Patella means knee in latin and luxation means that something can be moved; PL = movable knees. Even though knees has to be able to move:-) the fact is that when a vet tells you your cat has PL, he/she means that the knee is able to move to much and the cat can experience pain as well as having difficulties walking properly. If one part of the body isn't funtioning as it should, it can have an impact on other parts of the body, by putting a strain on them and that is something that both you, the owner, as well as your vet wants to prevent.

There are several levels PL can be catagories as and pending on how severe the PL that you cat suffers from is, your vet can either operate and/or administer painkillers. In some cases the cat has gotten so use to having PL, that when it's knee(s) "poops out", the cat will simply make a twist with the leg, bringing the Patella back into place. However in the long run this can cause arthritis in the femur and hip cup, which is why one should always consult with the vet, to see if something could or should be done, in order to give the cat a good qulaity of life.

PL is devided into the following degrees:

Borderline: the patella can be left/right slightly dislocated by twisting the leg with the heel outside, without putting pressure on it.
Grade 1: the patella closes left/right insufficient and can be dislocated by twisting the leg with the heel outside,without putting pressure on it.
Grade 2: the patella dislocates left/right sometimes/irregular while walking.
Grade 3: the patella is left/right permanently out of the groove, but can be put back into the groove.
Grade 4: the patella is left/right permanently dislocated and can not be put back into the groove.