Surgical Correction Can Be Curative
What Is Patella Luxation?
The patella is the scientific name for the knee cap; luxation means it moves out of its normal position when it shouldn’t. Patella luxation in canine patients is usually MEDIAL- meaning the knee cap slips out of its natural track and moves toward the inside of your dog’s body; a few may have lateral luxation where it moves toward the outside. Most dogs have underlying alignment issues which are hereditary. This can include rotation of the tibial tuberosity (front of the shin bone is crooked), abnormal rotation of the femur (thigh bone), or irregular hip joint formation.
The result is that the groove in the femur is usually too shallow and the strong quadriceps (thigh) muscles pull the patella out of position. As the patella rides back and forth over the edges of the groove, it wears away normal cartilage resulting in arthritis and pain over time.
Many dogs have progression of disease resulting in complete and permanent luxation, contracture of the quadriceps muscle and persistent lameness.
How Is Patella Luxation Diagnosed?
During a physical exam, your pet’s knee caps will be manipulated to determine if luxation is occurring. X-rays will be recommended to identify anatomical abnormalities to help plan the surgical correction.
Sedation is important when performing these X-rays as your pet will need to be carefully positioned on both sides and on their back to get complete diagnostic images. Dogs can be uncomfortable or unwilling to be positioned, so the sedation ensures proper diagnosis and surgical planning.
Sedation is reversible, so your pet will be able to walk out by the end of their visit with some residual sleepiness for a few hours after.
How Is Medial Patella Luxation Corrected?
Depending on the severity of disease and the underlying anatomical derangements, there are usually 4 basic components to correction.
Medial Desmotomy: This allows for release of tight tissue on the inside of the knee which pulls the knee cap out of position.
Lateral Imbrication: Tissue on the outside of the knee is tightened to oppose the medial pull and helps secure the patella in its normal alignment.
Deepening of the Femoral Groove: Surgically altering the width and depth of the groove using special instrumentation to allow the patella to rest deeply in the groove and move naturally.
Tibial Tuberosity Transposition: This involves detaching and replacing the front of the shin bone (tibia) into a correct alignment with the quadriceps muscle. The bone is then secured in the proper position with a small surgical pin.
Dr. Torok uses the X-rays, clinical presentation and appropriate corrections to ensure the best outcome with the least invasive techniques possible.
Will My Dog Have Surgery The Same Day As The Initial Consultation?
No, your pet will have a complete physical examination, X-rays and likely a sedated orthopedic exam as well. This allows for accurate diagnosis and helps ensure your pet’s surgery is planned as accurately and safely as possible. In addition, blood and urine testing with EKG will be performed prior to surgery to ensure your pet is healthy enough to safely undergo anesthesia.
How Long Is Recovery?
Your pet will need to be strictly rested for 8 weeks following surgery. This allows time for scar tissue formation and bone healing to occur. During this time, no “off-leash” activities are permitted. They will need to be kept away from slippery floors and will need to be leashed whenever they are outdoors. Stairs and furniture are not safe to traverse until your surgeon specifically tells you so.
When your dog is not in your immediate supervision, they should be confined to a crate or small room to avoid excessive activity which could compromise surgical outcome.
Is Physical Therapy Indicated After Surgery?
Just like a human, regaining strength in the muscles and regaining range of motion are crucial to a successful outcome. At-home exercises will be provided for you to accomplish daily following discharge. There are times throughout the 8 week recovery to increase difficulty as your pet heals. Formal PT options are available as well which include underwater treadmill, swimming and coaching for sessions. This formal PT is offered by our veterinary partners.
Many of our patients elect to add on a package of laser therapy and joint protective injections (Adequan) for the initial 4 weeks post-operatively. The more you do for your pet during recovery, the more successful their outcome will be.
What Happens If Surgery Is Not Performed?
Continued limb dysfunction and ongoing arthritis is expected. Once a patient begins to show signs of knee dysfunction, it is progressive with loss of function (jumping, running and playing become difficult), muscle loss, and worsened grade of luxation often occur.
Some pets may remain stable for several years before progression is seen. Surgical correction may not be indicated for every pet. Dr. Torok will discuss these indications during your consultation.
Both Of My Dog's Knees Have Patella Luxations; Can Both Be Operated On The Same Time?
In the majority of patients with patella luxation, both knees are involved. If both knees are problematic, depending on the size of your dog, it may be possible to repair both at the same time. This quickens the overall recovery and is less expensive than doing them one at a time. Staggering surgeries in larger dogs is recommended to avoid the potential for complications.
Do The Pins Need To Be Removed If A Tribal Tuberosity Transposition Is Performed?
Once the bone has healed, the pin’s job is done. However, because the implants rarely cause problems, routine removal is not recommended. If removal becomes necessary due to signs of infection or irritation, it is usually a minor outpatient procedure.
Can My Dog Re-Injure The Same Knee?
Re-injury after a patella repair has healed is uncommon. Rarely, dogs will require a second surgery to correct recurrent patella luxation. This is reported to occur in less than 6% of patients.