The most common cause of sudden rear leg lameness in dogs is the rupture of the cranial cruciate ligament (CCL).

This problem affects all ages and breeds of dogs. The onset of lameness is usually sudden, and the severity of lameness ranges from stiffness or very mild lameness to carrying the leg. The ligament may be partially or completely ruptured. People can go a long time without CCL repair, but arthritis develops quickly in dogs with total or partial CCL rupture because the joint is unstable.

Around 50 percent of complete ruptures are accompanied by meniscal tears in the joint. The menisci are two cartilaginous pads between the bones. These tears are visualized and removed using arthroscopic examination of the joint. X-rays are not diagnostic for CCL or meniscal injury, so physical exam and history are relied upon for presumptive diagnosis, and arthroscopic exam confirms both diagnoses.

Lateral suture stabilization (LSS) is another procedure that does not repair the CCL, but the suture, placed outside of the joint, mimics the action of the CCL. We use this procedure in smaller dogs for CCL injury and when the owner’s budget does not have room for the TPLO procedure or in very sedentary patients. Generally speaking, the smaller and less active the patient, the more satisfactory LSS is for treatment. Research has shown that arthritic changes continue to progress with LSS; however, the TPLO procedure is superior in maintaining normal joint function in athletic animals, without significant progression of arthritis.

After surgery the dog should remain inactive for twelve weeks. They should be walked outside on a leash for bathroom trips only. Special physical therapy beyond leash walking is optional except in old or otherwise debilitated animals.

Tibial plateau leveling osteotomy (TPLO) is currently the preferred procedure for cranial cruciate rupture or instability. More information on TPLO