A biomechanical study of two postoperative prostheses for transtibial amputees: a custom-molded and a prefabricated adjustable pneumatic prosthesis

We evaluated an adjustable pneumatic prefabricated prosthesis and a rigid custom-molded prosthesis for immediate postoperative use. Twelve transtibial amputations were performed on cadaver limbs. Differential variable reluctance transducers were placed subcutaneously across the wound edge medially and laterally. The limbs were then placed in either the pneumatic prosthesis (five limbs) or the rigid prosthesis (seven limbs). The specimens underwent static and cyclic loading to simulate weight bearing. The strain readings for static and cyclic loading were greater in the rigid prosthetic group. Only the mean medial strain measurement after cyclic loading was statistically significant. The results demonstrate that the pneumatic prosthesis places less strain across the wound than a rigid prosthesis.