An Overview of Cruciate Ligament Injuries in Working Retrievers

February 18, 2007



 

Introduction:

We’ve all heard of human athletes having knee injuries and sometimes ‘tearing’ their Anterior Cruciate ligament, at one time, this was immediately viewed as a career ender for those athletes.  In our Canine athletes, the Cranial Cruciate ligament (CCL) is the counterpart to the ACL in humans.  The CCL is located in the dog’s stifle (knee) joint and it plays a key role in the stabilization of the femur on the tibia.  When the CCL is ruptured the knee joint becomes unstable and if it’s not treated in a timely manner, painful and often debilitating arthritis can occur.  CCL tears can be complete or partial and are often the result of a twisting injury to the knee.  Sometimes the ligament can stretch slowly over time which results in chronic injury.  This is harder to diagnose and sometimes goes for a while without diagnosis.  When this happens, the dog might have a limp, but regain the use of the leg.  This may happen a few times before the ligament finally tears and the dog becomes lame.

Tuck, just prior to his injury

Diagnosing CCL Injuries

When the dog limps or becomes lame a trip to the veterinarian is warranted, the sooner the better. Treating these injuries early is important to stop further damage such as tears in the cartilage, which will further lead to arthritis.  The CCL and cartilage tears are soft tissue injuries that will not show up on radiographs.  In most cases, X rays are not needed.  Instead, the vet will observe the dog’s movement and will palpate the leg to feel for a ‘drawer’ sign, this may require sedation.  The drawer sign is done by bending the knee and pulling the lower leg to see if it can be pulled forward, forward movement is abnormal and indicates a tear in the CCL.

Surgical Options

With our Canine Athletes, surgical stabilization of the knee is the treatment of choice.   With CCL injuries, we have several types or methods of surgery at our disposal.   Each case is different and the best method may be different for each dog.  Prices for the different types can range from $600 to $3,000.

The main CCL surgical techniques include:

• Extra Capsular Suture: The “Normal” or ‘Old school’ surgical method. This method is done by sewing a strong surgical suture (similar to 100lb monofilament fishing line) around the knee joint to restore the stability of it.

• Tibia Plateau Leveling Osteotomy (TPLO): This procedure changes the angle of the tibial plateau so the cruciate ligament is no longer necessary to keep the femur from sliding down the plateau of the tibia. This is accomplished by cutting and rotating the top of the tibia and screwing in a bone plate so the bone will heal in its new, more sound, position.

• Fibular Head Transposition: In this method, the head of the fibula is rotated and the lateral collateral ligament is moved to mimic the cruciate ligament and it is held in place using pins and wires.

• Tibia Tuberosity Advancement (TTA): This method is very similar to the TPLO method of surgery. The TTA method stabilizes the knee by cutting and changing the angles of the knee and enabling it to work without a cruciate ligament. The TTA method is often considered to be less invasive than the TPLO method.
  
   

Which method is best?  It depends on the dog, the career plans for the dog and the owner’s budget.  The TPLO and TTA methods may be less invasive than the other methods.  This may decrease the chances of arthritis developing in the joint (if the injury was treated quickly), but they are also the most expensive methods.

                                                                                                                                       Tuck’s leg after his CCL surgery


Recovery

Surgical recovery can take anywhere from 6 to 16 weeks.  During this time, our companions must have their physical exertion severely limited, no running, jumping, or swimming should be allowed during the recovery time, extreme cage rest is needed. The time of recovery depends on the dog’s physical condition and age as well as the method of surgery performed.

                                                                                      For Tuck, Chemical sedation was necessary for the first few days post surgery.

Rehabilitation

After the initial recovery, rehabilitation is necessary for the dog to regain ‘normal’ function of the knee.  Many different methods may be recommended, discuss this with your Veterinarian.  Personally, I prefer swimming as it is low impact and builds muscle mass to aid in stabilizing the knee joint.  This is easily accomplished with our water loving retriever breeds.  Limiting dogs with a hard charging water entry may be necessary.

                                                                              Swimming is a great method to rehabilitate a knee post surgery.

Follow up

It is estimated that about 1/3 of the dogs that have CCL surgery in one knee will injure the remaining knee as well.  This could be because of a genetic predisposition or the added stress on the ‘good’ knee for compensating for the injured knee. 

There are several theories on prevention of CCL injuries.  One theory is that there is a genetic predisposition. Several studies are looking into finding a ‘correct’ angle or range of angles for healthy stifle joints. This may allow us to prevent or limit CCL injuries in the future by certification of knee joints similar to the programs for hip and elbows registration that we currently have (OFA/Penn Hip).  This would drive breeding selection towards healthy knees.  Another theory is that excess weight may play a key role of increased risk of CCL injuries.  So, we may limit the risk by having our companions in good physical condition year round.  Another way to limit injuries is to limit activity.  Couch potato dogs have a much lower incident of CCL injury.  This is not a practical method, especially for our canine athletes who work hard during and after the season.  Another theory is that we do not warm up our canine athletes like our human athletes do.  This warm up may prevent injury and is worth looking into.

About the Author:

Cray Stephenson lives in Milton, Fl with his wife Michelle Stephenson, DVM and their 2 sons, Patrick and Kelton. Together they own and operate Creighton Kennels Hunting Retrievers; a breeding and training facility dedicated to improving our hunting retriever breeds.

He was a founding member and Vice President of the Central Kentucky Hunting Retriever Association (http://www.ckhra.us), Has been active in the Hunting Retriever Club, the Super Retriever Series (http://www.superretrieverseries.com/) as both a judge and a handler and was one of only four judges chosen for the Inaugural World Retriever Championship (http://www.worldretrieverchampionship.com) in Oxford, MS, March 2005.

Cray can be reached at 850-983-0943, http://www.creightonkennels.net and contacted via email at patchio@bellsouth.net 

a Special thanks to Avery Outdoors (http://www.averyoutdoors.com/)