Ligament Structure, Injury, and Recovery for Your Dog or Cat or Other Pets-
Former title: Stifle (Knee) Ligament Ruptures (Torn ACL, CCL) Information Overview and Ligament Injury Recovery.
This is a piece I wrote as an overview of torn knee ligament originally in 2007 for a client of Dr. Dennis Sundbeck, DVM, owner and practitioner at Round Rock Animal Hospital for 35 years.
Dr. Sundbeck retired in 2014 and passed away April 15, 2018. Our community remembers him fondly as we celebrate his life and contributions to many aspects of Central Texas.
I remember Dr. Sundbeck specifically and warmly because he was possibly the first established, old school, veterinarian in my area to refer a case to me for non-surgical recovery of a torn knee ligament in a dog. I do not think he and I had been able to talk prior to the referral, however he must have read the materials I dropped off at RRAH when I began my business in January, 2007. Evidently my methodologies made common and scientific sense to him.
I have always held that situation deep in my heart as a beacon to support my work to switch veterinary medicine off of the all-too-quick referrals to surgeons for injuries like torn ligament, torn meniscus, and “bad hips”. RRAH continued to support my rehabilitation practice over the years and often supplied my recovery booklets for their clients.
This post has information about ligaments, ligament injury, surgery, and some guidelines for rehabilitation. The homework protocol I have written for use after surgery or instead of surgery and which has been used successfully for years is now available in book form, and here are the links: rehab books on Amazon.
What Are Ligaments?
A torn ligament is not a life or death situation in and of itself.
Ligaments are dense connective tissue structures consisting of fibroblasts, water, collagen, proteoglycans, fibronectin, and elastin that connect two or more bones (1, 2).
What Happens When My Dog or Cat Tears a Ligament?
Within hours of injury, the defect (injury) is filled with an organized hematoma and the surrounding tissue becomes edematous (swollen with fluid) from perivascular leakage of fluid. Monocytes and macrophages are found in the wound by 24 hours and respond by cleaning up the site and transitioning to the next phase.
How Long Does The Injury Last?
The acute injury phase lasts about 48-72 hours (2). The knee will swell, sometimes only a little, inside the joint. This makes the bony parts thicker or expanded due to fluid accumulation inside the joint. This is called effusion, and it is part of the healing process. Sometimes the knee (stifle) swells a lot inside the joint. Other times there is swelling in the soft tissue as well.
Does My Dog’s Torn Ligament Heal?
At this writing, a great deal of information remains unanswered regarding timing of ligamentous healing in canines, especially with respect to postoperative mobilization techniques (graft, suture, TPLO, TTA, CBLO, etc…). This is because ligaments heal differently depending on the location.
For example, the healing potential of the medial collateral ligament of the stifle is very good, but the cranial cruciate ligament, which has received the most investigation, demonstrates virtually no healing response following injury (2).
What Will My Pet’s Veterinarian Do?
Your veterinarian will most likely watch your pet walk, manipulate the injured limb and joint, and take an x-ray, radiograph (rads), of the knee or other injured area. Please do not protest the x-ray.
You are correct if you already know that we cannot see a torn ligament, per se, via x-rays (rads). What we can see, however, is cloudiness where the swelling I mentioned above is happening.
We may also see whether there is what I call a 1% issue in the knee or surrounding area. Sometimes there are hairline fractures at the tibia or growths that are irritating the leg or joint that we are able to see on rads.
I have seen a lot of what I call 1% cases in my practice, and I won’t take time to cover that here. Get the x-ray to see if your vet sees what they think they’ll see if they recommend an x-ray. Clients ask me to explain the need for the x-ray *all* the time.
My Vet Said My Dog Had to Have Surgery –
A ligament rupture is not a matter of life and death.
Many people come to me saying that they have felt forced toward surgery for this condition in their dog. In contrast, I’ve had client “body specialists”, some of whom are human medical doctors, with a different opinion. One in particular said, “I wish we could get people off of the surgery idea! We don’t even rush every human athlete into surgery, much less every person in general.”
Slatter’s Textbook of Small Animal Surgery
states that small dogs often do well without surgical intervention, and that based on particular studies, “it is prudent to wait for at least 6 to 8 weeks before recommending surgery for small dogs. These dogs are older at diagnosis and are often obese with concurrent medical problems. Small dogs that are lame for 6 weeks after diagnosis and show no improvement often have meniscal tears and are operated on for meniscectomy and joint stabilization.” (pg.1832)
Believe it or not, I have had clients who were told they’d need to euthanize their pet for this injury. Recovery without surgery works. If you cannot afford or do not want surgery for your pet, you definitely do not need to euthanize them because of this injury.
Drugs and Surgery Referral –
It is at this point that most veterinarians will recommend an anti-inflammatory drug for your pet and a consult to a veterinary surgeon.
If you are referred to a surgeon, there is a possibility that the surgeon will want to take their own rads. They usually do that if the originals did not come out as well as the surgeon would like to see and if they think there is something else worth seeing. I have been with surgeons in the room at the time of consult, and sometimes they say that “there’s no need for x-rays because you cannot see a torn ligament on x-rays”, and sometimes they want an x-ray.
Some veterinarians will have clients keep their pet restricted, with or without medications and without referring to surgery. There are many, many ways medical practitioners deal with injuries, and there is not one set method. Above are the top three situations I meet. Here are the first three steps I recommend after injury.
In newer news, many studies have linked non-steroidal anti-inflammatories (nsaids) to delayed healing of injuries. I have followed the research and I promote healing methods without nsaid use for both my human and veterinary clients.
Should I Use Ice on the Injury?
Practitioners often recommend ice during the acute phase of injury. The standard recommendation is 1-6 times per day, for 20 minutes each application, on average. The duration of application depends on fur density on the pet and type of ice used.
In the meantime, I have also been recovering a variety of human and pet injuries without the use of ice. Ice, too, delays recovery. The physician who developed the sports medicine standard, RICE (rest, ice, compression, elevation) has reversed his stance. Many of us in recovery work have followed suit.
I have a separate paper with icing recommendations on this site if you really feel that you need to use it. The method of delivery most recommended by others yet one of the least effective is frozen veggies, so check out the other options noted in my post.
More research in recent years shows that stopping the inflammatory process is not a good idea much of the time for this type of injury. The body may heal faster If we allow it to go through the natural inflammatory process. It also helps if there are pain medications like Tramadol or Gabapentin available. Ice and nsaids work against inflammation, and therefore also work against healing.
Should I Use Heat on the Injury?
This question is often in debate. Here is a link to a recent paper on the subject. I recommend that you NOT use heat on your or your pet’s injury unless you have read the recent science. In my experience, people want to use heat when they should be using ice. They usually don’t know how and when to use heat to help with healing. Check out the above link for more info.
Laser Therapy and Acupuncture –
Throughout the healing process using low-level laser therapy is a good idea if it is available to you. I use a class IIIb laser in my practice, and I have attended two national and world conferences on laser therapy. See these sites for more info: WALT and NAALT .
I haven’t yet posted much on acupuncture, so here is a random PubMed search link to papers on acupuncture for healing. I use laser therapy over acupuncture if only one option is possible. This is because of the added benefits laser therapy provides over acupuncture. USA law says if anyone is going to acupuncture your pets, it has to be a licensed veterinarian.
Acupuncture and laser therapy both work in manners that most people don’t necessarily understand. Acupuncture can be very effective for short-term pain relief. I rarely come across a human account of pain relief from acupuncture lasting more than a day. Acupuncture is also a great treatment for other conditions.
Laser therapy (LLLT) is effective for short and long-term pain relief. LLLT also stimulates cellular growth and production and it also breaks down scar tissue. Short story. Check out the websites I linked above for more information.
The main idea after injury is to lower the level of pain and to encourage healing, so use the best tools and information you have available. To that end, I believe forced specific range of motion exercises are unnecessary in a companion animal that is functional, one that is able to move their limbs on their own.
Supplements & Vitamins –
I do not recommend throwing the kitchen sink of vitamins and supplements at any injury, illness, or chronic condition. I recommend using specific, limited ingredient, supplements for specific conditions and expected results.
Ligament Support, Arthritis, and Instability –
In many cases, loss of ligamentous support invariably leads to progressive osteoarthritis, such as in cranial cruciate ligament (ACL) ruptures. Osteoarthritis will continue, even if you choose to have surgery. Another interesting paper from the “human side”, because the research on athletes and other humans is better than what we have available for advanced recovery protocol in veterinary medicine.
Most veterinarians learn in school or conferences that the pet is not using their injured limb for psychological reasons. I believe the greatest reason that humans and pets are not using a body part is due to pain. I discuss this more in this post. Instability also plays a small part in leg disuse.
Surgery Does Not Stop Arthritis –
Please understand that the arthritic process began when the first injuries occurred in the joint, when damage first occurred and then when tearing began. It is most likely that you know nothing about when the arthritis actually began to develop. A ligament usually will tear for some amount of time before total rupture. Sometimes people use my programs at first notice of injury, prior to a full ligament rupture. Most of those pets do not go on to fully rupture their injured ligament.
So What Does Surgery Do?
Clients tell me that veterinarians and others tell them that surgery will stop the arthritis. This statement is similar to the truth but it is not altogether true. Surgery immediately stabilizes the joint. Surgical stabilization can help keep the knee from moving incorrectly. In turn, that helps keep the joint from further damage.
The right exercise protocol after injury ALSO helps keep the knee (or other damaged joint ) from moving incorrectly. Moreover, the right exercise protocol strengthens the muscles of the leg with the damaged joint and keeps the other limbs from overloading and becoming injured, too.
By the same token, braces are not a more permanent fix for torn knee ligaments. They are no substitute for good recovery drills and exercise to gain long-term quality of life. Veterinarians and clients ask me about braces *all* the time. Here is my braces post.
Active Recovery –
Your pet needs an active recovery program correct for their status and situation, whether or not they have surgery. If your pet does not do an active recovery program, their muscles will not develop as well as they could to help stabilize the joint. Use my or a program designed by someone who has experience with exercise physiology, professional physical recovery techniques, and veterinary rehabilitation.
Moreover, your pet is likely to tear the ligament in the opposite leg if they’ve already torn one. My strong belief is that the opinion about the high likelihood of a dog tearing the knee ligament in the other leg after tearing the first ligament is based on poor recovery techniques. One day, I hope to run a study proving this.
Excessive exercise during periods of acute joint inflammation may be harmful to articular cartilage. (4) Greater stresses that are placed on the joint in the presence of ligament damage will cause joint damage. NO running, jumping, playing, etc…
Meniscal Tear, Too?
Your veterinarian may help you check whether or not your dog has a meniscal tear. If I am working with you and your pet, I can point out sounds and other signs that may indicate a torn meniscus. If we find s&s, you should follow up on that with your veterinarian.
It is also not necessary to have surgery for a meniscal tear. My programs for dogs with torn knee ligaments work for meniscal tears, too. I had an MRI of one of my knees several years ago to find out what was going on in it. It turns out I had already non-surgically worked through a very old meniscal tear of my own!
Keep in mind that the recommendations I cited from Dr. Slatter’s textbook do not include a return to function plan. Slatter’s instructions are most likely based on the fact that many dogs have improved over time without any specific intervention. If a thoughtful and proven program is performed, the dog or other pet should recover all the better!
No Surgery –
If you decide to not pursue surgery on your pet, then you will find great introductory recovery instructions here. Even if you opt for surgery, the recovery time and exercise protocol are virtually the same.
You may do all recovery for torn knee ligament or meniscus injury or surgery in your home environment. If you need to, enlist the help of technicians and vets at your pet’s clinic while using my programs.
What About Giant Dogs?
Additionally, I have used the same basic and advanced functional rehab protocol for large dogs. That is because successful programs are based on principles of athletic training and recovery. These will best address joint instability and muscle atrophy that occur along with knee damage in giant breed dogs.
My Great Dane, Grace, was the most orthopedically-challenged pet I have known. Without my rehab, she probably would have passed on at half her life of 11.5 amazing years.
Muscle Atrophy After (Known) Injury –
After loss of support and inflammation of ligament and joint, muscle atrophy is the next complication I address.
Muscle atrophy almost always occurs with or without surgery because the injury hurts and may feel unstable to the pet. This discomfort usually leads to their not using the injured leg as much. Rehab interventions are proven to aid in gaining strength and muscle tone in the affected limb.
Muscle Atrophy Before Known Injury –
Muscle atrophy usually occurs during the whole time the pet has been injured, prior to intervention. This is because the injury will have usually produced pain and instability, even if mild at first. Pain and instability encourage disuse and, therefore, muscle atrophy.
The degree of quadriceps muscle atrophy present before surgery for cranial cruciate ligament (CCL) rupture seems to correlate significantly with the degree of cartilage fibrillation, indicating a relationship with the severity of the condition. I refer you back to my info on pain and instability.
In studies, muscle mass improved 7 and 13 months after surgery, but significant residual muscle atrophy remained in many dogs even after 1 year. Muscle atrophy usually reverses in much less time when owners have followed my recommended protocol. I have also worked with many patients that have not previously regained muscle mass after injury or surgery. I have been able to correct the imbalance in most instances.
How Will Rehabilitation Help Ligament Injury Recovery?
Outside the scope of this writing is the argument as to whether a natural course of events follows evolution or deterioration without intervention; either way it is the primary purpose of rehabilitation interventions to improve upon what natural abilities would theoretically otherwise be realized.
A specific exercise program with frequent changes in protocol will indeed build muscle. It will also usually cause hypertrophy better than surgical repair alone or pain medication alone. I realized this first based on my observations in practice. There is also a lot of substantiating research on the topic(s). Try the National Strength and Conditioning Association for foundations in strength training if you have further interest in this specialty.
Whether or not an animal will do well on its own without intervention is inconsequential when the overwhelming benefits of rehabilitation intervention are considered. In light of this, rehabilitation treatment is indicated whether or not ligament repair surgery is performed.
So Now What Do I Do?
For non-surgical and surgical patients, rehab treatment may consist of conservative exercise that increases in difficulty as healing progresses. Both should receive therapies such as I have mentioned plus weight control plans.
For non-surgical patients, building muscle and supporting tissue will be important toward stabilizing the nearby joint(s). We also want to keep up protective interventions for affected joints. Use the therapies mentioned above and keep up dosing supplements and pharmaceuticals proven to aid with function and recovery. Nutrition supplement support includes glucosamine/chondroitin/MSM, Arnica Montana 30, and fish oil, among others.
Rehabilitation Practitioners –
A qualified rehabilitation practitioner should be able to design a basic appropriate plan of action. They and your pet’s vet can collaborate to meet your pet’s needs for recovery in the home environment. It is within the scope of this paper to briefly give information regarding ligament damage. I also inform more specifically on basics of rehabilitation recovery.
There were no written protocol that I could find that addressed specific exercise protocol and return to function for small animal veterinary medicine when I began professionally practicing in veterinary rehabilitation in 2004. This was especially true for ligament injury recovery. I subsequently began writing protocol based on how similar human injuries are managed and treated for athletes. This method has been very successful and very helpful to large numbers of people and pets.
1. Fowler D: Principles of wound healing. In Harari J, editor: Surgical complications and wound healing in the small animal practice, Philadelphia, 1993, WB Saunders.
2. Frank C et al: Normal ligament: structure, function, and composition. In Woo S, Buckwalter J, editors: Injury and repair of the musculoskeletal soft tissues, Park Ridge, Illinois, 1991, American Academy of Orthopedic Surgeons Symposium.
3. Moore KW, Read RA: Rupture of the cranial cruciate ligament in dogs. II. Diagnosis and management, Compendium of Continuing Education Pract Vet 18:381391, 405, 1996
4. Agudelo CA, Schumacher HR, Phelps P: Effect of exercise on urate crystal-induced inflammation in canine joints, Arthritis Rheum 15:609-616, 1972
Final Notes –
By the way, that case? From my prologue? Was a 2 yo in-tact male Chocolate Labrador hunting dog with extreme crate anxiety and parent-clients who both worked long hours in science-based jobs. I remain forever grateful for that referral.
And I continue to receive support from RRAH and Dr. Sharon Waters, most specifically, as they work to provide the best care for their patients.
(Copyright 2007, Deborah Carroll, Updated April 18, 2018)