Tuesday, October 26, 2010

Cruciate Ligament Injuries in Dogs

Reposted from April 2008.
Cruciate ligament problems are more common with big dogs than small, and with dogs that run and jump (think Frisbee) rather than those who merely walk around in yard and kitchen.

Keeping a dog lean, and not obese, can help prevent injury.

Small dogs (under 20 pounds) will often regain almost normal function without surgery (although they may develop some arthritis).

Finally, with use of anti-inflamatories and time, a lot of dogs will recover on their own. And even if they don't, a limping dog may not necessarily be in pain. The idea that every problem needs a solution is probably a concept we need to disenthrall ourselves of. This, of course, is not something you are likely to hear from a veterinarian.

An $80 Pet's $12,000 Bill

A Human Jock's Ailment Plagues Pooches

This Joint Problem Makes Dogs, Owners, Weak In the Knees

By Kevein Helliker, Wall Street Journal April 11, 2006; Page A1

A dog named Paddi was chasing a cat through a suburban Seattle neighborhood when suddenly she pulled up lame. So tender was Paddi's hind leg that her owner, physician Kevin Bulley, had to carry her home.

The diagnosis turned out to be a ruptured cruciate ligament, an injury that Dr. Bulley, a family practitioner, had associated only with humans. Cruciate ligaments hold in place the parts of the knee, and wrong turns on the athletic field often injure these cords.

The cost of fixing Paddi's knee was about $3,000. She had barely recovered from that surgery when the cruciate ligament in her other knee ruptured, prompting a second $3,000 procedure -- all for a mutt that Dr. Bulley and his family had adopted and grown to love. "She's the most expensive free dog I've ever heard of," says the physician.

Being an athlete is a well-known risk factor for cruciate-ligament injury. A larger -- but lesser-known -- risk factor is being a dog. The number of dog knees undergoing cruciate-ligament repair each year in America is estimated to now exceed 1.2 million. That's about five times the number of human procedures -- even though humans outnumber dogs in the U.S. by nearly five to one. And it's not as though dogs have more knees: The joint on their front legs are elbows that aren't vulnerable to the problem.

Dog owners often have no idea that this danger exists. Pennsylvania engineer Martin Yester, for example, investigated the medical history of his yellow Labrador, Sarah, before purchasing her as a puppy. Knee risks didn't come up -- until her cruciate ligament ruptured in December. Even though certain larger breeds have been shown to be more susceptible, "nobody talks about knee problems," says Mr. Yester.

The extraordinary rate of failure in dog knees is mystifying even to veterinarians. Is the prevalence of such canine injuries rising -- or are people less willing to let their pets hobble on three legs? "It's a bit of a mystery as to the cause," says Steven Budsberg, a veterinary surgeon who is director of clinical research at the University of Georgia College of Veterinary Medicine.

Today, cruciate-ligament repairs are the most common surgical procedures for injured or diseased dogs. And inside veterinary medicine, controversy is raging over the best treatments.

A relatively new technique, called tibial plateau leveling osteotomy, or TPLO, involves breaking and resetting the tibia, the long bone below the knee, in such a way as to obviate the need for a cruciate ligament. The surgery costs from about $2,500 to $5,000 per knee. That's about twice the cost of the conventional procedure, which like the human equivalent involves constructing a replacement ligament.

Many respected academic veterinary experts believe that TPLO offers a faster and fuller return of function. But published proof of that theory is lacking, prompting some to avoid the procedure.
For instance, surgeons don't perform it at the University of Pennsylvania School of Veterinary Medicine, says Gail Smith, chairman of the department of clinical research. He calls TPLO "a fashionable procedure."

Still, TPLO now is used for an estimated 50% of cruciate-ligament procedures in the U.S., and by all accounts that percentage is growing.

Such treatments have helped fuel a doubling of the number of veterinary surgeons in the U.S. in the last decade to 1,219 from 660.

It is also the largest factor in a near doubling of the average annual cost of veterinary surgery visits -- to $574 in 2004 from $289 in 2000, says the American Pet Products Manufacturers Association.

Like Dr. Bulley, hundreds of thousands of Americans are digging deep into their pockets each year for a surgery most never realized a dog might need. A November article in the Journal of the American Veterinary Medical Association estimated that Americans spent $1.32 billion to fix dog knees in 2003.

Without surgery, only 20% of dogs will regain normal function, says Dr. Michael Conzemius, an Iowa State University veterinary surgeon and a co-author of the November JAVMA article.

Even if Americans increasingly consider dogs to be part of the family, health insurers don't. According to the pet products industry and insurers, fewer than 3% of dog owners have purchased a medical policy for their pet.

A spokesman for the largest pet insurer, Veterinary Pet Insurance of Brea, Calif., says that cruciate-ligament problems in dogs accounted for nearly $4 million in claims in 2004, and that no other condition had a higher cost per claim.

One claimant was David Wright, a San Jose software engineer who several years ago bought two Labrador Retriever mixes for $80 each. The male, Sage, tore the cruciate ligaments in both of his knees in 2002. "The $80 dog became the $6,000 dog," says Mr. Wright.

Then the female, Kenya, wrecked both of her knees. Of the $12,000 that Mr. Wright spent on those surgeries, he says Veterinary Pet Insurance reimbursed him about $5,000. "Thank God I had that insurance," says Mr. Wright, adding that reimbursement for other, non-knee-related medical expenses already had exceeded the premiums he'd paid.

Unlike human knees, dog knees don't lock -- their back legs are always bent. That means the ligaments of the joint are tense whenever the animal is standing.

This helps explain why canine cruciate tears often occur over time in middle-aged dogs, while human ruptures can happen at any age, and almost always result from an acute twisting or turning of the joint. As in humans, the dog knee contains two cruciate ligaments, and the front-most ligament is likeliest to tear. In humans this is called the anterior ligament, in dogs the cranial ligament.

Few warnings exist for puppy purchasers or dog owners. The Web sites of breeding clubs typically make no mention of cruciate-ligament injuries while offering warnings and advice about screening for hip problems in dogs. The Web site of PetSmart Inc., the nation's largest retailer of pet supplies and services, offers advice about problematic hips in dogs, but not knees.

Diane Dahm, an orthopedic surgeon at the Mayo Clinic renowned for her knowledge of cruciate-ligament troubles in humans, says she isn't familiar with similar canine issues. "I'm aware of hip dysplasia in dogs," she says.

In fact, hips troubles aren't as common as canine knee problems. But hip problems have received attention in part because of a proven genetic component. Puppy buyers can demand certification of a family history free of hip dysplasia, a debilitating condition in which the ball and socket don't fit well together.

Some research suggests that cruciate-ligament tears also bear a genetic component. There always had been anecdotal evidence: For instance, Mr. Wright's two affected dogs are half siblings. An article in the January issue of the Journal of the American Veterinary Medical Association identified a gene that appears to predispose Newfoundlands to cruciate tears. Eventually, this discovery could lead to a test that would identify carriers of that gene, ideally enabling breeders to screen out problematic dogs.

Even now, some doctors say purchasers of puppies belonging to the larger, more at-risk breeds -- Labrador Retrievers, German Shepherds and such -- should ask about family history of cruciate-ligament disease. "Unfortunately, there's little you can do at this point except ask about it," says Dr. Conzemius.

For many pet owners, the thought of spending thousands of dollars on a dog knee remains laughable. "I'd never spend more than $300 on a dog, no matter how much I loved it," says Roger Holwick, whose eastern Kansas farm is home to eight dogs.

The fastest, an Australian Shepherd, has a bum leg that Mr. Holwick never considered getting fixed. "She rules the roost, and she doesn't even know she has a disability," he says.


Luisa said...

Bounce, the muddy pit bull in my sidebar [and on the bed at night, sans mud] has had both cruciates done. Another expensive pound dog, little Bounce.

Pit bull expert Diane Jessup of Lawdogs has written that she's convinced the popularity of dog crates is linked to the rise in cruciate injuries, and she may be on to something. If your dog has spent much of the day locked in a space with barely enough room for him to turn around, and then driven straight to the dog park for an hour of frisbee... ouch.

There is also some medical evidence that links neutering, and particularly early neutering, to a slight increase in the chances of cruciate trouble.

Add obesity and a genetic propensity for cruciate injuries to the mix, and you may as well get out the checkbook.

Anonymous said...

Hi Patrick,

Here is an interesting website that discusses treating canine ligament injury without surgery:


Anonymous said...

The mentioned website is absolutely a Godsend. My dog was just "diagnosed" with an ACL tear. I found this website and intend to follow all the recommendations. It's not the expense of the surgery that bothers me, it the fact that the surgery can cause repeated complications, plus the healing time is about the same.

Anonymous said...


The above website with all it's information has been a sigh of relief! Today my dog was diagnosed with ACL. The vet told me there is a 90% chance she has it...though no xray was taken (though this would not show up in an xray)and only a simple manipulation of her leg. After reading the above article in it's entirety it makes sense to first see if my dog will recover through conservative management. Surgery is always an option should she not. I am appalled vets don't recommend this option since the dog has to go through the same type of management after surgery. Also after surgery they have a much higher risk of developing the same injury on the other leg. Thanks to Max for the gift of information and truth!

Anonymous said...

I have a pit mix (Sasha, 5), a pit (Max, 6), and a pit/am bulldog mix (Charlie, 2). All three are rescues. Sasha and Charlie have both had their knees done. For Sasha, we went with the TPLO. Her bone was slow to heal and we were worried she would require another surgery for a bone graft - scary! So when Charlie tore his knee, we went to another vet with a lot of experience doing the more traditional, less invasive surgery. It actually failed the first time and he redid it for free. It's been 6 mos and Charlie's almost 90%. I do notice that Sasha is at 100% - so TPLO may be the way to go for a working/agility dog. For both of them, though, their other knees are starting to "go." You can tell b/c of the knot that forms on the inside of the knee. Sasha is much lighter on her feet, so we are probably going to let her recover naturally. Our new vet said that if the ligament is not completely torn, the body will grow scar tissue over it and heal itself - if allowed to rest (restricted exercise). That's really all a traditional surgery does - provide a new "ligament" which acts as a scaffold for the scar tissue. If the ligament is completely torn (like Charlie's - you've never seen a more wobbly joint), the knee has a harder time repairing itself, building scar tissue around the joint. The dog can receover, but will probably have terrible arthritis down the road (shorter and less quality of life). Charlie is much more of a clod, and already waits for our help to jump up onto the couch or bed. So we will probably have his done in the near future. The two with knee injuries both came from rescues and were spayed/neutered very early (at 3 mos). Max wasn't neutered until he was almost a year old. I never put it all together until I started comparing the physiology of my dogs (I'm a biologist). Max has much "tighter" joints, well proportioned joints and body composition. He cannot lay flat on his stomach in the "superman" position, like Sasha and Charlie can. Sasha and Charlie both seem more "leggy" and their back end is higher than their front end. I think the early speutering is what contributed to their "ACL" tears - we stopped the hormone flow before they were finished growing - leading to improper proportions and basic mechanical functioning. I know it's a catch-22 for the rescue groups, b/c they want to speuter before adopting out, but I have seen an increase in ACL tears in the rescue groups I work with. I also think Diane Jessup is on to something with the crating - unless it's just a coincidence that both Sasha and Charlie are crated during the day, while Max is allowed to roam (he's older and more well behaved). I might have to switch to confining them to a "dog room" where they cannot chew up anything.

Anonymous said...

Good info Patrick. We had TPLO done on one of my dogs on both knees a couple years ago ($7k total for both knees). It was (obviously) very expensive, but her recovery time was great and she has for a couple years now moved with full mobility and no apparently problems.

I know several owners that have done the ligament replacement surgery (similar to how it would be done in Humans) without the same recovery time or long-term success.

That said, it appears that the size of the dog has a lot to do with succes -- with larger dogs needing a more substantial-type surgery (ie, TPLO).

I'm sure we're going to learn a lot over time about the value of all the surgeries -- but I feel like I made the best decision at the time for my dog and so far so good.

heather said...

I have a lab that tore his knee while playing fetch. I had a great vet at the time who told me to rest the dog--no more running (ever), no jumping, no hiking for a month. After spending years focused on wearing out my dog, I didn't really understand that I needed to change my way of playing with my dog. I didn't rest him long enough.
My pup never did have the surgery. He doesn't put much weight on his bad leg when he's standing still, but he's not limping. He takes lots of joint pills and goes on regular long walks. Swimming, running, jumping, and climbing over rocks cause him to limp for a day or so.

Jen said...

Back in 1992 my female Rottweiler injured her Cruciate ligament I was told she had to have surgery and it would cost $500.00 I live in the USA.
I decided to get a second opinion and I am glad I did. The second vet said I had another option and that was to try to keep her off of it for 8 weeks. She was a puppy still, 8 months old and he said it wouldn't be easy but I kept her off of it as best I could and he prescribed pain meds for her pain. Jessie was her name and she lived to be 13 years old without even a limp. Love this site by the way.

terriergal said...

I recently had this recommended to me after my 8 yr old, 60lb airedale was fence racing (bad manners!!) in icy conditions and she pulled up very lame and it would not go away. Had her checked, and definitely got some drawer sign and meniscus clicking and crunching. Silly dope still refused to slow down (she of course would just transfer her weight to the other leg if she simply HAD to remove a squirrel from the yard. So it ended up we kept her on leash for potty runs and minimized stress on it for about 6 - 8 weeks. Teaching her not to rush the fence and bark at the neighbor dogs has been a chore. She gets into the 'zone' and tunes us all out. However in the last year since this happened she has slowed and gotten a little less intense about that, with time, and her limp is only intermittent again. So after having spent a couple hundred on a vet visit and $200 on an ortho consult for a second opinion, (also recommended TPLO but did suggest some options for conservative treatment as well), she's almost back to good as new, for an old girl. And we didn't spend the $2800+ or so that it was going to cost.

Most of the videos I have seen of 1 year post-TPLO surgeries don't show dogs that are any more mobile than she is now. In fact, some of them appear to move worse.

Unknown said...

For years there wasn't proof that TPLO worked better than the cheaper alternatives. That did change a few years ago so it is now the evidence-based preference if cost isn't an issue.

That said, there was a study (ref 1 below) that looked at the benefit of TPLO by an expert plus physio/weight control, vs physio/weight control by itself, in large, overweight dogs. Although at any point during the study the surgery group was doing better than the nonsurgery group, the difference was actually quite slight (about 10% difference if I recall correctly). What was more startling about this is that the nonsurgery group had no endoscopic investigation of the joint to assess for meniscal tears - the conventional wisdom is that if you have one of these you really need to fix it or you get nonhealing lameness. The study used conventional assessment and also force-plate analysis (which is widely considered to be gold-standard).

A study 2009 study (ref 2) at Bristol university looked at the effect of adding a fabella-tibial suture (the most common cheap(er) surgical alternative to TPLO in these parts) or not when performing arthrotomy to fix meniscal tears (via client questionaire) and found no significant differences in disability, activity, frequency of lameness, severity of lameness, ability to climb stairs or ability to sit down.

My current advice to owners of big dogs with cruciate disease is "If you can afford it TPLO is best, but if you can't afford it don't feel too bad because if you're sensible conservatively managed dogs do pretty well too - and some arthritis in this joint is inevitable no matter what you do".

One benefit of TPLO vs conservative management that I've heard cited is that, done correctly, the speed of return to weight bearing is much faster. The cynic in me wonders if the main benefit of the cheaper surgeries that is telling owners to rest the dog for 8 weeks may get less compliance than charging £lots for surgery and telling the owners that if they don't rest the dog for 8 weeks the money will have been wasted, although I suspect that the vast majority of vets who recommend that procedure do so in the belief that it is directly beneficial.

ref 1:
Short and Long term Outcome Measurements in Dogs with Cranial Cruciate Ligament Rupture that have Been Managed With and Without Surgery.

Katja L. Wucherer, DVM; Michael G. Conzemius, DVM, PhD, DACVS; Richard Evans, PhD; Vicki E. Wilke, DVM, PhD, DACVS

From the Department of Veterinary Clinical Sciences , College of Veterinary Medicine ,University of Minnesota, 1365 Gortner Ave, Saint Paul, MN 55108.

(this was pre-publication in the JAVMA - I heard about the study, got their email online and asked them nicely for a copy but it's marked "review only" so I'm afraid I can't pass it on).

Ref 2: Does a fabella-tibial suture alter the outcome for dogs with cranial cruciate ligament insufficiency undergoing arthrotomy and caudal pole medial meniscectomy?
M.S. Tivers;l E.J. Comerford; M.R. Owen, Vet Comp Orthop Traumatol 2009; 22: 283-288