The adage “old tear, no repair” is sometimes applied to these old injuries. What we mean by that, is that if the stifle is stable, then surgical repair is often not recommended. Remember the goal of surgery is to stabilize the knee to prevent “tibial thrust” or the movement of the tibia forward during movement or weight bearing. If there is no tibial thrust or instability to prevent, then surgery isn’t needed. In this case, your dog’s body has placed scar tissue, often large amounts of it, there to stabilize the knee. This occurs over time after an injury and when surgery was not performed.
But do these dogs need physical rehabilitation? Depends. If there is persistent muscle weakness then, yes, physical rehab will help. If there is osteoarthritis in the joint as a result of an old injury, then yes, physical rehab can help. If your dog still favors the leg, then yes, physical rehab can help. If your dog has not yet torn the other ACL, then yes, rehab can help. If your dog as just torn the other ACL, then yes, rehab can help. If your dog has no limping, no other issues, no pain and no apparent arthritis, then your dog probably doesn’t rehab for it. Your dog would benefit from a fitness program though. All of us benefit from a well designed fitness program. Physical rehabilitation can help prepare your dog for a fitness program too. There really is something for everyone!