Cruciate Rupture

590 Lark Street

Geneva, IL

630 232-8868

Cranial Cruciate Rupture

Cranial cruciate rupture of the stifle is a common cause of canine lameness. The ligament supports the knee to prevent cranial separation of the tibia (distal bone) from the femur (proximal bone). When the ligament is ruptured, increased cranial and medial occurs. This results in stretching of the surrounding soft tissue and also increased abnormal wearing of the joint cartilage. See pictures below for illustration.

Repair of the joint is usually performed by removing any diseased or abnormal tissue from the joint that results in inflammation. The ligament can not simply be sutured back together as it will not heal correctly to function. The joint is then flushed and the joint capsule closed. Sometimes, a tiny "C" shaped piece of tissue called the meniscus is torn or displaced and also needs to be removed. It is only removed if damaged as it provides a "Cushion" effect and is difficult to remove if not damaged. Stabilization of the joint is then accomplished by one of several methods, the most common are listed:

Retinacular imbrication (MRIT)- A strong suture is placed around the outside of the joint in a plane resembling that of the original ligament. Suture ligaments or bone "Anchors" are generally not used within the jont in canines as they have been found not to do well. This external stabilization suture will generally last for 6 months or longer, but often eventually breaks. The joint capsule and surrounding tissues will have healed well by this time and the suture is generally no longer required. This is the most common procedure used.

Fibular head transposition- This procedure involves displacing the lateral collateral ligament of the knee cranially (forward) to approximate the alignment of the cruciate ligament. This procedure is often combined with other forms of stabilization, and usually reserved for large dogs. It is a more involved procedure and may not be of great benefit in many cases.

TPLO- Tibial Plateau Leveling Osteotomy is a procedure that is quite involved. In theory the angle of the tibia is greater in dogs that rupture their cruciate ligament, thus putting more stress on the ligament. The procedures goal is to change this angle by breaking the proximal tibia and rotating the articular surface to a more level angle. In theory this creates less cranial "thrust" force on the tibia. Subjectively, this procedure is reported to work well and is gaining popularity. Very large dogs that may break down other implants may respond more favorably to this procedure.

Tibial Tuberosity Advancement (TTA) is a procedure where the tibial tuberosity (bony attachment of the patellar tendon on the tibia) is fractured and then an implant is placed that moves the tendon cranially. This creates more tension on the patellar tendon in an effort to stabilize the joint. This procedure does show promise but some concerns would be breakdown of the implant and that additional stresses are not placed on the patella and patellar tendon.