What is a transtibial prosthesis?
A transtibial prosthesis refers to an artificial lower leg that is inserted after the loss of the lower leg due to an accident or transtibial amputation. A transtibial prosthesis belongs to the so-called exoprostheses because it is attached outside the body (in contrast to endoprostheses, such as an artificial heart valve). A lower leg prosthesis is attached below the knee. The prosthesis is intended to replace the function of the missing part of the body as much as possible and enables the affected person to walk again without crutches.
Indications for a transtibial prosthesis
A transtibial prosthesis is inserted after transtibial amputations. A transtibial amputation may be necessary if the leg is irreparably damaged by an illness (e.g. peripheral arterial occlusive disease), a wound or an accident and a further peripheral amputation, e.g. at the ankle, is not possible.
During the operation, the surgeon attempts to create a residual limb with the greatest possible load-bearing capacity using a freely movable knee joint. After the wound has healed, the muscles of the remaining leg are specifically built up using physiotherapy and later a so-called initial prosthesis is made. Only after about half a year is the final prosthesis (definitive prosthesis) made, as the residual limb needs several months to heal completely and take on its final shape.
The definitive prosthesis is much more stable and is also cosmetically covered so that it adapts to the patient’s leg stump. The lower leg prosthesis is made individually for each patient and adapted to their needs. For example, it is possible for the patient to drive a car, jog or swim with the prosthesis.
What types of lower leg prostheses are available?
A distinction is made between several types of lower leg prostheses. Depending on how the prosthesis is attached to the leg stump, a distinction is made between those with a vacuum system, with a closure mechanism or with a two-shaft system. In a prosthesis with a vacuum system, the artificial lower leg is attached to the stump by means of negative pressure (either active or passive).
However, the prosthesis can also be attached by means of a closure mechanism, whereby a distinction is made between the so-called shuttle-lock and clutch-lock technique. Lower leg prostheses can also be classified according to their socket system. The prosthesis shaft connects the leg stump to the lower leg prosthesis and distributes the body weight evenly.
The shaft is attached either by means of an upper sleeve, a clasp technique (PTB prosthesis = patella tendon bearing or PTS prosthesis = tibial supracondylar prosthesis) or a so-called condylar bedding (KBM prosthesis = Münster condylar bedding). Furthermore, a distinction is made between the initial prosthesis, which is used for initial treatment and learning how to handle a prosthesis, and the definitive prosthesis, which is made individually for each patient after about six months. Finally, the classification can also be made according to the type of prosthesis.
In addition to the everyday prosthesis, which is worn by the patient at home, at work and during leisure time, there are also special sports or bathing prostheses. These prostheses must be waterproof or suitable for various sports, such as skiing, jogging or riding. Under special circumstances, it may be necessary to make your own prosthesis only for the workplace.
In addition to a simple lower leg short prosthesis, there are also lower leg prostheses with a femoral shaft (also called upper sleeve or upper shaft). This is a prosthesis which is additionally equipped with a removable femoral shaft. Usually the upper sleeve consists of a leather cuff, which can be attached to the remaining thigh by lacing, straps or a Velcro fastener.
The upper sleeve is mainly used to relieve the knee joint and is used for knee problems or extremely short leg stumps. This type of artificial lower leg is also used as a sports prosthesis. The thigh sleeve stabilizes the knee, thus avoiding increased varus or valgus stress (folding the knee joint outwards or inwards) on the stump. There are also waterproof lower leg prostheses that allow the affected persons to bathe or swim in salt and fresh water.The prostheses can be cosmetically covered so that the lower leg prosthesis looks very natural and is not recognizable as such at first glance. According to the law, every person who has undergone an amputation of the leg is entitled to a waterproof bathing prosthesis in addition to a prosthesis for everyday use.
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