The Bilateral Lower-Extremity Amputee

Victor Panitch, M.D.


The bilateral lower-extremity amputee presents an unusual and difficult problem to the pediatrician, orthopedic surgeon, and prosthetist, especially when the deficits are of congenital origin. Limb deficiency types are varied; different levels of amputations are found; joints are often abnormal and associated congenital anomalies influence significantly the type of apparatus used. Few people, even in the largest of amputee centers, have seen enough children in each of the various categories of anomalies encountered to formulate rigid prescription criteria. Individual amputee clinics therefore often deal with the same problem in quite different ways. As experience broadens and more cases are reported in the literature, this variability will undoubtedly lessen.

In this paper, we hope to review the general principles for handling these children, discuss a few specific patients who have been treated at this hospital, attempt to point out the problems that we have encountered, and demonstrate the various steps we have taken to seek solutions.

Parental Problems

The first problem to be met is concerned not with the treatment of the child, but with therapy for the parents who often have a strong guilt feeling concerning their part in the creation of their child's deformities. The parents must be assured and reassured that they were in no way guilty, consciously or subconsciously, of any deed which helped to produce this deformity. An attempt must then be made to give a realistic appraisal of the child's potential and the steps that will have to be taken to provide the child with as full and rewarding a life as possible. If parental understanding and cooperation is obtained early, the chance that the parents will reject the child or will unintentionally stand in the way of his rehabilitation becomes significantly lessened. In this connection it is valuable to have the parents visit the amputee clinic to see how well other children with similar deformities are managing.

The time to put children in lower-extremity prostheses is fairly well accepted. The age chosen is that at which a child shows evidence of readiness for ambulation. This occurs at approximately 12 months of age and is usually evidenced by the child's pulling himself up on the sides of the crib and attempting to stand or cruise. If the child is unfortunate enough to have upper-extremity anomalies also, this attempt at standing will necessarily be delayed. Even in these cases, however, the child usually is physiologically ready for standing and ambulation by the time he is 11 to 14 months of age and lower-extremity prostheses should be fitted at this time. Protective head gear, such as a football helmet, is often needed to protect these children from the inevitable tumbles. The prostheses should be as simple as possible. In the case of a bilateral below-knee amputee, we use standard below-knee willow wood sockets with thigh corsets and knee hinges, wood feet, and a shoulder harness auxiliary suspension. For above-knee amputees, "stubbies" are fitted. These are short straight prostheses without knee joints or feet to make ambulation as mechanically simple as possible. The problems of knee control and those of coping with walking over a foot are better delayed until the child's locomotor ability and nervous system are more mature. A child with one below-knee amputation and one above-knee amputation may be started with "stubbies" and then a standard below-knee prosthesis can be used on the below-knee side with an above-knee articulated limb on the contralateral side.

In the case of a child with symmetrical bilateral proximal femoral focal deficiencies, that is, with missing thigh or leg segments but with useful and stable feet, and with lower extremities of equal or almost equal lengths, prostheses are not indicated at an early age. These children can function much more efficiently without prostheses and social considerations are of no consequence to the young child. It is not until they reach the age of eight or ten years that these children become interested in cosmesis and are self-conscious about their height. At this time, a stilt-type prosthesis can be fabricated to increase the height of these patients to that of their peers. Even our most successful prostheses wearers in this category remove their prostheses as soon as they reach the seclusion of their home. They are also removed for any athletic activities. These prostheses are rather bulky, and for ambulation require a considerable expenditure of energy. These children function so much better without prostheses that ablation is never considered merely for cosmetic reasons.

On the other hand, when a child has a long extremity on one side, and a short extremity on the other so that a large limb-length discrepancy is present, the foot on the short side may be amputated to allow better prosthetic fit. It is obvious that such a child will always

require a lift on the short side and will be much more facile in a prosthesis than out of it. Hence, the reason for saving the foot is no longer present. There is one very important exception to this rule and that is when a child's hands are absent or have severe anomalies, in addition to the lower-extremity difficulties. In this case, the child will learn to use his feet in an amazing manner and become virtually independent in self-care activities through the development of an increased range of motion of the lower-extremity joints and prehensile skill between his great and second toes. This bipedal dexterity is all important to these individuals and both feet must be saved and somehow incorporated into the prostheses no matter what the prosthetic difficulty.

If amputation is indicated, it should be performed through a joint, if at all possible, so as to retain the distal epiphysis and obtain maximum growth. Growth tables of various bones are worthless when dealing with the limb-deficient child and a proximal epiphysis cannot be relied on to supply all the length necessary for an ideal amputation stump. Disarticulations also eliminate the problem of bony overgrowth so frequently encountered in childhood amputations through the long bones. Occasionally joint arthrodeses are needed, either because of gross instability or positioning incompatible with weight-bearing or prosthetic fitting. Such is the case in unilateral proximal femoral focal deficiency with a long distal femoral segment and no hip joint. If at all possible, this arthrodesis should be done from epiphysis to epiphysis sparing the epiphyseal growth lines. The epiphyseal line will ordinarily survive either a compression-type arthrodesis of the Charnley-type or an arthrodesis utilizing central intramedullary pins.

Specific examples of some of the possible combinations of amputations and anomalies are now presented.

Quadrimembral Deficits

J.H. (#7530) was born with transverse partial hemimelias of the upper and lower limbs, that is, with congenital bilateral below-elbow and below-knee amputations (Fig. 1 and 2 ). At 11 months of age, when the patient began making attempts to stand, he was fitted with modified patellar-tendon-bearing prostheses with cuff suspensions. These were found to be unsatisfactory, however, because of knee instability and poor suspension. Therefore the sockets were deepened and side bars and corsets were added together with auxiliary shoulder harness suspension. With this modified equipment, the patient did quite well. By the age of 14 months he was standing in a playpen holding himself upright and ambulated shortly thereafter (Fig. 3 A-C ). At 20 months of age, when the patient was readmitted for upper-extremity prostheses, he was walking without assistance (Fig. 3 A-C ). At the age of seven years, the shoulder auxiliary suspension was eliminated but the patient was kept in modified pateliar-tendon-bearing-type prostheses with side bars and corsets (Fig. 4 ). The patient is totally independent as far as the activities of daily living are concerned. Because of this experience, as well as others, we have given up fitting youngsters below the age of approximately six to seven years with standard PTB prostheses and cuff suspension. We find that the young child tends to slip out of his PTB prosthesis and will usually do better with a standard below-knee prosthesis with side bars and corset. The patients are ordinarily switched to PTB prostheses at about the age of six to seven years.

Bilateral Fibular Hemimelia

R.M. (#8476) was first seen at Shriners Hospital at the age of two years with bilateral proximal femoral focal deficiencies and bilateral terminal paraxial fibular hemimelia (Fig. 5 ). The child was ambulatory but demonstrated severe calcaneovalgus deformities of the feet. He was braced to hold his deformed limbs in weight-bearing position, was given crutches, and soon walked quite well (Fig. 6 ). At the age of five years, he was able to do without his crutches. It was not until age ten, however, that the patient would accept prostheses to elongate his legs; that is, to increase his height. At that time he was fitted with special willow wood sockets carved to accept his deformed feet. These buckets were set on single-axis knees with wood shanks and SACH feet (Fig. 7 and 8 ). The patient wears these prostheses to school and usually uses canes to control the sway of his body resulting from the lack of hip joints. As soon as he gets home, however, the prostheses are removed. Functionally he is better without them.

Asymmetrical PFFD

M.V. (#8429) presents a slightly different problem, with a small femoral segment and complete fibular hemimelia on the right but with a comparatively large femoral segment on the left (Fig. 9 ). As can be appreciated, the patient's right foot was not only severely deformed but was at so high a level, as compared to the left, as to be almost useless.

To enhance prosthetic fitting, therefore, the patient had a right forefoot amputation with fusion of the ankle and subtalar joints at the age of nine years (Fig. 10 ). This stump was then fitted with a modified Syme's prosthesis to equalize leg lengths (Fig. 11 and 12 ). In order to bring the patient's height up to that of his peers, his right Syme's amputation was fitted with an above-knee prosthesis when he was 11 years old. A stilt-type prosthesis was built to accommodate the patient's normal foot on the left limb (Fig. 11 and 12 ). The patient prefers the use of these prostheses when he is in public, but returns to the use of the modified Syme's prosthesis on the right and no prosthesis on the left at other times.

Knee-Flexion Deformity

B.K. (#9970) was born with a left hemimelia (knee disarticulation) and a right partial hemimelia (below-knee amputation). His below-knee stump was quite short and a 45-degree flexion deformity of the knee was present (Fig. 13 ). At age one and one-half years, the patient was standing up on his stumps and, at this time, a posterior release of the right knee was performed and the child was fitted with "stubbies" (Fig. 14 and Fig. 15 ). At age four, the patient's right knee-flexion deformity had recurred and interfered significantly with prosthetic fitting. Therefore, a supracondylar osteotomy was performed, completely correcting the knee-flexion condition. The child was then fitted with a standard below-knee prosthesis and thigh cuff on the right side and an above-knee prosthesis with quadrilateral socket and external knee joint on the left. On the left side, a toddler's harness was used as an aid to suspension. Within one year the flexion deformity had completely recurred and an attempt was made to build a new prosthesis to compensate for the condition, but this limb did not really solve the problem. Therefore, at the age of six years, the patient was again operated on and a posterior release of the right knee was performed. At this time the particularly tight iliotibial band was noted and divided. He was again fitted with a left below-knee willow wood socket with thigh corset and a right standard above-knee prosthesis (Fig. 16 ). The flexion deformity has remained corrected over the last eight years.

Summary

An attempt has been made to outline the broad principles which are applied in the prosthetic treatment of bilateral lower-extremity amputees. Four illustrative cases have been cited. However, each bilateral amputee has his own peculiar problems which often require individual and unique solutions.

Victor Panitch, M.D. is associated with the Shriners Hospital for Crippled Children Springfield, Massachusetts