LEARNING OBJECTIVES
1. 


 

2. what are the nutritional factors that may predispose to poor bone growth/function and 
therefore may make animal more susceptible to fracture with trauma?  The doberman is 
currently being fed Big Red Generic brand dog food. We do not have any information 
on what the dog was fed as a puppy but if not fed high quality food in correct 
proportions ( especially correct Ca2+ /P ratio) bone development may not have been 
optimal.  With any trauma it is reasonable to expect that there might be fractures, even 
with optimal nutrition but with suboptimal nutrition we may have bones that will fracture 
more readilyÉ We might also expect joints to not be as stable ( esp in the hip area, 
large breed, fast growing) but there was no indication of subluzations of the hip 
joint/sacroiliac joint; therefore we suspect that the trauma was severe enough along to 
cause the fractures.  We would like to discuss nutrtion with the owners post surgery in 
order to possibly facilitate better healing.

3. what does deep and superficial pain sensation indicate

The lateral spinalthalmic tract is the pain tract.  In animals this tract is transmitted both 
ipsi and contralateral.  Since superifical and deep pain fibers are smaller than those 
associated with motor function and proprioception,  ( and are located at deeper levels 
within the spinal cord as compared to more superficial location  of the proprioceptive 
and motor fibers) these are the last to loose function during compressive spinal cord 
disease.  The clinical significances of this fact is that animls with loss of motor function 
and proprioception but with intact pain sensation ( as in this case)  have a better 
prognosis ( less cord damage) than do those that have also lost deep pain sensation.  
Since both deep and superficial pain are present we are assuming that the primary 
problem is motor dysfunction due to trauma/instability of bone rather than spinal cord 
compression. 

4. what are reflex responses
what does it mean if they are not repeatable

Below are the major nerves that need to be checked for in a neurologic exam of the hind 
limb/pelvic.  The unrepeatability of the reflexes may be due to pain. We are actually still 
unsure as to what the unrepeatability means.  There may be occasional decreases in 
respsonse due to the tauma/muscle damage. The books we found were very extensive and 
seemed way too indepth to go into.


The major nerves of the pelvic limb are the femoral, obturator, sciatic, peroneal, tibial, 
pudendal, sacral and pelvic nerves, and caudal nerves.

The femoral nerve arises from the most cranial portion of the plexus and innervate the most 
cranial muscle mass in the pelvic limb ( the quadriceps).  The autonomous test site for the 
temoral nerve is just distal to the femoral epicondyle

Obturator is a purely motor nerve which supplies the adductor muscles. 

Sciatic nerve: intrapelvic portion is the lumbosacral trunk.  The sciatic nerve innervates the 
most caudal muscle groups on the thigh, the hamstrings.   At the level of the stifle the sciatic 
divides into the peroneal and tibial nerve.

Pudendal:  does not innervate any major limb muscles. Branches are motor to the muslces 
of the pelvic diaphragm and external anal and urethral sphincters.   

Sacral and pelvic nerves arrive independently from the caudal part of the plexus, and supply 
autonomic innervation to the pelvic viscera

Caudal nerves: arise from most caudal portion of caudal equina and supply innervatino to 
the tail.

5. why is one leg only locally swollen where as the other leg is diffusely swollen? Again 
we could not find any definites on this but we hypothesize that this is due to the way the 
animal was hit by the car. Potentially the area with more direct hit  had a more local 
swelling whereas the are that fell to the ground might have the more diffuse swelling due 
to the overall increase in surface area that was impacted.


6. what can cause subcutaneous fluid accumulation?
We are not quite sure what may have caused this be we suspect that there is a hematoma 
on the leg. Ruptured blood vessels leading to accumulation of fluid.

7. what are the different types of fractures?

First the classification is either as stable or unstable. Stable fractures are defined as : one 
that has fragments with some degree of interdigitation at the fracture site. Unstable 
fracture is defined as where there is no contact of the main fragments that would restrict 
movement.  It would appear that both of the fractures in this case are unstable.

     Next we need to classify as open or closed. Closed is characterized by intact integument 
at the fracture site;; loss of integrity of integument cause by penetration by object or bone 
fragment is considered an open fracture.   We believe that both of these are closed, however, 
did not see pictures of animal to confirm.

Green stick fracture: appear as lack of continuity or break in cortex of given segment of 
long bone with a deformity or bend at the site on the opposite cortex

Fissure or capillary fracture: these are subperiosteal cracks in the cortex that may extend 
longitudinally or spirally for the entire length of the long bone or the flat bone

Transverse fracture: one characterized by fracture line at appox right angles to the long axis 
of the bone 

Oblique fracture: similar to transverse except not at right angles to long bone.

Spiral fracture: presents a long curved fracture line and is very unstable

Comminuted fracture: splintering or fragmentation of the fragments.

Segmental: 3 or more segments of bone with fracture lines that do not converge at the 
fracture site

Impacted: results in the main fragments being driven together along the long axis of the 
bone
 
Avulsion: This is intrinsically induced fracture usually due to ligament or muscle pull in a 
traction epiphysis or or point of muscle attachment on a bony prominence

Physeal: this involves a growth plate or physis and often occurs in immature animals. 

Condylar: the condyle has epiphyseal, phyeal and metaphyseal components. Condylar 
fractures may involve the lateral or medial condyle or both condyles may be separate from 
the shaft.