Mid Michigan Veterinary Surgical Referral Center
Luxating patellas, or "slipped kneecaps", are most common in smaller dogs (less than 30 pounds) but can occur in any size of pet. In most cases, the pet is born with anatomy that predisposes the patella to slide out of joint and towards the inside of the body.
While in some instances the pet is able to compensate easily, in other cases it is severe enough to cause significant pain, limping, and osteoarthritis. For these pets, surgical fixation is the best option for controlling pain, restoring normal function of the joint, and limiting the progression of arthritis.
There are several different techniques for the surgical correction of luxating patellas. Our doctors typically combine two to three of the most commonly employed techniques in order to optimize your pets chance of a successful surgical outcome.
The first technique is called the Trochlear Block Resection, where the surgeon deepens the groove on the femur where the patella rides. Most pets with this condition have a very shallow groove and deepening the groove is an important part of stabilizing the joint.
The second technique is called the Tibial Tubercle Rotation, where the surgeon moves the bone that the patellar tendon attaches to. This enables the patella to ride in a straighter line, rather than being pulled towards the inside of the body. The bone is cut, rotated, and pinned into place until the body permanently heals the bone.
The third technique involves a combination of soft tissue modifications, including lateral imbrication and medial retinacular release. This alters the pull of the soft tissues on the patella in a way that encourages the patella to stay in joint. These methods are inadequate on their own, but when used in combination with one or both of the first techniques discussed, adds to the stability of the surgical repair.
The key postoperative healing period for your pet following surgical correction of luxating patellas is 10-12 weeks. Your pet must be placed under strict exercise restriction during this time period in order for the repair to be successful.
After 10-12 weeks, your pet should be re-xrayed either with your veterinarian or at MMVSRC in order to ensure the bone has healed at the osteotomy sites.
Click here for an example of postoperative care instructions for luxating patellas