Interpretation of results


Abnormal values on clinical pathology

Leukocytosis-There is a slight increase in white blood cells.  This could be due to an inflammatory reaction in the stifle.  Inflammatory mediators and chemotactic factors from the inflammation increased margination, bone marrow release and chemotaxis allowing more neutrophils to enter the site of injury.  The patient is also under stress from the pain associated with the injury to the stifle.  This could release corticosteroids from the adrenal cortex (zona fasciculata and reticularis).  Corticosteroids cause the numbers of marginated neutrophils and monocytes to decrease increasing the apparent number in circulation.  Corticosteroids also increase the release on neutrophils from the bone marrow.

Slight hypocalcemia-Due to decreased calcium carrying capacity caused by hypoalbuminemia.  40 % of calcium in bound to albumin in circulation and and is biologically inactive.  When the albumin decreases in circulation, the total amount of measured calcium is decreased.  This would not lead to any clinical signs however because the biologically active calcium is still normal.

Hypoalbuminemia-Inflammation causes increased capillary permeability leading to a slight loss of albumin into the exudate.  A protein analysis of the joint fluid should show an increase in protein content (3.0-5.0 g/dl) which would be characteristic of a non-septic exudate produced by inflammation.
 
Joint fluid analysis-There is a non-septic exudate consistent with a non-septic inflammatory reaction in the stifle joint fluid.  The fluid is reddish in color and clear with a cell count of 3500 cell/hpf made up mostly of neutrophils and macrophages.  The predominance of neutrophils would support an inflammatory process present in the stifle joint.  There was also a lack of bacteria present which would tend to ruleout an infectious process, infectious arthritis.  This fluid is indicative of an exudate which is non-septic due to the lack of bacteria or degenerate neutrophils.  

Radiography- Lateral- possible displacement of patellar fat pad.  We do not know if pressure was being applied so we cannot evaluate alignment with regards to cranial cruciate rupture.  No degenerative bony changes were seen.  Fluid density seen in joint.  
Anterior-Posterior- appears to be decreased joint space medially may be due to slightly oblique projection.  Small bony density located medially on distal femur, possible bone chip.