A Different Viewpoint On Overgrowth

Claude N. Lambert, M.D.


In a recent issue of the Inter-Clinic Information Bulletin (January 1966), Dr. Robert L. Romano and Dr. Ernest M. Burgess presented a report on "Extremity Growth and Overgrowth Following Amputations in Children." In this article the authors reported on 52 patients on whom amputation had been performed, 44 in connection with congenital deficiencies and eight others for acquired conditions. The authors state, "Of these cases, only two showed overgrowth." They did not indicate whether the patients in whom these overgrowths occurred were congenital or acquired amputees.

In the Juvenile Amputee Course given at Northwestern University the experience of the faculty has repeatedly been expressed in the statement that "bony overgrowth is the most common complication of juvenile amputee surgery, and that the bones most frequently involved are the humerus, the tibia, and the fibula." The order of frequency with which these bones are involved may change from time to time or with different series of cases. Originally it was felt that overgrowth occurred most frequently in the tibia, but as additional cases were added, involvement of the humerus became more noticeable.

In reviewing our present cases of overgrowth at the University of Illinois Amputee Clinic, we find our distribution is as follows:

Femur

1

Tibia

12

Tibia and fibula

1

Humerus

3

Total

17

Of these 17 patients, six had one revision only. One was in the femur, one was in the tibia and fibula, and four were in the tibia alone.

Eight patients required two revisions-six in the tibia and two in the humerus.

One child has required three revisions, involving both tibia and fibula. One has required eight revisions, all in the humerus.

This gives a total of 34 revisions in 17 patients. Of these 17 patients, three are so-called congenital amputations (terminal transverse deficiencies), two are conversions of anomalies to amputations, and 12 are acquired amputations.

It should be noted here that in the two conversions of the congenital anomalies, amputation was performed through the long bones: in one case through the midportion of the tibia and fibula rather than an ankle disarticulation procedure; and in the other patient through the distal femur rather than a knee disarticulation. Based on our experience with these two cases it is recommended that in this kind of conversion, amputation should be done through joints as a joint disarticulation, instead of performing a transverse section through the big bones.

Bony overgrowth seems to be related entirely to a growth factor-that is, when the epiphyses close, this tendency to bony overgrowth diminishes. However, bony overgrowth of a stump has no relationship to epiphyseal growth, since it cannot be prevented by epiphysiodesis. This conclusion has been reached by many who have done an epiphysiodesis and still had bony overgrowth occur.

Even more important is the evidence obtained by placing metallic markers in the stump at the time of the revision and noting further or recurrent appositional bone growth beyond the markers. Attempts at synostosis or capping of the ends of the bone involved has not proved successful. In cases of fibular overgrowth, complete extraperiosteal resection may solve the problem for this bone. There is no real proof that leaving longer soft tissue flaps will prevent this phenomenon.

Our present caseload totals 677 juvenile amputees--418 males and 259 females. Of these, 368--191 males and 177 females--have congenital amputations. The remaining 309 children--227 males and 82 females--have acquired amputations. Three children who had so-called congenital amputations and two who had anomalies surgically converted showed bony overgrowth for a total of five cases, or 1.4%. The remaining 12 patients who showed bony overgrowth were in relation to the group of 309 children with acquired amputations, or approximately 3.9%.

While these percentages are rather low, they are still significant enough to justify the statement that bony overgrowth constitutes the most common complication in juvenile amputees.

In conclusion, we would again stress the value of doing disarticulations at whatever level is indicated rather than transverse sections, since the disarticulation type of amputation preserves whatever epiphyseal elements are present and also precludes the necessity of repeated operative procedures .

Claude N. Lambert, M.D. is associated with University of Illinois Amputee Clinic Chicago, Illinois