Classification And Prosthetic Management Of Limb-Deficient Children

Leon M. Kruger, M.D.


In December 1961 Frantz and O'Rahilly1 published a paper describing a system of terminology for the classification of limb deficiencies in children. Since then, this terminology has come to have wide acceptance and use throughout the country. Sometime later an advisory group to the Subcommittee on Child Prosthetics Problems of the Committee on Prosthetics Research and Development proposed a revision of the Frantz-O'Rahilly terminology2. Both classification systems attempt to describe the anomalies in limb-deficient children in a manner which might enhance understanding of the deficiency and lead to improvement in therapy and/or prosthetic restoration.

It has been suggested that an effort be made to systematically relate recommended prosthetic treatment procedures to the various categories of deficiencies. In this paper we have attempted to follow this suggestion in relation to children with lower-limb deficiencies. In doing so the Frantz-O'Rahilly classification plan has been followed.

Aphalangia

It is evident that in aphalangia of the lower limbs functional disturbance is minimal. Certainly, no prosthetic restoration is indicated, and the only problem is that of attempting to improve cosmesis. On occasion callosities may occur beneath the heads of the metatarsals from abnormal weight-bearing stresses, and this problem can be treated satisfactorily with a metatarsal pad inside the shoe.

Adactylia

Cases of incomplete adactylia also require no prosthetic restoration, since the condition can be treated as a transmetatarsal amputation. Simply stuffing the toe of the shoe may be adequate treatment. On occasion it may be necessary to construct an insert for the shoe. Selection of a proper shoe is important.

Complete terminal adactylia presents a somewhat different situation. If no length discrepancy is associated with the condition it can be treated in infancy and early childhood by simply stuffing a high laced shoe with paper, foam rubber, or other similar material. The high lacer will hold the shoe about the ankle and the child will be able to ambulate satisfactorily. However, when the child reaches the age of two or three years, and even more so at the age of four or five when consideration is given to wearing a low shoe, it becomes apparent that there is insufficient foot to maintain the shoe in place. One must then think of cosmetic as well as functional restoration. Since there is no length discrepancy between the limbs, revision is indicated. This revision should be carried out in the form of disarticulation at the ankle, which in effect creates a Syme's-type amputation. Certainly, the end-bearing stump offers the best prosthetic restoration. In the very small child there is no problem from a bulbous stump. However, in the older child or young adult, this type of stump may present a prosthetic cosmetic problem. Sarmiento(3) has described a technique of beveling the malleoli so that a good cosmetic restoration can be attained in prosthetic fitting after such an amputation. We then have what amounts to a long below-knee end-bearing stump which can be fitted with a Syme's-type prosthesis or a modified patellar-tendon-bearing prosthesis with cuff suspension.

In the complete terminal adactylia where length discrepancy is present, revision of the stump is not necessary. However, the bulbous stump may require some modification in prosthetic technique or revision of the stump for cosmetic reasons.

Illustrative Case

M.A., who was born March 7, 1957, was first seen on May 20, 1957, with an anomaly classified as adactylia, left. It was possible to tie a high shoe above the malleoli, and she was ambulatory with this type of device until 1959. By the age of two years she had developed a 1-inch discrepancy in leg length and at that time was fitted with a Syme's prosthesis (Fig. 1 , Fig. 2 and Fig. 3 ). She wore this type of prosthesis until 1963, when at the age of six years a below-knee amputation was requested for cosmetic reasons and pressure over the malleoli (Fig. 4 ). This amputation was effected in October 1963, following which she was fitted with a below-knee prosthesis and since then has been ambulatory with this type of limb (Fig. 5and Fig. 6 ). There have been no complications. It should be pointed out, however, that with today's knowledge, disarticulation and modeling of the malleoli would have been carried out so she could have continued with an end-bearing Syme's-type prosthesis.

Partial Hemimelia

This condition is, of course, the simplest type of limb deficiency to treat prosthetically, and always requires a below-knee prosthesis. It has been our practice to fit the very small child with a willow-wood socket and an auxiliary waistband or shoulder-strap suspension. The wooden socket prolongs the life of the prosthesis, since socket adjustments can easily be made as the child grows and the shank portion can easily be lengthened. It has further been our experience that in the very small child a short below-knee stump does not have the contouring necessary for a patellar-tendon-bearing plastic laminate fitting. We have, however, found the plastic laminate socket with cuff suspension to be satisfactory when the child reaches the age 5 or 6 years.

Illustrative Cases

J.G., who was born November 28, 1958, was first seen on February 14, 1959, when his deficiency was classified as partial hemimelia, right. In November 1959, at age one year (Fig. 7 ), his first prosthesis was ordered and fitted to him (Fig. 8 and Fig. 9 ). He has been ambulatory since that time with a below-knee prosthesis (Fig. 10 and 11 ). His only difficulty occurred when an effort was made to switch him from side hinges to a PTB cuff suspension, which he could not handle very well.

M.P., born March 16, 1952, was first seen on March 28, 1953, at at the age of one year with a partial hemimelia, right (Fig. 12 and Fig. 13 ). At the age of 18 months he was fitted with a below-knee prosthesis (Fig. 14 and 15 ). He ambulated immediately and except for an overgrowth of his stump, which required revision (Fig. 16 and 17 ), he has never experienced any difficulty being fully active and taking part in all athletics.

Hemimelia

In complete hemimelia (knee disarticulation) we prescribe a quadrilateral socket with Silesian band suspension and outside knee hinges. If there is a discrepancy in the length of the femora on the two sides, it may be possible to prescribe a single-axis knee joint and, as the child grows older and is able to handle it, suction suspension. It has been our experience in the hemimelia or knee disarticulation that as the child grows older a length discrepancy does indeed develop in the femur so that, as a rule, revision is not necessary. If, because of prosthetic considerations (i.e. placement of knee joint or need of friction), it is desirable to revise the length of the stump, this should be deferred until such time as there is no longer any need to retain the distal femoral epiphysis for growth purposes.

Amelia

The amelic patient is fitted as a hip disarticulation amputee with a Canadian hip disarticulation prosthesis. In the very young child it is advisable to lock the knee for simplicity of ambulation or to apply a pylon to the hip hinge (Fig. 18 and 19 ). As the child reaches the age of three or four years, he is usually able to handle a Canadian hip disarticulation prosthesis with a free knee joint (Fig. 20 ).

Paraxial Fibular Hemimelia

Progressive length discrepancy is the major consideration governing amputation and prosthetic restoration in the juvenile patient with paraxial fibular hemimelia, terminal4. It is our opinion that end-bearing amputation is far and away the procedure of choice when length discrepancy does necessitate amputation. In the older male child with paraxial fibular hemimelia it has been our practice to fuse the os calcis to the tibia and disarticulate through the tarsal joints. This procedure creates a bulbous end-bearing stump which the prosthetist finds quite satisfactory for fitting with a Canadian Syme 1 s prosthesis, which is the best functional unit. However, in the very small child, disarticulation at the ankle joint gives an equally good end-bearing stump. In the female patient we prefer disarticulation. With proper modeling at the malleoli, excellent cosmetic as well as functional restoration can be expected.

The above considerations likewise pertain for the patient with intercalary paraxial fibular hemimelia.

Illustrative Case

S.T., born October 21, 1953, was first seen at our clinic on April 17, 1954. The diagnosis was terminal fibular hemimelia, right. Only a one-inch discrepancy in leg length was noted. By the time the boy had reached five years of age, however, the length discrepancy was 2 1/2 inches (Fig. 21 and 22 ). It was felt that amputation was indicated and a modified Boyd-type amputation was performed (Fig. 23 ), following which the boy was fitted with a modified Syme's prosthesis (Fig. 24 and 25 ). He was immediately ambulatory, has had no complications since, and performs all normal activities.

Paraxial Tibial Hemimelia

Here also, the indications are the same for the terminal and intercalary forms of the limb deficiency. It has customarily been the practice to disarticulate the fibula from the femur and fit the patient with a quadrilateral socket with outside knee hinges and Silesian suspension. As the child grows, a length discrepancy of the femora is apt to develop so that the standard single-axis knee joint can be utilized. If this difference in length does not occur, revision of the stump can be carried out at such time as the distal femoral epiphysis may safely be sacrificed. At this time, likewise, suction suspension can be considered.

About three years ago, Dr. Brown in Indianapolis described his surgical technique of implanting the fibulabeneath the femur and then treating the patient as a below-knee amputee following disarticulation at the ankle 5. This procedure certainly is to be commended, since it saves the knee joint and gives the patient considerably increased stability in ambulation.

Illustrative Case

S.D., born May 11, 1953, was first seen April 17, 1954, with a diagnosis of tibial hemimelia (Fig. 26 and 27 ). Disarticulation at the knee was carried out November 23, 1954, at the age of 16 months (Fig. 28 ). At the age of 18 months the patient was fitted with his first prosthesis (Fig. 29 and 30 ). He has progressed from the molded leather type prosthesis originally fitted to a UCB quadrilateral suction socket limb which he now wears (Fig. 31 ). He was fully independent and was experiencing no difficulties when he was last seen at the age of 15 years.

Intercalary Deficiencies

As mentioned above, treatment of the intercalary forms of paraxial fibular hemimelia and paraxial tibial hemimelia is the same as that of the terminal deficiencies .

The complete distal phocomelia would be treated as a tibial hemimelia, with disarticulation at the knee level and an above-knee fitting.

The complete proximal phocomelia and the proximal femoral focal deficiencies, however, present an entirely different problem. Recent articles in the literature have extensively described the treatment of these deficiencies, and in an effort to simplify this discussion I think that first we must divide the patients into unilateral and bilateral groups.

The patient with unilateral complete proximal phocomelia can be treated by disarticulation of the foot. The tibia and fibula can then be fitted into a quadrilateral socket modified as necessary for the abnormal shape of the stump. While Silesian bandage suspension is adequate for many of these individuals, a pelvic belt with hip joint may be required for some.

The multiple forms of proximal femoral focal deficiencies (PFFD) which may occur have to be individualized. In general, if there is sufficient length of femur and the hip joint is intact, the patient may be treated as a below-knee amputee, even though knee levels are unequal. On the other hand, if the hip joint is absent a different situation obtains. If the remaining femoral segment is quite short, the foot may be disarticulated and an above-knee fitting carried out as in the proximal phocomelia. However, if the remaining femoral segment is longer than three or four inches, the problem becomes considerably more complicated. With a femoral segment of this length the hip and knee are most apt to be flexed, and any attempt at prosthetic restoration without revision of this situation is complicated by two problems: First, the weight-bearing line is in front of the center of gravity of the body, and second, with each step the remaining amputation stump is apt to come out of the socket as hip and knee flex further. In such individuals, fusion of the knee joint to create a single rigid segment of bone following amputation of the foot is the procedure of choice. This stump can then be aligned beneath the pelvis reasonably well and fitted with a modified UCB socket.

Illustrative Cases

T.R., born January 21, 1950, was first seen September 25, 1954, with PFFD left (Fig. 32-34 ). In May 1956, at the age of years, a modified Boyd amputation and a modified Syme's fitting were carried out (Fig. 35 and 36 ). However, this treatment was totally unsuccessful because of the instability of the hip and knee. Therefore in February, 1960, a left knee arthrodesis was performed, giving the boy a single stable bone in his stump (Fig. 37 ).

It was then possible to fit him with a very slightly modified UCB above-knee quadrilateral socket, following which he ambulated independently without any difficulties. He was last seen in 1966, at age 16 years, when he was fully ambulatory, with no complaints and an excellent gait, in spite of his hip disability.

L.C. was born June 20, 1948, with bilateral hemimelias in the upper limbs and a PFFD in the right lower limb (Fig. 38 and 39 ). In October 1957, the foot was amputated (Fig. 40 ). A modified UCB quadrilateral socket with a modified Silesian suspension was fitted (Fig. 41 and 42 ). He is fully ambulatory with his prosthesis (Fig. 43 ).

Bilateral Proximal Phocomelia Or Proximal Femoral Focal Deficiencies

Those patients with the proximal segments of the lower limbs bilaterally absent frequently have concomitant anomalies. However, assuming that the upper limbs are normal, these patients become ambulatory even with bilateral paraxial fibular hemimelia. Their major problem is not the hip pathology nor even the foot pathology which may exist. The problem is solely one of stature-for these individuals are, in a broad sense of the word, dwarfs, and even when fully grown rarely attain a height of more than three and a half or four feet. It has, therefore, been our opinion that these patients should be fitted with a modified type of prosthesis which leaves their feet intact. Ambulation with modified above-knee-type prostheses which articulate below , the child's feet requires considerable energy. The patients whom we have fitted in this manner have been delighted with the cosmetic as well as the functional result, but because they tired easily were anxious to remove their limbs when cosmesis was not a factor of importance. When the feet are intact, they are able to ambulate in their homes without the prosthetic devices. We feel that it is important to understand that ambulation with these prostheses requires a great deal of effort, and we are not yet certain how long an individual will continue to be able to ambulate on such limbs. At the present time, we have one patient who is 27 years of age and married with two children; she continues to do well with this type of prosthetic restoration. Whether she will be able to manage them when she is 47 or 57 remains to be seen. This is a good reason to leave the feet intact.

In the patient with asymmetrical bilateral PFFD, prosthetic considerations must be individualized to suit the specific problem. It is beyond the scope of this paper to cover each of the possibilities which may arise.

Illustrative Cases

R.M. has symmetrical bilateral PFFD's (Fig. 44 and Figure 45-47 ). This boy was born March 5, 1950, and was first seen at our clinic on October 13, 1951. In 1959, at the age of 9 years, it was felt that he was a candidate for bilateral above-knee stilt-type prostheses. Accordingly he was admitted to the hospital and his limbs were constructed. At first his ambulation was a bit slow, and he required canes, but then he became independently ambulatory on these prostheses (Fig. 48=51 ). Although the boy developed considerable obesity, he has continued to wear limbs of this type until the present time (Fig. 42 and 43 ):. N.T. was born December 27, 1948, with asymmetrical bilateral PFFD's. In 1959, at the age of 11 years, he was fitted with asymmetrical limbs (Fig. 54-56 , Fig. 57 and 58 ). The right was an above-knee-type fitting with prosthetic knee joint, the left a below-knee-type fitting using his own knee joint. This asymmetrical fitting is not nearly as satisfactory as the symmetrical fitting, and the boy has tended not to wear the limbs because of the extreme effort required.

Leon M. Kruger, M.D. is associated with the Child Amputee Clinic Shriners Hospital Springfield, Massachusetts

References:
1. Frantz, CH., and O'Rahilly, R. , "Congenital Skeletal Limb Deficiencies , " JBJS, 43A:1202-1224, December 1961. 
2. Burtch, Robert, et al, "Nomenclature for Congenital Skeletal Limb Deficiencies, A Revision of the Frantz and O'Rahilly Classification," Artificial Limbs, Vol. 10, No. 1:24-35, Spring 1966. 
3. Sarmiento, A., Gilmer, R.E., and Finnieston, A., "A New Surgical Prosthetic Approach to the Syme's Amputation, A Preliminary Report," Artificial Limbs, Vol. 10, No. 1: 52-55, Spring 1966. 
4. Kruger, Leon M., and Talbot, Richard D., "Amputation and Prosthesis as Definitive Treatment in Congenital Absence of the Fibula," JBJS, 43A:625-642, July 1961 
5. Brown, Frederic W., "Construction of a Knee Joint in Congenital Total Absence of the Tibia (Paraxial Hemimelia Tibia)," JBJS, 47A, No. 4:695-704, June 1965.