery and several weeks after, as it can hinder the healing process.
- You should not consume any solids or liquids at least 8 hours prior to surgery.
- You should arrange for someone to drive you home after surgery.
- A signed informed consent form will be obtained from you after the pros and cons of the surgery have been explained.
Procedure for Upper Extremity Tendon Transfer
Upper extremity tendon transfer surgery may involve any part of the affected arm, including the wrist, hand, elbow, and humerus. Tendon transfer surgery is usually performed under general anesthesia. An incision is made along the section of the affected upper extremity and the damaged tendon is exposed and removed. A healthy tendon is identified, cut at its normal insertion, rerouted through the soft tissues and bones, and then sutured to another bone in the arm. A tunnel may be drilled to allow the tendon to pass through and then sewn on itself, fastened with a metal or plastic screw, or attached with anchor sutures. A tendon transfer may or may not be performed in combination with selected nerve transfers. In addition to the tendon transfer, you may also require additional small surgical procedures to your upper extremity to maximize the benefits of your tendon transfer. Finally, after confirming satisfactory repair, the soft tissues and incision are closed. The success of the procedure will depend upon the strength of the donor muscles, the overall strength of other arm muscles, the flexibility of your joints, your general health, and your involvement in exercises/therapy.
Post-Operative Care and Recovery
In general, postoperative care and recovery after upper extremity tendon transfers will involve the following steps:
- You will be transferred to the recovery area where your nurse will closely observe you for any allergic/anesthetic reactions and monitor your vital signs while you recover. Most patients require two to three nights of hospital stay following surgery.
- Following the surgery, your arm will be placed in a supportive sling, brace, or splint for a specified period to rest the arm and promote healing.
- You may experience pain, swelling, and discomfort in the operated area. Pain and anti-inflammatory medications are provided as needed to address these.
- You may also apply ice packs on the area to help reduce swelling, pain, and additional comfort.
- Instructions on incision site care and bathing will be provided to keep the wound clean and dry.
- Usually, a tendon transfer surgery will require a period of 1-2 months to heal completely. After the tendon transfer has healed, your surgeon will recommend physical therapy for strengthening muscles and improving range of motion.
- It is important to take care that you do not start movements too early as it may cause rupture of the tendon transfer and at the same time do not delay the movements. Delayed movement can lead to scarring of the tendon and stiffness.
- Strict adherence to prescribed medications, diet, incision site care, and follow-up instructions are strongly advised for a successful recovery.
Risks and Complications
As with all surgeries, upper extremity tendon transfer surgery may be associated with certain complications, such as:
- Infection
- Adverse reactions to anesthesia
- Allergic reactions
- Bleeding
- Clot formation
- Damage to adjacent blood vessels and nerves
- Non-healing, rupture, or loosening of the tendon
- Need for further surgery
