A Functional Chopart Prosthesis

GUSTAV RUBIN, M.D., F.A.C.S. MICHAEL DANISI, CO.


Aprosthesis for the Chopart amputation, which incorporates some of the basic characteristics of the Teufel Ortholen Drop Foot Brace, has been developed. This prosthesis provides stability, and by virtue of Ortholen's elastic properties it accommodates motion at the ankle plantarflexion on heel strike, and dorsiflexion followed by "toe-break" in the late phase of stance. Flexion of the Ortholen solepiece during dorsiflexion and toe-break provides a spring effect during push-off. These features enable the patient to walk and climb stairs in a more normal fashion than was the case when he wore previous Chopart designs.

The added security provided by a long upright lever of the Ortholen prosthesis permits the patient to balance securely when standing solely on the amputated extremity. The device is light, inexpensive, and cosmetically acceptable.

Fabrication time is shorter than with other designs and it is possible to deliver a prosthesis of this type on the day of the initial visit a significant saving of time and effort for both patient and fabricator. With conventional Chopart prostheses it is usually necessary for the patient to make two or three visits.

One clinic indicated that they did not adhere to any developmental criteria but felt that as soon as the child was three or four months old a prosthesis could be fabricated with adequate socket fit. It was their belief that the earlier the socket was fitted the better.

It is hoped that persons responsible for prescribing prostheses might consider the criteria proposed by other clinics for fitting of prostheses for congenital upper-limb amputees. The advantages that prompted the change from preschool age fitting to fitting at the developmental level of independent sitting continue to exert an influence toward still earlier fitting. The greatest advantage claimed is that of acceptance of the prosthesis. Logically, if the artificial limb is provided before a one-handed activity pattern is developed, chances for acceptance are increased. It would further seem logical that when the capacity for two-handed grasp in the midline develops (at approximately four months) a prosthetic limb should be there to oppose the normal limb. The proximal stability necessary for control is developed previously in the on-elbows position.

Many factors interact to affect the age of initial fitting. The age at which the limb-deficient child is referred to the clinic is certainly a significant one. Parental attitudes are closely associated with this consideration. The development of prosthetic parts specifically designed for children is important, as is the increase in knowledge in the entire field of prosthetic management of the juvenile amputee. Disseminination of this knowledge to the related health fields, especially to those individuals in contact with the mother of the newborn child with limb deficiencies, may promote earlier referral to the appropriate prosthetic team.

Fabrication

The basic component of this prosthesis is the Teufel brace, which was designed as a drop-foot brace and fabricated from Ortholen (a thermoplastic polyethylene material). This material can be heat-worked after heating to 300 deg. F., or it can be cold-worked, i.e., hammered to effect small changes or modifications.

The Teufel brace is currently available in three sizes?small, medium, and large. We select the size most appropriate for our patient (slightly oversized) and then modify the brace to provide an exact anatomical fitting.

The Ortholen is extended the full length of the shoe innersole but distally the material is thinned out slightly ( Fig. 1 ). The amount of thinning introduced helps to control flexibility of the toe break and spring resistance at push-off.

Velcro straps are attached to the calf band with rapid rivets to form the calf cuff, and an ankle cuff is riveted above the ankle to hold the leg and foot more securely in the prosthesis ( Fig. 2 ).

The proximal border of the cork toe filler ( Fig. 2 ) should be approximately 1/2 in. distal to the end of the stump to allow room for flexion of the Ortholen during push-off.

Frabrication

The basic component of this prosthesis is the Teufel brace, which was designed as a drop-foot brace and fabricated from Ortholen (a thermoplastic polyethylene material). This material can be heat-worked after heating to 300 deg. F., or it can be cold-worked, i.e., hammered to effect small changes or modifications.The basic component of this prosthesis is the Teufel brace, which was designed as a drop-foot brace and fabricated from Ortholen (a thermoplastic polyethylene material). This material can be heat-worked after heating to 300 deg. F., or it can be cold-worked, i.e., hammered to effect small changes or modifications.

The Teufel brace is currently available in three sizes-small, medium, and large. We select the size most appropriate for our patient (slightly oversized) and then modify the brace to provide an exact anatomical fitting.

The Ortholen is extended the full length of the shoe innersole but distally the material is thinned out slightly ( Fig. 1 ). The amount of thinning introduced helps to control flexibility of the toe break and spring resistance at push-off.

Velcro straps are attached to the calf band with rapid rivets to form the calf cuff, and an ankle cuff is riveted above the ankle to hold the leg and foot more securely in the prosthesis ( Fig. 2 ).

The proximal border of the cork toe filler ( Fig. 2 ) should be approximately ½in. distal to the end of the stump to allow room for flexion of the Ortholen during push-off.

Veterans Administration Prosthetics Center New York, New York