Extremity Growth And Overgrowth Following Amputations In Children

Robert L. Romano, M. D. Ernest M. Burgess, M. D.

According to the literature, the most common complication of amputation performed on children is overgrowth of the bone, leading ultimately to need for revision of the amputation. It has also been stated that this sequela is not generally recognized, because most surgeons see relatively few juvenile amputees.

However, bony overgrowth did not seem to be a problem at our Amputation and Prosthetic Clinic at the Children's Orthopedic Hospital. For this reason we recently conducted an evaluation of our patients to determine the incidence, if any, of overgrowth in our case load.

Two Complications

It is well known that two complications incidental to growth may occur in the amputation stump of a juvenile amputee. First, overgrowth of the bone may occur. This is a phenomenon which is peculiar to the juvenile amputee. Revision of the stump for this problem is said to be the major complication of amputation surgery in children. Second, relative shortening of the stump with respect to the opposite extremity may occur. This is not a common problem clinically and arises primarily in amputations of the distal femur. Since the proximal femoral epiphysis contributes only 15 percent to the total growth of the lower extremity, a stump may become relatively shorter with time when the extremity is amputated at the distal femoral diaphysis. In juvenile amputees, therefore, the distal femoral epiphysis should be preserved if at all possible. It would be our recommendation that a knee disarticulation be carried out whenever feasible.

This problem of relative shortening does not occur in below-knee and above-elbow stumps, as the upper humeral and upper tibial and fibular epiphyses contribute more than 50 percent to the longitudinal growth of the extremity. However, amputations at these levels produce the more serious problem of overgrowth. This is essentially a problem of continued bone growth without equivalent soft tissue growth. The bone continues to grow and stretches the skin tightly, eventually leading to ulceration and finally to protrusion of the bone through the skin. The reason for this development is simply that the circulation to the epiphysis remains intact after the amputation and the bone grows normally, but the soft tissue loses its potential to grow because of muscle atrophy and diminished blood supply.

Reported Frequency

This complication has been described as almost commonplace by some authors. Von Saal 1 described a series of 20 juvenile below-knee amputees, 16 of whom had bone protrusion or painful long stumps with tightly stretched skin and soft parts. He also described the development of bone protrusion in five of 20 femoral amputations. Other authors have also reported a high incidence of this complication. The problems reported have included overgrowth of the fibula (sometimes to extreme degrees, necessitating reamputation), and spurs protruding from the tibia, causing "tenting" of the skin and reamputation.

Remedies Proposed

Some authors have recommended that amputation be performed at the ideal length and that epiphysiodes is then be carried out to prevent further bone growth. Other authors have recommended the following procedures: a synostosis involving a terminal cap or plug to prevent overgrowth of the fibula; utilization of long skin flaps with complete excision of the fibula; or only that the fibula be resected.

Seattle Patients

Fifty-two amputees, three of whom had bilateral amputations, were evaluated at the Children's Orthopedic Hospital. Amputation was performed on forty-four patients in connection with congenital deficiencies. Eight others had amputation subsequent to trauma, for tumors, or other conditions. Of these cases, only two showed overgrowth; one had a tibial spur, the other overgrowth of the humerus.

Thus, in our experience this problem of overgrowth has not been as great as would be indicated by a review of the literature. For this reason we do not feel that epiphysiodesis should be performed. This procedure will produce additional scarring, and unequal growth can occur because of unequal epiphyseal arrest. We also do not feel that resection of the fibula is necessary, since this would not control spiking of the tibia, and the results of the synostosis procedure are not reliable.

Recommended Procedures

We would recommend that (1) the soft tissue flaps be left longer in children than in the adult amputee; (2) the fibula be cut short and that the bone be handled carefully so that splintering or undue trauma which may cause spurring will not be produced; and (3) the parents be advised that there could be problems of bone overgrowth and that revision of the amputation stump may be necessary in the future.

Heart Defects Linked With Arm And Hand Malformations

From Rehabilitation Literature December 1964, "Events and Comments", page 384

Kenneth B. Lewis, M.D., of Johns Hopkins Hospital, Baltimore, Md., told the Scientific Sessions of the American Heart Association on October 23, that cardiac defects often coexist with inborn abnormalities of the upper limbs. Without a special effort to discover such defects, they may be undiagnosed for many years.

With earlier diagnosis, the parents may be properly advised about exercise, medication, and diet, in preparation for the time when surgical correction, if indicated, may be done. Prompt diagnosis can prevent irreversible changes in the lungs, which might make surgical correction impossible later on.

Since the embryonic heart and large blood vessels are forming at the same time the upper limbs are (fourth week of gestation), anything affecting the embryo may disturb both structures. Dr. Lewis stated that the disturbing influence could be an error in the genes or environmental factors, such as drugs or exposure to German measles.

Robert L. Romano, M. D. and Ernest M. Burgess, M. D. Are associated with the Child Amputee and Congenital Deficiency Clinic Children's Orthopedic Hospital Seattle, Washington

1 von Saal, Frederick, "Amputations in Children," Surgery, Gynecology and Obstetrics, 1:708, 1943.