Hypothesis 2

Right tibial fracture with left hind proximal joint damage

Some crepitation was found during the orthopedic exam.  This could be due to a 
dislocated hip or stifle joint.  When the trauma occurred, one of the joint ligaments such 
as the ligament of the head of the femur, or one of the ligaments of the stifle may  have 
ruptured, causing laxity in either of these joints.  
Rupture of the joint capsule may have also occurred causing joint effusion, and 
therefore the swelling present in the left hind leg.  Inflammatory mediators were also 
attracted to the site, causing diffuse inflammation and swelling.
Furthermore, fracture could have occurred on one of the joint surfaces, such as the 
acetabulum of the hip joint, or the trochlear surfaces of the stifle, or the menisci of the 
stifle could have been damaged.  This could also induce inflammatory mediators, 
crepitation, and lack of weight bearing due to pain.

In this case, either of the other two hypotheses may be valid as well, with the joint damage, it is very likely that soft tissue injury occurred, and nerve damage may have occurred as well.

It must be noted that the entire body must be taken into account.  The integrity of the 
bladder must be assessed as well as that of the thorax.  With the traumatic incident, the 
bladder may have ruptured, and pneumo thorax or traumatic myocarditis may have 
occurred.