What really is a CCL?
The Cranial Cruciate Ligament or CCL (also known as the Aniterior Cruciate Ligament or ACL in humans), is a ligament that attaches the femur (thigh bone) to the tibia (shin bone) thus stabilizing the stifle (knee) joint.
Make up/
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The Cranial Cruciate Ligiament is slpit into 2 bands - the Cranial Cruciate Ligament and the Caudal Cruciate Ligament. During both flexion and extension of the stifle joint, the Craniomedial Ligament is taunt, although only during extension the Caudolateral Ligament is taunt, therefore lax in flexion. the ligaments are made of mechanoreceptors and affeient nerve endings. Innervation serves as proprioceptive feedback mechanism to prevent excessive flexion or extension. This stimulation is possible through stimulation/relaxtion of muscle groups that lend support to the joint
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Function |
The stifle joint is normally stabilized by both passive constraints (ligaments, menisci and joint capsule) and active constraints (muscles and tendons). The CCL functions primarily to limit cranial translation of the tibia relative to the femur, to limit internal rotation of the tibia and prevent hyperextention. When the stifle is flexed, the cranial and caudal cruciate ligaments twist on each other, limiting the degree of varus - valgus to support the flexed stifle joint. This is why they are called cruciates- because the 2 bands form a crucifix when together.
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Who? |
Most often we see young, active, large-breed dogs with CCL tears. The young guns seem to recieve a torn CCL because they are active and still puppies, so they arent that worried where their limbs hang.It is common to see the CCL tear when a patient jumps or gets their foot stuck in a hole or a fence, therefor twisting and pulling to be released, not only releases their foot but along with this CCL. On the the other hand, older dogs are also seen with CCL tears because of degenerative and traumatic causes. Breeds such as Mastiffs, Chow Chows, Labrador Retrievers and Golden Retrievers. CCL tears are very uncommon in cats but again an overweight cat has an increased risk.
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Why it happens |
CCL tears occur from both degenerative and traumatic causes. You could say that these 2 categories are interrelated due to the fact that ligaments weaken by degeneration over the years, making the patient more susceptible to trauma. A HIGH incidence of CCL trauma in dogs suggests that there is premature degeneration. Other reasons to why CCL tears are so common could be, conformation abnormalities ( straight rear limbs), medical arthropatries and increased TPA which leads to chronic excess loads on the CCL.
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Why to fix it |
When you pet tears their CCL, not only are they in constant pain, but, without a procedure being complete to solve the problem, not only will the pain increase but many other problems can arise leading to an every bigger bill. With a untreated torn CCL, lameness is often associates, along with, medial meniscus damage ( bucket handle tears) and progressive radiographic signs of osteoarthritis. An untreated CCL can also lead to a cascade of events that weaken the stifle such as Synovitis, Articular Cartilage degeneration, periarticular Osteophyte, Fibrosis and Degenerative Joint Disease (DJD). All these problems and more lead to an unattractive pet who is in constant pain, which can lead to aggression.
For more information about the effects of an untreated torn CCL refer to the article attached to the link below: http://www.veterinarypracticenews.com/Vet-Editorial-Blog/Cutting-Edge/July-2010/10-Deadly-Sins-Of-Untreated-ACLs/ |
30 - 40 %. of CCL tear patients will rupture their bilateral CCL within 2 years. of the original."