12/29/2009 - Patella Surgey

I finally got to talk to the OS last night to discuss the options. I made an appointment for her surgery but I didn't want to give it a go unless I knew what he would be doing. He told me that TTT might be necessary, in addition to the other two procedures. He will not know until he cut her knee open. He will also try to remove the TPLO plate/screws and have arthroscopy done to see if there is any damange to her meniscus.

Update:
He did NOT have to do TTT. Turned out she had both medial and lateral luxation. The patella was sliding to both sides. He did limbrication (tucking in the ligament) and Trochleoplast (deepening the groove) then removed the TPLO plate/screws. Her meniscus was healthy and he didn't see any arthritis. (GREAT news!) I was actually surprised that they were in good shape considering how long she had this condtion for. Maybe the supplements helped? She stayed overnight. I was miserable without her.


More info on Luxating Patella on the web:

http://www.marvistavet.com/html/medial_luxating_patella.html

LATERAL IMBRICATION (ALSO CALLED LATERAL REINFORCEMENT)
This procedure alone may be adequate for a mild case but is often used as an adjuctive procedure to supplement one of the other surgeries. When the patella slips out of its groove, the joint capsule surrounding it is stretched to allow this motion. Imbrication simply involves taking a tuck in the joint capsule. The tightened joint capsule does not allow for the slipping of the kneecap and the kneecap is confined to its proper groove.

TROCHLEAR MODIFICATION
The patella rides in a groove at the bottom of the femur (thigh bone). In toy breed dogs this groove is shallow which allows the patella to slip. If the groove is deepened, the patella stays where it belongs. The normal groove in the femur is lined by slippery lubricated cartilage, called “hyaline cartilage”. This cartilage is peeled or cut away, the bone underneath is sliced out to form a deeper groove, and the cartilage is replaced. Techniques that do not preserve the original cartilage are no longer recommended.

TIBIAL CREST TRANSPOSITION
If the knock-kneed conformation has already started to set in, the tibias (or leg bones) will have rotated. In particular, the crest on the tibia where the thigh muscle (the quadriceps femoris) attaches, may have migrated inward. If this is the case, the crest will have to be removed and pinned back where it belongs to straighten out the leg. Severe rotation of the tibias may involve actually cutting through the entire bone and de-rotating it back into place.

Grade 2 luxations occur when there is occasional spontaneous lameness but the
patella returns to normal positioning easily enough that the dog usually isn't pained much by it. This is typically the dog that occasionally carries a rear leg for two or three steps on occasion but then puts it back down and goes as if nothing was wrong.

Most veterinary orthopedic surgeons recommend repairing dogs in Grade 3+ without question and advocate fixing grade 2 dogs frequently. So a 2.5 grade is probably one in which the examining veterinarian is leaning towards thinking surgery is necessary. That is just my best guess on the interpretation, though. It is better to ask the vet who made it. I think that most dogs generally get worse over time and move from Grade 1 to Grade 2 or from Grade 2 to 3, for example. The changes may not happen until later in life, though. A lot of dogs with Grade 1 or Grade 2 patella luxation early in life will have pretty stiff knee joints when they are 14 or 15 years old that probably are at least partially this way due to arthritis from the years of luxating patellae. There is a lot of other wear and tear in a long life so this is only a partial contributor but I know that some surgeons really feel that when the whole lifetime is looked at early surgery looks better. On the other hand, there are dogs who have bad 0utcomes from the surgery, too. I lean towards leaving knees alone until the Grade 3 stage, personally.