Diagnosing and Treating Cranial Cruciate Ligament Injuries
Diagnosing the CCL starts with a good history. The lameness usually occurs with some trauma that occurs, even if there is evidence of chronic tearing. The veterinarian will then perform the cranial drawer test. This will demonstrate the instability of the joint by allowing the tibia to thrust forward. The instability can be graded based on the amount of “drawer” or cranial movement of the tibia with grade 1 being very little instability and grade IV being a complete rupture. The stability of the joint is also checked by the indirect method by flexing the hock and observing for abnormal movement of the tibia. Radiographs are commonly taken to assess the amount of joint disease present and the relative position of the tibia to the femur. At this time it would be prudent to also take radiographic views of the hips to evaluate for hip dysplasia.
Treating a tear or rupture of the CCL.
There are many ways to treat the CCL injury. This depends on the severity of the tear and the signalment of the patient. Partial tears or sprains may be treated conservatively with rest and anti inflammatories, complete ruptures will usually require surgical intervention. In the future we will also discuss some other non surgical treatments available for partial tears such as joint injections, hyaluronic acid, platelet rich plasma, low level laser therapy and stem cells. For now we will discuss surgical options.
Extracapsular surgery: MRIT
One common method (there are many procedures) of extracapsular repair is the MRIT procedure which uses a large heavy suture placed in the same plane as the intra capsular ligament. This stabilizes the joint and reduces the “drawer” movement that occurs when the ligament is torn. By stabilizing the joint we reduce the “abnormal” movement and cause a return to function. Stabilizing the joint also reduces the amount of joint disease that occurs. This joint disease causes pain, discomfort, loss of function and range of motion as your pet ages. In later parts of the article, we will discuss management and therapies that can help reduce the amount of joint disease and arthritis that occur in the joint as a result of the instability.
TTA or TPLO procedures are effectively doing surgery that changes the geometry of the stifle joint and the forces of the joint in weight bearing position. This force can be corrected by either cutting the Tibial Plateau and rotating it into a more flat position (TPLO) or by counteracting this force by changing the angle of pull of the very strong Patellar Tendon by advancing the Tibial Tuberosity (TTA). A quick internet search can provide lots of information on either of these procedures.