Below are some of the more common procedures our mobile surgery service performs. If you do not see your pet’s procedure listed, please do not hesitate to contact us for more information.
TPLO & MRIT
The canine knee is a joint where the lower end of the femur rests on the upper end of the tibia. In dogs, the tibial surface is sloped such that during weight bearing, the lower part of the femur has a tendency to slide backwards, like a ball rolling down a hill. In a healthy knee, a ligament called the cranial cruciate ligament prevents the femur from sliding; however, when this ligament tears, the femur will slide backwards each time the patient puts weight on the leg, causing pain and lameness. This sliding will put additional stress on two cartilage pads(meniscus) within the knee, causing additional tearing in those pads.
How do we correct this condition?
There are two procedures that can help stabilize the knee; however, the size of the pet and activity level will determine which procedure is best suited. Typically, for dogs over 30lbs, we recommend a TPLO (Tibial Plateau Leveling Osteotomy), and for smaller dogs an MRIT (Modified Retinacular Imbrication Technique).
This procedure corrects the fundamental reason why ACL tears occur so frequently in the dog, the presence of a slope or incline in the tibial plateau of 20 to 30 degrees. Following a thorough surgical exploration of the knee and removal of any torn cruciate ligament fragments and/or meniscus, a curved bone cut or osteotomy is performed on the tibia below the knee. The tibial plateau is rotated until it is flat, preventing any further femoral slide. The osteotomy is stabilized with a specialized plate and screws, so the bone will heal in this new position. This occurs in approximately 12 weeks. It is very important that outside activity is limited to leash walking only during this 12 week period. This procedure returns most dogs to 90 to 95 % of their pre-injury function on the limb. It is important to be aware that approximately 30% of dogs will tear the cruciate ligament in their other knee within the next two years.
The knee joint is thoroughly explored, and any torn ACL and cartilage cushion are removed. In this technique, a large Monofilament Nylon Suture is passed from an anchor point behind the lower femur to a corresponding anchor point at the front of the upper tibia, mimicking the direction of the cranial cruciate ligament. The nylon acts as a scaffold for scar tissue formation, stimulating an extensive scar tissue reaction in the orientation needed for stability. The scar tissue band overcomes the effect of the tibial slope, preventing the femoral slide. It takes approximately 6 to 12 weeks for sufficient scar tissue to develop, and until this has taken place, stifle stability is dependent on the monofilament nylon. It is very important that outside activity is limited to leash walking only to prevent stretching or snapping of the nylon. Most patients will recover 85 to 90 % of their pre-injury function on the limb. It is important to be aware that approximately 30% of dogs will tear the cruciate ligament in their other knee within the next two years.
PATELLA LUXATION CORRECTION
The Patella, or knee-cap, is a small bone that glides in a groove at the front of the knee joint to support the knee when in flexion. Sometimes the patella will luxate, or pop out of place, resulting in lameness or an abnormal gait. This can occur in all breeds and sizes of dogs and, to a lesser degree, in the cat, but is most common in the toy breed dog. If the lameness is severe or frequent, we recommend repair.
Patella Luxation Correction usually involves a combination of techniques, including deepening the groove if it is too shallow, moving the attachment of the patella ligament to realign the patellar mechanism, and/or releasing and tightening up soft tissues around the patella. Correction of the luxation is successful in 90% of cases using a combination of the above techniques. Recovery typically takes 4 to 6 weeks, during which time activity needs to be severely restricted. This includes leash walking only when outside, and no running, jumping or stairs while indoors.