Problems of Treating and Fitting the Patient with Proximal Femoral Focal Deficiency

Leslie C. Meyer, M.D. Dewey Friddle, Jr., C.P.O. Russell W. Pratt, M.D.


With an entity as protean as PFFD few set rules can be rigidly formulated regarding the management of patients with this congenital defect. In almost every instance the ingenuity of the surgeon and prosthetist is necessary to habilitate these patients successfully. A workable classification and modern techniques of prosthetic fitting have made the task easier.

In an effort to trace the historical management of PFFD patients, all cases seen at the Shriners Hospital for Crippled Children, Greenville, S.C., over the past 35 years were studied. This series totaled 37 patients, representing a total of 47 extremities. The details of this study have been presented elsewhere7 and will not be repeated here. The statistical findings are very similar to those reported for other large groups of these patients. It was somewhat surprising to find that the methods of treating this condition, dating from 1935, were essentially the same as those followed at the present time. An initial platform prosthesis with a thigh cuff or an ischial ring was used until the child was old enough for accurate determination of the amount of femoral growth that would occur. This early management was followed by ankle disarticulation, fusion of the knee, and fitting of a prosthesis. No attempt was made to create an arthroplasty of the hip. On one occasion an effort was made to transplant an entire upper fibular segment to replace a defective upper femur. This attempt failed. One arthrodesis of the hip which was carried out was not considered to be successful.

Surgical procedures in the form of osteotomy of the upper end of the femur to improve the mechanics of the hip joint in Class A PFFD (Aitken's classification system for PFFD is used throughout; see reference 6) were performed. Bilateral cases were never converted if weight-bearing feet could be salvaged.

In two cases of Class A PFFD with significant shortening, tibial and femoral lengthening associated with shortening on the opposite side, either by femoral shortening or epiphysiodesis, was attempted. This surgery was done in response to the parents' desire to retain the foot at all costs. It proved to be unsuccessful. Only one Van Ness procedure was carried out and, while fitting did not prove to be a problem, retaining the desired rotation was difficult. Noticeable derotation began within a few weeks after fitting. In recent years greater emphasis has been placed on early disarticulation at the ankle, Syme-type, preferably before the age of four years. Fusion of the knee and epiphysiodesis as indicated are used to provide a single lever arm suitable for fitting with an above-knee prosthesis with a standard friction knee joint.

Kruer, our consultant in child psychiatry4, now advises us that the earlier amputation can be accomplished the better it is for the child. It is essential that the amputation be done before he develops an identity with his foot. It is much better for him to identify with a prosthesis. Between the ages of five and eight years particularly, it is thought that as little as possible should be done in the way of elective surgery because during these years the child believes that any surgical procedure is a direct personal assault.

The final conclusions of the reported study were :

  1. The hip joint-no surgical procedures were performed except for subtrochanteric osteotomies in patients with Class A PFFD after bony continuity of the femoral shaft and neck had been established.
  2. The knee joint-where production of an above-knee stump was feasible, an arthrodesis in full extension with epiphysiodesis was performed at the appropriate time, following careful growth studies.
  3. The ankle joint-disarticulation of the Syme's type has proven most satisfactory over the long term with no fitting problems encountered.
  4. The prosthesis-while a platform type of prosthesis may be used for early ambulation, early disarticulation and fitting as soon as possible after walking begins is the procedure of choice.
  5. Bilateral cases-no hip or knee surgery is advocated. Retention of the foot at all costs is recommended, cosmesis being the major indication for prosthetic fitting.

Numerous problems occur in the fitting of PFFD patients. We would now like to present two patients with rather unusual difficulties and the methods used to solve them:

Case No. 1-C.A.L., Shriners Hospital No. 10146 (Fig. 1 ), had a diagnosis of: 1) myelodysplasia; 2) hemivertebra; 3) proximal femoral focal deficiency; 4) absence of sacrum, complete; 5) scoliosis, secondary to hemivertebra; 6) plantar-flexed talus on the right; and 7) urinary incontinence. This patient was converted by modified ankle disarticulation of the Syme's type on the left. Because of the absence of bladder control, an ileal conduit was provided. The patient presented problems of both fitting and suspension, particularly since the ileal conduit was placed low in the abdomen on the right side. This, together with his scoliosis, made suspension difficult. The problem was solved by the use of an elastomer window suspension with a ship's-ventilator-type socket modified to control rotation (Fig. 2 ). The patient has worn this apparatus successfully and has been quite active. At the age of 16 years he continues to use this type of prosthesis without apparent complications or difficulty.

Case No. 2-C.E., Shriners Hospital No. 11925, is a Class D PFFD with a very short femoral segment and no functional power about the hip (Fig. 3 ). Obtaining stability in this case presented a considerable problem. The patient could only ambulate with a swing-to gait. Her gait was improved by fitting with a ship's-ventilator-type socket. The prosthesis was attached to a laminated pelvic band or belt similar to the proximal portion of a Canadian hip-disarticulation prosthesis. The band and prosthesis were connected by a drop-lock hip joint which, in the locked position, retained about 5 deg. of motion (Fig. 4 ).

This motion made a swing-through gait possible. For stability the knee axis was set behind the trochanter-ankle line as it is in the Canadian hip-disarticulation prosthesis (Fig. 5 ). This type of prosthesis improved the patient's reciprocal gait and helped control rotation.

Summary

  1. The findings of a historical study of 35 years of treatment of proximal femoral focal deficiency in a single institution are presented.
  2. Two problem cases with the methods of management used are discussed.

Shriners Hospital, Greenville, South Carolina

References:
1. Badger, Virginia M., Evaluation of foot conversions for congenital anomalies: Syme, Boyd, and Chopart. Inter-Clin. Information Bull., 8:12:1-17, Sept. 1969. 
2. Donaldson, William F., and H. Andrew Wissinger, Prosthetic fitting of a child with marked bilateral proximal femoral deficiencies, Inter-Clin. Information Bull., 6:6:1-13, Mar. 1967. 
3. Kruger, Leon M., Classification and prosthetic management of limb-deficient children, Inter.-Clin. Information Bull., 7:12:1-25, Sept. 1968. 
4. Kruer, Ingeborg, Personal communication. 
5. Meyer, Leslie C, Harry L. Bailey, and Dewey Friddle, Jr., An improved prosthesis for fitting the ankle-disarticulation amputee, Inter-Clin. Information Bull., 9:6:11 15, Mar. 1970. 
6. National Academy of Sciences, Proximal femoral focal deficiency-A congenital anomaly, Std. Book No. 309-01734-3, 1969. 
7. Ogden, William, and Leslie C. Meyer, Proximal femoral focal deficiency, presented at South Carolina Orthopaedic Association, Hilton Head Island, Sept. 1970.