Cranial Cruciate Ligament Rupture
By Roger Ross DVM
One of the more common lameness injuries we see in dogs is caused by the tearing or damage of the cruciate ligament in the knee.
Dog and cat knees are similar to humans knees. Damage to the cruciate ligament is also a common injury in humans...especially athletes. Sometimes it doesn't take much; just a misstep or a twist when landing from a jump. Any of the structures in the knee can be damaged, but in both humans and dogs, the most common injury is to the anterior or cranial cruciate ligament. Damage to this ligament leads to an unstable knee and it hurts. Especially for the first few weeks after tearing the ligament.
By the way, the ligament is similar to twine in that it's made up of many twisted fibers. When just some of the fibers are torn we usually describe the injury as a ligamental tear. When the entire ligament is torn, we say it is ruptured. Actually, such nomenclature is sort of meaningless in the sense that it's hard to tell on physical exam how badly damaged the ligament is, because either way it hurts and on exam there's excessive play in the joint.
It does matter, though, in terms of healing. Without surgery, a completely torn ligament has no chance of healing. But with a little luck, time, and support, a partially torn ligament might heal without surgery. Especially if the patient is small and not too active.
If you have a limping pet, your vet has a good chance of detecting the cause during the initial exam because she or he will be able to detect the excessive play in the joint.
However: sometimes the veterinarian who first examines your pet misses the problem because the initial swelling and inflammation from the injury hides the excessive joint play, so understand that the cruciate damage may not be detected at first. If you didn't know this, you might think the first vet was stupid. But if you think about it, there's a lot of situations in life where it's necessary to check your work a second time before you discover what you're looking for.
The cruciate ligament keeps the femur (upper leg bone) from sliding too much on the tibia (lower leg or shin bone) when you put weight down. Without a healthy, intact cruciate ligament, this extra sliding causes wear and tear on the joint cartilage (and miniscus).
This really hurts at first, but given time and rest the initial pain resides and a lot of pets will start using their injured limb again after a month or so. But because the knee is less stable, re-injury is much more likely. And if the knee isn't repaired surgically, it's very likely that the knee will become arthritic with time.
What To Expect When You Go To The Vet
(Of course, other vets may do things differently)
A Good Exam and History.
If your pet is limping, we will check out the entire pet to assess general health and other problems. We will want to know how long your pet has been limping and if there have been other rear end problems in this patient. We will check out the toes and paws, check for abscesses, feel the lymph nodes behind the knees and in the inguinal or crotch region. We will stretch out the leg, and do a series of range of motion tests...all of which will narrow the problem down to the knee if your pet's problem is a torn cruciate ligament. There are a couple of simple motion tests we will do looking for excessive play in the knee called "drawer movement" which is tell tale for curciate tears. This is often simply and quickly determined by an experienced vet, but sometimes it will take a little extra effort (see below) to pin the problem down. And as I mentioned in the introduction, sometimes we miss the problem entirely during the first visit, but pick it up in the recheck visit.
Also, lack of drawer movement doesn't rule out cruciate tears: partial tears that don't result in drawer movement are common and can be quite difficult to diagnois.
Another sign your vet will be checking for is scar tissue to thickening called a buttress on the medial or inside side of the knee. This scar or bony reactive tissue isn't present early on in the disease but is noticed after several months of stress to the joint.
Diagnostic Procedures
Once your vet detects excessive drawer movement suggesting a torn cruciate ligament, he or she may want to:
1. Run blood work to see if there is a high white blood count indicating infection of the joint, electrolyte or mineral imbalances, and as a routine check of other organs prior to anticipated anesthesia and surgery
2. Sedate or pet to allow better range of motion tests and palpation of the joints and limb. Sometimes pets are too antsy, tense, or resistant to do a good lameness exam without muscle relaxers or sedation.
3. Your vet may trot your pet and then recheck the limb. Sometimes the lameness is more evident after a little workout.
4. Radiograph the knee to rule out damaged bone and cartilage structures. And while ligaments don't show up on xrays, they are still quite useful: radiographic evidence of increased joint fluid is usually associated with cruciate tears.
5. Fancier Stuff: Other vets may have more sophisticated equipment and experience and may suggest an MRI or scoping the joint.
Treatment Options
Conservative, Non-Surgical Treatments:
1. Short term steroids, other anti-inflammatories, and pain medication for the intial swelling and pain are likely to be used at first whether or not you elect to surgically repair the knee in the future.
2. Forced Rest and/or support bandages are often helpful in getting the swelling and inflammation under control quickly. This also prevents further damage to the joint.
3. Heat wraps, Heat Rubs, BenGay etc.
NOT Recommended I mention this possible treatment because a lot of people are used to using this type of treatment on themselves and on horses with lamenesses.
But we rarely use heat rubs on dogs mainly because they get sick when they lick them off. I suppose heat wraps might have some benefit, but I haven't heard of any vet using them. It's difficult to wrap dog knees.
4. Glucosamine, MSM, Anti-Oxidants, and Omega 3 Fatty Acids might very well be recommended for their properties of reducing damage and speeding healing of cartilage etc.
5. Weight loss. Being fat puts a lot of extra stress on joints.
6. Time, rest, and patience. Most patients with cruciate damage would benefit from surgery. But, if for reasons of money or other circumstances you elect to avoid surgical repair, your pet will probably heal without surgery to the point where it will use the leg ginergly or adequately. It all depends, but the more active and robust and big the dog, the more likely your pet will have life time problems and pain using the leg unless the problem is corrected surgically. Surgery will also minimize future arthritis.
Surgical Repair
There are quite a few different types of surgical repair techniques done on damaged cruciates in both humans and pets. That's because no one has come up with a perfect repair procedure yet. Whenever we in medicine discover a great treatment procedure for a problem, it doesn't take long for word to get out and soon that's the way everybody does it, because it's the best. But there are lots of problems for which we have helpful treatments or surgeries but not perfect solutions...fixing damaged knees are in this latter category.
But nothing is more likely to make your pet weight bearing and functional again than surgery. Nothing is as likely to minimize and prevent future arthritis, pain, and further injury than surgery.
The most common types of knee surgery involves connecting the back of the femur to the front of the tibia using heavy suture material or surgical wire. This tightens up the joint and reduces slipping and sliding. Over time, scar tissue will cover the suture and act somewhat like the original ligament.
Most pets recover full or near normal use of the knee over a period of 1-3 months.
Post Op Monitoring
It's important to rest the knee after surgery and to daily check the support bandaging for slippage, abrasions, ulcers, and odor. Your pet will probably be on post op medications for pain and inflammation. I often prescibe short term sedatives if needed for "over active" pets.
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Veterinary History
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Introduction
What To Expect When You Go To The Vet With A Dog With A Bad Knee
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JOKE TIME:
While checking some things online today, I just learned some very sad news.
Please join us in remembering a great icon of the entertainment community.
The Pillsbury Doughboy died yesterday of a yeast infection and complications from repeated pokes in the belly.
He was 71.
Doughboy was buried in a lightly greased coffin.
Dozens of celebrities were on hand to pay their respects, including Mrs. Butterworth, Hungry Jack, the California Raisins, Betty Crocker, the Hostess Twinkies and Captain Crunch.
The gravesite was piled high with flours.
Aunt Jemima delivered the eulogy and lovingly described Doughboy as a man who never knew how much he was kneaded.
He rose quickly in show business, but his later life was filled with turnovers. He was not considered a "smart cookie", wasting much of his dough on half-baked schemes.
Depite being a little flakey at times, he still, as a crusty old man, was considered a roll model for millions. He would never just loaf around the store. He appreciated every slice of life and was usually puffed with pride at his work.
Doughboy is survived by his wife, Play Dough; two children, John Dough and Jane Dough; plus the bun they had "in the oven." He is also survived by his elderly father, Pop Tart.
The funeral was held at 3:50 for 20 minutes.
May he rest in piece.
Another Joke:
In October, the Indians asked their Chief if the coming winter was going to be cold or not. Not really knowing the answer,
the chief replied that the winter will be cold and that the members of the village should collect wood to be prepared.
Being a good leader, he then went to a phone booth, called
the National Weather Service and asked, "Is this winter to be
cold?"
The man on the phone responded, "This winter is indeed going to be very cold."
So the Chief went back to encourage his people to collect
even more wood to be prepared. A week later he called the
National Weather Service again, and asked again, "Is it going to be a very cold winter?"
"Yes," the man replied, "it's going to be a very cold winter."
The Chief went back to his people and ordered them to go out and bring back every scrap of wood they could find.
Two weeks later he called the National Weather Service
again. "Are you absolutely sure that this winter is going to be very cold?"
"Absolutely" the man replies, "the Indians are collecting wood
like crazy!"
Something Interesting:
Now that we veterinarians are getting crash courses to refresh us about Anthrax and other possible diseases that might be used by terrorists, I've learned that biological warfare has been with us a long time.
The ancients poisoned the wells of their enemies with the bodies of animals and humans who had died of epedemic diseases as a matter of course.
According to Dr Anthony Daniels article in the National Review, the beginning of the Black Death in Europe
...which ended up killing a third of the population...
started because the Tartars were besieging the Genoan trading outpost of Caffa on the Cimean coast in 1346 when plaque broke out among them.
Turning this catastrophic disease into a weapon, the Tartars lobbed the dead with catapults over the city walls...and the poor Genoans fled by ship back to Genoa...
taking the plaque with them from whence the Black Death spread throughout Europe.
The British used blankets to spread smallpox among the American Indians, knowing they were especially susceptible to this disease.
The same disease wiped out much of the South American Indians making the Spanish conquest of South America easy, although there is no evidence that the Spanish infected the native peoples on purpose as the British did.
In the Great War, the Germans tried to infect Romanian Sheep destined for export to Russia with anthrax!
And the French likewise tried to infect German horses with glanders.
In 1915, Dr Dilger, a German resident of Washington DC, secretly infected horses, mules, and cows being shipped to the Allies with anthrax that he produced in his own house.
He succeeded in infecting several hundred military personnel in the process.
Prior to World War ll, the Japanese developed and experimented with the largest scale biological warfare programs in history...
using (killing) thousands of conquered Chinese people in Manchuria as guinea pigs.
They also infected the wells and rivers of China with typhoid, which led to God knows how many deaths...
but at least 1700 of their own Japanese soilders.
The list goes on.
Shortly after WWI, towards the end of the influenza epidemic which claimed more lives than WWI did, the Post Office fashioned paddles with embedded spikes and paddled all of the quarantined mail, perforating it.
Then, the mail was shuttled to large fumigators which would kill any
mail-borne influenza
