A tendon transfer is a surgical process in which the
insertion of a
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
is moved, but the
origin
Origin(s) or The Origin may refer to:
Arts, entertainment, and media
Comics and manga
* Origin (comics), ''Origin'' (comics), a Wolverine comic book mini-series published by Marvel Comics in 2002
* The Origin (Buffy comic), ''The Origin'' (Bu ...
remains in the same location. Tendon transfer involves redistribution of muscle power, not recreation. Tendons are transferred at the distal attachment from lesser to more important functions so that the overall function is improved. Tendon transfers provide a substitute which can be permanent or temporary, when muscle function is lost either due to nerve injuries or injuries to the muscle/tendon unit. Tendon transfers are also performed to correct the imbalanced muscle tone due to
spasticity
Spasticity () is a feature of altered skeletal muscle performance with a combination of paralysis, increased tendon reflex activity, and hypertonia. It is also colloquially referred to as an unusual "tightness", stiffness, or "pull" of muscles.
...
resulting from injuries to the
central nervous system
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...
.
Principles
Preoperative evaluation of the patient is required to map out functional deficits, and determine which muscles are available for transfer. Time from injury, type of injury, and success of previous treatment should also be taken into account.
Electrodiagnostic
Electrodiagnosis (EDX) is a method of medical diagnosis that obtains information about diseases by passively recording the electrical activity of body parts (that is, their natural electrophysiology) or by measuring their response to external elect ...
studies may be useful in determining the extent of motor loss and predicting the muscle recovery. It may also be useful to detect abnormal nerve pattern such as median-to-ulnar nerve anastomosis, which may influence the choice of transfer.
The donor muscle must have enough strength (work capacity) to duplicate the recipient function. The work capacity depends upon muscle fibre's length and cross sectional area, which are proportional to muscle mass and volume. In other words, a larger muscle produces more force and a longer muscle has a greater excursion. There are potential factors that may result in loss of muscle strength including postoperative adhesion, difference in vector of motion.
The donor tendon must also be expendable. In other words, it must not result in functional deficit after transfer. The remaining muscles must have enough level of strength to account for the loss of the original function of the donor muscle. Transfers can generally be classified into either power or positional transfers. Power transfers are done to perform motion, and therefore requires relatively more powerful donor muscles. Positional transfers, on the other hand, do not require powerful donors. The strength of the antagonist muscle should be similar to the donor to avoid overcorrection and to maintain correct posture.
Tendon excursion, or distance a tendon travels upon movement, should be similar to that of the recipient to adequately restore the function.
Any transfer of a tendon for another function will generally lose one
grade of power. For example, M4 muscle power grade will become M3.
A single tendon should be used to restore a single function. Transfer of one tendon to restore multiple functions will compromise strength and movement.
Medical uses
These are examples of commonly performed tendon transfers.
History
Many of the lower extremity tendon transfers were performed during the nineteenth century to improve ambulation in
polio
Poliomyelitis, commonly shortened to polio, is an infectious disease caused by the poliovirus. Approximately 70% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe s ...
patients due to post-poliomyelitis paralysis. In the beginning o twentieth century, tendon transfers were used to correct congenital
talipes equina. Tendon transfers were extensively performed during World Wars I and II to patients with upper extremity injuries.
References
{{Muscle and soft tissue procedures
Orthopedic surgical procedures