Transtibial & Symes Amputation & Rotationplasty
Dynamic Response Foot
The dynamic response foot provides energy storage and return for active amputees (K3, K4). This foot is often prescribed for active amputees who walk greater distances or run.
External Suspension Sleeve
The external suspension sleeve is for transtibial (below knee) amputees. The sleeve is made of elastic fabric, silicone, or a combination of the two that extends from the socket of the prosthesis onto the patient’s thigh. The sleeve can be used alone or in conjunction with another form of suspension to keep the prosthesis attached to the patient’s body.
Joints and Thigh Corset Suspension
The joints and thigh corset suspension is used by transtibial (below knee) amputees. It is a combination of metal joints that extends from the medial and lateral (sides) surfaces of the socket and attaches to a leather corset worn around the thigh. This combination is designed to provide maximum mediolateral (side to side) stability and to share weight bearing with the thigh. This is one of the original suspension designs and is used today by patients who have very short residual limbs or who experience poor control of the knee during ambulation.
Multi Axis Foot
The multi axis foot provides inversion, eversion and rotation at the ankle of the prosthesis. This type of foot is typically prescribed for active prosthetic patients (K3, K4) who need to traverse uneven surfaces.
The multi-durometer insert is made of two types of material. (Durometer is a way of measuring the hardness of a material.) Usually the material next to the patient’s skin is made of a soft durometer to cushion the residual limb. The outer layer is a firm durometer material that makes the liner more durable for normal wear and tear. This style of insert is used by patients who require a soft insert because of their tissue type, but need durability for their activity level.
Patellar Tendon Bearing Socket
The patellar tendon bearing (PTB) socket is a transtibial (below knee) socket design in which the weight bearing of the prosthesis is not evenly distributed on all surfaces of the residual limb. In this style, weight bearing is primarily on soft tissue or pressure tolerant areas, such as the patellar tendon and muscle tissue. It is designed to eliminate pressure on sensitive areas of the limb, such as the tibial and fibular remnants (shin bones).
A Pelite insert is a removable dense foam insert in the socket of the prosthesis. It is worn over prosthetic socks and is sometimes used in conjunction with another insert. Its function is to protect the patient’s limb and to allow for modifications to the fit of the prosthesis due to fluctuation in the volume of the residual limb.
Rigid Dressing (Pylon Cast)
A rigid dressing or pylon cast is applied to an amputated limb 4-5 days after surgery. This is a non-removable dressing used to protect the residual limb and control edema (swelling). When this dressing is applied following a transtibial amputation (below the knee), it is often made of plaster and held in place with an elastic strap and a waist belt. Depending on the mobility of the patient, the cast may have a prosthetic foot attached to it. Then it is called a pylon cast. This allows patients to bear a small amount of weight on the amputated limb and begin gait training. A patient will typically be in this type of cast for 4-6 weeks.
A rotationplasty procedure is a limb salvage/function salvage technique. This is a surgical procedure that is usually performed on children who have developed osteosarcomas in or near the knee. This procedure removes the infected segments of bone, but allows the healthy lower leg and foot to be rotated 180 degrees and then reattached to the femur (thigh bone). This, in effect, creates a knee joint from the patient’s ankle.
The SACH foot is typically provided to amputees who most often walk at single speeds and on even surfaces (K1, K2). This foot is also used for new amputees while they are learning to use a prosthesis. It provides stability and a smooth transition from heel to toe during a normal gait cycle.
Silicone inserts are used for comfort, skin protection, and/or suspension of the prosthesis on the patient’s limb. These are worn inside the socket of the prosthesis next to the patient’s skin. When silicone inserts are used for suspension, a suspension locking mechanism is necessary to attach the patient’s limb to the prosthesis.
Single Axis Foot
The single axis prosthetic foot has a movable ankle joint. This joint allows the patient to reach foot flat quickly, thus increasing stability. This foot is often prescribed for above knee amputees and patients who require greater stability (K1, K2).
Supracondylar Cuff Suspension
Supracondylar cuff suspension is designed to work with transtibial (below knee) prostheses. In this design, a leather strap encompasses the patient’s thigh just proximal (above) to the femoral condyles (wide boney parts of the knee) and the patella (knee cap). It then attaches to the medial and lateral (sides) surfaces of the prosthesis. This is one of the original suspension styles for transtibial (below knee) amputees. Today this technique is primarily used for patients who have experienced difficulty with, or cannot tolerate, other forms of suspension.
The supracondylar socket design is a suspension option for transtibial (below knee) amputees. A dense foam insert is worn inside the prosthetic socket. This insert is fabricated with a wedge that creates purchase over the medial femoral condyles (wide boney parts of the knee) to suspend the prosthesis on the patient’s body. This combination provides mediolateral (side-to-side) stability and is indicated for patients with shorter residual limbs or weak musculature.
The suprapatellar socket design is an option for transtibial (below knee) amputees. It offers extra stability mediolaterally (side-to-side) and anterior-posteriorly (front to back). The socket of the prosthesis extends above the patella (knee cap) on the anterior and lateral surfaces (front and sides) of the patient’s knee. This design is used for patients with short residual limbs or weak musculature.
Suspension Locking Mechanism: Attachment Pin & Lock Body for Lower Extremity
Suspension locking mechanism is a term used to describe the way the prosthesis will be attached to the patient’s residual limb. The two most commonly used types of suspension locking mechanism are the attachment pin and lock body, and the lanyard strap. The attachment pin and lock body method is often used by transtibial (below knee) amputees. A pin is attached to the distal (bottom) end of a silicone or urethane insert. As the patient dons (puts on) the prosthesis, the pin is inserted into a lock in the bottom of the prosthetic socket. The prosthesis is removed from the patient’s body by pushing a button on the outside of the socket to release the lock.
Suspension Locking Mechanism: Lanyard Strap for Lower Extremity
Suspension locking mechanism is a term used to describe the way the prosthesis will be attached to the patient’s residual limb. The two most commonly used types of suspension locking mechanism are the attachment pin and lock body, and the lanyard strap. The lanyard strap method is often used with transfemoral (above knee) prostheses. The lanyard is attached to the distal (bottom) end of a silicone or urethane insert. As the patient dons (puts on) the prosthesis, the lanyard is fed through a hole in the bottom of the prosthetic socket, through a buckle on the anterior (front) surface, and secured in place with Velcro.
A Syme amputation is an ankle disarticulation surgery in which the tibia and fibula (shin bones) are separated from the talus (ankle bone). The foot and ankle are then removed from the body. Because this surgery does not cut through the bones, most patients will have end bearing capabilities.
The Syme prosthesis is worn by patients who have undergone ankle disarticulation surgery. This socket uses the principles of the PTB socket, but the patient usually can tolerate some end bearing. Patients with a Syme amputation typically have a bulbous distal end shape (the limb is larger around at the bottom than in the middle). In this design, special modifications must be made to don and doff (put on and take off) the prosthesis. This can be accomplished by using a soft insert or by creating an opening in the medial (side) or posterior (back) wall of the socket.
Total Surface Bearing Socket
In the total surface bearing socket design, the entire residual limb shares the pressure and weight bearing of the prosthesis as evenly as possible.
The transtibial (below knee) amputation is a surgical procedure in which a portion of the tibia and fibula (shin bones) is cut and removed from the body along with the foot.
Transtibial Rigid Removable Dressing (Protector)
The transtibial (below knee) rigid removable dressing (or protector) is typically applied after the rigid dressings (pylon casts). A patient will usually start using this dressing about 5-7 weeks after surgery. The incision line is covered with non-stick gauze and a nylon sheath is applied to hold the gauze in place and protect the patient’s skin. Two mild compression socks are then added to control edema (swelling) before the cast is applied. This dressing is held on the patient’s limb with compression socks.
A urethane insert is often prescribed for amputees with difficult residual limb shapes or for residual limbs with scarring or very sensitive skin. This insert molds itself to the limb, creating weight bearing relief, and compression areas to absorb and dissipate shock, shear, and mechanical forces that would otherwise be transmitted to the residual limb.
Vacuum Assisted Suspension
Daily volume fluctuations of the residual limb cause an inconsistent fit of the prosthesis for many amputees. By using vacuum assisted suspension, this can be better controlled. In this suspension style, vacuum is introduced into the sealed socket by an external vacuum pump. This pump produces up to 24 mm/hg of negative pressure to provide one of the best forms of positive suspension available to lower limb amputees. This often results in better limb health and more stable limb volume.
Waist Belt Suspension
Waist belt suspension is designed to work with transtibial (below knee) prostheses. The patient wears a belt made of leather, cotton webbing, or nylon webbing around his/her waist. An elastic strap extends from the belt to a leather strap attached to the medial and lateral (sides) surfaces of the prosthetic socket. This design provides assistance with extension of the residual limb and is indicated for patients with weak musculature. The waist belt is one of the original suspension styles for transtibial (below knee) amputees. Today it is primarily used for patients who have experienced difficulty with, or cannot tolerate, other forms of suspension.