Emily Jane is a 10-year- old female spayed Yorkshire Terrier that was presented to Southpointe Veterinary Hospital for sudden lameness of the left rear leg after coming in from outside. The owner rubbed the limb and the lameness resolved. Upon physical exam, Emily was found to have a mild medially luxating left patella (loose kneecap) with mild grinding (mild arthritic change). X-rays were taken and found to be unremarkable. As a puppy, we found loose kneecaps on Emily, but she never had a problem until now.

Emily
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Initially, Emily responded very well to an oral non-steroidal anti-inflammatory medication (Deramaxx). However, the lameness returned and Emily was referred to Michigan Veterinary Specialists for an orthopedic evaluation. Emily saw Dr. Kyle Kerstetter, a board-certified surgeon. Dr. Kerstetter agreed with our diagnosis and operated on Emily's left knee. The surgery involved two procedures to stabilize her kneecap, as well as a reconstruction technique of her tibia (the lower bone of the knee joint) to help straighten her left limb. Emily's prognosis is good, and she should be using her left limb very well 2 to 3 months postoperatively.

Patellar luxations (loose kneecaps) occur frequently in dogs and occasionally in cats. This orthopedic condition is commonly seen in most small animal practices. These luxations are classified according to their severity and the direction in which they move. Small breeds of dogs are affected more frequently, although there has been an increase in patellar luxations in large and giant dog breeds in recent years.

Emily's Knee
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Concurrent rupture of the knee's cranial cruciate ligament (often termed ACL in people) is present in 15 to 20 percent of middle-aged to older dogs with chronic patellar luxation. These luxations are often congenital (a medical condition that the pet is born with) and not associated with trauma. In severe cases, clinical signs can be seen in puppies. In more mild cases, such as Emily's, the clinical signs do not present until adulthood. Clinical signs also vary dramatically with the degree of luxation (kneecap displacement). With mild displacement, lameness is evident only when the kneecap is out of place. The leg is carried with the knee flexed but may touch to the ground every third or fourth step when walking quickly. In more severe cases of luxation, the pet may exhibit a crouching, bow-legged stance with most of the weight transferred to the front legs. This condition could affect one or both legs.

Surgical correction is recommended in severe cases or in mild cases that are unresponsive to medication. Most dogs having corrective surgery will regain the ability to walk well again. If arthritis is already present in the knee at the time of surgery, heavy exercise or weather changes may cause stiffness of the affected limb. There are medications that can be given if stiffness occurs (such as non-steroidal anti-inflammatory medications or joint supplements). Glucosamine/Chondroitin supplements, such as Dasuquin, are often given to help offset some of the symptoms of arthritis. These are often given life-long.

Emily
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If you have any questions about luxating patellas or other orthopedic conditions, please feel free to call and speak to one of our knowledgeable staff members.