CHAPTER 30
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The Child with a Limb Deficiency
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A
B
FIGURE 30-7.
A,B
: Type Ib fibular deficiency (Achterman and
Kalamchi), in which the proximal fibula is missing. This type is often
associated with proximal focal deficiency, as in this child.
A
B
FIGURE 30-8.
Type II fibular deficiency. The entire fibula is missing, and there is an
anterior tibial bow and missing lateral foot rays.
Birch et al. (76) have proposed a functional classification
on the basis of the functionality of the foot and the limb-length
discrepancy as a percentage of the opposite side. The central
question in this classification is “is the foot functional?” If it is,
the degree of shortening is defined. Those with lesser amounts
of shortening can be managed by epiphysiodesis or shoe lift
(<5%), single lengthening (6% to 10%), at least two lengthen-
ing (10% to 30%), and multiple lengthening or amputation
(>30%). For those with a nonfunctional foot, amputation is
advised, unless there is concomitant upper extremity deficiency
such that the foot is functionally used as a hand.
Epidemiology and Etiology.
Considering congenital
lower extremity limb deficiencies, fibular deficiency is the most
common long-bone deficiency, with an incidence between 7.4
and 20 per million live births (5, 77). The incidence of fibular
deficiency would be much higher if up to 80% of patients with
PFFD having fibular deficiency were included. The etiology of
fibular longitudinal deficiency is not known but is sporadic.
Clinical Features.
Although the name fibular deficiency
implies a localized deficiency, patients often have typical
clinical features throughout the entire limb. There is a wide
variation in the scope of the deficiency. Typically, the limb
is characterized by a rigid valgus foot, often with one or two
