Ruptured Cruciate Ligament - TPLO Surgery
Rupture or tearing of the cruciate ligament
A Common Knee Injury in Dogs
Rupture, or tearing, of the cranial cruciate ligament in the knee is a very common and painful injury among human athletes. The same injury in a dogs’ stifle joint (‘knee’) causes pain, lameness and arthritis. It is one of the most common orthopedic injuries in dogs and a major cause of arthritis. The cranial cruciate ligament is inside the stifle joint, connecting the femur and tibia bones. It helps maintain a stable joint by preventing forward and backward sliding of the femur on the top of the tibia (tibial plateau), as well as preventing internal rotation and hyperextension. Two other important structures in the knee are the medial and lateral menisci (cartilage pads). These pads are also prone to injury when the stifle joint is unstable. The Tibial Plateau Leveling Osteotomy (TPLO) surgery has proven effective in returning injured stifle joints back to full function.
When the cranial cruciate ligament tears, pain, swelling and obvious lameness occur. Partial tearing can cause less pain and mild lameness. Simple rest and anti-inflammatory medications do not help with these symptoms. To diagnose rupture of the cranial cruciate ligament, we will examine your dog’s gait, feel the joint, and check for abnormal forward and backward mobility of the joint (called cranial drawer or cranial tibial thrust). It may be necessary to put your dog under mild sedation to allow x-rays to be taken to look for arthritic changes and swelling.
Preoperative x-rays are taken to measure the tibial plateau angle, which is used to calculate the degree of rotation required to level the tibial plateau. During the TPLO surgery, the angle of the tibial plateau is altered by making a curved cut in the top of the tibia and then rotating the piece so that the load-bearing surface of the bone is flat. The meniscus is also evaluated and may require surgery (meniscal release) at that time. A plate is then attached to hold the piece of bone in this new position as it heals.
Pain management is important to your pet’s recovery. We take a proactive approach to ensure that your pet is as comfortable as possible during the recovery and healing process using advance care pain medications.
As with any surgery, complications may arise. Most complications arise from the dog licking or chewing at the surgical site. This can cause minor to severe complications. It is highly recommended an E-Collar (cone collar) be placed on your pet at all times until the surgical staples are removed (usually 14 days). Complications following TPLO surgery are infrequent but possible. Fracture of the narrow front part of the tibial crest can occur, but will usually heal without further surgery. Osteomyelitis, an acute or chronic bone infection, usually caused by bacteria, can occur and is treated with antibiotics. Tearing of the meniscus can occur, and might require further surgeries, though this is less common with TPLO than other joint repair surgeries. If your dog is not restricted during the healing phase, a number of problems can arise including breakage or loosening of the screws and plate holding the bones, straining of other ligaments in the stifle, and poor or slow healing of the bone.
Healing and Rehabilitation
Confinement and controlled movement is important during the healing process. Because the surgery results in a dramatic decrease in joint pain, a major problem during recovery is too much activity by your dog before the bone is healed. Your doctor will have a specific postoperative rehabilitation program ready for you. Generally, most dogs will begin weight-bearing on the limb within a week after surgery. X-rays six to eight weeks after the TPLO surgery will show healing of the bones. At this time, most dogs will show little or no lameness. Most dogs recover to restricted exercise in two months, and full activity in three to four months. A return to athletic competition (hunting, agility, etc.) can take up to six months. Unconstrained activity prior to six months can cause damage to the soft tissues of the stifle resulting in a prolonged recovery. Arthritis usually is present at the time of surgery. TPLO surgery cannot reverse the arthritic and degenerative state of the joint, but the surgery can help to minimize the progression.