Client Education

From BonnieÕs physical exam and radiographs, we have diagnosed her with 
a ruptured cranial cruciate ligament of her left knee.  This is the same injury 
that human athleteÕs often receive on the ski slopes or the basketball court.  
Only in humans, we call it the anterior cruciate ligament or the ACL. The 
cranial cruciate ligament holds the femur and the tibia close together.  We 
can tell it has been ruptured because we can move the shinbone farther 
forward when compared to the thigh than we normally could.  The rupture of 
this ligament is causing the pain, inflammation and lameness that you saw 
and brought her in for.  The blood work and joint tap fluid are consistent 
with the fact that we have inflammation in the joint, other than that they are 
fine.  The radiographs show an increased joint space where the ligament 
normally is in place, and increased joint fluid.

As you have said, Bonnie is a very active dog.  She probably received the 
injury while exercising, either by twisting the knee inward or by 
overextending it.  This is why the signs appeared so suddenly.  Bonnie is 
also overweight, which along with age and activity, is a predisposing factor 
in this type of injury.

The good news is that BonnieÕs injury can be surgically corrected.  The 
success rate for surgery is 90%.  Her prognosis is decreased slightly due to 
the fact that she is overweight and active, but we believe that she has a good 
chance to return to normal function.  She may never be quite as active as she 
once was, but she will be able to live a normal, happy life.  Without surgery, 
the injury may lead to degenerative, arthritic changes in the joint, and 
permanent lameness.  Large, active breeds are generally candidates for 
surgery rather than just conservative management.

The goal of surgery is to reestablish the stability of the joint and to look for 
other joint damage, such as a tear in the meniscus, that may have occurred.  
We will use a combination of techniques to give her the best chance at 
success.  We will do a reconstructive surgery where we use other tendons in 
the knee to create a graft that will stabilize the joint.  A metal screw and 
washer will be used for this.  Then we will use suture to further stabilize the 
reconstruction.  Bonnie will be receiving an opioid, morphine-like, drug 
while in the hospital to relieve pain.

Some possible problems with surgery that may occur include loss of graft 
strength, irritation from the metal or suture, development or arthritis.  Our 
biggest concern is that it is possible for Bonnie to damage the ligament in 
her right leg with time.  This happens in about 20% of patients.  Weight loss 
will be important in reducing the chance of this happening.

After surgery, Bonnie will have on a soft bandage that we will keep on for 2 
weeks.  She will need to come in for bandage changes.  She will need to be 
confined to a cage or crate for about 10 days. We will send you home with 
non-steroidal anti-inflammatory drugs to control the pain and inflammation. 
For about 12 weeks, Bonnie needs to be restricted in her activity, with a 
controlled exercise program consisting of leash walking and swimming.  The 
time and distance of walks should gradually be increased. It is very 
important not to let her exercise too much. Also, if you can spend time 
gently flexing and extending the joint, this will help increase her range of 
motion. She should be returning to normal at about this 12 week time frame.  
After 6 months, we will remove the screw and washer that we installed at 
surgery.

To decrease the chance that Bonnie will injure her right cranial cruciate 
ligament, and to improve overall health, we strongly recommend that she be 
placed on a weight reduction diet.  She is currently receiving too many 
calories for her ideal weight and her activity level.  Now, her activity level is 
going to be decreased, and she will need even fewer calories.  Instead of just 
reducing the amount of food she gets, we recommend placing her on a 
special weight reduction diet such as HillÕs Science Diet w/d.  Then, she will 
be receiving the correct amount of vitamins and minerals while receiving 
fewer calories.  We will calculate the amount of food to give based on her 
target weight for her sex and breed.


* Numbers for controlled exercise, time until screw removal, etc. were 
obtained from SlatterÕs Small Animal Surgery.  Numbers were a little 
different in the class notes.