Weinstein Lovell and Winters Pediatric Orthopaedics 7e

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CHAPTER 30  |  The Child with a Limb Deficiency

FIGURE 30-46.  The nonconven- tional or extension prosthesis allows the child to “stand” on the prosthe- sis, extending his limb to the floor and accommodating the deformity. A,B : The nonconventional or exten- sion prosthesis without a knee joint, which is usual. It is possible to add a knee joint to the prosthesis.

A

B

Suction sockets are not typically used for the pediatric population because of tight tolerances in fitting that cannot be maintained by a growing child. With the suction socket, the residual limb is pulled into a socket that incorporates a one- way valve in its design (Fig. 30-47). Once the valve is in place, the amputee expels air every time the prosthesis is in contact with the ground. During swing phase, the negative pressure within the socket holds the prosthesis in place. Air that leaks into the socket is quickly expelled through the one-way valve, and a constant negative pressure is maintained. Total contact suction sockets are generally used for the transfemoral amputee with a mature residual limb and at the completion of skeletal

growth. Short limbs, volumetric changes, and severe scarring are contraindications for the suction-suspended socket. Transtibial Prosthesis.  The transtibial prosthesis is used the least in the pediatric population. Although most amputations in children are disarticulations, growth changes in the fibular defi- ciency often result in a transtibial-level residual limb that is a dis- tal-end weight-bearing limb. The true transtibial socket is most often required for the traumatic amputee. Total contact design allows for increased pressure bearing over the patellar tendon, medial flare of the tibia, medial shaft of the tibia, and lateral shaft of the fibula, and the anterior and ­posterior ­compartments.

FIGURE 30-47.  Methods of suspension for transfemoral prostheses. A : The Silesian belt is almost universally used in the young pediatric patient to suspend a transfemoral prosthesis or occasionally a knee disarticulation or transtibial prosthesis. B : The suction socket is a tight-fitting socket design with a one-way valve that allows air to be expelled with weight bearing to main- tain a suction fit on the residual limb. It is best suited for the older child or adolescent, who has a mature limb that is not changing in size.

A

B