After a torn ACL has been diagnosed, the next obvious step is what the treatment options are. We will be discussing the most common surgical repair, the tibial plateau leveling osteotomy (TPLO). The diagnostic xrays taken prior to surgery are used to measure the angle at the top of the shin bone, known as the tibial plateau angle. The surgical goal is to reduce this angle to eliminate the abnormal “thrust” caused by the torn ligament.
During surgery, the joint itself is opened and the torn ligament removed. This decreases inflammation and the pain associated by the ligament rubbing within the joint capsule. Additionally, when the ligament ruptures, the menisci (the “pillows” within the joint) can be damaged and need removal. After the joint itself is examined, a curved saw blade is used to make a half-moon cut into the tibial bone itself. The cut bone piece is then rotated to the pre-calculated angle to create the appropriate “tibial plateau.” A stainless steel plate is then placed on the tibia to hold the bone together as it heals over the following 6-8 weeks.
The most important thing to remember with the TPLO procedure is that the plate placed on the tibia during surgery is to hold the bone in place as it heals in its new position. It is not meant to fully bear the weight of the dog; this is why appropriate rest and exercise restriction is a critical part of the healing process. It takes a full six to eight weeks (at least) for the bone to fully heal. After the bone has fully healed, the plate is no longer necessary. However, unless there is an infection or a complication, dogs typically have the plate for the remainder of their lives. As the plate causes them no pain or discomfort (and they don’t need to pass through TSA as much as we do!), we don’t do another surgery to remove it unless it is medically warranted. Once the healing process is complete, dogs return to a normal quality of life.