Definitions for "Patellar luxation"
(Skeletal) Abnormally shallow groove in the knee, so that the knee cap (patella) slips in and out of position, causing lameness. Though seen in many breeds, it is most common in small dogs. Special Diagnostics: radiograph of stifle (knee)—though not always necessary.
Congenital displacement of the knee-cap (patella); rare in horses.
A polygenic congenital defect whereby the knee cap (Patella) pops out of its proper position. It can be classed into four categories (not covered here).