Socket considerations for the patient with a transtibial amputation.

This paper reviews the theory of transtibial prosthetic socket designs from a historic perspective to the present. The patella tendon bearing socket originated in 1959, and is the standard from which the new alternative socket designs have evolved. Although the patella tendon bearing socket is still the most commonly prescribed socket for a transtibial prosthesis, the total surface bearing and hydrostatic sockets are becoming increasingly accepted. The total surface bearing socket still may incorporate the weightbearing characteristics of the patella tendon bearing socket, but often will be accompanied by a shock absorbing gel liner. The hydrostatic socket does not incorporate the standard patella tendon bearing design characteristics, but instead depends on a method of pressure casting that in theory produces a socket with equally distributed pressure over all of the residual limb soft tissue. These three designs are reviewed as current options for the socket portion of the transtibial prosthesis.