The cruciate ligaments are two ligaments that run through the stifle (knee) joint forming an X when the stifle is viewed from the side. They are called the cranial (anterior) cruciate (CCL or ACL) and the caudal/posterior cruciate ligament.
Partial or complete rupture of the cranial (anterior) cruciate ligament is a very common injury in the dog and also occurs in cats. Rupture causes instability of the stifle (knee) joints. This also causes acute pain and over time leads to degenerative joint disease or osteoarthritis. Quite commonly, there is also a tearing of the meniscus (cartilage) within the joint which occurs concurrently with or following cruciate ligament rupture.
Diagnosis may be possible at the initial consultation. However most awake patients are sore and nervous, and tense the muscles of the leg, making it impossible to feel the instability in the joint. Usually a sedation is needed to allow the veterinarian to make this diagnosis.
Without surgical repair, dogs with ACL lameness over time will develop degeneration and arthritis within the joint due to the femur and the tibia shearing against each other with each step. Surgery is therefore recommended for any dog with ACL damage. Surgery stabilises the femur and tibia to stop the ongoing shearing forces.
The most common surgical procedure called a D#Angelis Procedure involves the following:
– Opening the joint to examine the menisci (cartilage which cushions the knee) for damage which can occur as a result of the ACL injury. Removing any damaged cartilage and the torn ligament. Tightening and suturing closed the joint capsule.
– Replacing the function of the ruptured ACL with a strong non-absorbable suture material external to the joint. This line is stabilised with 2 stainless steal crimps which hold the line with great strength.
– Closing other tissues below the skin tightening at the same time to help strengthen the joint.
– Closing the skin incision.
Pain relief medication is given to assist recovery and to make the patient as comfortable as possible. This involves the following:
– Non steroidal pain killers given intravenously before the procedure.
– A morphine type analgesic pain killer injection called Temgesic.
– A morphine type trans dermal patch called a fentanyl patch which lasts 3 days giving great pain relief.
More advanced techniques for cranial cruciate repair are also offered including:
– TWO (Tibial Wedge Osteotomy Procedure)
– TPLO (Tibial Plateau Levelling Osteotomy)
– The usual recovery period is 6 to 12 weeks. A series of 4 anti-arthritic injections are given weekly after surgery.
– Exercise is slowly built up over this period.
– We aim to have dogs #off lead# and back to normal by 12 weeks post surgery.
The long term outcome for most patients is excellent. This is influenced by the activity level of the dog, the dog’s size and whether the dog is overweight – large, active, overweight dogs have a poorer prognosis. A significant percentage of patients injure the ACL in the opposite knee within 3 years. The chance of this occurring may be reduced with early surgical intervention of the first torn cruciate.