Weinstein Lovell and Winters Pediatric Orthopaedics 7e

1539

CHAPTER 30  |  The Child with a Limb Deficiency

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

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.