Lateral: 3 year old American Bulldog

• The infra-patellar fat pad is all but obliterated and there is aparent distention of the joint caudally.
• There is widespread osteophytosis
  • "Tidemark" caudal to trochlear ridge
  • Irregularity of fabellae
  • Cranial extent of trochlear groove
• In this patient, as is almost always the case, the stifle OA is secondary to cranial cruciate ligament failure. Here, the tibia is displaced cranially relative to the femur - this is an occasional radiographic finding following cruciate ligament failure.