Tenotomy is the cutting of a tendon. This and related procedures are also called tendon release, tendon lengthening, and heel-cord release (for tenotomy of the Achilles tendon).
Purpose
Tenotomy is performed in order to lengthen a muscle that has developed improperly, or become shortened and is resistant to stretch.
Club foot is a common developmental deformity in which the foot is turned inward, with shortening of one or more of the muscles controlling the foot and possibly some bone deformity as well.
A muscle can become shortened and resistant to stretch when it remains in a shortened position for many months. When this occurs, the tendon that attaches muscle to bone can shorten, and the muscle itself can develop fibrous tissue within it, preventing it from stretching to its full range of motion. This combination of changes is called contracture.
Contracture commonly occurs in upper motor neuron syndrome following spinal cord injury; traumatic brain injury; stroke; multiple sclerosis; or cerebral palsy. Damage to the nerves controlling muscles lead to an imbalance of opposing muscle forces across a joint, which may allow one muscle to pull harder than another. For instance, excess pull from the biceps, unless opposed by the triceps, can bend the elbow joint. If the shortened bicep remains in this position, it will develop contracture, becoming resistant to stretching. Tenotomy is performed to lengthen the tendon, allowing the muscle to return to its normal length and allowing the joint to straighten.
When one muscle pulls much more strongly than its opposing muscle, it may cause the joint to become partially dislocated, which is called subluxation. Tenotomy is also performed to prevent or correct subluxation, especially of the hip joint in cerebral palsy.
Chronic pain or bone deformity may prevent a person from moving a joint through its full range of motion, leading to contracture.
Contracture also occurs in a variety of neuromuscular diseases, including muscular dystrophies and polio. Degeneration of one muscle can allow the opposing muscle to pull too hard across the joint, shortening the muscle.
Demographics
Tenotomy is performed in infants with clubfoot, and in older patients who develop contractures or subluxations from neuromuscular disease, the upper motor neuron syndrome, or other disorders.
Description
During a tenotomy, the tendon is cut entirely or partway through, allowing the muscle to be stretched. Tenotomy may be performed through the skin (percutaneous tenotomy) or by surgically exposing the tendon (open tenotomy). The details of the operation differ for each tendon.
During a percutaneous lengthening of the Achilles tendon, a thin blade is inserted through the skin to partially sever the tendon in two or more places. This procedure is called a Z-plasty, and is very rapid, requiring only a few minutes. It may be performed under local anesthesia.
More severe contracture may be treated with an open procedure. In this case, the tendon may be cut lengthwise, and the two pieces joined lengthwise to form a single longer tendon. This procedure takes approximately half an hour. This type of tenotomy is usually performed under general anesthesia.
If multiple joints are to be treated (for example, ankle, knee, and hip), these are often performed at the same time.
Diagnosis/Preparation
Patients requiring tenotomy are those with contracture or developmental deformityleading to muscle shortening that has not responded sufficiently to treatment with casts, splints, stretching exercises, or medication. Tests performed before surgery include determining the range of motion of the joint involved, and possibly x rays to determine if there is a bone deformity impeding movement or subluxation.
Patients undergoing general anesthesia will probably be instructed not to eat anything for up to 12 hours before the procedure.
Aftercare
After tenotomy, the patient may receive pain medication. This may range from over-the-counter aspirin to intravenous morphine, depending on the severity of the pain. Ice packs may also be applied. The patient will usually spend the night in the hospital, especially children with swallowing or seizure disorders, who need to be monitored closely after anesthesia.
Casts are applied to the limb receiving the surgery. Before the cast is applied, the contracted muscle is stretched to its normal or near-normal extension. The cast then holds it in that position while the tendon regrows at its extended length. Braces or splints may also be applied.
After the casts come off (typically two to three weeks), intensive physical therapy is prescribed to strengthen the muscle and keep it stretched out.
Risks
Tenotomy carries a small risk of excess bleeding and infection. Tenotomy performed under general anesthesia carries additional risks associated with the anesthesia itself.
Normal results
Tenotomy allows the muscle to stretch out, proving more complete range of motion to the affected joint. This promotes better posture and movement; and may improve the ability to walk, stand, reach, or perform other activities, depending on the location of the procedure. Pain may be reduced as well. Club foot is usually completely fixed by proper treatment. Contracture and subluxation may be only partially remedied, depending on the degree of muscle shortening and fibrotic changes within the muscle before the procedure.
Morbidity and mortality rates
Properly performed, tenotomy does not carry the risk of mortality. It may cause temporary pain and bleeding, but these are usually easily managed.
Alternatives
Tenotomy is usually recommended only after other treatments have failed, or when the rate and severity of contracture or subluxation progression indicates no other more conservative treatment is likely to be effective. Aggressive stretching programs can sometimes prevent or delay development of contracture.
