Comparing Treatment Options for Cranial Cruciate Ligament Disease
The cruciate ligaments are two bands of fibrous tissue inside the stifle (knee) that create a hinge between the femur and tibia. The ligaments criss-cross inside of the joint (the word cruciate means "to form a cross"), and allow the knee to flex while restricting side-to-side motion. Unfortunately, stifles lack 'interlocking' bones, like hips or elbows, making them more injury-prone. You can think of a rupture of the cranial cruciate ligament (CCL) in dogs like the common human injury, an anterior cruciate ligament (ACL) tear.
When the CCL is torn, each step causes the tibia to thrust forward like an opening drawer from underneath the femur. The sliding motion causes damage to the cartilage and bones inside of the joint, and makes the knee feel unstable and painful. Your veterinarian will check for this instability through a physical exam - sometimes mild sedation or radiographs (x-rays) are needed to confirm the diagnosis.
(video of tibial thrust here)
To restore use of the joint, surgical stabilization is recommended. Performing surgery as quickly as possible will reduce pain and permanent joint damage. In some circumstances, conservative management may be the only treatment option available.
When surgical stabilization is opted for, an owner is faced with a plethora of options. The tibial plateau leveling osteotomy, or TPLO, surgery has historically been promoted for use in active large breed dogs or dogs with excessive tibial plateau slope. This surgery involves specialized equipment and is typically performed by a boarded veterinary surgeon, or DACVS.
Some dogs may be candidates for a less invasive method for stabilization of the joint. Instead of cutting the bone, a SwiveLock Bone Anchor Stabilization passes a synthetic ligament-like biomaterial called FiberTape through a small drilled hole in the tibia, to a bone anchor placed in the femur. Fibertape is a Kevlar-like material that acts as an artificial stabilizing ligament. As this material has very little stretch to it compared to other lateral suture repairs, the stabilization is more secure and lasts longer.
The fact that several options are available to address the same surgical problem indicates that no one procedure is perfect for all cases and all situations. We are happy to discuss options and schedule a consultation to help you decide on the right treatment plan.
Surgical TreatmentWith surgical correction and physical rehabilitation, the dog will feel much better and have improved use of the knee. Surgery lessens the arthritis development in the knee and helps relieve pain. This is especially important for younger dogs to give them higher quality of life.
Tibial Plateau Leveling Osteotomy (TPLO) is one of the "bone-cutting" techniques and is designed to change the anatomy of the knee so that it no longer has abnormal movement of the bones. A semicircular cut is made at the top of the tibia with a curved saw so that the tibial joint surface is "leveled out", to prevent forward slipping of the joint. A plate and screws are inserted to stabilize the cut bone during healing.
Lateral Suture Stabilization used to be the most common technique for surgical treatment of CCL disease. A suture (similar to fishing line) is placed around another ligament and into the tibia to provide stabilization of the joint during healing. The stabilization is temporary as the dog makes new scar tissue around the knee for long-term joint stability.
Image provided and copyrighted by Arthrex Vet Systems.
The TightRope procedure was developed in 2005 to provide a minimally invasive and improved method for stabilization of the joint. This technique does not require cutting of the bone like the TPLO. Instead, it uses two small, drilled tunnels in the femur and tibia to pass a synthetic ligament-like biomaterial. The biomaterial used for the TightRope is called FiberTape. It is a Kevlar-like material that is used extensively in human orthopedic surgery. The FiberTape acts as an artificial stabilizing ligament. As this material has very little stretch to it compared to the fishing line-type suture, the stabilization is more secure and lasts longer.
The SwiveLock Anchor procedure is very similar to the TightRope. FiberTape is used with this procedure as well. Instead of drilling two bone tunnels, only one is made. In replacement of the second bone tunnel, an orthopedic implant called a bone anchor is placed in the femur. This procedure is even less traumatic than the TightRope and a little faster to complete.
40-60% of dogs that have CrCLD in one knee will, at some future time, develop a similar problem in the other knee.
Partial tearing of the CrCL is common in dogs and progresses to a full tear over time.