Titan has an intermittent Grade III / IV non-weight bearing lameness. The physical exam revealed 
the problem centers around the stifle joint, with no other abnormalities in other joints, bones, or muscles in 
the right rear leg. There is a definite thickening of the cartilage on the medial side of the stifle joint (medial 
buttressing), and when the leg is extended the patella was easily luxated from its normal position to the 
medial side of the trochlear groove. 
We feel that this lameness originated from a traumatic incident about one year ago, but the injury 
temporarily healed, and now either additional trauma, degeneration of the original repair, or everyday wear-
and-tear on the joint produced additional stress and caused the lameness to reoccur. With Titan favoring his 
right leg for several months, the left leg and stifle have probably been overused and have supported 
additional weight and stress. This has caused the pain and sensitivity we now see in the left hind leg.
This is a relatively serious lameness that has developed in both hind legs, but if we treat Titan now 
his prognosis will be good. Titan will need some radiographs taken of the area to assess any osteoarthritic 
changes, and a joint aspirate will be taken to look for inflammation or degeneration that may be occurring. 
Inflammation and osteoarthritis were not detected on the physical exam, so if they are present they have not 
progressed very far and are in the early stages of the process. Because Titan is experiencing lameness and / 
or pain in both stifles radiographs and joint aspirates should be performed on both stifle joints. Medial 
buttressing of the right stifle suggests a torn cranial cruciate ligament, which may have occurred from the 
original fall. This usually occurs when the cranial tibia is twisted sharply medially with enough force to tear 
the ligamentous fibers. 
With Grade III non-weight bearing lamenesses arthroscopic surgery is recommended to correct the 
underlying cause and to begin the healing process. Although we don’t see fast degenerative changes 
occurring now, they usually get progressively worse rather quickly without surgical intervention. There are 
several different procedures we have to choose from, and we will know which of those is most appropriate 
once we conduct the pre-surgical testing. The patella must be stabilized or it will continue to erode at the 
medial trochlea of the femur and cause disproportionate weight-bearing and progressive lameness. We also 
like to conduct a complete blood count (CBC) pre-surgery to make sure Titan has adequate clotting factors, 
erythrocytes, and blood volume to handle the surgery. A CBC will also indicate if generalized infection or 
inflammation is present, and will help us to prepare Titan’s system for the surgery (treat active infections, 
pre-surgery antibiotics).