Learning Issues:
1. Cranial Drawer: excessive cranio-caudal movement 
of the tibia relative to the femur as a result of 
cruciate ligament injury.  0-2mm is found in 
normal stifle joints.  Sedation is necessary to 
eliminate muscle tension that would otherwise 
mask results.

2. Ligaments of Stifle: (listed in Hypotheses 1)

3. Pathophysiology of rupture of CCL: internal 
rotation or hyperextension

4. Effusion: an escape of a fluid into a part; 
exudative or transudative, inflammatory mediators 
increase vascular permeability.

5. Anatomy of Cranial Cruciate Ligament: arises from 
lateral condyle of the femur within the 
intercondylar fossa and runs cranio-distally to 
attach to the tibia

6. Degree of Lameness: Bonnie has a partial weight 
bearing lameness and she is putting her paw down 
when standing for balance.  This suggests a Grade 
III lameness.  

7. Neoplasms that could affect stifle region: 
osteosarcoma, synovial cell sarcoma, 
chondrosarcoma, fibrosarcoma, metastatic 
neoplasia

8. How tumors cause pain: space occupying lesions 
that distend joint capsule and/or elevate the 
periosteum.  Both have the potential to place 
pressure on nerve endings eliciting pain.  


9.Pathophysiology of Osteoarthritis: described in      
Hypothesis 2.