PROXIMAL FEMORAL FOCAL DEFICIENCY-A REVIEW OF TREATMENT EXPERIENCES

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This is Section 5 of 5 from PFFD: A Congenital Anomaly,
National Academy of Sciences, 1969.

G. WILBUR WESTIN, M.D.

FINN 0. GUNDERSON, M.D.

PROXIMAL FEMORAL FOCAL DEFICIENCY-

A Review of Treatment Experiences

To evaluate the treatment of proximal femoral focal deficiency (PFFD), 165
cases of this relatively uncommon anomaly have been reviewed. It was believed
that by gathering cases from all of the Shriners Hospitals, reviewing the
history and treatment of these patients, and reporting on composite experience,
a rational approach to this difficult problem would evolve. In the past,
treatment had involved the accommodation of the deformity in some type of
prosthesis or brace. Collective experience now favors early elimination of
the defect by surgical conversion to an amputation-type stump which provides
improved function and cosmesis.

MATERIAL

All seventeen units of the Shriners Hospitals for Crippled Children contributed
detailed information on 165 cases of PFFD. These cases were located with
the help of the central office in Chicago, where computer records of all
Shriners Hospital patients, past and present, are located. A total of 400
patient records were reviewed by the doctors in each unit, and those falling
into the category of PFFD were reported in detail. Further information, including
copies of operative reports, x-rays, and progress notes, was obtained. Treatment
has ranged from prosthetic fitting alone to multiple surgical procedures.
Of the 165 patients in the PFFD category, 70 were treated without surgery
and 95 with surgery. The surgical approach to these 95 patients was evaluated
in detail.

THE DISEASE STATE

The etiology of PFFD is unknown. It is known that the development of the
limb buds takes place early in fetal life, beginning at about four weeks'
gestation. Various factors act upon the developing limb, resulting in rotation,
segmentation, longitudinal growth, and differentiation of elements. The most
proximal elements of the limb develop first (4, 6), and the hand
and foot follow, being fully formed by the seventh week. Chemical toxicity
(6), radiation (6), enzyme alterations, viral infections (6), and mechanical
trauma (10) have produced limb anomalies in humans and experimental animals.
Ring (14, 15) has stated that the primary problem is in the enchondral
ossification of defective cartilage. Gardner (6) pointed out that failure
of skeletal elements to form may be due to factors operating during the period
of differentiation. This critical period-at four to eight weeks of fetal
life-was defined by studies of thalidomide babies. It is apparent from these
and other studies that as the severity of the defect increases, so does the
incidence of associated anomalies. A multifocal process must be supposed,
and it must act over a period of time, the severity and variety of involvement
increasing with the duration of the process. The frequency (50 percent) of
congenital absence of the fibula in cases of PFFD (Table 1) supports this
theory, since the more distal portions of the limb develop last.

TABLE 1        Associated Anomalies (in percentage)

The theory advanced by Morgan and Somerville (10), that mechanical trauma
to the advancing growth plate interferes with the development of normal infantile
valgus, may be appropriate for simple coxa vara, but it does not explain
the wide dissociation of fragments seen in the typical case of PFFD. Among
the unexplained features of this anomaly is the frequent presence in the
acetabulum of a vestigial femoral head, often completely dissociated from
a small shaft element. Perhaps the head has a separate impetus to develop
associated with its position in the acetabulum. Review of the prenatal and
familial history in these patients reveals no consistent factor. Breech
presentation was the only frequently recorded variation from normal (18 percent).
Two cases of nonidentical twins were found, and in each set only one of the
twins had phocomelia. There is one reference to a set of twins (14) with
phocomelia present in both children. This variability raises the question
of individual susceptibility, whatever the cause. We believe that the evidence
points to an etiology extrinsic to the fetus.

THE CLINICAL PICTURE

The deformity is commonly noted at birth. The thigh is shortened and bulky.
There are usually flexion contractures of the hip and knee. After the patient
learns to walk, there is a short-leg gait, a gluteus medius limp, and the
foot is in equinus. Relative shortening of the extremity is progressive,
carrying the knee higher and higher. In mild cases, early x-rays may show
absence of the capital femoral epiphysis and a normal femoral shaft. This
picture often leads to an erroneous diagnosis of congenital dislocation of
the hip (Figure 1-A).

The deformity makes bracing or prosthetic fitting increasingly difficult.
The hip- and knee-flexion contractures and associated anomalies contribute
to the orthotic problem. Symptoms are related to the shortening of the limb
and hip instability. Hip pain is seldom a complaint (9). In spite of the
complete separation of the shaft from proximal elements, little or no telescoping
occurs with weight-bearing. Apparently the short rotators and iliopsoas
contribute to this stability. The abductor lurch is quite prominent.

TREATMENT

Since 1950 the majority of these patients have been treated surgically. The
purpose of the surgery has been to: (1) improve prosthetic fitting and use,
(2) improve hip stability and prevent increasing deformity, and (3) equalize
leg lengths.

Amputation, knee arthrodesis, and occasionally rotation osteotomy have been
used to help prosthetic fit and use. Leg lengthening has been attempted with
little real success. Hip surgery has included a number of procedures, the
most common being valgus osteotomy. Arthroplasty has not been a success in
reconstituting a satisfactory femoral-acetabular joint. Soft tissue release
at the knee or hip done solely for flexion contracture has failed
repeatedly!

AMPUTATION

The most common procedure has been amputation, which was performed on 59
patients (Table 2). The Syme's type of ankle disarticulation has been the
most satisfactory operation performed. Four of the below-knee and one of
the foot amputations (a Chopart's) required revision. The goal of amputation
is a long, above-knee, end-bearing stump that can be easily fitted in a standard
prosthesis.

TABLE 2         Amputation Levels

KNEE ARTHRODESIS

Knee arthrodesis was performed on 31 patients (Table 3). Amputation accompanied
the arthrodesis in 25 of these cases. It was found that after knee arthrodesis
in full extension, the hip-flexion contracture was spontaneously corrected.
One or both of the epiphyses at the knee can be excised, the goal being a
long above-knee stump at maturity. Two knee fusions were considered delayed
unions after the patients fell during the healing process, requiring further
immobilization to achieve union.

TABLE 3             Knee Arthrodesis

LEG LENGTHENING

Leg lengthening has been attempted in nine cases with little success and
frequent complications (Table 4). In no instance was leg length equalized.
One of the criteria (18) for consideration of femoral lengthening is the
presence of a stable hip and knee rarely found in PFFD.

TABLE 4             Leg-Lengthening Procedures

ROTATION OSTEOTOMY

Eight patients have had the Borggreve rotational osteotomy (as described
by Van Nes, 17 ) or a modification thereof; (Table 5). This operation externally
rotates the foot 180 deg by tibial or femoral osteotomy so that the ankle
joint functions as a knee joint. Power from the plantar flexors is used to
extend the prosthetic leg. Attaining 180 deg of rotation usually requires
two or more operations and frequently many months in the hospital. In our
group of cases, only two of the eight patients so treated can be classified
as successful. Two cases were complete failures, necessitating return to
the original position. The other four patients failed to gain full rotation.
The cosmetic deformity of a foot  pointing the wrong way could be
distressing to some patients, especially girls. This, together with the prolonged
treatment time, may outweigh the functional advantage.

TABLE 5           Rotational Osteotomy

EXCISION OF THE FEMORAL FRAGMENT

In nine patients the proximal end of the tibia was placed into the acetabulum
after excision of the short femoral fragment (Table 6). Deepening of the
acetabulum accompanied four of these transfers. The growing tibial epiphysis
tends to accommodate to the shape of the acetabulum. The procedure is usually
accompanied by Syme's amputation. The abductors, when present, are transferred
distally on the shaft of the tibia to give added abductor strength.

The patients had a decreased range of motion and especially had decreased
flexion power in the reconstructed hip In the more severe types of PFFD there
may be no acetabulum. Without an acetabulum, we would caution against this
type of conversion.

TABLE 6                   Excision
of the Femoral Fragment (a)

(a) When excision of the femoral fragment is accompanied by arthroplasty,
stability is increased. Good extension power is retained, but flexion is
weak. Excision of the femoral fragment eliminates the hip- and knee-flexion
contractures.

PROXIMAL FEMORAL OSTEOTOMY

The most common surgical procedure at the hip joint was subtrochanteric valgus
osteotomy (Table 7). These procedures have been successful in correcting
varus in only one third of the operations performed. The low success rate
is attributed to failure to recognize the abnormal anatomy of the femur at
the time of osteotomy. Some hips have no femoral head ossification or significant
development of the acetabulum. Others have an intact cartilaginous continuity
from the short femoral shaft to the ossifying femoral head. In all our cases
where such a cartilaginous bridge was present, osteotomy was unsuccessful
(Figures 1-A through 1-G). Only when ossification of the femoral head, neck,
and shaft have progressed to bony continuity at the site of osteotomy (Figures
2-A, 2-B, and 2-C), or when the cartilaginous portion can be excised to produce
bony continuity, will this procedure be successful.

The success rate of the osteotomies done to correct varus was directly related
to the amount of unossified cartilage between the head and the shaft, and
to the age of the patients. A fair success rate was achieved in coxa vara
with shortening where the growth plate was narrow. In those cases where a
wide, abnormal cartilaginous bridge was present, the osteotomy always failed
-the pin or plate pulled out of the cartilage and the fixation was lost.
Further ossification occurs with age, and the defect can then be excised
with fusion of the neck or head of the femur to the shaft in valgus. This
procedure is usually possible by the age of eight to ten years. The abnormal
proximal growth plate does not represent a significant consideration.

TABLE 7               

 Proximal Femoral Osteotomy

ARTHROPLASTY OF THE HIP

In nine patients, attempts were made to obtain increased stability of the
hip by arthroplasty. Six of the thirteen operations performed were reported
as increasing stability (Table 8). Four of these were in the previously mentioned
cases where excision of the femoral fragment was followed by acetabular
deepening. One patient died during surgery. Bilateral procedures were performed
in two cases. In one of these, mold-shaft arthroplasty apparently gave a
fair result. Two fascia lata arthroplasties were failures. In the remaining
cases the acetabulum was cleared of bone remnants and fibrous tissue and
the proximal femoral shaft or trochanter reduced into it. Only one of these
was reported as having a good result.

Evaluation of these results is difficult; hence, status has been indicated
as accurately as possible, or questionnaire has been quoted. It appears that
the majority of these procedures have not been successful in increasing function.
In only one was the Trendelenberg test negative.

TABLE 8      Arthroplasty of the Hip

HIP ARTHRODESIS

Hip arthrodesis has not usually been a beneficial procedure (Table 9). Such
a procedure is contraindicated if a prosthesis is to be fitted on the same
side.

TABLE 9               Arthrodesis of the
Hip

CONCLUSIONS AND RECOMMENDATIONS

Most of the Shriners Hospitals' surgeons have struggled through similar patterns
of treatment. The following recommendations are made as a result of this
review:

Hip Joint: No surgery except subtrochanteric osteotomy in the presence
of (or being able to obtain) bone continuity of the femoral neck and shaft.

Excision of the femoral fragment has produced a satisfactory result in a
few cases, especially when accompanied by acetabuloplasty. It should be
considered only in the more severe cases where there is no proximal continuity,
as it precludes the possibility of performing other procedures for hip stability
should future bone development unite the femoral head to the shaft.

Knee Joint: Arthrodesis in full extension. Excise (neither, one,
or both) adjacent epiphyses dependent upon projected future growth.

Knee fusion provides a stable extremity in good alignment under the pelvis
and well suited for fitting an above-knee prosthesis. Enough bone should
be removed to obtain full extension at the operating table without soft tissue
release. Postoperatively it may be necessary to cast the involved extremity
in considerable flexion and/or abduction. However, after removal of the cast,
the extremity readily assumes full extension, thereby correcting flexion
contractures of the hip as well as the knee joint.

Ankle: Disarticulation using the heel pad for end-bearing. The
Syme's-type ankle disarticulation provides excellent endbearing and simplifies
the fitting of a prosthesis.

Prosthesis: The prosthesis should be designed for end-bearing
(total-contact socket).

Conversion of the patient to an amputee is recommended as soon as the growth
potential of the extremity can be determined with reasonable accuracy. This
should be done before the child attends school and hopefully may make it
possible for him to proceed in an unrestricted fashion throughout growth
and development.

ACKNOWLEDGMENT

The authors wish to express appreciation to each unit of the Shriners Hospitals
for contributions of information and participation in the analysis of the
data contained in this paper.

BIBLIOGRAPHY

1. Aitken, G. T. Amputation as a treatment for certain lowerextremity congenital
abnormalities. J. Bone Joint Surg. 41A(,7): 1267-1285, 1959.

2. Amstutz, H. C., and P. D. Wilson, Jr. Dys2enesis of the proximal femur
(coxa vara) and its surgical management. J. Bone Joint Surg. 44A(l): 1-24,
1962.

3. Babb, F. S., R. K. Ghormley, and C. C. Chatterton. Congenital coxa vara.
J. Bone Joint Surg. 3 IA: 1 15-131, 1949.

4. Borggreve, J., Kniegelenksersatz dutch das in der Beinlangsachse um 180'
gedrehte Fussgelenk. Arch. Orthopad. Chir. 28:175-178. 1930.

5. Frantz, C. H., and R. O'Rahilly. Congenital skeletal limb deficiencies.
J. Bone Joint Surg. 43A(8):1202-1224, 1961.

6. Gardner, E. D. The development and growth of bones and joints. A.A.O.S.
Instructional Course Lecture. J. Bone Joint Sure. 45A(4):856-862, 1963.

7. Golding, F. C. Congenital coxa vara. J. Bone Joint Surg. 30B(l): 161-163,
1948.

8. Lloyd-Roberts, G. C., and K. H. Stone. Congenital hypoplasia of the upper
femur. J. Bone Joint Surg. 45B(3):557-560, 1963.

9. Mital, M. A., K. S. Masalawalla, and M. G. Desai. Bilateral con-enitai
aplasia of the femur. J. Bone Joint Surg. 45B(3):561-565, 1963.

10. Morgan, J. D., and E. W. Somerville. Normal and abnormal growth at the
upper end of the femur. J. Bone Joint Surg. 42B:264-272, 1960.

11. Noble, T. P., and E. D. Hauser. Coxa vara. Arch. Sur-. 12:501-538,1926.

12. Ollerenshaw, R. Congenital defects of the long bones of the lower limb.
J. Bone Joint Surg. 7:528-552, 1925.

13. O'Rahilly, R. The development and the developmental disturbances of the
Limbs. Irish J. Med. Sci., No. 397:30-33, 1959.

14. Ring, P. A. Congenital short femur. J. Bone Joint Surg. 41B: 73-79, 1959.

15. Ring, P. A. Congenital abnormalities of the femur. Arch. Dis. Child.
36:410-417, 1961.

16. Trueta. J. The normal vascular anatomy of the human femoral head during
growth. J. Bone Joint Surg. 39B:358-394, 1957.

17. Van Nes, C. P. Rotation-plasty for congenital defects of femur. J. Bone
Joint Surg. 32B: 12-16, 1950.

18. Westin, G. W. Femoral lengthening using a periosteal sleeve. J. Bone
Joint Surg. 49A(5):836-854, 1967.

19. Wood, W. L., N. Zlotsky, and G. W. Westin. Congenital absence of the
fibula; treatment by Syme amputation-indications and technique. J. Bone Joint
Surg. 47A(6):1159-1169, 1965.

This is Section 5 of 5 from PFFD: A Congenital Anomaly,
National Academy of Sciences, 1969.