Luxating Patella Or “floating Kneecap”

We employ several methods to correct luxation of the patella: x-rays and an exam determine what procedure[s] will be employed. Many patients with luxating patella have an angular limb deformity; our goal is to neutralize the forces on the patella to prevent luxation. We will generally employ one or both of the procedures listed below.

request an appointment

Tibial Tuberosity Transposition[TTT]

A small piece of bone is removed where the patella attaches to the tibia. This segment is moved or transposed toward the luxation and re-attached to the tibia with either screws or wires as pictured above. Following surgery the tension for the patella to slide out of the patellar groove has been removed as it now travels straight when the knee bends.

“RidgeStop – Prosthetic Trochlear Ridge

The aim of this procedure is to make sure the patella slides in its groove without slipping to the side, causing lameness. The surgery works by applying the prostetic implant called the “Ridgestop” to the side of the Femur on the side where the patella was luxating thereby creating a barrier to luxation. This procedure can be used for severe cases of luxation where historically the joint surface had to be cut to accomplish the same result.

Read More

What Is Luxating Patella Surgery?

It is a dog knee surgery that our veterinarians perform to correct the popping or luxation of the kneecap. A luxating patella is caused by congenital malformation that establishes abnormal pressure on the kneecap, making it move out of the groove where it normally lies.

Grading System for Patellar Luxation

Patellar luxation is graded based on the kneecap’s mobility in the groove found at the femur base.

Grade 1 – luxating knee cap with manual pressure but returns to its position on its own.

Grade 2 – When the knee cap luxates occasionally and is associated with skipping lameness, it can be manipulated into the correct position.

Grade 3 – When the knee cap has been luxated permanently. Although it can be manually manipulated, it will pop out again.

Grade 4 – Refers to when the knee cap has been luxated permanently and cannot be replaced manually.

Tibial Tuberosity Transposition

Our animal doctor uses tibial tuberosity transposition surgery to realign the tendon insertion between the shinbone and the kneecap. In most cases, the bones tend to heal better than tendons. Therefore, our veterinarian will cut the bone attached to the tendon and move it into a better position. Our animal doctor will secure the shin with a wire, and the bone will heal between 4 to 8 weeks.


We also provide RidgeStop, which is a surgical implant of a synthetic ridge that’s held in place with standard cortical screws. This is done to build up the sides of the patella groove where it is insufficient or eroded due to degenerative conditions. We apply this special implant where the knee cap is luxating, creating a barrier to luxation. This procedure does not involve cutting or shaving any bones, leading to no risks of fractures.

Contact Our Animal Hospital for Dog Knee Surgery in Holmen

There are numerous factors to consider when contemplating orthopedic surgery for dogs. At Wisconsin Veterinary Orthopedics in Holmen, WI, we assure you that our team will provide your dog with the treatment they need and deserve for a full recovery. You can call us today on (608) 526-2200 to schedule a consultation or inquire for more information regarding dog knee surgery. Contact us to learn more about how our veterinary professionals can help.