Help! My Dog Has a Torn CCL! (Vet Answered)
This question has been answered by a vet
Veterinarian & Animal Behaviorist
With nearly two decades in veterinary medicine, Dr. Paola brings hands-on experience across multiple species. A graduate of the University of Guadalajara, she specializes in preventive care, animal welfare, and positive reinforcement training.
The Question
“Hi Dr. Paola,
My active, 70 lb, 8.5-year-old Lab mix Allie had successful FHO when he was 1.5 years old. Now she limps on that leg. Vet says it is torn CCL and recommends TPLO. I am concerned that the femur is not stable enough since it is no longer in the hip socket and will slide. Also, how could she get torn CCL if there is no stress of femur on tibia due to femur’s flexibility?” – Tad
Quick Info about Allie
Hi Tad,
Thank you for providing such a thoughtful question. It’s completely understandable to be concerned about Allie’s limb stability given her surgical history. A femoral head ostectomy (FHO) does change the way the weight is transferred through the hind limb, but it doesn’t eliminate all forces on the stifle (knee) joint. After an FHO, the femur no longer articulates directly with the acetabulum, but over time, a fibrous pseudo-joint forms that allows a relatively functional range of motion. While this alters the mechanics in the hip, the stifle joint still bears significant force during weight-bearing, particularly during active movement like running, turning, or jumping. These activities can still place stress on the cranial cruciate ligament (CCL), especially in an athletic or older dog.
A torn CCL in a dog like Allie is unfortunately not uncommon, even in a limb that has undergone FHO. The FHO does not remove the femur’s role in transmitting load to the tibia. Instead, the altered mechanics and long-term compensation patterns may actually increase strain on the knee over time. Regarding your concern about Tibial Plateau Leveling Osteotomy (TPLO), it is a valid question. Surgeons take previous orthopedic procedures into account when evaluating candidacy. TPLO changes the angle of the tibial plateau to neutralize the shear forces that lead to instability when the CCL is torn. It can still be effective in dogs with a prior FHO, depending on the individual case. A second opinion from a veterinary orthopedic surgeon may provide more clarity on whether TPLO is the best option, or if alternatives like Tibial Tuberosity Advancement (TTA) or conservative management are more suitable based on Allie’s muscle condition, gait, and comfort level.
It’s nice to read that you are clearly focused on her long-term well-being and want to be well-informed. With her being so active and already compensating for a modified hip, ensuring the stability of her stifle is essential to protect her overall mobility and prevent additional strain on the rest of her body. I hope she gets the very best treatment!
– Dr. Paola