TPLO Information

TPLO in Canines

If your dog has been diagnosed with a torn cranial cruciate ligament, you will probably be considering surgical treatment options that may include a tibial gf plateau leveling osteotomy (TPLO).  The procedure is tough enough to say, let alone understand!  The development of the TPLO is one of the most interesting stories in veterinary medicine.

A basic summary of this history will help in understanding why the TPLO has generated so much controversy.  Descriptions of cranial cruciate ligament tears can be found for more than half a century in veterinary literature.  Indeed, cruciate disease is the most common orthopedic problem in dogs.  In the early 1960s, surgical techniques were developed to try and replace the damaged ligament or to eliminate the instability created in the stifle joint by tearing of it.  Some techniques worked better than others, but all had their drawbacks, and none completely stabilized the injured joint or prevented the development of significant arthritis.

Dr. Barclay Slocum, a surgeon who spent much of his career practicing in Eugene, Oregon, looked at the problem from a different perspective.  Dr. Slocum’s father was a human orthopedic surgeon who frequently did corrective osteotomy procedures to treat knee ligament problems in people.  In these procedures, the bones around the joint are cut and realigned to change abnormal forces within the knee.  With these procedures in mind, Dr. Slocum examined the canine knee from the perspective of the dynamic forces that occur during weight-bearing and movement when the cranial cruciate ligament is torn.  His examination of the dynamics combined with what was published in veterinary literature in the early 1980s lead him to several conclusions.

First, he noted that the top surface of the tibia (shin bone) that works together with the femur (thigh bone) at the knee joint had a tibial slope.  Specifically, the top of the tibia slopes from front to back within the knee.  The angle of this slope varies between dogs from degrees in the high teens to clearly abnormal slopes over 35 or 40 degrees.  An average tibial plateau slope would be in the 21–24-degree range for most breeds.

Slocum noted that the cruciate ligament ran between the femur and tibia and acted to hold the end of the femur in place atop the tibial plateau.  He characterized the ligament as “a rope tying a wagon to the top of a hill.”  When the rope (ligament) is broken, the wagon (the end of the femur) tends to slide down the hill (the tibial plateau slope).  He characterized this instability, which had been named cranial tibial thrust, as the most important component of the dynamic instability that occurs in the stifle when the ligament tears.  Further, he theorized those previous surgeries had been attempts to “replace the rope” and had met with only fair success.  He wondered whether it might be more productive to “level the slope.”  Slocum went about achieving this goal in a few different ways before he settled on what we now refer to as the TPLO.

How is the TPLO performed?

Before surgery, an x-ray of the stifle is taken to measure the angle at the top of the shin bone, called the tibial plateau angle.  The goal of the surgery is to reduce this angle so that dynamic joint instability (cranial tibial thrust) is eliminated.  This is usually accomplished by creating a post-surgical angle of between 4 and 10 degrees, an angle not much different than is found in the human knee.  In most cases the surgical procedure starts with an exploration of the inside of the stifle joint.  This can be done arthroscopically or with open joint surgery.  The purpose is to assess the meniscal cartilage for any possible damage.  Damaged cartilage must be removed if the dog is to regain normal pain-free function.  The TPLO procedure itself involves the use of a curved saw blade to make a curved cut on the inside, or medial, surface of the top of the tibia.  The cut top portion is then rotated to create the desired tibial plateau angle.  A stainless-steel bone plate is then placed on the bone to hold the two pieces in their new alignment.

Now that you know a bit about TPLO, let’s review some questions about the procedure.

Is TPLO Right for Your Pet?

Not all dogs with CCL injuries are candidates for TPLO, as the suitability of the procedure depends on various factors, including the dog’s size, age, and activity level. It’s essential to consult with a board-certified veterinary surgeon to determine the most appropriate treatment plan for your pet.

Tibial Plateau Leveling Osteotomy (TPLO) is a groundbreaking procedure that has transformed the lives of many dogs suffering from CCL injuries. It offers hope for enhanced mobility, reduced pain, and a brighter future for our canine companions. If your dog experiences CCL issues, consider consulting with a veterinary specialist to explore the potential benefits of TPLO and ensure your pet’s continued well-being and quality of life.