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CHAPTER 30
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The Child with a Limb Deficiency
as type II in the original Kalamchi classification. Jones type
3 tibial deficiency is extremely rare and consists of absence
of the proximal tibia with presence of the distal tibia. Finally,
in type 4 deficiency, there is diastasis of the distal tibiofibular
joint, where the talus is wedged between the distal tibia and
fibula and can articulate with the fibula alone or the fibula
and tibia.
The presence or absence of intact extensor mechanism
function is the primary initial decision point in the treatment
of these children. This usually coincides with the presence or
absence of a proximal tibia (cartilaginous or bony). This usu-
ally (but not always) depends on the presence of a proximal
tibial segment. A good radiographic clue is that in patients
who have a proximal portion of the tibia, the distal femoral
condyle is wider and the ossification of the epiphysis is better
than if it is not present.
An unusual type of tibial deficiency is that seen in asso-
ciation with fibular dimelia. Kumar and Kruger summarized
the sporadic reports until 1993 and presented the findings,
associated anomalies, and treatments in six patients (102). In
this deficiency, the tibia is absent and there is a duplication
of the fibula. These patients have a high incidence of other
anomalies, including visceral anomalies. The authors recom-
mended knee disarticulation if the femur is of normal length
and fusion of the fibula to create a sufficient lever arm if there
is associated PFFD.
Epidemiology and Etiology.
Tibial deficiency is much less
common than fibular deficiency, with an incidence reported
to be 1 in 1,000,000 live births (126). Also in contrast to
fibular deficiency, tibial deficiency can be genetically inher-
ited. Although most commonly this is seen as with autosomal
dominant inheritance, cases of autosomal recessive inheri-
tance have been reported by several authors (127–129). The
majority of patients with tibial deficiency will have associated
anomalies of the musculoskeletal and other organ systems,
with an incidence of approximately 75% (124, 130, 131).
Several well-described syndromes include tibial deficiency
among the list of findings (127, 132–134), and genetic coun-
seling is recommended.
Clinical Features.
The typical appearance of an infant
with tibial deficiency is a markedly shortened tibia with a rigid
equinovarus-supinated foot pointing toward the perineum
(Fig. 30-23). Preaxial polydactyly is the classic appearance of
the forefoot, although the absence of the preaxial rays or a split
foot deformity can also be seen. The fibula is prominent at the
proximal lateral aspect of the knee, and the knee is most often
unstable to AP and varus/valgus stress testing. The examin-
ing physician should actively look for other musculoskeletal
anomalies, such as preaxial upper limb polydactyly, hip dislo-
cation, or scoliosis.
Radiographic Features.
The Jones classification encom-
passes many of the radiographic features seen in these patients
with respect to the lower leg segment. Other findings include
proximal dislocation of the fibula into the distal lateral thigh
segment, which gives its common appearance on physical
exam. As mentioned previously, the distal femoral epiphysis
can exhibit delayed or absent ossification in Jones type Ia tibial
deficiency.
Other radiographic features are those of commonly asso-
ciated anomalies, such as hand or foot anomalies (preaxial
polydactyly, missing digits, or split hand or foot anomaly),
hip anomalies (DDH, PFFD, coxa valga), or spine anomalies
(congenital scoliosis).
FIGURE 30-22.
AP radiograph of the lower extremity in a patient
with type 1b tibial longitudinal deficiency. Note the increased ossifica-
tion of the distal femoral epiphysis as compared to Figure 30-21.
FIGURE 30-21.
AP radiograph of the lower extremity in a patient
with type Ia tibial longitudinal deficiency. Note the severely delayed
distal femoral epiphyseal ossification and absence of tibial ossification.
