Surgical Ablation Of The Remaining Femoral Segment In Proximal Femoral Focal Deficiency: An Assessment of Three Cases
Edward F. Wenzlaff, M.D.
The bearing of weight through the hip which has no skeletal continuity with a dependent lower limb or stump usually results in a gait which is far inferior to that of the normal. Nevertheless, we marvel at times at the dexterity developed by children and adults who have this lack of bony continuity and the quality of the gait that they do develop.
From the recent literature it would appear that some surgeons are developing fairly definite opinions concerning the surgical and nonsurgical management of the various classes of PFFD. However, there is obviously still no unanimity of practice in the treatment of this entity. A decade ago, clear-cut treatment guidelines for the practicing surgeon were less evident than is the case today so that treatment was often based on the best individual judgment at the time. This paper presents seven- to ten-year follow-up information on three cases treated at this center.
In the late fifties an effort was made in our clinic to increase the hip stability of one of our PFFD patients. The approach was that of attempting to fuse the femoral segment to the pelvis. This attempt ultimately resulted in failure, since the fusion site broke down and a pseudarthrosis developed.
Later, in considering the problems involved in the prosthetic fitting of PFFD patients, it was felt that resection of the remaining femoral segment might be advantageous in walking and in fitting the prosthesis. Firstly, it was reasoned that resection of the femoral segment might make it possible to place the tibia in a closer relationship to the pelvis and/or the acetabulum, and thereby achieve some degree of stability in the relationship of the extremity to the pelvis. Secondly, removal of the femoral segment, it was hoped, might diminish the massive bulge of proximal thigh muscles, thus simplifying the fitting of the prosthesis. Thirdly, shortening of the extremity, it was believed, would contribute to the equalization of the prosthetic and normal knee centers.
Case No. 1
Fusion of the distal femoral segment to the pelvis was performed in August 1958 when J.S. was three-and-one-half years of age. Initially, it was felt that adequate healing was occurring but, in March 1959, a pseudarthrosis was evident (Fig. 1 ). In August 1961, the remaining femoral segment was resected. The operative area healed per primum and the child was fitted with a new prosthesis which incorporated a plastic socket with an anterior removable panel, a knee lock, SACH foot, and Silesian bandage. This boy has continued to demonstrate a satisfactory gait. It is doubtful, however, that removal of the femoral segment produced any real difference in his gait. Since the distal femoral segment was resected subperiosteally, there has been some regrowth of the distal femur, and an area of calcification measuring 3 cm x 3 cm has developed at the site of the residual femur (Fig. 2 ). At present, this boy is 14 years of age. His gait is characterized by a rolling lurch during the stance phase and considerable vaulting on the uninvolved extremity. The prosthetic knee joint is maintained in the locked position. He has been offered amputation of the right foot, primarily for cosmetic reasons and for greater ease in prosthetic fabrication, but has declined amputation.
Case No. 2
On September 19, 1961, when S.G. was two-and-one-half years of age (Fig. 3 ), the femoral segment was excised. The wound healed uneventfully and by February 1962 the child was walking well in a new prosthesis. Her gait over the years has been satisfactory. In September 1968, a Syme's amputation of the foot was carried out. She has good end-bearing on the stump but, of course, continues to demonstrate the gluteus medius rolling lurch-type gait. Recent X-rays have revealed calcification at the site of the excised femoral segment, much the same as was seen in the first case (Fig. 4 ). It is doubtful that resection of the femoral segment produced any advantages in this case.
Case No. 3
K.M. was 13 months of age when excision of the left femoral segment was performed on February 15, 1962 (Fig. 5 ). Postoperatively, the wound healed per primum and a pylon-type prosthesis was provided. There was rather marked abduction of the extremity for a year postoperatively, and satisfactory ambulation actually was not achieved on the first prosthesis. Push-pull films of this lad's left hip area taken in 1962 revealed that the proximal tibia was riding above the acetabulum (Fig. 6 ).
At this point consideration was given to the formation of an acetabular shelf, since his progress in gait training was slow. It was felt that some degree of stability about the hip might have been lost following the resection of the distal femur. However, by February 1963, his gait had greatly improved without further surgical procedures.
This boy has progressed satisfactorily and, by November 1968, he was able to walk quite rapidly but required Silesian strapping to retain the artificial limb. In this case there had been no appreciable amount of new bone formation at the site of the excised femoral segment such as was found in the two earlier cases.
The first goal, that of achieving placement of the proximal tibia in closer proximity to the pelvis and/or acetabulum, was not realized in any of these cases, and no increase in stability of the hip was obtained as a result of the operation. Indeed, it may well be that in those cases where the femoral segment was of adequate length, its removal would preclude the knee fusion which is sometimes attempted in these cases. With regard to the massive bulge of the proximal thigh muscles, removal of the femoral segment did not produce any appreciable change or diminution in the size of the muscle mass. In fact, the tissue bulk may actually have increased, at least temporarily, while the proximal tibia migrated still further proximally.
It can be stated that removal of the femoral segment produced no good results in the three cases outlined above. It is our feeling that in these cases resection of the foot by Syme's amputation, which is probably the most often performed surgical procedure, would have provided improved cosmesis and made prosthetic fitting much easier. We have had no experience with knee fusion or rotational osteotomy of the distal tibia.
Edward F. Wenzlaff, M.D. is associated with the Kernan Hospital Amputee Clinic Baltimore, Maryland