Biomedical Engineering Reference
In-Depth Information
Etiology/Risk Factors/Transmission/Species
Acute orthopedic injuries may occur in nonhuman primates
as the result of intraspecies aggression, falling or jumping
from excessive heights, attempting to remove an entrapped
limb from faulty caging materials, and poor capture tech-
nique. Injuries include fractures, ligament or tendon
ruptures, sprains, and luxations. Animals that reside in
outdoor breeding colonies are at much higher risk for acute
orthopedic injury than those that are housed indoors
because of exposure to large peer group social housing, the
presence of climbing structures, increased vertical space for
climbing, and open range for running and subsequent
athletic type, musculoskeletal injury. This section addresses
the medical care that should be provided from the time of
presentation to surgical repair of severe orthopedic injuries.
Open fractures are the most serious type of orthopedic
injuries listed above and require prompt assessment and
treatment to prevent long-lasting or irreversible negative
sequelae. This section will primarily describe management
of open fractures since these are the type of orthopedic
injuries that most often require emergency treatment and
critical care. Open fractures are categorized based on the
direction and amplitude of energy causing the wound. For
example, a Type I open fracture is caused by low-energy
protrusion of a bone fragment through the skin with
minimal tissue damage and a skin wound of less than 1 cm
in length. On the other hand, a Type II open fracture
involves a penetrating external wound. Type II open frac-
tures are always more contaminated than Type I open
fractures and are also more likely to be comminuted, with
minor crushing injury to surrounding soft tissues. Type III
open fractures are the result of high-energy external forces.
They are likely to be severely contaminated and commi-
nuted with more extensive crushing to the associated soft
tissues. Finally, Type IVopen fractures involve amputation
or near-amputation of
patient has multiple injuries, some involving systems other
than musculoskeletal. Severe injury to other systems must
be addressed prior to proceeding with the orthopedic
emergency unless the orthopedic emergency is life threat-
ening (e.g. hemorrhage or fracture fragment protrusion into
a vital organ). Once the general physical examination is
completed and the patient is stabilized, an orthopedic
examination is performed. Palpation may reveal displace-
ment of bone ends, crepitation, or abnormal mobility.
Range of motion should be determined for joints and
a notation made of any muscle atrophy or asymmetry when
the injured limb is compared to the contralateral limb.
There may be specific diagnostic tests utilized to diagnose
ligamentous injuries such as the presence of cranial drawer
movement in the stifle joint or laxity and hyperextension in
a luxated radiocarpal joint. The degree of tissue perfusion,
temperature, presence of hemorrhage, degree of contami-
nation, and response to stimulation should be noted in the
injured limb. If the diagnosis is not evident immediately,
observation of the animal's gait may add important infor-
mation to establish or confirm which limb is involved.
Radiographs in the dorsoventral position and lateral views
should be taken in any case in which orthopedic trauma is
suspected. Culture and sensitivity should be performed on
any wounds that appear to be contaminated or infected.
Treatment/Management/Prognosis
Initial management of acute orthopedic trauma is aimed at
reducing contamination, immobilizing the limb, preserving
the vasculature, and minimizing pain. Analgesic therapy
should be instituted. If the fracture is closed, the aim is to
prevent it from converting to a Type I open fracture
(
Figure 15.10
). Open fractures are always contaminated
and should be considered surgical emergencies. If not
treated until 8 hours after injury or more, open fractures
should be treated as infected. Delay in fracture stabilization
longer than 48 hours after injury is associated with a poorer
functional outcome, especially when joints or growth plates
are involved (
DeLong et al., 1999; Grant and Olds, 2003
).
The first step in managing an open fracture is to assess the
vascular and neurological status of the limb (
McCarthy,
2009
). Distal extremities are palpated for a pulse or for
a temperature to ensure adequate blood flow. The wound
should be assessed, but not probed so as to avoid further
contamination. If bone is protruding from the wound, the
best course of action is to avoid pushing it back into the
wound so as to avoid further contamination.
The wound should be debrided within 6
an extremity (
Mann, 2006;
McCarthy, 2009
).
Clinical Signs
Clinical signs of orthopedic trauma include lameness,
angular limb deformity, and severe soft tissue swelling.
Open fractures have associated wounds, which may include
bite wound trauma if the injury is the result of intraspecies
aggression. Depending on the extent and cause of the
injury, other signs of trauma may be observed in systems
other than musculoskeletal.
8 hours and
lavaged with sterile saline or 0.05% chlorhexidine using
strict asepsis. The treatment of traumatic soft tissue wounds
should follow the procedures as described in the wounding
section of this chapter (see the section “Fight wound
trauma” above). Wounds that are surgically clean may be
e
Diagnostics
A thorough physical examination should be performed
prior to focusing on the presenting orthopedic emergency to
rule out involvement of other critical systems that would
require emergency intervention. In many of these cases, the
