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This is Section 2 of 5 from PFFD: A Congenital Anomaly,
National Academy of Sciences, 1969.
RICHARD E. KING, M.D.
Whenever a large sample of chaotic elements is taken in hand and
marshalled in order of their magnitude, an unsuspected and most
beautiful form of regularity proves to have been latent all
along.
-GALTON..,Natural Inheritance, 1889
By definition, the term "proximal femoral focal deficiency" implies that
the proximal femur is lacking in completeness. That this incompleteness is
only part of the problem was made clear by the study of many x-rays in an
attempt to cull true cases of this type from the morass of what has been
frequently classified as proximal femoral focal deficiency. A study of the
past literature has also revealed that not uncommonly cases of congenital
short femur, epiphyseal coxa vara, and phocomelia have been included with
the PFFD group (3, 18. 20, 25, 31, 45, 48, 51, 52 59).
CLASSIFICATION OF TYPES
It remained for Aitken (1) to present a workable classification that is easily
understood and that can serve as a background for the surgical correction
of this condition (Figure 1). As seen in Figure 2, Types A and B show elements
of the Proximal femur, i.e., acetabulum and head; whereas Types C and D show
no evidence of acetabulum and consequently no head or neck of the femur.
These four types all present clinically with a thigh that has the appearance
of a ship's funnel and is almost always flexed, abducted, and externally
rotated (Figure 3). It is not uncommon for the ankle on the affected side
to lie at the level of the knee joint on the normal side. Complete absence
of the fibula on the affected side is frequently associated with proximal
femoral focal deficiencies. Nilsonne (45) reports a 50 percent incidence,
Aitken (1) 70 percent, and Amstutz (2) 80 percent.
EMBRYOLOGY
Ossification is commonly delayed in congenital deformities, and this delay
is seen in proximal femoral focal deficiency also.
Because of the delayed ossification of the femoral head, ingenious attempts
to attain pelvi-femoral stability by bone graft from the shaft of the femur
to the acetabulum have been described in the literature (35, 50, 52).
Lloyd-Roberts (38) performed arthrography in two cases in order to outline
the process of delayed femoral head ossification, which was present in both
of his cases.
Much of this confusion can be resolved when we realize that the ilium and
proximal femur develop from a common cartilage anlage. The elements of head
and neck of the femur are actually hewn from this common block of cartilage,
and the hip joint appears as a cleft between the head of the femur and what
is later the acetabulum (19,30,32,36,47,56,57).
Laurenson (36) states that the head of the femur and the acetabulum gradually
separate from each other by formation of a cleft and then formation of a
definitive joint cavity. At nine weeks the embryonic hip joint resembles
the general form of the adult.
Figure 4-A represents a 17-mm embryo and shows the approximate size of the
limb bud. The development of the hip joint at this stage is shown in Figures
4-B and 4-C. The ilium, ischium, and pubis still consist of precartilage,
and the acetabulum shows little increase in its concavity. By this time the
head of the femur is slightly rounded, and while the acetabulum is not much
more concave than in younger specimens, there is nevertheless a slight depression
more marked medially which contains loose tissue and indicates a primitive
acetabular fossa (19, 56, 57).
At 22 mm (Figures 5-A, 5-B, and 5-C), the acetabulum deepens medially. Both
trochanters are now well defined, but the neck of the femur is short. Note
the beginning of cavitation at the periphery of the interzone where dissolution
is occurring to form the acetabular cleft. As chondrification proceeds in
the blastemal anlage, the portion of the blastema between femur and acetabulum
remains unchondrified to form a disc or interzone. However, at 20 mm its
middle portion becomes lighter in staining density and a three layered
arrangement is evident (19,56,57).
At 30 mm (Figures 6-A through 6-D), the acetabular cavity is well developed,
but obliterated at the center. Figures 7-A through 7-E trace embryological
development in fetuses from 73 to 270 mm. Figure 7-A shows the acetabular
fossa, fovea capitis femoris, and early vascularization at the femoral neck
and near the glenoid lip at 73 mm. In Figure 7-B, at 106 mm, vascularization
is considerably advanced and ligaments are well defined. Figure 7-C shows
increased ossification and vascularization at 180 mm. Figure 7-D, at 250
mm, depicts the proximal extent of diaphyseal ossification. At 270 mm, the
fovea capitis, filled with vascular tissue sharply demarcated from cartilage,
is shown in Figure 7-E (19,56,57).
A composite of fetuses from 44 mm to 126 mm is shown in Figure 8 to indicate
the relative external appearance of the lower extremity.
Since the lower limb develops in a proximodistal direction, and in view of
the embryological development described above, may we not infer that if an
acetabulum is visualized at birth a femoral head will appear? Conversely,
may we not assume that if no acetabulum is present at birth no elements of
proximal femur will appear?
This conclusion has been corroborated in our review of x-rays on over 100
cases of proximal femoral focal deficiency collected from various juvenile
amputee clinics throughout the United States. When we establish that a femoral
head is present, although delayed in ossification, our attempts at surgical
correction can be initiated earlier and without confusion as to whether or
not a femoral head is present (33, 34).
We can only postulate that the cause of this error of development is some
type of insult sustained by the embryonic lower extremity at the time that
the cleft which later represents the hip joint is being formed. Whether this
insult is some transient physical or chemical trauma to the limb bud at this
stage, we are not prepared to say (61, 62). It is significant that
Duraiswami (15), injecting insulin into the yolk sac on the sixth day of
the developing chick embryo, was able to produce some deficiency of the proximal
femur (Figures 9-A and 9-B).
TREATMENT
CONSERVATIVE
The nonstandard prosthesis typically fitted to all types of patients with
uncorrected proximal femoral focal deficiency usually includes a wide-mouthed
socket, a platform for support of the foot, and outside knee joints (Figures
10-A and 10-B). Functionally and cosmetically this prosthesis leaves much
to be desired.
SURGICAL
General Principles
Because of dissatisfaction with the results of conservative management, an
attempt has been made to convert surgically the existing elements of the
femur to a single skeletal lever so that a standard conventional prosthesis
could be used.
The usual deformity presented is one of external rotation, flexion, and abduction
of the proximal portion of the femur. The surgery performed usually does
not require that special attention be directed to these contractures, i.e.,
surgery directed toward completion and achievement of an intact skeletal
lever usually is sufficient to correct the contracture about the hip area.
Analysis of the skin, nerves, bone, joint, and musculature of a proximal
femoral focal deficiency reveals that a single skeletal lever with adequate
skin, no disturbance of the nerves or circulation, adequate bone, good joint
function, and musculature sufficient to move the skeletal lever can be achieved
surgically. In providing a skeletal lever, every effort should be made to
provide pelvi-femoral stability also.
It cannot be emphasized too frequently or strongly that each individual case
requires careful analysis if an appropriate solution to this formidable problem
is to be found. Also, the surgeon must be aware that if an acetabulum is
present at birth, elements of a femoral head will eventually develop Awareness
of this developmental sequence will obviate unnecessary attempts at obtaining
pelvi-femoral stability by such means as bifurcation, osteotomies, and bone
grafts (34,50,52).
Specific Surgical Techniques for Each of the Four Types of
Proximal Femoral Focal Deficiency in the Aitken Classification
Type A Type A proximal femoral focal deficiency can
be realigned by osteotomy for better mechanical leverage. This procedure
should be done at the subtrochanteric level, and the osteotomy site can be
held by internal fixation, pins, etc. A case in point is that of B.B., who
was first seen at the age of nine months. X-rays revealed a Type A proximal
femoral focal deficiency (Figure 11-A). At eighteen months x-rays revealed
developing varus with bending occurring at the subtrochanteric level (Figure
11-B). An osteotomy was done at the subtrochanteric level and fixed at 90
deg in a spica cast. Subsequent healing is shown in Figure 11-C. When the
patient was last seen, in May 1968, x-rays revealed complete remodeling of
the proximal femur (Figure 11-D). Clinical photographs of the stump and of
the patient in his prosthesis were made at this time (Figures 11-E and 11-F).
Type B Type B proximal femoral focal deficiency requires
realignment of the fragments to create a skeletal lever. Two case reports
demonstrate a planned approach to the achievement of this end.
P.M., initially seen at the age of 2 1/2 years, presented the flexion, external
rotation, and abduction of hip deformities typical of proximal femoral focal
deficiency (Figures 12-A and 12-B). This patient had never walked because
of lack of stability in the hip area. An attempt was made to align the skeletal
fragments over an intramedullary rod.
The area of pseudarthrosis between the neck of the femur and the elements
of the distal femur and its epiphysis was removed (Figure 13). This was good
cartilage in a dormant state of endochondral ossification, and mere realignment
of the fragments in a semblance of weight-bearing position was sufficient
to awaken it so that normal endochondral ossification could ensue (Figure
14) (8,51,52,59).
Figure 15 shows the fragments of the proximal and distal femur fixed over
an intramedullary rod, with the rod presented distally in the region of the
foot.
A knee arthrodesis was performed, concomitant with the realignment of the
femoral segments (Figure 16).
Figure 17 shows the final realignment of knee fusion and seudarthrosis to
make a single skeletal lever.
Approximately two months later a disarticulation at the ankle was performed.
The knee fusion was solid and the intramedullary rod was removed at the time
of the disarticulation (Figure 18). This procedure retains intact the epiphyses
of the distal femur and proximal and distal tibia. It is noteworthy that
the ankle disarticulation at this age provides a stump the distal end of
which is level with the opposite knee for a cosmetic prosthetic application
(Figures 19-A, 19-B, and 19-C).
With the skeletal lever stabilized, the range of motion and strength available
for prosthetic control is quite impressive (Figures 20-A, 20-B, and 20-C).
The patient was fitted with a conventional thigh-corset prosthesis with hip
control (Figures 21 -A and 21 -B).
At present, this patient plays on a soccer team and is active in every phase
of everyday childhood life. Sufficient time has not yet elapsed for proper
evaluation of the epiphyses of the distal femur and proximal and distal tibia.
However, the latest x-rays on this boy, taken in January 1967, still show
the epiphyses to be open, and 2 cm of growth have occurred in the single
skeletal segment (Figure 22).
P.D. was initially seen shortly after her birth on September 19, 1960, and
was followed through the Georgia Crippled Children's Service. The child's
thigh had the typical ship's funnel appearance, with the usual flexion, external
rotation, and abduction contractures (Figure 23-A). The patient was fitted
with an extension brace and ambulation was permitted., The child was referred
to the Juvenile Amputee Clinic in February 1965, at which time x-rays revealed
a Type B proximal femoral focal deficiency (Figure 23-B).
In April 1965, an attempt was made to place the sharpened spike of the distal
femur into a mortise in the femoral head (25,35,52). At the same
time a knee fusion was performed. The sequence of procedures was as follows:
a 6-mm intramedullary Kuntcher rod was driven retrograde through the tibia
and out of the foot. The femur was then threaded onto this rod to complete
the knee fusion. The rod was driven proximally into the femur. At this time
the sharp spike of the femur was placed into the mortise in the femoral head.
However, the upper end of the femur was bowed, and the intramedullary rod
came out laterally. Therefore, the entire limb was held in 90-deg abduction,
and the rod was driven into the anterior inferior spine of the ilium, thus
stabilizing the femoral-tibial segments in this position, as well as offering
a supporting strut to the epiphyseal-diaphyseal fusion (femoral head to the
femoral shaft). The patient was placed in a double spica cast with the affected
extremity in 90-deg abduction.
Sections from the proximal femur showed viable cartilage (Figure 24), and
sections from the epiphysis of the femoral head showed a viable but somewhat
disorganized epiphyseailline (Figure 25). On July 7, 1965, the spica was
removed, and x-rays revealed a thin spicule of bone from femur to femoral
head (Figure 26). It was felt that this spicule represented a precarious
attachment, and another spica was applied for an additional month. When this
cast was removed on August 11, 1965, x-rays were made in adduction and abduction,
and it was believed that the femur and femoral head moved as a single unit.
By February 15, 1966, the patient had been putting some weight on the foot,
and x-rays revealed that the thin spicule of bone had hypertrophied and was
now the thickness of a thumb (Figure 27). The knee also appeared to be solid.
The intramedullary rod was removed and at the same time a Syme's amputation
was performed (Figure 28).
On Much 23, 1966, the patient was found to have a stable hip with no flexion
contracture (Figure 29). Satisfactory stump abduction, flexion, and extension
were present (Figures 30-A through 30-D). On this date the patient was fitted
with a plastic funnel-shaped socket with an ischial seat, metal hip control,
single-axis knee, and SACH foot (Figures 31-A, 31 -B, and 31 -C).
The patient received prosthetics training and is now ambulating well. When
seen in July of 1966, x-rays revealed further apparent hypertrophy of the
proximal femur with a suggestion of increased growth of the femoral head.
The patient had developed an inexplicable line of translucency in the femoral
shaft (Figure 32). Perhaps this zone represented an area through which bending
may occur to cause a subsequent coxa vara. If necessary, osteotomy to realign
this bending could be performed later and should cause this zone to close.
However, x-rays taken in March 1967 showed this translucent zone to be closing
with use of the prosthesis (Figure 33).
Type C Patients with Type C proximal femoral focal
deficiency can only be offered a knee fusion to achieve a skeletal lever
since no pelvi-femoral stability exists or can be provided. Since the femur
usually presents as a long segment, the ankle joint lies at a level below
the knee joint of the normal leg. An example of this type of case is A.R.,
who was seen shortly after birth (Figures 34-A and 34-B). Subsequent x-rays
show surgical fusion of the knee. A below-knee amputation at the level of
the opposite knee was done after the knee fusion was solid (Figures 35-A
and 35-B). Follow-up two years after amputation has shown no evidence of
overgrowth.
Amputation of the affected leg will be at the below-knee level rather than
through the ankle in order to bring the prosthetic knee level with the normal
knee joint.
Since the distal tibial epiphysis is removed, this amputation should be done
as near growth completion as possible to decrease the chance of overgrowth
of tibia and fibula.
TYPE D Type D proximal femoral focal deficiency presents
a formidable problem, and we can only offer our contemplated plans for surgical
conversion. Pelvi-femoral stability can be achieved by a preliminary Chiari
tmnsirmominate osteotomy. Then the element of the distal femur can be fixed
to the pelvic shelf to allow the knee joint to serve as a hip joint. Later
a disarticulation of the ankle can be done so that a conventional prosthesis
may be worn. We have not as yet tried this procedure, but we feel that sufficient
musculature is present to flex and extend the knee joint so that it could
be made to act as an effective hip joint (Figures 36-A and 36-B).
CONCLUSIONS
An attempt has been made to use a classification system for proximal femoral
focal deficiency developed by Aitken that allows us to proceed to a planned
surgical approach for each of the four types identified. Each case should
be treateded separately, and the type of surgical conversion best suited
to the elements of the proximal femur present should be performed. It has
not been found necessary to correct the contractures present by a separate
procedure. In the conversions described in this paper, the contractures of
flexion, abduction, and external rotation are probably released through the
soft tissue dissection and femoral shortening associated with the knee fusion
which is done at the same time. The principle of establishing a single skeletal
lever by alignment of fragments over an intmmedullary rod has so far proven
sound. It has provided pelvi-femoral and skeletal stability of the femoral
segment upon which existing musculature can act to operate a prosthesis.
Although this is a preliminary report based on six cases of surgical conversion,
we have not as yet noticed any closure of epiphyseal lines due to the central
penetration of epiphyseal plates by an intramedullary rod. These thoughts
are presented in the hopes of stimulating others to an awareness that reasonable
function, comfort, and cosmesis result from this approach to these formidable
deformities.
BIBLIOGRAPHY
1. Aitken, G. T. Instructional Course Lecture, American Academy of Orthopaedic
Surgeons, 1967.
2. Amstutz, H. C. Personal communication.
3. Amstutz, H. C., and P. D. Wilson, Jr. Dysgenesis of the proximal femur
(coxa vara) and its surgical management. J. Bone Joint Surg. 44A(l): 1-24,
1962.
4. Arey, L. B. Developmental Anatomy, 6th ed. Philadelphia:W. B. Saunders
Company, 1954.
5. Bagg, H. J. Etiology of certain congenital structural defects. Amer. J.
Obstet. Gynec. 8: 131-141, 1924.
6. Bagg, H. J. Hereditary abnormalities of the limbs, their origin and
transmission; ii A morphological study with special reference to the etiology
of club-feet, syndactylism. hypodactylism, and congenital amputation in the
descendants of x-rayed mice. Amer. J. Anat. 43:167-219, 1929.
7. Bardeen, C. R., and W. H. Lewis. Development of the limbs, bodywall and
back in man. Amer. J. Anat. 1: 1-35, 1901.
8. Blenche, Mittheilung aus der orthopadischen Heilanstalt von Dr. Blenche
in Magdeburg. Ueber congenitalen Femurdefect. Z. Ortho. Chir. 9:584-656,
1901.
9. Borggreve, J. Kniegelenksersatz dutch das in der Beinlangsachse um 180
deg gedrehte Fussgelenk. Arch. Orthopad. Chir.28:175178, 1930.
10. Breasted, J. H.. ed. Edwin Smith Surgical Papyrus. Chicago: University
of Chicago Press, 1930 (Vol. 3, Univ. Chicago Oriental Inst. Publications).
11. Burgess, E. The surgical means of obtaining hip stability with motion
in congenital proximal femoral deficiency. ICIB I(3): 1-4, December 1961.
12. Campbell's Operative Orthopaedics, Vol. 2, pp. 2040-2042 (3rd Ed.). St.
Louis Mo.: The C. V. Mosby Company, 1956.
13. Cohn, I. Skeletal disturbances and anomalies, A clinical report and review
of the literature. Radiology 18:592-626, 1932.
14. Colonna, P. C. Some common congenital deformities and their orthopedic
treatment. N.Y. State J. Med. 28:713-714, 1928.
15. Duraiswamni, P. K. Experimental causation of congenital skeletal defects
and its significance in orthopedic surgery. J. Bone Joint Surg. 34B:646-698,
1952.
16. Duraiswami, P. K. Personal communication.
17. Fraser, F. C., and T. D. Fainstal. Causes of congenital defects: Review.
Amer. J. Dis Child. 82:593-603, 1951.
18. Freund, E. Congenital defects of femur, fibula and tibia. Arch. Surg.
33:349-391, 1936.
19. Gardner, E., and D. J. Gray. Prenatal development of the human Infants
and hip joint. Amer. J. Anat. 87:163-211, 1950.
20. Golding, F. C. Congenital coxa vara and the short femur. Proc. Roy. Soc.
Mod. 32:641-648, 1939.
21. Golding, F. C. Congenital coxa vara. J. Bone Joint Surg. 30B: 161-163,
1948.
22. Gordon, G. C. Congenital Deformities Edinburgh: E. & S. Livingstone,
Ltd., 1961.
23. Gruenwald, P. Mechanisms of abnormal development. Arch. Path. 44:398-436,
495-559, 648-664, 1947.
24. Gruenwaid, P. Developmental pathology; A new field in medicine. Amer.
J. Obstet. Gynec. 58:1-14, 1949.
25. Guilleminet, M., L Michel, and C. R. Michel Les absences congenitales
du femur. Rev. Chir. Orthop6d. 46:15-46, 1960.
26. Hall, John E. Rotation of congenitally hypoplastic lower limbs to use
the ankle joint as a knee. ICIB VI(2):3-9, 1966.
27. Hamilton, W. J., J. D. Boyd, and H. W. Mossman. Human Embryology. Baltimore:
Williams and Wilkins, 1952.
28. Haring, O. M., and F. J. Lewis. The etiology of congenital developmental
anomalies. Int Abstr. Surg., S.G.O. 113:1-18, 1961.
29. Harris, H. A. Congenital abnormalities of the skeleton, Chap. 18. In
The Chances of Morbid Inheritance. C. P. Blacker, ed. London: H. K.
Lewis, 1934.
30. Harrison, T. J. The influence of the femoral head on pelvic growth and
acetabular form in the rat. J. Anat. 95:12-24, 1961.
31. King, R. E. Concepts of proximal femoral focal deficiencies. ICIB
I(2):1-7,1961.
32. King, R. E. Proximal femoral focal deficiencies. ICIB 111(9): 1-5, 1964.
33. King, R. E. Surgical correction of proximal femoral focal deficiency.
ICIB IV(10):1-10. 1965.
34. King, R. E. Providing a single skeletal lever in proximal femoral focal
deficiency. ICIB VI(2):23-28, 1966.
35. Langston, H. H. Congenital defect of the shaft of the femur. Brit. J.
Surg. 27:162-165, 1939.
36. Laurenson, R D. Bilateral anomalous development of the hip joint. Post
mortem study of a human fetus, twenty-six weeks old. J. Bone Joint Surg.
46A(2):283-292, 1964.
37. Lewin, P. Congenital absence or defects of bones of the extremities.
Amer. J. Roentgenol. 4:431-448, 1917.
38. Lloyd-Roberts, G. C., and K. H. Stone. Congenital hypoplasia of the upper
femur. J. Bone Joint Surg. 45B(3):557-560, 1963.
39. Mall. F. P. On ossification centres in human embryos less than one hundred
days old. Amer. J. Anat. 5:433-458, 1906.
40. Manohar, K. Congenital absence of the right femur. Brit. J. Surg. 27:158-161,
1931.
41. Meyer, D. M., and W. Swanker. Anomalies of Children. New York: McGraw-Hill
Book Company, 1958.
42. Miller, H. C. Symposium on congenital anomalies: Scope and incidence
of congenital abnormalities Pediatrics 6:320-324, 1950
43. Murphy, D. P. Congenital Malformations. Philadelphia: J. B. Lippincott
Company, 1947.
44. Murphy, D. P. Symposium on orthopedic surgery; congenital malformations.
S. Clin. N. Amer. 33:1623-1631, 1953
45. Nilsonne, H. Uber den Kongenitalen Femur Defekt. Arch.Orthopadische
Unfall-Chirurgie. 26:138-169, 1928.
46. Ollerenshaw, R. Congenital defects of the long bones of the lower limb.
J. Bone Joint Surg. 7:528-552, 1925.
47. O'Rahilly, R. Morphological patterns in limb deficiencies and duplications.
Amer. J. Anat. 89:135-194, 1951
48. Reiner, M. Ueber den Congenitalen Femurdefect. Z. Ortho.Chir. 9:544-583,
1901
49. Reisner, G. A. The Hearst Medical Papyrus, University of California
Publications, Egyptian Archaeology, Vol. 1. Leipzig: J. C. Hinricks, 1905.
50. Ring, P. A. Congenital short femur. J. Bone Joint Surg. 41B: 73- 79,1959
51. Ring, P. A. Congenital abnormalities of the femur. Arch. Dis.Child.
36:410-417, 1961 .
52. Sideman, S. Agenesis femur-report of case. J. Int. Surg. 40:152-165,
1963.
53. Smith, G. E., and F. W. JoneL Archaeological Survey of Nubia, Report
for 1907-1908. VoL I and II. Report of Human Remains. Cairo: National Printing
Company, 1910.
54. Smith, G. E., and W. R. Dawson. Egyptian Mummies. London: Allen and Unwin,
1924.
55. Stransky, E., and Abad-Vasquez. On congenital malformations of the femur.
Ann. Pediat. 200:31-38, 1963.
56. Strayer, L., Jr. Embryology of the hip joinl Yale J. Biol. 16: 1-26,1943.
57. Strayer, L., Jr. Congenital deformities of lower extremity. A.A.O.S,
Proceedings, VoL VII, 1950.
58. Streeter, G. L. Focal deficiencies in fetal tissues and their relation
to intrauterine amputation. Contributions to Embryology, Carnegie Inst. of
Washington 22(414):I-44, 1930.
59. Teal, F. Personal communication.
60. Van Nes, C. P. Rotation-plasty for congenital defects of femur. J. Bone
Joint Surg. 32B:12-16, 1950.
61. Warkany, J. Some factors in the etiology of congenital malformations.
Amer. J. Ment Def. 50:231-241, 1945.
62. Warkany. J. Congenital anomalies. Pediatrics. 7:607-610, 1951.
This is Section 2 of 5 from PFFD: A Congenital Anomaly,
National Academy of Sciences, 1969.