Partial Tear of the Cruciate Ligament
Retriever Field Trial News - August 2004
Cal Cadmus, DVM
Ed Note: Cal Cadmus DVM has been involved in Field Trials for more than 20 years and won the '86 National Amateur Championship with NAFC-FC Winsom Cargo. His office is located in Oakdale, California where he specializes in TPLO repair (cruciate injury).
Over the past few months our five year old lab, "Max," has shown a slight lameness in his right rear leg. He seems fine in the morning but after a few retrieves and some time in the crate he comes out holding it up. Our vet checked him and took x-rays. He says that although he can't feel any problems there does seem to be increased water in the knee on the x-ray. His best assessment is that "Max" has a partially torn anterior cruciate ligament. He gave us the following options: wait and see and take anti-inflammatory medication. Have him do a surgery with fishing line, or take "Max" to a specialist for what is called a TPLO surgery. "Max" is still young and we hunt test, field trial, and hunt him. We would I like to continue all of these activities. What do you think we should do?
Wow, that is a good and unfortunately too often asked question. Assuming your veterinarian's tentative diagnosis is correct and I suspect it is, your doctor gave you the correct options. Let us take a look at each, but first let's discuss the anterior cruciate ligament function in the stifle. The primary role is to prevent the tibia from sliding forward on each step, a complete tear would allow significant forward thrust to occur and a partial tear will allow proportionally less thrust. Therefore, the more stretch and tear, the more thrust.
This thrust results in which instability leads to inflammation and eventually arthritis and degenerative joint disease. The thrust also allows for a crushing or pinching of a cushion in the back of the joint called the miniscus. This also adds to the pain and lameness.
Rest and anti-inflammatory medication, although at one time was thought to be the treatment of choice is now considered only palliative and the associated arthritis will continue to get worse. I see no benefit to the "wait and see" approach, and the sooner "Max's" joint is stabilized the better he will do.
The literature has described many surgical stabilization techniques. Some of these involve ligament graft replacement inside the joint and others involve tightening of the soft tissues outside of the joint. I think of these as a surgical ace bandage, the fishing line suture is one of these. It is very important that the affected joint be inspected either with a scope or a traditional surgical exploration. All of the damaged ligament be removed and the miniscus be inspected and treated.
Although all of the above techniques benefit the patient, the larger dogs (lab size) and up, tend to achieve less than ideal results and arthritis usually will continue to develop.
In the early 80's, Dr. Barcley Solcum developed a revelotomy technique that actually changes the mechanics of the rear leg such to eliminate the need for the cranial cruciate ligament. The details of the procedure have been published in the RFTN July 2002. The unique quality of the Tibial Plateau Leveling Osteotomy (TPLO) procedure is that when done properly, it essentially halts the development of additional arthritis.
The procedure is both technically difficult and patented. Therefore should be undertaken by an experience certified veterinary surgeon.
Often, I am asked if the patient were my dog what would I do? The answer is easy, I hunt and trial two labs that have three TPLO surgeries between them.
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