Tibial Plateau Leveling Osteotomy (TPLO)

Dr. Barklay Slocum developed this sophisticated surgery for the treatment of a tear or rupture of the cranial cruciate ligament (CCL) in dogs.  Veterinarians around the world are being specially trained and certified to perform this procedure.  Because this surgery is so successful, it is our belief that it will replace all other surgeries performed for this condition.

Dogs normally have a downward slope on the top part of their shin bone (tibia) from front to rear.  The degree of this slope varies from dog to dog.  It has been found that the steeper (greater) the slope, the higher the incidence of CCL tear (known in humans as ACL tear).  The normal function of the cruciate ligaments is to keep the thigh bone (femur) sitting directly on top of the shin bone.  When the cranial cruciate ligament tears, the thigh bone slides off the top of the slope of the shin bone towards the back (downhill) side of the slope.  Every time the dog puts weight on the leg, the thigh bone partially "dislocates" as it slides down the slope.  This causes pain, instability (like a "trick knee"), and eventually irreversible arthritis.

The TPLO surgery levels the slope so when the dog puts weight on the knee, the thigh bone remains centered on the top of the shin bone.  Technically speaking, an x-ray of the shin bone is taken and the angle of the slope is measured.  An incision is made in the skin along the inside of the knee and the top of the shin bone.  Another small incision is made farther down the shin bone.  A small "key hole" incision is made into the joint, then the meniscus is also inspected for tears.  If found, these tears are removed – similar to a person having the torn cartilage in their knee removed.  Next, a jig is placed and, using a very specifically designed nitrogen-driven bone saw, a "C" shaped cut is made in the top part of the shin bone.  A calculation using the preoperative degree of slope is then made and the top (cut) part of the shin bone is rotated so that the slope in the bone becomes level.  A metal plate and six screws are inserted to hold the bone in place.  The entire leg is then bandaged to keep post operative swelling to a minimum.  This bandage is removed prior to discharge from the hospital.  A technician will meet with you at the time of discharge to review all home care instructions and also to instruct you in a very simple physical therapy program designed to enhance return of function.

The bone heals in approximately eight weeks and during this post-operative period, exercise must be limited. Patients are not permitted to go up and down stairs, jump on furniture, play with other pets, run around the house, or be off-leash outside.  Skin sutures or staples are removed two weeks after surgery and at 4 weeks, your regular vet will evaluate the healing progress and make sure nothing has moved out of place.  Eight weeks post-operatively, another x-ray is taken to confirm that bone healing has occurred.  If it has in full, exercise can be resumed.  The plate and screws are not removed and stay in the leg for the life of the animal.  On rare occasions, the animal may have a reaction to the plate and screws and only then will they be removed.

Previous surgeries designed to "hold" the thigh bone in its correct position at the top of the slope have been developed through the years (normally referred to as a *Classic* ACL Repair).  These procedures included the use of large gauge sutures, stainless steel wire, and strips of nearby tendons and ligaments.  None of these procedures, however, correct the basic underlying problem and seem to work best on smaller dogs.