Indoor dog/Supervised outside - unknown trauma is unlikely because dog is 
supervised 
most of the time
Playmate - trauma could have occurred or exacerbated by playing
Grade 3/4 lameness - Lameness is significant and needs treatment
Medial buttressing in stifle - indicative of chronic instability
Cranial Drawer Neg - Not complete cruciate ligament rupture
11.6 pounds - possibly overweight
Owner's complaint - this is the issue we need to address - localized to right 
rear leg - 
severe enough for owner to notice
Female, Pomeranian, 3yo - Could be breed, sex or age related
Fell off bed - Trauma present in history
Patella luxated in extension - problem in stifle - structural damage
Weightbearing lameness previously - supports history of trauma
Mild lameness 6 mos later - Problem seems to be recurrent/intermittent
Patella luxation returns to norm on flexion
Treated with antiinflammatory drug with no effect - seems to be non-inflammatory 
or 
wrong drug or dose
Lameness not progressing - condition is stable
Vx and Hw current/ Dewormed 2 months ago - parasitic cause not likely
Benadryl for allergies - important to consider all drugs administered
Palpation of left hind elicited pain Ð the dog could have been irritated Ð 
should repeat under anesthesia
Dorsal flexion of tail elicits pain response Ð possibly  related back pain
Tartar buildup Ð related to type of food dog is eating