The Surgical Means Of Obtaining Hip Stability With Motion In Congenital Proximal Femoral Deficiency
Ernest M. Burgess, M. D.
During the excellent meeting of the Subcommittee on Children's Prosthetics Problems in Washington, D. C, this past spring, a good deal of discussion centered around the surgical and prosthetic problems involved in congenital proximal femoral deficiencies. Dr. George Aitken, who has been particularly interested in this subject, presented his classification of cases and suggested means of surgical management. His observations were of great value to me and, I am sure, to the other surgeons present. Dr. Richard E. King, who is investigating the problem, wrote an article on this topic last month for the Inter-Clinic Information Bulletin. I am forwarding my thoughts on the subject together with several case studies to Dr. King.
I have eleven children under the age of fourteen with a total of thirteen involved extremities under active observation at this time. At normal walking age, we fit the child with a quadrilateral socket limb, carefully contoured for weight bearing about the pelvis. Initially, a fixed knee is used with a SACH Foot. The socket encompasses the entire remaining portion of the limb unless technical problems of limb length require modification. A pelvic band with single axis hip joint is usually required. Surgical revision of the limb, which is carried out before adolescence in most cases, permits the wearing of a standard prosthesis (usually A/K or knee disarticulation level).
The type of surgical revision depends, of course, upon the length of the limb, as well as the nature and function of component anatomy distal to the defect. A surgical arthrodesis of the knee may be necessary. The planning and execution of this surgery does not create any difficult problems except, of course, those posed on occasion in securing parental consent.
Selective Case Studies
The pelvi-femoral area presents the chief deterrent to proper limb fit and gait. The question of how to achieve stability and still retain a satisfactory degree of motion in the antero-posterior plane is very important. In the deficiency with a major portion of the femur remaining and with a capital epiphysis in the acetabulum, it may be possible to obtain a useful and stable hip by early radical osteotomy. The accompanying photographs depict one fifteen year and one nine year follow-up in which this was the case. The older child, now in high school, wears a suction above-knee prosthesis. She has, after a series of osteotomies performed at our hospital, developed a remarkably useful hip joint. Both represent what can be accomplished in certain selected cases.
In my opinion, this is the happiest possible result one could achieve in view of the initial problem. I would commend this surgical approach for your consideration in the selected long femur cases. The remarkable physiological stress response is an unforgettable lesson in the adaptive reaction of growing bone. In a future article, I hope to present in detail the technical aspects of the parallel pelvic support osteotomy we use.
With increasingly severe defects, we have attempted to center the proximal femur in the acetabulum either by osteotomy or re-position. By this means, we hope to improve stability and still not sacrifice too much hip motion. This surgical approach is complicated by the fact that the
axis of knee motion is usually transverse (at a right angle) to the line of body progression. We have attempted to more closely correlate the two planes of movement while performing the hip stabilizing surgery. I am certain all of you have attempted the same surgical maneuver with indifferent to poor results. It is our feeling that a degree of benefit has been obtained in a few of these cases.
In those patients with the very short distal femur and with the knee joint almost at the level of the hip, great difficulty is encountered in attempting to obtain stability by reposition or osteotomy. I now have two children on whom we hope to rotate an additional 80-90° by osteotomy so that the knee joint faces directly backwards and tibial flexion is carried along the line of body progression. I am sure that this can be done surgically. It is possible that two operations would be involved - one to obtain stability of the femoral fragment against the pelvis and the second to convert the axis of knee movement; or it may be possible to accomplish both by a single operative procedure. This is experimental surgery and the functional benefit is problematical .
The final approach to this problem is, of course, to do no surgery at hip level and to compensate by exerting all ingenuity possible in limb fabrication and design. There is certainly no point in carrying out extensive surgery if little is accomplished. It is my firm belief, however, that we can improve these cases by one or more of the three surgical approaches outlined. This deformity is uncommon. I am certain that the Inter-Clinic approach will be especially valuable in problems of this type.
Ernest Burgess is Chief, Amputations and Prosthetics, Childrens Orthopedic Hospital Seattle, Washington