Ruptured Cranial Cruciate Ligament in Dogs
Dr. Nicholas Trout
Lateral suture technique. This procedure is quite straight forward and works well on many dogs, particularly those less than 70 to 80 lbs. Under anesthesia, having examined the inside of the knee joint to tidy up the remnants of the cruciate ligament and assess and address meniscal injury, a suture is passed around the knee joint, below the skin, in a configuration that will restore the normal position and stability of the femur on the tibia, acting to produce the same result as an intact cruciate ligament. With time, the implant may give a little, may stretch or even break, which will lead to increased thickening of the soft tissue around the knee and progression of bony arthritis. Despite this, the vast majority of dogs do well with this technique.
The majority of small dogs (86 percent in one study) did not require surgical intervention and did just as well with strict rest, weight loss and the use of short courses of anti-inflammatory medication. Should the lameness persist, then surgery is recommended. Restriction like this for 6-8 weeks will not detrimentally affect the surgical outcome, should it prove necessary later on.
Broadly speaking there are two categories of surgery known as intracapsular techniques, where an effort is made to replace the damaged cruciate ligament with a natural or synthetic replacement, or extracapsular techniques, which aim to restore the function of the cruciate rather than the ligament that was damaged. Over recent years, intracapsular techniques have become less popular. The following are major extracapsular techniques:
Fibular head transposition. This procedure uses a natural ligament, the lateral collateral ligament, to stabilize the femur on the tibia by modifying its normal position and function, by changing its attachment to the fibular, the smaller of the two bones below the knee joint. Some surgeons are very pleased with the clinical results they can achieve with this technique.
Tibial plateau leveling osteotomy (TPLO). This surgery has been described and patented by Dr. Barclay Slocum of Eugene, Ore. In simple terms, the femur slides on the tibia, in fact, the tibial plateau, because a slope exists, a slope, that to a large extent, is combated by virtue of an intact cruciate ligament. So, in a normal knee, no sliding takes place, but if the cruciate is damaged, the sliding, as seen with a cranial drawer test, occurs every time the dog puts weight on the leg.
The idea behind this surgery stems from the fact that any kind of replacement for the cruciate ligament, be it natural or synthetic, can never be as good as the original. So, instead of trying to replace the damaged ligament, why not try to make it redundant, by getting rid of the slope that it was trying to offset. In other words, if we make the slope, the tibial plateau, level, then there is no need for a cruciate ligament; the ligament becomes redundant. This is a complicated surgical procedure and requires certification from Dr. Slocum in order to be performed.