Cranial cruciate ligament disease, also referred to as the Anterior Cruciate Ligament (ACL), is the sudden (acute) or progressive failure of the cranial cruciate ligament. This results in partial to complete instability of the stifle joint and is a major cause of degenerative joint disease (progressive and permanent deterioration of joint cartilage) in the stifle joint; rupture may be partial or complete.
In acute cases, the pet may hold the leg up in a partial bent position (flexion) while standing. In a more chronic or gradual onset, an intermittent lameness is noticed that may last from weeks to months. This lameness and disuse of the leg will cause muscle atrophy. If the condition is untreated, the instability of the joint will wear the cartilage, cause inflammation and result in chronic and permanent arthritis.
The causes of cranial cruciate ligament disease and rupture are related to the breed and use of the pet, as well as the conformation of the leg. The pet as compared to how a human stands on the rear leg at an angle that stresses the ligament. This angle may be exacerbated in some breed conformation and certain conditions, such as the pet being overweight, which may contribute to the stress on the ligament. These stresses cause gradual tearing of the fibers of the ligament, which weaken the ligament. Sudden failure may be due to physical stress on a weakened ligament. Such stress may occur when a pet plants the foot and turns rapidly, or when running, the leg may drop into a hole causing the body to move abruptly forward of the leg. Most cases that have complete rupture of the ligament in one leg, have partial damage to the ligament in the other leg. In addition, concurrent abnormalities such as hip dysplasia and patella luxation may predispose a pet to having cruciate ligament disease.
Breed SpecificThe breeds that have a predilection to this problem are the Airedale Terrier, Akita, Alaskan Malamute, American Staffordshire Terrier, Boxer, Chesapeake Bay Retriever, Chow Chow, Labrador Retriever, Large breed dogs, Mastiff, Neapolitan Mastiff, Newfoundland, Rottweiler and Saint Bernard.
DiagnosisA diagnostic evaluation for cranial cruciate rupture will include a cranial drawer test, which involves specific manipulation to assess the status of the cranial cruciate ligament – this test may require sedation in painful or tense pets. Radiographs also show signs of stifle joint laxity, increased joint fluid, arthritis, and osteophyte formation on areas stressed by the instability of the joint.
Conservative TherapyConservative therapy consists of cage rest, restricted activity, weight control and appropriate nonsteroidal anti-inflammatory (NSAID) medications. If improvement does not occur, surgery is recommended.
Surgical TherapyThree common surgical strategies exist for treating canine cruciate ligament disease:
- Extracapsular suture procedures using monofilament or multifilament braided materials.
- Geometric-modifying osteotomy procedures.
- Tibial plateau levelling osteotomy (TPLO)
- Tibial tuberosity advancement (TTA)
- The newer Simitri Stable in Stride plate.
Here, at Safari, we offer these three different surgical techniques, but recommend the TTA as the best alternative in our hands.
It is important to realize that joint contact mechanics are altered by all current surgical techniques.
Stem Cell TreatmentComplete rupture of the cranial cruciate ligament results in an unstable joint that eventually progresses to arthritis. Surgical stabilization of these joints is essential in the prevention of arthritis. When the ligament is completely ruptured there is no scaffold for the stem cells to use to repair the ligament. So, stem cell based regeneration of a ruptured ligament is not a successful strategy. Stem cells can, however, be used to regenerate partially ruptured ligaments. Stem cell therapy is recommended in the opposite stifle joint to reduce the degeneration of the ligament and to reduce the likelihood of a rupture in that ligament.
Many pets presented with chronic lameness of the stifle that have ruptured cranial cruciate ligaments also have arthritis that will not be managed by surgery alone. In these pets, it is recommended that stem cell therapy be used to manage the on-going damage to the joint due to this arthritis. Stem cell therapy combined with PRP and PRP-L have been shown to have long-term positive effects on the status of the cartilage in the damaged joint.
- Mesenchymal Stem Cell Therapies for Arthritis
- Mesenchymal stem cells (MSCs) that we use at Safari have an inherent ability to convert their cell type to chondrocytes (cartilage cells) and to secrete several growth factors and cytokines (cellular metabolism modifiers) which promote cartilage repair and regeneration. A single injection of MSCs into a joint can have permanent lasting effects on an arthritis joint.
- Platelet Rich Plasma
- Platelet Rich Plasma (PRP) is created from your pet’s blood. It is created by concentrating the blood platelets then stimulating them to release their growth hormones. These growth and repair hormones when used alone in joint disease cause reduction in inflammation and the destructive actions of arthritis on cartilage. PRP also has the effect of stimulating stem cells to grow faster and more effective. PRP plus stem cells creates a synergistic effect on the healing of an arthritic joint.
- Platelet Rich Plasma Lysate
- Platelet Rich Plasma Lysate (PRP-L) is created like PRP but it is 100 times more powerful because the platelets release many more of their growth chemicals in this new process. PRP-L takes 48 hours to make.
Both the affected leg and the opposite leg will be treated. PRP-L is reserved for joints that have severe arthritis before the procedure and is only applied to the affected joints.