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Chapter 17

The Leg

III NORMAL SKELETAL ANATOMY
injuries. Fractures of the femoral head, especially those
The leg of a bird is composed of a femur, tibiotarsus, involving the underlying growth plate (termed capital

fibula, tarsometatarsus, a single metatarsal bone (the physeal fractures), are often hard to see in the ventro-

first), and four digits. Some variation exists among the dorsal (VD) projection because of superimposition by
various species, depending on how and where the legs the overlying pelvic bones. Oblique VD views, which
are used (Figure 17-1). are very helpful in small mammals, usually provide
little or no additional information.
The radiographic diagnosis of femoral body frac-
III RADIOGRAPHY tures is usually straightforward, although hairline
breaks are exceptions that may require one or more
Radiography of the leg is similar to that of the wing oblique projections to identify with certainty. Just as in
(Figure 17-2) (see Chapter 1); however, there are some small mammals, minimally displaced distal femoral
important additional considerations. The fi rst consid- growth plate fractures can also be difficult to diagnose

eration is safety. The talons of a raptor are potentially unless a comparable projection of the opposite leg is
quite dangerous and exceedingly difficult to remove made.

once they have been deeply embedded in the fl esh of Distal femoral condylar fractures, particularly older
a person’s hand or arm, especially if the bird is strug- injuries in which there is substantial fragment dis-
gling to escape. For this reason, it is always advisable placement, can prove extremely challenging, as illus-
to wear protective leather gloves when handling trated in Figure 17-4. If the full extent of the injury is
raptors in preparation for radiography. not clear or appears confusing, the standard two-view
When radiographing a bird’s legs, it is important to study can be supplemented with lateral and medial
extend them fully to avoid end-on projection (termed oblique projections, in addition to at least two com-
the gun barrel sign), which is a sure indication the parison views of the opposite leg.

femurs were inadvertently flexed during the exposure
(Figure 17-3). Failure to properly extend the legs also III INJURIES TO THE GENUAL JOINT
results in a portion of the upper thigh superimposed
on the lateral aspects of the pelvis, making it hard to Fracture
discern bony detail.
It is imperative that all displaced, intraarticular frac-
tures of the distal femur or proximal tibia be reduced
III FEMORAL FRACTURES to avoid development of osteoarthritis, as well as the
pain and disability that typically accompany such an
Femoral fractures occur occasionally in birds but not outcome (Figure 17-5).
nearly as often as midextremital or lower extremital Text continued on p. 167.
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