Cruciate Ligament Injury

Cranial Cruciate Ligament Rupture

Springfield District Vets have skilled orthopaedic surgeons who confidently operate on dogs diagnosed with Cranial Cruciate Ligament Rupture. We hope that you find this document useful in understanding the mechanism and surgical repair of this condition. Please do not hesitate to ask for assistance or for a follow-up appointment if you have further questions. We are most happy to assist in any way we can.

A ruptured cranial cruciate ligament (CCL) is a common cause of hind limb stifle or 'knee' lameness in dogs. There are two cruciate ligaments that cross inside the stifle: the cranial cruciate and the caudal cruciate, named according to where their lower attachment is found. The cranial cruciate ligament prevents the tibia (lower large bone of the hind-leg) from slipping forward out from under the femur (top bone of the hind-leg). Rupture of this ligament causes instability of the joint, causing degenerative joint changes and extra bony growth (osteophytes) resulting in acute, then chronic pain. This process can be minimised by surgery, but cannot be reversed.

The stifle contains two extra pieces of cartilage between the bones called menisci, which help to cushion the joint. When the cruciate ligament ruptures, the medial (inner side of the stifle) meniscus frequently tears and must often be partly or completely removed.

Causes

Causes of cranial cruciate ligament rupture include excessive trauma such as turning quickly when running. It is a common injury in footballers! Overweight older dogs are prone to this kind of injury as the ligament may have been stretching and tearing over time. Rottweilers in particular appear to have a genetic propensity for this problem and will at times rupture one, followed by the second some months later.

Diagnosis

The “cranial drawer sign” is definitive for diagnosing CCL rupture – this is where the tibia moves forward separate from the femur indicating a rupture or partial tear. Anaesthesia may be necessary for this test as the dog may be too painful.

If the rupture occurred some time ago, there will be swelling on the side of the knee joint that faces the other leg, called a medial buttress.
X-rays do not show ligaments or other soft connective tissues, but they can show fractures, tumours and signs of degenerative joint disease (bone spurs or irregular bone wear) as well as the presence of excess joint fluid, which commonly occurs with CCL rupture.

Treatment

The ruptured CCL is not directly repaired. The remnants of the ligament are removed and the joint is

stabilised by methods which take over the role of the CCL. There are several different techniques; the most suitable for your dog will be discussed.

Lameness will always be present if the joint is not surgically repaired, but may improve somewhat, without treatment. Surgery is always recommended.

Surgical Techniques

1. De-Angelis Extra-Capsular repair – better for smaller animals, a strong suture is anchored behind the stifle and anchored through a hole drilled in the front of the tibia.
2. LigaFiba Iso-Toggle repair – this is a relatively new method, which involves thick suture material threaded through holes drilled in specific points through the tibia and femur, and anchored in place by ‘buttons’.
3. Triple Tibial Osteotomy (TTO) – 3 cuts are made are in the tibia and a small wedge is removed to change the level of the top of the tibia and a plate is screwed into place. This surgery is performed by a visiting specialist at SDVC.
4. Surgery on damaged meniscii will be performed with each technique if necessary.

Treatment also includes weight reduction, anti-inflammatories to alleviate pain, cartrophen injections weekly for 4 weeks after surgery and joint supplements.

Possible Complications

1. Complications from surgery include adverse reactions to anaesthesia and infection. Careful aseptic technique and intravenous antibiotics are given during surgery to minimise the chance of infection.
2. Fluid may build up at the site of the incision (seroma) post operatively, needing drainage (aspiration).
3. Occasionally animals have a reaction to the internal suture material.
4. After surgery, the animal should rest until the joint is fully healed to avoid re-injury. The joint may be unstable or the surgical repair may fail and another surgery may be required, especially if the animal is over-active after surgery.
5. Animals with a ruptured CCL are likely to rupture the other within 18 months after surgery.
6. Up to 15% require additional surgery to repair damage to meniscus may occur after surgery.

Post-Operative Care

SDVC provides a free 3-day check after surgery, then sutures require removal 10-14days after surgery. Pain medication will be prescribed. A supportive bandage may be applied overnight, and removed prior to sending the animal home.
The animal must be confined and activity strictly limited for several weeks after surgery, however short leash walks are allowed immediately. The diet should be modified for weight loss as required and to prevent weight gain. SDVC staff will assist in choosing a suitable diet. Your dog must be on a leash at all times during toilet walks. Exercise may be gradually increased after 6 weeks. Normal activity usually resumes within 3 months after surgery, however ball and stick chasing would be ill advised throughout the dogs' life from that point on!  Physiotherapy and hydrotherapy (underwater treadmill and swimming) is strongly recommended to help strengthen the leg, and plays an important part in recovery. SDVC has recommendations for these facilities.

Prognosis

Prognosis is generally good after surgical repair; however it is important to remember that your dog no longer has a CCL and so some lameness may remain. The improved joint stability will reduce but not halt the progression of pre-existing arthritis.  Weight bearing is expected from 3 weeks and after 6 weeks normal activity may be resumed; however there should be no jumping or vigorous exercise for at least 6 months. Ongoing medical management for arthritis includes exercise, diet and weight management, formulated medications and supplements. SDVC staff are most happy to assist in all of these areas.