Cruciate disease - tears, ruptures, degradation - is the most common orthopaedic disease in mature dogs that may require surgical intervention. The cranial cruciate ligament is a large, strong ligament located within the knee joint. It is not actually a single structure but is, in fact, made up of a bundle of individual fibres tightly bound together to form the ligament. Joint instability occurs as an accumulation of several minor tears of these fibres and ongoing breakdown of the ligament rather then a complete single tear.When a cranial cruciate ligament is torn, it causes sudden pain and often results in your pet holding its leg up. It also causes instability in the knee joint. The pet may put the leg down and start using it within a day or so but will continue to limp for several weeks. Normally, at the end of several weeks, the initial pain subsides and the pet is willing to use its leg more; however, the joint remains unstable. Every time your pet puts weight on the leg, the tibia (shin bone) slides forward in relationship to the femur (thigh bone). This abnormal motion causes wear and tear on the joint cartilage causing pain and leads to arthritis. This motion can also put excessive stress on the menisci (C shaped pieces of cartilage within the knee joint) causing damage or tearing. There are numerous surgical procedures that may be performed to improve your dog's function and delay the onset of osteoarthritis. The most common procedures that we offer are listed below.
This operation is based on the biomechanical analysis performed by Dr Slobodan Tepic, which revealed that in order to remove the shear strain from the cranial cruciate ligament the tibial plateaux should be perpendicular to the patellar ligament. There are two basic ways to achieve this; i) advance the tibial crest (the basis of the tibial advancement technique (TTA) described by Professor Montavon and ii) alter the alignment of the tibial plateaux to the patellar ligament to 90 (a modification of the Slocum technique). The TTA procedure is designed to move the patella ligament so that it is positioned at 90 degrees to the tibial plateau. This is achieved by first performing an osteotomy of the tibial tuberosity and then advancing it with a titanium cage. The correct cage is selected for both thickness and width and is then secured to the tibia with two stainless steel screws.
Dr Warrick Bruce reasoned that rather than doing one technique or the other, there is merit in doing a little of both to achieve the same outcome as the TTA but with less radical angular changes. In the operation of triple tibial osteotomy (TTO) a small closing wedge osteotomy is performed and this simultaneously advances the tibial crest.The cut bone is secured using a T-plate and six stainless steel screws. This has proven to be a very robust method of reconstruction with very good early return to function.
Extra-capsular or lateral banding
This is a modification of the DeAngelis procedure, which involves placing a very strong, polyester or nylon band from the back of the femur, across the joint to the front of the tibia. This will tighten up the joint and stabilize it. Over time, scar tissue will form around the joint to form a structure that mimics the function of the normal cranial cruciate ligament. The majority of animals will regain near normal use of their leg after the surgery and after a period of rehabilitation. Total rehabilitation time, can be six to 12 months.