Percutaneous Achilles Tendon Lengthening

Indications

A Percutaneous TendoAchilles lengthening (PTAL) is a procedure that lengthens the Achilles tendon. This lengthening is needed if the ankle joint has limited motion in an upward direction (for example the person can easily walk on the toes, but not on the heels). A shortened or tight calf muscle is called an equinus contracture, and the lengthening surgery improves the ability for the ankle to move upwards (dorsiflexion). This may be indicated in children with an equinus contracture (inability to fully bring the foot upwards) such as may occur in clubfoot deformity. It also may be indicated in adults who have a flatfoot deformity, a contracture due to stroke, or have diabetic foot issues which have caused an equinus contracture.

Procedure

A percutaneous Achilles tendon lengthening is performed in the operating room or other designated procedure setting. The procedure is not lengthy, and is done through a series of small incisions over the Achilles tendon, at the back of the lower leg. Typically, the three-incision technique described by Hoke in the 1930’s is used. In this procedure, the Achilles is identified, and, using the first small incision (often called a “stab” incision) the tendon is cut part way through. The first incision is made close to where the tendon inserts into the heel bone (Calcaneus). The cut is done in such a way that the scalpel is taken through the skin and half of the tendon is cut – usually the inside (medial) half. The second incision is then made one half to one inch (1-2cm) further up the leg. Again, half of the Achilles is cut but in this case the opposite half of what was previously cut; usually the outside (lateral) half. A third incision is then made still further up the leg, usually one-half to one inch (1-2cm) from the second incision. This third incision releases the inner half of the tendon. After half of the tendon has been cut in each of these three spots, gentle pressure is applied to the foot. This allows the fibers of the cut areas of tendon to slide over each other and the Achilles tendon is gently lengthened. At this point, the incisions are closed and the patient is immobilized with the ankle joint in a neutral angle (right angle) position.

Recovery

The cut Achilles tendon does need to heal. In adults, this typically requires six weeks of relative immobilization in a cast, boot, or splint. Partial weight-bearing is often possible early on. This is often followed by another six weeks of gradual increasing of activity. The actual recovery may be dictated more by the other procedures that are often done in addition to the Achilles lengthening.

Patients may experience an aching or cramping of the calf muscle for a few days after surgery. The incision sites may be tender initially, but heal quickly.

Potential Complications

General Complications

Like other operative procedures, there are general complications that may occur when a percutaneous Achilles lengthening is performed. In children, the complications are generally much less severe, but can still occur. Fortunately, because of the small incisions, these complications are relatively uncommon but may include:

Specific Complications

Complications that are specific to this procedure include:

Rupture of the Achilles tendon. When performing a percutaneous Achilles lengthening, it is quite possible to over-lengthen or rupture the Achilles during the surgery. This may require a more definitive open surgical assessment of the Achilles tendon, or may lead to a longer period of casting/bracing and specific exercises to promote healing of the tendon at the desired length.
Sural Neuritis. A sural nerve injury may also occur. This nerve runs on the outer side of the lower leg, and can be accidentally injured during one of the incisions. If this nerve is cut or injured, there may be numbness on the outside of the foot and/or some burning-type pain at the site of the nerve injury.
Postoperative swelling. The surgery causes some weakness of the calf muscle. The muscle usually “pumps” fluid up the leg. This can be short-lived, or last for several months.
Calf weakness. The lengthened tendon means that the calf muscle may work differently, or the new position of the foot may feel awkward or weak when walking up stairs or ladders, or if attempting to jump, sprint or stand on the toes.

Edited July 3, 2017

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