Congenital Foot Deformities Requiring Surgery And Prosthesis In Lisfranc's Amputations

William E. Gazeley, M.D. James E. Holmblad, M.D.


Advances made in the fields of biophysics and prosthetics, particularly in the materials used, have revived interest in Syme's, Pirogoff's, Chopart's, and Lisfranc's amputations. Although the techniques for these amputations have been known for over a hundred years, they are seldom used- Lisfranc's being the most common. Consciously or unconsciously we have come to equate looks with function, i.e., to believe that in order for a prosthesis to function well it should have a good appearance; although when we stop to think of it we are fully aware that a prosthesis which offends someone's aesthetic bias is not necessarily one that functions poorly.

In the June 1966 issue of the Inter-Clinic Information Bulletin Dr. Edward Haslam described his experience in the surgical treatment of segmental giantism of the foot.(1) In the following issue the staff of the Child Amputee Prosthetics Project at the University of California at Los Angeles reported on the cosmetic problems associated with the partially amputated foot. (2)

This report relates our experiences with two cases of congenital foot deformities and with several amputations at the Lisfranc level. It is our hope that, in a small way, the presentation of our experience will serve as a sequel to the previous ICIB communications on these subjects .

Congenital Foot Deformities

Case 1 (D.D.) This male patient was two years of age when seen in one of our regional outpatient clinics (Fig. 1 and 2 ). In addition to the gross enlargement of the soft tissues and the phalanges of the second and third toes, a large neurofibroma on the sole of the foot extended back to the anterior aspect of the heel. Since we were hesitant about removing either the second or third metatarsal heads, the third toe was disarticulated at the metatarsophalangeal joint. The distal phalanx of the second toe was removed, together with a great deal of the excess tissue.

The neurofibroma was removed through an S-shaped incision in the sole of the foot. This approach provided an excellent exposure and has left a most satisfactory scar (Fig. 3 ). Fig. 4 and 5 show the foot at the present time.

Case 2 (L.B.) This little girl was also seen in a regional outpatient clinic. Her parents were unable to find shoes to fit her feet, which were too wide for any of the shoes commercially obtainable. This condition was regarded as supernumerary large toes bilaterally (Fig. 6 and 7 ). Fig. 8 shows the feet after bilateral removal of the most medial rays, involving disarticulation at the juncture with the first cuneiform bones. It is believed that each foot has a true prehallux, which articulates with the navicular.

Partial Foot Prostheses

Eight patients with amputations through the midfoot are under our care. Six of these are amputated at the tarsometatarsal junction, hence may be classified as true Lisfranc's amputations; one has a navicular bone in addition to the talus and calcaneus; and the other has a Cho-part's amputation. Patients with transmetatarsal amputations are not included in this discussion, since prosthetically the use of a soft toe piece (FIg. 9 ) seems to answer their problem.

Of the midfoot amputations, two are congenital and six are the result of trauma. To find a prosthesis that was entirely satisfactory for these patients has been a difficult and often frustrating problem. Although we fully appreciate that this is a minor problem compared to many that are encountered in an amputee clinic, it is hoped that our experience may prove worthwhile to others who have had similar difficulties with this type of case.

Earlier Models

In the early years of our clinic the first prosthesis used in midfoot amputations was the type referred to as a "conventional" prosthesis for the Chopart amputation in the CAPP staff report mentioned above. We agree that these prostheses are bulky and unsatisfactory from a cosmetic standpoint; in addition, breakage of the foot pieces at the amputation site is not uncommon.

A number of prostheses of a less bulky type have been used, these being essentially of a high-shoe configuration. Fig. 10 , for example, shows one fabricated about 15 years ago and still being worn. Examination of this prosthesis revealed that it had been fabricated with a piece of hard wood shaped to fit the contours of the stump. The usual toe break allowed flexion of the toe piece in the metatarsal area with the toe piece connected to the proximal portion by rubber belting. Both pieces were then covered with horsehide and a leather sole provided. For suspension, a leather anklet was fastened to the bottom portion of the device and laced up the front.

Fig. 11 shows another high-shoe type prosthesis which incorporates a small SACH-foot-type toe covered with soft silicone. The sole or keel of chrome leather extends to the heel, with a soft leather heel cuff attached. A soft silicone plug in the toe helps keep the foot back in contact with the heel cuff. As it is presently made, this item is not acceptable from a cosmetic standpoint.

The one Chopart's amputation treated has been fitted with the type of prosthesis shown in Fig. 12 and 13 . The shoe has been filled with silicone, and the foot is held in the shoe by a leather cuff extending above the ankle and laced up the front. This foot, as well as all of the others, functioned well in dorsi- and plantar-flexion. There were no fixed equinus deformities and therefore neither the necessity nor the opportunity to do a subcutaneous tendo calcaneus tenotomy, as advised by Dr. Ernest Burgess.(3)

The type made over a Monel Metal Whitman arch support and covered with leather has served well if worn in a sneaker or soft-soled shoe, but if worn in an oxford shoe it tends to break at the site of amputation even if a toe break is provided. Presumably the soft-soled shoe provides a better distribution of weight.

One little girl came to us wearing a custom-made shoe which accurately fitted her foot, but had no toe. This shoe had become unacceptable to her as she grew older. She was fitted with the Whitman-arch type mentioned above and had no trouble with it as long as she wore soft-soled shoes. She moved away, and when her prosthesis wore out, she was fitted with a new one (Fig. 14 ) at another clinic. She was unhappy with it because it broke just behind the toe break, as can be seen. It is now being held together with adhesive plaster. In addition, the slit in the dorsal aspect pinched and blistered the skin beneath it. The appliance depicted in Fig. 15 has proved acceptable if worn in a shoe with a 1 1/2-inch heel and six eyelets.

It is felt that a satisfactory prosthesis requires the solution of two problems: (1) the prevention of breakage at the site of the amputation and (2) the provision of a snug fit.

New Approaches

At the present time we are studying two new approaches to this problem. The first (Fig. 16 and 17 ) involves a modification of the appliance shown in Fig. 11 . It incorporates a Neoprene crepe or SACH toe smaller than would normally be used for the size of the shoe. This toe is covered with soft silicone, and at the point of contact with the front of the stump a soft silicone plug, 1 1/2 inches deep, is inserted to provide the elastic compression necessary to hold the back of the foot securely against the heel cup. Chrome leather is used as a keel, and various materials have been tried in the heel cup. Our experience with this model has been too brief to determine its limitations.

The second approach (Fig. 18 and 19 ) involves an intriguing idea, provided by a General Electric structural engineer working in our research project on upper-extremity prostheses. Spring steel thin enough to be as flexible as the Neoprene crepe in the SACH toe is to be used. The toe is built up in the same manner as in the preceeding prosthesis, using the same 1 1/2-inch plug of soft silicone. The keel of the steel is arched up under the stump. The heel cup is steel and covered with thin leather. The foot can be easily placed in the prosthesis by pressing it against the soft silicone and depressing the flexible keel at the heel. On weight-bearing, the arched steel depresses, tightening the hold of the prosthesis on the foot stump.

A report on this study may seem premature at this time, but it is our hope that those who may have found a satisfactory solution to this problem will be willing to share their experience with us. It also seems possible that if a perfectly satisfactory prosthesis can be made available, it may lead to our re-evaluating the usefulness of Lisfranc's amputation.

William E. Gazeley, M.D. and James E. Holmblad, M.D. are associated with the Child Amputee Clinic Sunnyview Rehabilitation Center Schenectady, New York

References:
1. Haslam, Edward T.: Surgical Treatment of Segmental Giantism of the Foot, ICIB, V:1-6 (June) 1966.
2. UCLA Child Amputee Prosthetics Project Staff Members: Cosmesis: Can It Be Defined?, ICIB, V:4-9 (July) 1966.
3. Burgess, Ernest: Prevention and Correction of Fixed Equinus Deformity in Mid-Foot Amputations, Bul. Pros. Res., BPR 10-5 Spring, 1966.